Turbo on RX-8

[Herblenny]

I figure we have a discussion about this....

Far as I know, I have no intention of putting turbo on the 8... But who knows... Maybe some people have put one on and made decent power.. But to me, I don't think its worth it.

I just read somewhere that someone dropped 13k to get a turbo put on their 8 by Mazsport... All I can say is, I rather spend 13K on another FD than to spend it on some turbo charger to make mid 300 HP... That kind of HP on high compression engine only means trouble in my mind... And how to they control it?? Who tunes it and how?? What kind of injectors and how do they control it??

I even read mazsport wanting to upgrade ignition system and such for what... mid 300 HP??? I don't know.. maybe because I been an 7 owner, I'm bit confused why people are spending insane money and not just put 13B-REW??? stock twins with stock ignition will make 320HP?? Iam I missing something here?? Why are so many 8 owners wanting to run turbo on fake peripherial port engines (non traditional)??? For what.. Maybe 100 HP?? Am I out of touch on whats going on with the 8?? Is there a reliable turbo out there??

Someone keep me updated!

[85rx-7gsl-se]

Didn't WE3RX-7(Spelling?) have a Turbo 8 at one point?

[sumdeus]

12k on a turbo? Not to sure about that, Mazsport has a kit that is $5500 and is supposed to be good for 300, but is capable up to 350-375 with injectors and coils. There is also a kit from Esmeril Racing, includes injectors. Greddy also has a kit that is essentially a bolt on for about 3500. It is a small turbo but 270-280 is what some people are getting out of the box with no major tuning other than the int-x.

[Herblenny]

Far as I know, most of these require some sort of piggyback system to control. I've heard assessport you could get maps.. but in some ways, each set up will be slightly different and external environment will cause change of map.. So, I'm not sure if its well worked out system or not.. Of course I haven't driven one.. But I have seen one with a turbo couple of years ago.. but that car ran like ass.

Also, why coil upgrade?? RX8 coils are used by Le Mans 3 rotors making more HP NA at higher RPM?? I can't imagine stock coils are that bad that you need upgrading for 350RWHP?? Stock FD coils will handle over 400 with out any issues.. Some run over 500!

But most importantly, its the design of the engine that gets me... It lost so much exhaust pulse before it hit the turbo.. I'm guessing running anything large would be very laggy.....

For 5000+ you could get a new rebuilt 13B-REW and stock 99 280HP twins that will make easy 320-350 RWHP.... and have money for a PFC.. Turbos will be very responsive and proven by 3rd gen owners that it will last!

[fikren]

The intercepter-X is a popular piggyback for alot of people. I have not looked in to it much but I think it is programable with the software yourself rather than having to send off for new maps like assessport.

I've actually heard more bad about the Greddy turbo kit than good, enough that I don't want to touch it plus it is a smaller turbo and I think if you try running more than 5 psi or so you end up with some issues so it seems to be very limited for the money.

Apparently people have had a lot of problems with the 8's coils. I don't know for sure if this was just on early models and was later fixed or if it is still an issue with some people. Basic of it was that the coils were weak and the cause of some ignition breakup, weak spark, etc. That was why mazsport produced their setup.

One thing to remember about mazsport is they are insanly expensive on just about everything. I don't have any of their stuff, I've heard good things about them so not knocking their products but they are high high.

Personally I think it is a waste of money to mess with a turbo on the 8's engine. Doesn't really matter what setup you try to run the exhaust ports are still going to limit how effective its going to be. I guess you could seal up the stock ports and open up the two ports like the 13B-REW and you would have more gain but then might as well just put a 13B-REW, would probabley be cheaper in the long run. The money is an issue. You can buy a complete kit for the 7 from a good shop like A-Spec that will produce, when tuned, 5-600hp for the same money you will spend on the 8 for a possible 100hp gain if that.

What we need is a thread and some research on the 8's sensor system and electrical and options there for standalones or piggybacks because if I were going to try and dump the money in the 8 for a turbo system to produce any kind of worthwhile gains then I'd be dropping a 20b in it first. For the same price or close to it, you could run a NA 20B and probabley see better gains than a turbo'd 8 engine.

[sumdeus]

Anyone know of anyone that has does a 13B-REW swap?

[djmtsu]

I thought the 13B-RE (Cosmo) is becoming a popular option since it is easier to mount than the REW. Maybe not, but I swear I heard someone say that at DGRR this year.

[fikren]

I thought the 13B-RE (Cosmo) is becoming a popular option since it is easier to mount than the REW. Maybe not, but I swear I heard someone say that at DGRR this year.
I'm not sure DJ, haven't looked into it. In my mind if I'm going to get into an engine swap the 20B is the only option I would entertain. Right now I'm just driving the piss out of the car while its all under warranty. :smilielol5:

[I8U]

12k is insane! I know BHR/MazdaManiac have developed a kit which uses most of the GReddy kit for 7k and it's putting down 370whp at 7psi.

[BBullet8]

All I know is that speedforceracing has the best turbo out there for the rx8 it does 326hp and around 240ftlbs of torque. All of this is done with a very rich mixture and at 9psi. this turbo has also been on an 04 and the car has had the turbo on it for 60,000 miles and no major problems. there is no piggy back system with this it is a complete rewire which maybe why it has lasted so long it is around the 7,300 dollar mark but is way better than anything that mazspeed is making.

[fikren]

All I know is that speedforceracing has the best turbo out there for the rx8 it does 326hp and around 240ftlbs of torque. All of this is done with a very rich mixture and at 9psi. this turbo has also been on an 04 and the car has had the turbo on it for 60,000 miles and no major problems. there is no piggy back system with this it is a complete rewire which maybe why it has lasted so long it is around the 7,300 dollar mark but is way better than anything that mazspeed is making.
what do you mean complete rewire? you still have to have an ecu with some kind of tune on it. I'd be interested in any more info you can provide.

[85rx-7gsl-se]

Jeremy, it says the system uses a Powermod EMS... Not sure what that means but....

[BBullet8]

it in no way uses the stock ecu. where some piggy back systems use some of the lower rpm range this ecu that they have uses nothing that is stock on the car. go here and check it out call them if you want they are really cool http://www.speedforceracing.com/productsmazda_rx8turbokit.php

[fikren]

Powermod EMS still uses the stock ecu.

http://www.dnamotorsport.com/PowerMod/PowerMod.html

discription mentions how it won't lose tune if you flash your ecu and how it intercepts from the ecu then sends data based on its tune to the engine.

Sounds interesting though.

[Herblenny]

LOL!

Its so funny!! Please don't get in the hype of things... BBullet8.. I think I had this conversation with you regarding to this.. Trust me, its not worth it...

First, look at the dyno chart..
http://www.speedforceracing.com/images/products/mazda/rx8/tubokit/rx8_1_6.jpg
Their description states, "fire-breathing turbocharged 326WHP Rotary that screams to 10,000 rpms with 9 psi of intercooled boost."
They didn't even get close to 10K.. Why not?? Trust me, 10K, high compression, turbo charged engine, what 6 x 550cc injectors... Hmm.. all I can say is, I wouldn't drive that thing..

ECU:
Its a piggy back!!! Just like the back in the day Purple box by PFS for FDs. These are junk in my mind... except you could control timing (I don't think you could with PFS purple motor eaters).... But I don't think it does split and any compensation. JUNK!!!

Again, Why spend 7K to have something that you either have to have multiple maps or super conservative map to make measly 320HP. Also, by looks of it, its not coming on until 4+K RPM... Again, why not REW, twin turbo, fully programable ECU, and make 320 seq. turbo HP...

[Herblenny]

Here is a dyno map of rew seq at 19lbs
http://www.dragtimes.com/images_dyno/14792-1994-Mazda-RX-7-Dyno.jpg

[Herblenny]

Ok...

