TitaniumTT's I hope I make it to DGRR '09 Build

[NoDOHC]

I don't know how you made any boost at all with the charge relief vale open

361 WHp is even more impressive considering that.

If you can make 15 psi, than 400 WHp should be pretty easy.

Not only do you get the fast spooling of the twins, you get good power too (perfect for autoXing).

You have no idea how much you are tempting me to throw a set of BNR twins on my engine instead of the GT37.

The reason that I was curious about the NA power is this:
361 WHp @ 6700 rpm = 283 W lb-ft of torque.
283 Wlb-ft * 14.8/(11.5+14.8) = 159 Wlb-ft of torque (which is identical to what my engine makes at 6700 rpm). This indicates to me that either your engine flows a lot better than mine (which is very possible, as you have the 3rd gen intake and I have a 2nd gen intake) or I can use very simple math to compute the power increase by adding a turbo (power ratio = intake pressure ratio).

The properties of torque at a given air fuel ratio are basically fixed for the fuel type, compression ratio, combustion chamber design and intake port timing (exhaust port timing does not matter for peak power AFR). Since you have identical characteristics in all except for port timing (which is not significantly different) and maybe the compression ratio (I think you have 9.0:1, where my 8.5:1 rotors are machined down to 8.2:1 - but it has a small effect anyway). I would expect our engines to perform similarly for torque vs AFR.

That is why I thought it was awesome that you were running 13.0:1 AFR (which is about where I found peak power NA) so I can compare. I made 10 lb-ft (6%) less torque at 12.3:1 as I did at 13.0:1. I made a LOT less torque at 11:1 (like 20% less). I intentionally dynoed my engine NA so that I could compare the power numbers with and without a turbo (The goal being to make 2X NA power (430 WHp) at 14.5 psi boost).

It almost seems like you are doing a little bit of the development for me (and you are giving me hope that it can be done).

Keep up the good work!!

edit: The above was meant for both Brian and Dave, as I have no intention of discounting or ignoring the critical part Dave is playing here, 361 WHp and drove it home because the tuner knew when to quit.

[FC3S Murray]

I think he is running S4 N/A rotors...not sure though, maybe even S5 N/A.

Man I wish I had a rotary tuner close to home. I have had to learn all tuning via forums and some automotive engineers/ professional tuners. It has worked out so far BUT there is a part of me that wounders if I am missing some "secret" insight that would yield better results. My last "shit" motor felt outstanding at 15 psi and I tuned it to about 11.5:1 keeping the top end within .1-.05 AFR of each cell range.

I am very curious to see what I will put down for power come dyno this spring especially in regards to torque since I have been studying timing correlation and mid-range torque.

[TitaniumTT]

Originally Posted by NoDOHC

I don't know how you made any boost at all with the charge relief vale open

361 WHp is even more impressive considering that.

If you can make 15 psi, than 400 WHp should be pretty easy.

Not only do you get the fast spooling of the twins, you get good power too (perfect for autoXing).

You have no idea how much you are tempting me to throw a set of BNR twins on my engine instead of the GT37.

The CRV is connected to the end of a 3/4" hose that takes two quick 908 turns and also vents through a filter so it's not like it's wide open but yeah, I'm pretty surprised she was able to do what she did all things considered.

As for the BNR's........... some have made more power with them and others report losing power. I spoke with one forum member recently about his BNR's running full NON-seq with all the valves cut out, holes welded shut and the mani and turbine housings ported...... he made 344 rwhp. Then again in talking with Bryan I believe he said that the highest reported sequential was 412. I would pick up a set of stockers first to see how your setup likes it then upgrade if necessary.

In all honesty though, my next project with be twin GT28's, externally gated hanging of a very similarly prepped 13B-RE in an FD chassis Maybe even GT30's who knows. Need to find a roller first damnit.

Originally Posted by NoDOHC

The reason that I was curious about the NA power is this:
361 WHp @ 6700 rpm = 283 W lb-ft of torque.
283 Wlb-ft * 14.8/(11.5+14.8) = 159 Wlb-ft of torque (which is identical to what my engine makes at 6700 rpm).

Where did all of those numbers come from?

Originally Posted by NoDOHC

This indicates to me that either your engine flows a lot better than mine (which is very possible, as you have the 3rd gen intake and I have a 2nd gen intake) or I can use very simple math to compute the power increase by adding a turbo (power ratio = intake pressure ratio).

I'm running the Cosmo intake, with everything portmatched and cleaned up. I made everything as effiecient as I possibly could specifically for the goal of 400 wheel.