I looked at the Speedforceracing turbo again... Now look at this..

http://www.speedforceracing.com/images/products/mazda/rx8/tubokit/rx8_2_4.jpg

Hmm.. Can anyone else see the problem with this manifold?? Personally, I think its JUNK:)

[Herblenny]

And this statement makes so much sense..
A cold air intake is part of the package.We understand that it is important to get as much cold air into that turbo as possible.We located the airfilter in the front of the car so it gets as much cold air as possible. Details like this is what makes the Speed Force Racing turbo system superior to anything else being offered for the fourth generation RX-8.

Sounds like they are building a Honda Civic..

Why you ask?? Well, first of all, intake restriction is more important than temperature. I rather have zero 90 degree bends than try to suck in air from the front of the car...

Second, this is why you have IC:)

Third, this kit comes with pre programed map. I'm sure its tuned for conservative not peak HP (which I'll be scared to run or turn the boost above 9lbs). And second, 6 x 550s, top fed injectors.. well, I just don't quite trust running them 100% or close to that with this set up..

[djmtsu]

The runners out of the manifold look like ass (and different sizes) and they slam straight into the main runner. Looks like an awful design to me, and I am no expert.

[Phoenix7]

Ok...

I looked at the Speedforceracing turbo again... Now look at this..

http://www.speedforceracing.com/images/products/mazda/rx8/tubokit/rx8_2_4.jpg

Hmm.. Can anyone else see the problem with this manifold?? Personally, I think its JUNK:)so, can we chuck it into the huge garbage bin along with the supercharger for the NA FC?

I've been following your thread for a while and it looks pointless. RE-Amemiya did a turbo 8 and sells it as a Greddy kit (if it's even on sale) and they put out lame numbers on it and it still looked slow. Why would you want to turbo an 8 anyways?

[85rx-7gsl-se]

I would almost go LSx swap before turbo'ing the stock 8 engine.

[Phoenix7]

I would almost go LSx swap before turbo'ing the stock 8 engine.
me-->:beatdeadhorse5:
you-------^

[85rx-7gsl-se]

Me.....Gives no shat what u think :D

[Phoenix7]

:lol: we both know that's a lie but I do agree on modding the NA renesis. It's just like modding an NA. Take it as far as you can without wasting too much money on useless crap.

Intake, exhaust, fuel, timing and reliability mods.

[85rx-7gsl-se]

Renesis in stock form in a FB or FC would be pretty sweet, but in a FE, just needs more pep. But still, even the 13BT> Renesis from a tuning standpoint.

[BBullet8]

well regardless of what you all think I will turbo my car with that turbo.

[Herblenny]

The runners out of the manifold look like ass (and different sizes) and they slam straight into the main runner. Looks like an awful design to me, and I am no expert.

Exactly!!

Lets look at the design again..
http://www.speedforceracing.com/images/products/mazda/rx8/tubokit/rx8_2_4.jpg

Just HORRIBLE manifold.. 5 turns before it hits the turbo (and how long it is before turbo) and GOD, those runners from the engine... GEEZ!! Its like its designed by some idiot who knows NOTHING about turbo... At least Mazsport's manifold looks reasonable..

Then the after turbo.. Another 5 turn before midpipe..

By the way, to put things in perspective... I just looked at what used 2004 rx8 trade in is and its now sub 10K... So, this turbo is 70% of what used 04 might be:)

[Phoenix7]

well regardless of what you all think I will turbo my car with that turbo.it's your money. :lol:

[85rx-7gsl-se]

Seriously, does anyone know how much Brian Hinson's kit is going to cost for a LSx? Seems like it would be a better investment than 7k to boost a N/A motor and get only a little over 300hp :)

[Herblenny]

I've talked to Hinson and he was trying to get LSx into an 8. But I don't think he has done it yet...

Cost, it will be 7-12k, pending motor.

But the problem I might see is how the motor will sit (renesis sits very low) and the LSx ems will work with rx8s ems which controls abs, traction, etc..

But at the end, LSx 8 vs older Z06, you aren't getting much benefit... FD vs. older Z06, at least you have the weight advantage, but not with the 8.. I guess if you want to be cool with V8 under instead, I guess i could see that;) But I would rather just go out and buy an Z06 instead the headache of conversion... Few FD V8 owners have done that after their conversion... go out and buy the original that came with the LSx engine..

[Herblenny]

well regardless of what you all think I will turbo my car with that turbo.

It is your money... But I'm trying to help you see why it will be waste of your money...

That manifold is JUNK!!! Go look at other turbo manifolds... Others have much better design!!

If I were to run the turbo on renesis (I will never do as I think its waste of money) I would get either greddy manifold or mazsport, get a nice small ball bearing turbo, and get that powermod ems or other piggy back that will let you datalog and tune yourself. The whole cold air intake BS with 2-3 90degree bend is BS. Just put a filter or screen on your turbo. IC is important when you get into high boost.. but you are not going to make more than 10lbs with out going into changing your fuel system.

I mean, if I were to go do all this, I would just put a REW with stock twins (99 280s)! Thats what Mazda should of done fromt he beginning. with 280 99 twins, you'll get great response with max turbo potential of about 380RWHP (16-18lbs) and could run it reliably.

[RCCAZ 1]

Guys,

MazdaManiac here in Phoenix has probably the best kit on the market for making power (Greddy Kit with upgraded turbo). He also is an expert on the Cobb Access port, which is quickly becoming the tool of choice for unlocking the potential of the stock Mazda EMS.

[Phoenix7]

Greddy kits are RE-Amemiya kits renamed for the U.S. MArket aren't they?

[Herblenny]

Guys,

MazdaManiac here in Phoenix has probably the best kit on the market for making power (Greddy Kit with upgraded turbo). He also is an expert on the Cobb Access port, which is quickly becoming the tool of choice for unlocking the potential of the stock Mazda EMS.

Hope He will get on and describe more about this Cobb Access thing....

[fikren]

I think there are probabley plenty of places that offer a "nice" kit. I think the main point of Phil's thread though was does the cost of these "nice" kits compared to the relativly small gains justify turboing the 8's engine or would it be better money spent to do some sort of swap.

[mazdamaniac]

Guys,

MazdaManiac here in Phoenix has probably the best kit on the market for making power (Greddy Kit with upgraded turbo). He also is an expert on the Cobb Access port, which is quickly becoming the tool of choice for unlocking the potential of the stock Mazda EMS.

Thanks Tim. You are too kind.

Greddy kits are RE-Amemiya kits renamed for the U.S. MArket aren't they?

No. Amemiya re-badged the GReddy kit for his A/T application. Repriced it accordingly as well!
The GReddy kit fits all RX-8 applications without retrofit, so Im' not sure what the JDM response was to the Amemiya offering.

Hope He will get on and describe more about this Cobb Access thing....

I'll jump in your thread about that.

Its interesting to me, coming here for the first time, how insulated the markets can get.
Some of the discussion in this thread is straight out of RX-8Club, circa 2005!

You can read about my GReddy upgrade on my site (link is in my SIG - click on Satan's Hairdryer)

As far as output from the various offerings (build quality aside), you can use these graphics for comparison:

http://www.mazdamaniac.com/images/misc/rx8club_hp.jpg

http://www.mazdamaniac.com/images/misc/rx8club_tq.jpg

[Herblenny]

WOW! Mazsport one is laggy!!

MM version looks the best so far;)

[BBullet8]

what I think is that there are enough people on this site that are smart enough and know enough people to build a kit that will be most efficient and fairly cheap. it just seems to me that we all complain about something yet we do nothing. Phil I know that you have done a lot with the 7s is there anything that you have learned from those that we could apply to the 8 and make it awesome.

[mazdamaniac]

Air = Power.
That is pretty much all there is to it.
Folks will go on about "lag" (which it usually isn't) and "boost" (which is a symptom, not an effect) and sometimes "flow" will be mentioned in the same breath as "restriction" or "loss", which isn't strictly possible.
You move air mass through an engine. It makes power. That is all there is to it.
You need to select the proper device for the job and then give it a place to live and breathe.
The problem is, superstition, tradition and secrecy abound in all levels of this hobby/industry - mostly fostered by a fear of being wrong or being "found out". Often, its just plain sloth.

For the most part, if someone claims to "know the secret" but won't talk about it, its because they don't "know the secret". Mainly, because there isn't one.

I tend to go the other way. When I've figured something out, I lay it all out there. I've got nothing to protect. Those that already know how to do this stuff already know what I know.
Those that don't, won't learn a damn thing to save their life, so who cares what they see.

The only good reason to hold your cards close is to protect your mental health.
I keep most of my "tuning secrets" to myself just because I don't want to answer the million questions from people that are striving to misapply my data. If you know this stuff, there is nothing I can say to improve your hand.

[WE3RX7]

I've been on vacation so sorry for the delay in this post.

Yep - I had an '04 Turbo 8. It was the first greddy kit produced and came with the shitty e-manage. The car NEVER drove right with the "bolt-on" kit from Greddy. Once the interceptor-x became available, the e-manage was quickly ditched for it. I had used microtech before on other 7s, so the interceptor-x was a much more comfortable area to play in.

I ran the car up 8.5psi to 7K RPM at which time the stock GReddy wastegate configuration flipped out and would fluctuate from 3psi to 7psi every 500rpm or so.

The car never made over 300whp, but did drive very smooth, full boost at 2200rpm and was very "useable".

I'll answer any technical detail you might want - but the short and sweet is my current 8 will stay NA. Turbo Renesis' just arent worth it.

[fikren]

I've been on vacation so sorry for the delay in this post.

Yep - I had an '04 Turbo 8. It was the first greddy kit produced and came with the shitty e-manage. The car NEVER drove right with the "bolt-on" kit from Greddy. Once the interceptor-x became available, the e-manage was quickly ditched for it. I had used microtech before on other 7s, so the interceptor-x was a much more comfortable area to play in.

I ran the car up 8.5psi to 7K RPM at which time the stock GReddy wastegate configuration flipped out and would fluctuate from 3psi to 7psi every 500rpm or so.

The car never made over 300whp, but did drive very smooth, full boost at 2200rpm and was very "useable".

I'll answer any technical detail you might want - but the short and sweet is my current 8 will stay NA. Turbo Renesis' just arent worth it.

Would you say your problems were with adding a turbo to the renesis or would you say the problems were more the greddy turbo kit (wastegates and all) and ecu problems. I guess what I'm getting at was it the turbo and engine as a whole that left a sour taste in your mouth or possibly just the components that left a sour taste?

[fikren]

I'll jump in your thread about that.

Its interesting to me, coming here for the first time, how insulated the markets can get.
Some of the discussion in this thread is straight out of RX-8Club, circa 2005!

You can read about my GReddy upgrade on my site (link is in my SIG - click on Satan's Hairdryer)

As far as output from the various offerings (build quality aside), you can use these graphics for comparison:

http://www.mazdamaniac.com/images/misc/rx8club_hp.jpg

http://www.mazdamaniac.com/images/misc/rx8club_tq.jpg
Curious as to what your $6200 kit includes. I briefly looked at the website and saw just a garret upgrade kit and the accessport listed. What does the kit you have listed for the dyno stuff at 6200 include.

Also what exactly is the biggest holdback on the engine. I guess I'm more use to the 7's where its almost the sky's the limit (within reason) with turbo size, boost, etc. What exactly is holding the 8 back, is it the exhaust ports, or what. On the 7 its common to see 850cc primarys and 1600cc secondaries yet on the 8 it seems to be 5-600cc injectors. Are we speaking in general terms as a "easy" bolt on without major modifications and thats why leaving the option of new fuel system etc opening alot more doors or is it just the engine itself.

Thanks for chimming in on these posts too, its nice to get some good info for those that are interested.

[WE3RX7]

To be honest, its a combination of things that turn me off from wanting to do the turbo renesis again. Cost, time, resources, frustration, etc

As a whole, I was pretty happy with the end result. The car had what the renesis was missing, which was a bottom end and STRONG mid range that pulled. The problem was it fell off at 7k, no matter what you do, that problem is in the hardware. I think with a different turbo and manifold setup, the renesis exhaust ports would easily support upwards of 10-13psi and make well over 300whp all day long reliably, but at what cost?

The biggest problem is the engine. I just dont see a configuration that will come online early enough and still maintain a high enough level of boost to make big numbers (500+) on the renesis. I hope someday I'm shown differently. I'd love to see a bolt on 500whp kit for the renesis...

Probably the biggest turn off is that I was/am a seven guy. You can get so much more for much less effort with an old style 13B.

I am still VERY happy with the NA 8s power though. Sure, my current 8 doesnt have the HP the last one did, but its still fun. I think with all the bolt ons and the soon to come out RB header - the NA renesis will make plenty of good power for a daily driver and weekend track day. After all, its still a 200+ hp NA 13B, thats good in any book.

My big HP goals will be achieved the old fashioned way - big port, big turbo, old car :)

[Phoenix7]

^^^ isn't that like asking for a 400hp bolt-on kit for the NA FC? It seems a tad on the idealistic/dream side to want 500hp bolt-on for the NA 13B or am I not giving the Renesis due credit?

[85rx-7gsl-se]

^^^ isn't that like asking for a 400hp bolt-on kit for the NA FC? It seems a tad on the idealistic/dream side to want 500hp bolt-on for the NA 13B or am I not giving the Renesis due credit?


I believe that is his point, he would love to see it happen, but knows it won't happen ;)

[mazdamaniac]

Curious as to what your $6200 kit includes.

The upgrade kit is $1800. That price is the upgrade kit plus the GReddy base kit plus the AccessPORT.

Its going to be interesting in making the attempt to bring people up-to-speed here. The last few posts above are almost perfect examples of the kind of thinking I was referring to in my previous post in this thread.
At least its not as bad as 7-Club. :icon_no2:

There is a LOT of old thinking out there that simply isn't in step with modern technology.

Really, I'd be happy just to see people stop using the word "boost" all the time when they are talking about FI. Its meaningless.

[Herblenny]

mazdamaniac, I'm guessing you are using stock maf system and using the stock ems to adjust?? Where as traditional "boost" uses map sensor bases system (in rotaries)... which I'm guessing is the difference... maybe i could be wrong as I have not done much renesis turbo systems or seen many until this thread...

By saying that, I know very little about the limitation of maf system. Last time I got in a conversation about it was about 5-6 years ago with a good friend SPOAutos. Im sure most of us here know very little as most of us never dealt with maf based system. Can you tell us what kind of issues or limitation (HP) it will handle before going with map based system??

Personally, I do like the idea that you use the stock EMS and maf (which I could be wrong). And since its maf based, maps could be interchangeable from car to car without the traditional idea about each cars needing specific tune etc... Please correct me if I'm way off... I would like to know and who knows, maybe renesis technology could be used on my FD or my duece. I do have a spare renesis at home:)

Also if you could tell us what kind of compensation the stock ecu does (ie air temp, coolant, etc)...

[Herblenny]

it got me thinking during my work morning...

I guess some of the down fall of maf system would be similar to what i had by using KN filter?? If your turbo's bad and oil in your intake, could cause MAF to be cleaned?? Or is their by pass to this??