Originally Posted by NoDOHC

The properties of torque at a given air fuel ratio are basically fixed for the fuel type, compression ratio, combustion chamber design and intake port timing (exhaust port timing does not matter for peak power AFR). Since you have identical characteristics in all except for port timing (which is not significantly different) and maybe the compression ratio (I think you have 9.0:1, where my 8.5:1 rotors are machined down to 8.2:1 - but it has a small effect anyway). I would expect our engines to perform similarly for torque vs AFR.

Running 9.0:1 rotors and depending where we land, I MAY be swapping them out for some 9.7:1 rotors. I really want to compare my graphs to Chadwicks when we get the sequentials working. His low end torque was obscene.

Originally Posted by NoDOHC

That is why I thought it was awesome that you were running 13.0:1 AFR (which is about where I found peak power NA) so I can compare. I made 10 lb-ft (6%) less torque at 12.3:1 as I did at 13.0:1. I made a LOT less torque at 11:1 (like 20% less). I intentionally dynoed my engine NA so that I could compare the power numbers with and without a turbo (The goal being to make 2X NA power (430 WHp) at 14.5 psi boost).

I drove up to grab a sensor and was talking to my EMS guru a few days ago and showed him the dyno graph's the car etc etc etc..... told him we were shooting for .8L He was very surprised. I explained the reason and while he agreed with it, he kept pestering me to run her @ .85L just once to see how much she woke up. .85L = 12.5:1 AFR getting close to that dangerously lean part. Lets not forget I warped 2 Apex seals @ 13.5 AFR in one boost spiking pull. I'm alot more comfortable @ .8, but will probably use the overall trim to take a percent or two out and make one pull to see the gains from .8 to .82/.83..... MAYBE. I'd rather have a fat, dumb and happy engine than one that's running a little closer to the ragged edge and one hiccup pops it. We'll see though, she did wake right up though.

Originally Posted by NoDOHC

It almost seems like you are doing a little bit of the development for me (and you are giving me hope that it can be done).

Keep up the good work!!

edit: The above was meant for both Brian and Dave, as I have no intention of discounting or ignoring the critical part Dave is playing here, 361 WHp and drove it home because the tuner knew when to quit.

I love Dave to death, he's a very conservative guy which is nice to know, especially when you think about the things we're asking this little engines to do. When Bill came up and we had that sticking cornerseal, Dave asked what I wanted to do, dyno or no dyno.... you could see the tension leave his face when I said I didn't want to risk it.

Originally Posted by FC3S Murray

I think he is running S4 N/A rotors...not sure though, maybe even S5 N/A.

Man I wish I had a rotary tuner close to home. I have had to learn all tuning via forums and some automotive engineers/ professional tuners. It has worked out so far BUT there is a part of me that wounders if I am missing some "secret" insight that would yield better results. My last "shit" motor felt outstanding at 15 psi and I tuned it to about 11.5:1 keeping the top end within .1-.05 AFR of each cell range.

I am very curious to see what I will put down for power come dyno this spring especially in regards to torque since I have been studying timing correlation and mid-range torque.

Yeah Sean, running 9.0:1 rotors, basically S5/6 turbo compression. Thinking about 9.7:1 depending on where the torque curve falls.

I would say that 11.5 to one is a tad too rich. My EMS guy and I had a very interesting conversation about this on Tuesday.... he by the way does the setup and engine dyno's, or did rather, for Perez Here's what he had to say about running too fat dumb and happy.... in a nut-shell, paraphrased, and I'd also like to add that this is ONE reason I think these engines spontaneously detonate.
Basically by running TOO rich you are leaving unburnt fuel in the combustion chamber, hanging on the rotor, seals, maybe even the housing surface itself. This is fuel, it's partially or completely vaporized and just waiting to be ignited. It's in the perfect environment as well. With the opening of port, incomes more oxygen, and all it needs is a little too much heat, or some exhaust gases to sneak by through the overlap or the trailing sparkplug hole and BAM - autoignition and bye bye.... game over. Is this likely to happen @ 11.5? Probably not unless your plugs are crap but how many people run around in the 9's and 10's? ALOT, how many people pop engines? What are the circumstances behind them? I'd love to study a TON of datalogs from blown engines and see if there is a pattern developing.

Of course he finished this off with..... I've never tuned a rotary to be street driven before though. My world with Rotaries starts @ C16 The guy has an impressive resume though. Alot of big name guys both piston and rotary, drag, circuit and road race all go to him so I think we'll make one pull at .825 and then go right back to .8

[antman0408]

I couldn't make it up there last week, others things came up, but I'll be able to make the 22nd. Maybe I could put my car on the dyno if there's enough time, I'm curious as to what its putting down.