Also, I'm also guessing there is some sort of limitation to maf?? ie volume of air (high boost/cfm) and turbo choices?? How would this maf would work for FD, low compression engine that you want to run 20lbs?? sequential?? Would sequential turbos cause problem as it transition from primary to both?? Just few things I was thinking..

I do however like the MAF idea (not thought about in years) and if it works, it will eliminate some tuners out there..

[Herblenny]

One more thing.. I remember.. I remember back when reading about BOV needing to recir. back to post MAF sensor?? Is this necessary if 8 would use MAF system??

[mazdamaniac]

There are several ways to figure out how much air is going into your motor. A MAF is the only method that actually measures it directly.
MAP-based systems need to compute the air mass by comparing pressure to temperature.

The OE PCM is very powerful. It has a different fuel map for each pair of gears and compensation tables for every possible operating condition.
It compensates for intake temp, coolant temp, throttle position, barometric pressure and vehicle speed. It even has compensation for time at a particular load!
It has different latency tables for each bank of injectors (to answer an earlier question, the Renesis has 3 injectors per rotor, instead of the old 2 injector setup; many of us are running the equivalent of a 500/1200 setup by splitting the secondaries into two staged groups for very fine fuel control in boost) and a progressive ignition dwell table that resolves down to .001ms.
There are separate throttle control tables for each gear to adjust throttle sensitivity independent of pedal position and "acceleration" tables that not only compensate for throttle opening rate, but can adjust for engine RPM delta.
There are tables to adjust when to be in open or closed loop for each gear and load level and trim for closed loop at different load levels.

Ignition control is equally dense with completely independent tables for the leading and trailing ignition, idle control matrices with inputs for temp, RPM, gear, vehicle speed, throttle position and delta and engine load.

The best part is that the PCM takes all of the operating condition data and compiles it into a single value - calculated load - that is then applied to the engine RPM to compute the target injector duration based on commanded target lambda.
You don't need to know how much duty cycle you need at a given RPM and boost level, you just tell it you want 11.5:1 at 6500 RPM and it does the rest.

If a Power FC is a knife and a Haltech or Motec is a scalpel, the OE PCM is a laser.

The MAF on the RX-8 is sitting in a 3.375" i.d. tube and driven on a 5v circuit. It has enough resolution to see .001 g/sec variations at idle (~6 g/sec) and still measure out to ~360 g/sec at full load.
For those doing their due diligence, that is about 47 pounds of air or 450 HP.
Realistically, I'd say the OE MAF is pegged at 420 crank HP.
Of course, you could just put it in a slightly bigger housing and rescale it.
Or, you could replace it with the MAF from a Cobra.

On a draw-through application, a boosted motor is going to vent after the MAF, so metered air is allowed out of the system and an over-rich condition may happen between shifts, etc.
In practice, this is negligible with proper tuning, but it can be completely negated by recirculating the BOV.

[Whizbang]

i would have to say i am impressed with what the stock computer can do!

[mazdamaniac]

i would have to say i am impressed with what the stock computer can do!

I've only touched on a fraction of it.

I've tuned Microtech, Motech, Haltech, Electromotive, Apexi, GReddy, HKS and a few others - many of those on rotary motors and nothing comes close to the PCM in the RX-8.

Now, it would be nice to have some more AUX channels (you can use the VFAD, for instance, to trigger water injection), but that isn't really a legit complaint.
If I needed to control more aux channels, I'd throw a $60 used GReddy e-Manage blue on there just for that.

[85rx-7gsl-se]

Great info maniac. I enjoy this MAF info.

[Whizbang]

how adaptable could the computer be, with the proper tunning abilities? Could you use it on an earlier 13B engine with proper controls and related adapted and adjust everything accordingly?

[mazdamaniac]

how adaptable could the computer be, with the proper tunning abilities? Could you use it on an earlier 13B engine with proper controls and related adapted and adjust everything accordingly?

I don't see why not.
You would have to address the wiring harness in a serious way and have to adapt a few important sub-systems from the 8 (the anti-theft system is particularly invasive).
It should work, though.

I'd enjoy that challenge, actually.

I've contemplated putting an REW in the RX-8.

[Phoenix7]

There are several ways to figure out how much air is going into your motor. A MAF is the only method that actually measures it directly.
MAP-based systems need to compute the air mass by comparing pressure to temperature.

The OE PCM is very powerful. It has a different fuel map for each pair of gears and compensation tables for every possible operating condition.
It compensates for intake temp, coolant temp, throttle position, barometric pressure and vehicle speed. It even has compensation for time at a particular load!
It has different latency tables for each bank of injectors (to answer an earlier question, the Renesis has 3 injectors per rotor, instead of the old 2 injector setup; many of us are running the equivalent of a 500/1200 setup by splitting the secondaries into two staged groups for very fine fuel control in boost) and a progressive ignition dwell table that resolves down to .001ms.
There are separate throttle control tables for each gear to adjust throttle sensitivity independent of pedal position and "acceleration" tables that not only compensate for throttle opening rate, but can adjust for engine RPM delta.
There are tables to adjust when to be in open or closed loop for each gear and load level and trim for closed loop at different load levels.

Ignition control is equally dense with completely independent tables for the leading and trailing ignition, idle control matrices with inputs for temp, RPM, gear, vehicle speed, throttle position and delta and engine load.

The best part is that the PCM takes all of the operating condition data and compiles it into a single value - calculated load - that is then applied to the engine RPM to compute the target injector duration based on commanded target lambda.
You don't need to know how much duty cycle you need at a given RPM and boost level, you just tell it you want 11.5:1 at 6500 RPM and it does the rest.

If a Power FC is a knife and a Haltech or Motec is a scalpel, the OE PCM is a laser.

The MAF on the RX-8 is sitting in a 3.375" i.d. tube and driven on a 5v circuit. It has enough resolution to see .001 g/sec variations at idle (~6 g/sec) and still measure out to ~360 g/sec at full load.
For those doing their due diligence, that is about 47 pounds of air or 450 HP.
Realistically, I'd say the OE MAF is pegged at 420 crank HP.
Of course, you could just put it in a slightly bigger housing and rescale it.
Or, you could replace it with the MAF from a Cobra.

On a draw-through application, a boosted motor is going to vent after the MAF, so metered air is allowed out of the system and an over-rich condition may happen between shifts, etc.
In practice, this is negligible with proper tuning, but it can be completely negated by recirculating the BOV.so, the electronics are capable of reaching high HP goals. How about the motor itself? Why are the turbo applications yielding such little hp?

[Herblenny]

Thanks Mazdamania!

Now its making my head turn:)

Hmm.. I tought about MAF based few years back and never thought about doing it as I didn't see any aftermarket computer I saw.

So, what you are saying is its possible to run REW with RX8 harness and EMS, with larger MAF to run higher boost (or push more air)?? I'm already thinking about getting 4 secondary LIM and using this system.. What do you think?? How about 3 rotor?? Any MAF EMS that might be able to run that??

Sorry about all these questions.. Obviously I know too little to get myself in trouble... And far as tuning, Is it that easy, just putting in n value?

[Whizbang]

You might be able to mimic the signals that the anti theft produces to fool the computer.

But generally speaking, with some knowledge of systems, it might be cheaper than buying a standalone, albeit not easy.

I don't see why not.
You would have to address the wiring harness in a serious way and have to adapt a few important sub-systems from the 8 (the anti-theft system is particularly invasive).
It should work, though.

I'd enjoy that challenge, actually.

I've contemplated putting an REW in the RX-8.

[Herblenny]

Well, I have 2004 complete engine/transmission/harness/ems... I'm about to tear down the renesis to check it and rebuilt... But, if I could incorporate this system and as how mazdamaniac describes it, I might try to use the harness, sensors, etc to run REW with bigger MAF. Seems like this system once dialed in could work seemless in any condition.. At least thats the take I'm getting from reading mazdamaniac's post.

[mazdamaniac]

so, the electronics are capable of reaching high HP goals. How about the motor itself? Why are the turbo applications yielding such little hp?

What do you mean? My "public" dyno at 9 PSI on my nice, extremely streetable turbo is over 315 RWHP.
With meth and a bit more boost, I made 20% more over that.
If someone wanted a 400 HP RX-8 and wanted to deal with the street performance liabilites of that (just like the 400+ HP club of RX- owners do), they could go to a GT3571 or similar and be there all day.

The problem is, most people don't want a high-HP car - they just want to brag about owning one.
A 400+ HP turbo rotary is annoying at best in stop and go traffic. Add summer to the mix and the sacrifices you make in vehicle comfort to make use of that power and you have a car that no one wants to drive anywhere but straight down the 1/4 mile.
RX-8 owners like their DSC/TCS, A/C and power seats. Did I mention the cup holders and the Bose 9-speaker stereo?

On a road course, I destroy cars that are supposed to outclass me by a considerable margin.
Watch as this "500 HP", single-turbo 300 ZX desparately tries to catch me on the 1/2 mile straight at Firebird Raceway as I hit nearly 150 MPH.
Then watch as I out-brake him!
VIDEO (http://www.mazdamaniac.com/wot.htm)
The Cobra and the Saleen did the same thing, only I watched them spin behind me in the second corner after that straight.
Very sad. I almost spilled my latte.

[Herblenny]

mazdamaniac, I'm glad you got on this forum... I'm learning something new and its firing my interest and thinking how this could apply on other levels.. I never thought about MAF nor 8 EMS and that kind of capabilities..

Question..

What's your take on this system in Low compression motor vs. high?? Maybe this is myth, but I've always heard problems with high is detonation is likely and needs to run richer to save engine..

[mazdamaniac]

Hmm.. I tought about MAF based few years back and never thought about doing it as I didn't see any aftermarket computer I saw.

So, what you are saying is its possible to run REW with RX8 harness and EMS, with larger MAF to run higher boost (or push more air)?? I'm already thinking about getting 4 secondary LIM and using this system.. What do you think?? How about 3 rotor?? Any MAF EMS that might be able to run that??

Sorry about all these questions.. Obviously I know too little to get myself in trouble... And far as tuning, Is it that easy, just putting in n value?

You could do that.
The tuning is ALWAYS as simple as putting in a value.
The trick is knowing that value.
You do have to get the calibration for the MAF and other sensors right, also.

[Whizbang]

your site has more flash per square than another other mazda website in history.

that and i dig the Mx-3. I have been eyeing buying one from a local with 2.5

[mazdamaniac]

your site has more flash per square than another other mazda website in history.

Yeah. Sorry. A bit of Macromedia vanity, that. I wish I had more time to play with it.

that and i dig the Mx-3. I have been eyeing buying one from a local with 2.5

Mine was stupid. On a good launch, I'd practically torque-steer off of the track.
Then again, I am the suckiest drag racer on the planet.


You might be able to mimic the signals that the anti theft produces to fool the computer.

Well, its CAN bus, so its not "signals", per se.
The two systems talk to each other like PCs on a network.
If they don't give the secret handshake, you don't go anywhere.

[mazdamaniac]

What's your take on this system in Low compression motor vs. high?? Maybe this is myth, but I've always heard problems with high is detonation is likely and needs to run richer to save engine..

Compression is compression.

If you don't have it static, you create it dynamically with the turbo.

a 10:1 motor on 9 PSI is the same thing as an 8.5:1 motor on 12 PSI.*

If you manage charge temps and fueling/ignition correctly, a high-compression motor with less boost will run circles around a low-compression motor with more boost at the same power levels because the off boost and throttle transition areas with be faster.

*(very, very, very rough and inaccurate exaggerated example, of course)

[Whizbang]

hmm...maybe you can bring the anti theft system onboard and then fool THAT into thinking everything is peachy keen

[mazdamaniac]

hmm...maybe you can bring the anti theft system onboard and then fool THAT into thinking everything is peachy keen

That is exactly what I do with the Grand Am cars.
Just wire-tie it up under the dash board and tape an ignition key fob to it.

[Phoenix7]

What do you mean? My "public" dyno at 9 PSI on my nice, extremely streetable turbo is over 315 RWHP.
With meth and a bit more boost, I made 20% more over that.
If someone wanted a 400 HP RX-8 and wanted to deal with the street performance liabilites of that (just like the 400+ HP club of RX- owners do), they could go to a GT3571 or similar and be there all day.

The problem is, most people don't want a high-HP car - they just want to brag about owning one.
A 400+ HP turbo rotary is annoying at best in stop and go traffic. Add summer to the mix and the sacrifices you make in vehicle comfort to make use of that power and you have a car that no one wants to drive anywhere but straight down the 1/4 mile.
RX-8 owners like their DSC/TCS, A/C and power seats. Did I mention the cup holders and the Bose 9-speaker stereo?

On a road course, I destroy cars that are supposed to outclass me by a considerable margin.
Watch as this "500 HP", single-turbo 300 ZX desparately tries to catch me on the 1/2 mile straight at Firebird Raceway as I hit nearly 150 MPH.
Then watch as I out-brake him!
VIDEO (http://www.mazdamaniac.com/wot.htm)
The Cobra and the Saleen did the same thing, only I watched them spin behind me in the second corner after that straight.
Very sad. I almost spilled my latte.good post. Looks like I'm not giving the Renesis the credit is deserves. Thanks for patiently clearing things up.

Now regarding hi/lo comp:
I can understand how a high compression motor can match/outperform a low comp one at lower or the same boost levels. HP-wise the high comp motor wins but isn't the lower compression motor safer for boost application, like Herb said, for the safety of the motor? Or is this another misconception? I know that tuning plays a huge role in the safety and longevity of the motor but doesn't the high comp motor wear and tear at a higher rate?

Also, thanks for joining and taking the time to bear with some of us.

Also, What I meant by "yielding little power" was : yielding little HP per dollar spent (compared to the older rotaries).

[Herblenny]

You could do that.
The tuning is ALWAYS as simple as putting in a value.
The trick is knowing that value.
You do have to get the calibration for the MAF and other sensors right, also.

how about sequential system?? Do you see any problem running it?? or solution to it??

I feel like now I'm just picking your brain... SO, I apologize if its wasting your time..

[mazdamaniac]

HP-wise the high comp motor wins but isn't the lower compression motor safer for boost application, like Herb said, for the safety of the motor? Or is this another misconception? I know that tuning plays a huge role in the safety and longevity of the motor but doesn't the high comp motor wear and tear at a higher rate?


Every motor has a finite number of puffs in it. The more powerful those puffs, the fewer it will make over its lifetime.

Tuning is everything. Period.
If a motor is properly built, tuning can extract power out of it right up to the point it breaks from load.
Almost no one ever gets that far before they make a mistake or get it too close to the edge of what available fuels and prevailing conditions allow.

Also, What I meant by "yielding little power" was : yielding little HP per dollar spent (compared to the older rotaries).

Now, that is a different question completely.
The people that have figured out how to make power with this motor are charging what the market will bear. Wouldn't you?
Do it yourself and the material investment is no different than any other motor.

As the charts I posted indicate, +300 HP is reachable for about the same cost as it would be on any motor that only made 190 or so to begin with.

[mazdamaniac]

how about sequential system?? Do you see any problem running it?? or solution to it?

You mean sequential turbo?
First, why?
Second, air is air. The motor doesn't care how it got there.

These days, the water-cooled, ball-bearing turbos are so fast and so powerful, there is no good reason for multiple turbos on a tiny motor like the rotary.
Now, a 7 liter V8 is a different story, but they do fine with a big BB turbo as well.