[NoDOHC]

Quote:

Where did all of those numbers come from?

I am so sorry, I never explained a thing.

You said that you are at sea level. Thus atmospheric pressure is 14.8 psi.

You said that you were running 11.5 psi of boost. This means that your intake manifold pressure was 14.8 (atmosphere) + 11.5 (boost) or 26.3 psia.

I was running about 14.5 psia at 6700 rpm (800 ft of altitude, no turbo).

A rule of thumb for diesel engines is that the torque boosted = the naturally aspirated torque X the boost ratio (absolute manifold pressure ratio). Diesel engines all run lean of stoic and the AFR is basically the same for turbo and NA.

Thus, if a diesel engine made 159 Wlb-ft at 800 ft elevation Naturally aspirated, it would make 159*(14.8+11.5)/14.5 or 288 lb-ft of torque at 11.5 psi boost and sea level.

I was thrilled to discover that your engine made 283 Wlb-ft of torque at 11.5 psi, as that is very close to that rule of thumb. (Obviously, the rule of thumb is seldom true for gasoline engines due to the excessively rich fuel mixes that must be run for a reliable turbo setup). I always theorized that if the AFR were the same on a boosted engine as it was on a NA engine, the ratio would work out (and it did).

Now unfortunately, You have a better compression ratio (which helps your power) and a better intake manifold, so there is a good chance that I will not see these improvements when I turbocharge my engine. But I really do intend to run at 13.0:1 AFR at 14.5 psi boost and I am relying on my intercooler, my low compression ratio and my ultra-polished combustion chambers to save me from detonation.

First I must experiment with the effects of compression ratio on a NA engine before I put the 8.2:1 rotors back in and install the turbo.

[TitaniumTT]

Originally Posted by antman0408

I couldn't make it up there last week, others things came up, but I'll be able to make the 22nd. Maybe I could put my car on the dyno if there's enough time, I'm curious as to what its putting down.

Hey man, that would be sweet.... but we changed the date, I'm heading there on Tuesday the 20th.

Originally Posted by NoDOHC

I am so sorry, I never explained a thing.

You said that you are at sea level. Thus atmospheric pressure is 14.8 psi.

You said that you were running 11.5 psi of boost. This means that your intake manifold pressure was 14.8 (atmosphere) + 11.5 (boost) or 26.3 psia.

I was running about 14.5 psia at 6700 rpm (800 ft of altitude, no turbo).

A rule of thumb for diesel engines is that the torque boosted = the naturally aspirated torque X the boost ratio (absolute manifold pressure ratio). Diesel engines all run lean of stoic and the AFR is basically the same for turbo and NA.

Thus, if a diesel engine made 159 Wlb-ft at 800 ft elevation Naturally aspirated, it would make 159*(14.8+11.5)/14.5 or 288 lb-ft of torque at 11.5 psi boost and sea level.

I was thrilled to discover that your engine made 283 Wlb-ft of torque at 11.5 psi, as that is very close to that rule of thumb. (Obviously, the rule of thumb is seldom true for gasoline engines due to the excessively rich fuel mixes that must be run for a reliable turbo setup). I always theorized that if the AFR were the same on a boosted engine as it was on a NA engine, the ratio would work out (and it did).

Now unfortunately, You have a better compression ratio (which helps your power) and a better intake manifold, so there is a good chance that I will not see these improvements when I turbocharge my engine. But I really do intend to run at 13.0:1 AFR at 14.5 psi boost and I am relying on my intercooler, my low compression ratio and my ultra-polished combustion chambers to save me from detonation.

First I must experiment with the effects of compression ratio on a NA engine before I put the 8.2:1 rotors back in and install the turbo.

Gotcha, that all makes sense actually..... Dave is higher than sea level though. I don't know what his altitude is but I seem to remember MAP sensor reading something 97.5 kpa. I can look at the logs and tell you what the MAP reading was. That will give you the absolute pressure. Whatever the actual boost was plus whatever the atmosphere was.

[FC3S Murray]

Originally Posted by TitaniumTT

I would say that 11.5 to one is a tad too rich. My EMS guy and I had a very interesting conversation about this on Tuesday.... he by the way does the setup and engine dyno's, or did rather, for Perez Here's what he had to say about running too fat dumb and happy.... in a nut-shell, paraphrased, and I'd also like to add that this is ONE reason I think these engines spontaneously detonate.
Basically by running TOO rich you are leaving unburnt fuel in the combustion chamber, hanging on the rotor, seals, maybe even the housing surface itself. This is fuel, it's partially or completely vaporized and just waiting to be ignited. It's in the perfect environment as well. With the opening of port, incomes more oxygen, and all it needs is a little too much heat, or some exhaust gases to sneak by through the overlap or the trailing sparkplug hole and BAM - autoignition and bye bye.... game over. Is this likely to happen @ 11.5? Probably not unless your plugs are crap but how many people run around in the 9's and 10's? ALOT, how many people pop engines? What are the circumstances behind them? I'd love to study a TON of datalogs from blown engines and see if there is a pattern developing.