[Herblenny]

Why?

I'm kind of thinking in terms of the market.. maybe for you..

If you could get this system to work for stock turbos and extract as much power potential as you claim (close to 400WRHP), just by the swap, stock FD set up without changing the turbo, you'll hit the market! Especially, you work out the maps and sending it to people... people no longer need so called tuners tuning cars. Like how you are doing with the 8 owners. It would be simple solution to quite a lot older turbo car users..

[Phoenix7]

well, I don't know if I'd agree with the last line about costing the same as a 190hp car. The TII is 160-170whp and with ~1200 bux you can make 300HP (BNR turbo, accompanying fuel and electronics). You can add another 1200 if you want to use a standalone. LIke you said, we're talking older technology, maybe that's what makes the differences in prices.

As far as sequentials:
I thought it might help with the top end. I see that the Greddy upgrade in your charts has great low end that tapers off after 6K RPMs in one graph and 7.5K RPMs in the other. Wouldn't a second turbo maintain linear power all the way through the powerband? Similar to the FD setup? :dunno:

[Whizbang]

I see VNT technology being good for this application

[Herblenny]

yeah, I think its the difference in time.. I mean, I remember when PFCs were 1500+.. Now its only 700.

I'm beginning to like the idea of this and makes more sense. I guess i totally forgot about the whole maf system and been involved too much in tuning map based system.

I'm very intrigued to learn more about this as this could work for older generation turbo systems.. I think its bit more complex compare to map, but I do see the advantage over it.

[mazdamaniac]

The TII is 160-170whp and with ~1200 bux you can make 300HP

Its already a turbo car. Doesn't count for this comparison. Try making that power that cheaply on the GTU.


As far as sequentials:
I thought it might help with the top end. I see that the Greddy upgrade in your charts has great low end that tapers off after 6K RPMs in one graph and 7.5K RPMs in the other. Wouldn't a second turbo maintain linear power all the way through the powerband? Similar to the FD setup? :dunno:

Power tapers in the high-end of the Renesis because of the flow restriction of the exhaust ports.
The Renesis has a very wide power band, but it isn't going to be all at the top like a peripheral port 13b.
Once the gas velocities get really high, the right-angle turn of the exhaust ports becomes a restriction.
The high power output Renesis applications you will see in the future will make their peak tq at 6200 and hp at 7200 max.


If you could get this system to work for stock turbos and extract as much power potential as you claim (close to 400WRHP), just by the swap, stock FD set up without changing the turbo, you'll hit the market!

The problem with the FD turbos are they don't flow enough air.
You can tune all day, if the air is hot coming out of the turbos (low mass) the power won't happen.

[Herblenny]

The problem with the FD turbos are they don't flow enough air.
You can tune all day, if the air is hot coming out of the turbos (low mass) the power won't happen.

People have made upwards 380ish RWHP sequential via MAP system on stock twins.

99 sequential turbos also made around that HP with quicker spool.

BNR's have made over 400RWHP sequential in MAP system.

So, Are you saying that its the temperature of the air that might cause problem of tuning MAF based system?? Again, I'm not an expert in MAF tuning.. but doesn't air temp gets measured by MAF sensor?? or is there another sensor after TB?? And when running EtOH/Water inj. Do you shoot before MAF or after??

[Whizbang]

i think the problem is the turbos are getting out of their efficiency range when you start getting up there.

[Phoenix7]

Its already a turbo car. Doesn't count for this comparison. Try making that power that cheaply on the GTU. you got me there. You're right.



Power tapers in the high-end of the Renesis because of the flow restriction of the exhaust ports.
The Renesis has a very wide power band, but it isn't going to be all at the top like a peripheral port 13b.
Once the gas velocities get really high, the right-angle turn of the exhaust ports becomes a restriction.
The high power output Renesis applications you will see in the future will make their peak tq at 6200 and hp at 7200 max.:icon_tup: Makes sense, what exhaust manifold does the MM turbo use?


The problem with the FD turbos are they don't flow enough air.
You can tune all day, if the air is hot coming out of the turbos (low mass) the power won't happen.

[mazdamaniac]

:icon_tup: Makes sense, what exhaust manifold does the MM turbo use?

Its the GReddy cast iron manifold.
Pretty decent piece - the flow cross-section is about equal to the port area.
I've been thinking about an Extrude-Hone to increase flow a bit.

i think the problem is the turbos are getting out of their efficiency range when you start getting up there.

Exactly.
Even though the pressure is rising, the mass is holding because the heat is going up.

[Herblenny]

So are you saying that with MAF system can't hit XX Horsepower that MAP system will hit with the same turbo(s)??

[fikren]

can we get a mod to sticky this one, lots of good info coming out maybe useful in the future.

[mazdamaniac]

So are you saying that with MAF system can't hit XX Horsepower that MAP system will hit with the same turbo(s)??

??
MAF or MAP has nothing to do with it.
You just are limited by the turbos themselves.
The units that come on the FD are dinosaurs.

[Herblenny]

I understand that different turbos have different efficiency and limitation..

Maybe I read it wrong.. But if your turbo makes 400hp top as its limitation on MAF based system and stock REW twin turbo (99s) will make close to 400 as its limitation on MAP.. I'm wondering if using MAF system on REW will produce similar HP...

I guess maybe I got confused when you stated about temp and efficiency being the issue and wondering if thats one of the downfall of MAF based system to so called hitting maximum potential of turbo.

I personally do not think FD units are junk/dinosaurs... Its very responsive and still one of the best sequential systems out there (mazda made FDs til 2002).. Many still prefers it vs. single, not just money but for its performance.. I mean, I still prefer it.. and really money wasn't an issue... I have a gigantic single at home that I could put on and make 500hp (T78BB) if I wanted to... but I know its not all about HP.

BNRSupercar just recently put 99spec (280HP turbos from mazda) and at 14lbs of boost (MAP) on bone stock motor made 321RWHP. Conservative tuning and super responsive (I think full boost at 2300-2500RPM). If FD turbo system is dinosaurs and when compared to Modern Renesis motor and modern BB turbo, why is it that people not putting Renesis in FDs (like person like me with a spare renesis at home and 2x FD)?? is it because of money?? or is it because there is nothing to do with difference between MAF or MAP?? I think that's the bottomline I'm trying to get to.. Is MAF based system so much superior without any catch that even "dinosaur" turbos could be ran better??

[Herblenny]

By the way Jeff, don't take me personally.. I do think MAF system definitely has its advantages... I just don't know its disadvantages...

I hope you understand I'm not trying to argue with you saying MAP is better than MAF.. I just don't know much about the MAF and knew better about MAP.

I'm just trying to learn more by asking stupid questions..

[fikren]

By the way Jeff, don't take me personally.. I do think MAF system definitely has its advantages... I just don't know its disadvantages...

I hope you understand I'm not trying to argue with you saying MAP is better than MAF.. I just don't know much about the MAF and knew better about MAP.

I'm just trying to learn more by asking stupid questions..
The only stupid questions are the ones not asked......oh and any that phil asks. :rofl:

[mazdamaniac]

I am, by no measure whatsoever, insulted or offended.
I LOVE people that are inquisitive and I LOVE talking about this stuff.
So, bear with me, because I get side tracked easily and have the memory of a flea, so it takes me a while to get things straight.

[RCCAZ 1]

:lol: ... yea, Jeff's our little flea, flea :lol:

[scotty305]

The Lancer Evo and WRX STI include both MAP and MAF sensors. I won't pretend that I know much about how their stock ECUs work, but they are two good examples of modern turbocharged engines. It would be much cheaper to use only one sensor as opposed to two, so that makes me think that there are enough advantages and disadvantages that the OEMs would want to use both.


It's pretty apparent that a MAP sensor alone doesn't tell you how much fuel to inject: for instance the MAP sensor will measure about 10psi on a bone-stock FD3S that makes about 250hp at the crank. I don't have a specific example in mind, but the same MAP sensor could measure 10 psi with an upgraded turbocharger, ported engine, and free-flowing intake and exhaust setups on a car that could be making over 300 hp at the wheels. The more powerful motor will require a lot more fuel, which is a good sign that it's flowing a lot more air. This is one example of how a MAF sensor could be very useful; a properly calibrated MAF sensor can accurately measure how much air is going into the engine (if properly calibrated) and simplify the tuning process (if you know how to use the data from your properly calibrated MAF sensor). Modern MAF sensors are not much more restrictive than an Intake Air Temperature sensor, you can install them in a bung that fits in any diameter of intake pipe (although you may need to re-calibrate the sensor voltage vs. airflow if you change the diameter of the pipe).


Then again, there's more to tuning an engine than just making sure it runs at your desired air/fuel ratio. I don't know how a MAF sensor would help determine the "correct" ignition timing settings for making power.


As with anything else, the most powerful ECU in the world won't do you much good if your tuner can't use it. You will need to find a tuner who is familiar with MAF-based systems or learn it yourself. Part of learning often involves making mistakes, and we all know how costly mistakes can be when turbocharged rotary engines are involved.



By the way, cool site Mazdamaniac, and thanks for sharing a bit about the RX-8 ECU.



Edit: meant to post this in the "MAF vs MAP tuning" thread in the ECU section. Nonetheless, thanks for sharing about the RX-8 turbo setups.

[rx8man]

Reading some of the posts in this tread, has made me think again... maybe it is worth turboing a rx8???
Good info guys:)

[mazdamaniac]

maybe it is worth turboing a rx8???


I think so.

Its a matter of having clear goals and making correct choices.

If you are building a dyno queen or a drag car, I'd say putting a turbo on the Renesis (as it sits) is a waste of time.
If you are addicted to horsepower, the same holds true.

However, if you want a streetable screamer that you can track respectably and still put your 1.5 kids in the back and go on a road trip while embarrassing STi and Cobra owners, than a turbo Renesis is more than up to the task.

[rx8man]

I think so.

Its a matter of having clear goals and making correct choices.

If you are building a dyno queen or a drag car, I'd say putting a turbo on the Renesis (as it sits) is a waste of time.
If you are addicted to horsepower, the same holds true.

However, if you want a streetable screamer that you can track respectably and still put your 1.5 kids in the back and go on a road trip while embarrassing STi and Cobra owners, than a turbo Renesis is more than up to the task.


"streetable screamer "-- is about all I'm after, having done a 20b in a rx7, -- which was heaps of fun, but once (well, what I found) you get up in the hp (kw) numbers (maybe toque?)-- then a the drive train weak(er) link will be found.
In my 20b case--2nd gearboxs and clutch were getting replaced.

But to embarrass STi (and Evo) owners I would be more than happy with:)

[Nutsid]

Perhaps it is just me, but I feel that newer cars aren't worth tuning. I mean, twenty years ago if a car did a 14 second quarter mile out of the box, it was damn near super car status. I don't know about any of you, but honestly, racing the STi from stop light to stop light just isn't fun to me.

I'm blessed with windy roads all around me. It is all pretty flat, but taking country roads semi quick will always be more fun than just going fast, and the Rx8 does that remarkably well.

I understand that people are always going to want to go faster, and be faster than such and such car and so and so. I just don't see the Rx8 as the car to really do it in. When I drive the car it doesn't even feel like a sports car until I really want it to be. It feels more like a regular car. It doesn't stir emotions in me that other sports cars I've owned have (I don't like FC's, but even they stir more of a sports car feel in me than the Rx8). The Rx8 just feels like it was made to be too comfortable while maintaining the sports car characteristics. A sports car like no other because it is almost the perfect blend of comfort, practicality, and a sports car.

It makes it sound like I don't like the Rx8 at all, but its quite the opposite. I love the car. It just isn't a pure sports car to me, which makes me feel like it is worthless to turbocharge, or modify to any great deal. The car is a blend of everything, and it does it perfectly well. Modifying one just takes away that balance a bit too much in my mind.

Now that goes without saying that in ten years I'd probably be more than willing to pick up another Rx8, turbocharge the bastard, and modify it like any true sports car, but that is when parts will be significantly cheaper, and the only practical rotary to modify will be an Rx8 (FB's will be like Rx3's are now, and FC's will be like FB's now, etc. etc.)

[Wangan_X]

The Lancer Evo and WRX STI include both MAP and MAF sensors. I won't pretend that I know much about how their stock ECUs work, but they are two good examples of modern turbocharged engines. It would be much cheaper to use only one sensor as opposed to two, so that makes me think that there are enough advantages and disadvantages that the OEMs would want to use both.


are you talking about the 08 models? If not I must correct you, the Evo 9 and 8 both have a MAF, which is why when they run VTA BOV's they run like poo.

[warwickben]

i bought a 05 rx8 a few weeks ago as my daily(yeah i know a daily 8 in new england isnt th best idea). my other car is a 1980 sa. i love my 8 so much even tho ive had a clutch problem with it since i got it. iam glad i sat down and read this thread. i can read this stuff all day long.

yeah i would love to get more power out of my 8, but like spock(mazdamaniac) said in a way........ most people would rather have a streetable screamer that they could drive every day then a super high hp car that they have to baby drive 90% when they have it on the road. i drive 100 miles every other weekend in rush hour traffic to hang with my friend for the weekends.i drove a buddys wrx sti up there once that was making 500 hp and id never want to do that again.

mazdamaniac i wish you could help me with the 84 mercury turbo 2.3 capri me and my buddy are building. it has a vain air meter. if you could give me tips on that ect id love you to the end of time. the whole tunning area scares the crap out of me. thats why iam a welder/ fab guy on the capri. if you could do we have to redriect the bov back in to the intake or can we vent it out with a vain. i know we could run with out and just on map but we want to have a car that the motor will last.

[rotaryextreme]

bump

[CyberPitz]

Extremely great information here....glad it got pumped!

[Nutsid]

Upon doing a lot more research on the topic, I think I would much rather do an engine swap, whether it be a 13B-REW or a 13B-RE, that would be personal preference. But you'd get a 13B much more capable of putting out gobs of horsepower, more torque, and all at around the same price as a turbo kit with aftermarket standalone system.

That would be the route I would take at least.

[rotaryextreme]

http://www.rx8club.com/showpost.php?p=3154778&postcount=346

bridgeport rx8 renny plus turbo, for you rx7 guys to take a look at.

Pretty impressive.

[Rotary Inspired]

That's with a custom made upper intake mani and a half bridged motor. I would hate to tell you what the same modifications would yeild on a older 13BT. I am over 400whp w/ stock intake manis and a 60-1 turbo. If I had all the mods he has and I wasn't over 600 on a 13BT I would be very dissapointed. Yes I have an 8 too. Great car its just not going to make the same power.

[rotaryextreme]

Well, with as much money he spent, I am 100% possitve a 13b rew would be at around 700 to 800 whp.

He said he has like 15k invested.

Still, its nice to see the renesis getting this attention.

I'm everyone is waiting to see what this infamous 16x will do when it comes out.

[Nutsid]

I'm not really a big fan of turbocharging the Renesis. I think I've made that pretty decently known in this thread already. On one hand I wish the Rx8 had more power, but on another I just wish it had less weight. The power is plenty enough to be fun stock, it just feels like it needs to go on a bit of a diet. The more I drive the car the more I get confirmation of this. Obviously this is all my opinion.

There will always be the power hungry out there, and I can understand that and appreciate that. I'm glad to see the Renesis finally putting out some decent numbers, but the cost efficiency just isn't there. I'd rather do a three rotor swap and keep it all motor with a big street port, or do a 13B-RE or REW swap into it with a big street port for the kind of money it takes to even make 350 horsepower out of the Renesis. And with any of the other three engines built like that it would be well over the 350 mark.

I just think that the Renesis is a fantastic engine naturally aspirated, and it should stay that way. Do intake, bridge it if you must, throw on some exhaust, get it tuned and you should have ample amounts of power. Get rid of the catalytic converters if you don't have emissions testing. If you want gobs of power, do an engine swap.

[Chibana]

While I can agree that compared to older rotary powered vehicles the RX-8 is heavy, this isn't a fair comparison. All modern cars are heavy. Compared to almost any other car you could compare it too, the RX-8 is lighter, sometimes by several hundred pounds. I think Mazda did a good job in keeping it's weight under control when so many other performance cars and supposed sports cars are pushing 3500 or more pounds. Hell, the new Camaro is what, 3900 lbs. with the V8? Even with the V6 it's still over 3800 lbs., I think. I'm all for a smaller, lighter 16x powered car for the next generation, but then again, I may not fit in such a car (the MX-5 was out for me for just that reason).

Having said that, I'm curious as to why the RENESIS is not as good at producing higher power numbers as older Wankels. As far as I can tell, it's the side exhaust port configuration, resulting in that 90 degree bend in the exhaust path. Are there other issues?

[Herblenny]

I like how my 8 drives.. I think turbo'd 8 does sound great.. but I'm curious how reliable it would be (as street car).

I bought a renesis motor that came out of a turbo 8 (blown motor) and it was toasted.. all 3 apex seals are gone! But the side seals were fine :) I'm guessing its similar to why some of us don't use high compression rotors + high boost... its bit more difficult to tune but you do gain bit of low end torque and power.

I think if I see consistent results with the set up, I might consider it. But if you add the cost involved, its still hard for me to justify. FD with BNR stage 3, upgraded IC, with 2 more 850s and it will make close to 380 in sequential set up... that's total of maybe 15-16K for the set up total (including the car).. Or buy one built for about 16K +/- 2K.

I just like how my 8 is now.. Its a good daily with back seats that I really don't use as I don't have kids and my wife hates riding in it... 90+% of time, I'm the only one driving it.. My next daily will be a G35/37.. prefer auto as I'm sick of shifting gears and want to be on the cell phone while I drive to work and home :)

[Nutsid]

While I can agree that compared to older rotary powered vehicles the RX-8 is heavy, this isn't a fair comparison. All modern cars are heavy. Compared to almost any other car you could compare it too, the RX-8 is lighter, sometimes by several hundred pounds. I think Mazda did a good job in keeping it's weight under control when so many other performance cars and supposed sports cars are pushing 3500 or more pounds. Hell, the new Camaro is what, 3900 lbs. with the V8? Even with the V6 it's still over 3800 lbs., I think. I'm all for a smaller, lighter 16x powered car for the next generation, but then again, I may not fit in such a car (the MX-5 was out for me for just that reason).

Having said that, I'm curious as to why the RENESIS is not as good at producing higher power numbers as older Wankels. As far as I can tell, it's the side exhaust port configuration, resulting in that 90 degree bend in the exhaust path. Are there other issues?

Oh, I agree with the weight by today's standards entirely. I actually think that a base model is really light all things considered. I'm simply stating my personal preference. I could do without my electric seat, my sunroof, my heated seats. The R3 package, for example, sounds perfect to me. Well, at least as close to perfect as you can get in a modern day car. I'm sure I'd still be longing for more weight loss, but I can understand entirely that modern day regulations prohibit the days of the FB. :lol:

And the reasoning the Renesis can't make the power older rotaries can is because of the ports. Older rotaries (ie - 13B-RE and 13B-REW) utilized large intake ports. The Renesis, albeit large, is also sacrificing port size due to its six port design (at least in the manual version), and therefore you can't have the ports as large. If you made a solid opening for the intake ports in a Renesis, however, you'd sacrifice your low end torque, and let's face it, it isn't a grand amount down there.

The six port design for a rotary only works excellent as a means to stay naturally aspirated. Four ports are what you want for a turbo application. Having said that, I am really curious as to what would happen if you ported a four port to have the same closing timing as a six port, and turbocharged it using lower compression rotors. If I had way too much money I'd test that out. If you'd notice, though, all the turbocharged rotaries that Mazda has ever produced have been four ports. Good reason for that.

[05rex8]

I love my turbocharged 8. To all you haters: :fawk:

:)


Seriously though, the rx8 is not an rx7. I wish people would stop comparing the 2. The 8 is what it is. You CAN turbocharge or supercharge it safely. It's well documented at 8 club and mazdamaniac covered it in this very thread already.

And wow does it turn it into a completely different car. You don't even need gobs of boost either. Keep it at low boost and it will put a smile on your face every time you drive it. When it comes down to it, dyno numbers mean nothing. It's how the car feels to you. That's what matters. But I guess if you would rather brag on internet forums how much of a dyno queen your car is, I guess the rx8 is not a good choice. :cheers2:

[reddozen]

Oh, I agree with the weight by today's standards entirely. I actually think that a base model is really light all things considered. I'm simply stating my personal preference. I could do without my electric seat, my sunroof, my heated seats. The R3 package, for example, sounds perfect to me. Well, at least as close to perfect as you can get in a modern day car. I'm sure I'd still be longing for more weight loss, but I can understand entirely that modern day regulations prohibit the days of the FB. :lol:

And the reasoning the Renesis can't make the power older rotaries can is because of the ports. Older rotaries (ie - 13B-RE and 13B-REW) utilized large intake ports. The Renesis, albeit large, is also sacrificing port size due to its six port design (at least in the manual version), and therefore you can't have the ports as large. If you made a solid opening for the intake ports in a Renesis, however, you'd sacrifice your low end torque, and let's face it, it isn't a grand amount down there.

The six port design for a rotary only works excellent as a means to stay naturally aspirated. Four ports are what you want for a turbo application. Having said that, I am really curious as to what would happen if you ported a four port to have the same closing timing as a six port, and turbocharged it using lower compression rotors. If I had way too much money I'd test that out. If you'd notice, though, all the turbocharged rotaries that Mazda has ever produced have been four ports. Good reason for that.

I'm actually having mine bridge ported currently. While I can agree with some of your statements, I think a lot of people are underestimating the Renesis. Chris is getting 500HP with his setup, yes, but he's not currently using the 5th or 6th ports, and he's only boosting to 15~16lbs of boost. Once he's popping the aux ports and running a higher boost, there's no telling just what kind of power he'll be putting down. He wants to run 19~20lbs.

They'll trying porting a 4 port eventually, but I don't think the ports are all that bigger than the ones in the 6 port in regards to the Renesis. Regardless, it'll be hard to tell which is better till more people are playing with them.

I was going to do an engine swap in the 8 till I got to talking to Brian Cain about it, and we both kind of agree that there's a lot of untapped potential in the Renesis block. Even with a bridge port, I'll have a lot less overlap than a stock 13b. Bigger port and more well behaved motor. Just my thoughts really, but we'll see once everything's in and running.

Chibana,
The exhaust port isn't the weak link. It's the upper intake manifold. This starts to get choked for air between 450~500 HP.

[rotaryextreme]

Yo...

Whats up Reddozen,

Everybody, lets think about it.

The Renesis makes almost 100 more hp then the last n/a rotary they put out.

I am sure the surface is just being scratched with the porting.

And this motor is a very reliable platform.

I am excited not just because there is a 16x comming out, I am excited how the 16x will respond to all the same modifications. And soon I'm sure somebody will have the cashflow to make a 3 rotor 2.4 from a 16x...yum.