Of course he finished this off with..... I've never tuned a rotary to be street driven before though. My world with Rotaries starts @ C16 The guy has an impressive resume though. Alot of big name guys both piston and rotary, drag, circuit and road race all go to him so I think we'll make one pull at .825 and then go right back to .8

I know it is rich but I have two reasons why I think it is safe for me: 1) All we have in MT is good old 91 octane....fun shit. 2) I understand your reasoning with the small amount of unburnted gas from overly-rich conditions and the extra added exhast gas from overlap BUT I would think that the small amount of unburnt gas even if ignited would not be suffiecient or have enough energy too actually cause lethal detonation. Plus, wouldn't the extra fuel actually cool the chamber(although not wise to use an flammable source to cool a piping hot metal chamber) I could be wrong BUT I also am very conservative with AFR's because that is what the "mob" recommends.

I hope random engine popping isn't casued from being conservative

[TitaniumTT]

It's kind of a scary thought but entirely possible that too conservative can pop engines. If exhaust gas is sneaking by through the overlap, the intake port is now open adding more fuel to the fire so to speak. Add the backpressure created by a turbo and exhaust gas is now being forced into the combustion chamber. Personally, I don't think you'll have any problems at 11.5. But there is such a sweetspot where these engines like to run it's frightening. @ 13.5 you can warp Apex seals under high enough boost

[FC3S Murray]

Originally Posted by NoDOHC

But I really do intend to run at 13.0:1 AFR at 14.5 psi boost and I am relying on my intercooler, my low compression ratio and my ultra-polished combustion chambers to save me from detonation.

First I must experiment with the effects of compression ratio on a NA engine before I put the 8.2:1 rotors back in and install the turbo.

What do you have for heat shielding in your engine bay?

I have read numerous 3rd gen owners that have spent large amounts of time working on heat dissipation with heat shielding, coolant passage mods, ceramic coating, fresh air ducting, ect..all to keep the MAIN enemy low as possible. I think you could run 13.0:1 AFR IF your temps are all very low and stable. It is the continued abuse and boosting at that specific AFR that improper heat prevention could be the killer.

There is a 3rd gen owner in the rx7club who has Einstein as his avatar(forgot name) but he has focused on heat prevention more then anything else and he is making 500 whp on pump gas constantly.

I have focused on this on my new motor all except the coolant passage way milling(most important..wish i would have). I will say my temps under the hood with my heat shielding, ceramic coating, exhst wrap and fresh air ducting and UIM and LIM coating have been impressive BUT until full boost my observations are just that...observations, nothing concrete or substantial til then.

[MaczPayne]

^You wouldn't happen to be talking about Howard Coleman? He's a BIG advocate of Auxiliary Injection, and his research has gotten me interested in it as well.

[FC3S Murray]

^
No I don't think thats him. I believe he is Goodfella's father .

I TOO have been thinking AUX injection might be this winter's big project besides suspension.

[TitaniumTT]

Originally Posted by FC3S Murray

What do you have for heat shielding in your engine bay?

I went ahead and ceramic coated everything on the engine, headwrapped the DP, BIG ASS rad and intercooler.

Originally Posted by FC3S Murray

I have read numerous 3rd gen owners that have spent large amounts of time working on heat dissipation with heat shielding, coolant passage mods, ceramic coating, fresh air ducting, ect..all to keep the MAIN enemy low as possible. I think you could run 13.0:1 AFR IF your temps are all very low and stable. It is the continued abuse and boosting at that specific AFR that improper heat prevention could be the killer.

I dunno man, I think that's a little bit of a stretch. My engine runs 173ish*'s all day long and I warped 2 seals pretty damn quick. I would like to know what the egt difference is between 13 and 13.5

Originally Posted by FC3S Murray

There is a 3rd gen owner in the rx7club who has Einstein as his avatar(forgot name) but he has focused on heat prevention more then anything else and he is making 500 whp on pump gas constantly.

I have focused on this on my new motor all except the coolant passage way milling(most important..wish i would have). I will say my temps under the hood with my heat shielding, ceramic coating, exhst wrap and fresh air ducting and UIM and LIM coating have been impressive BUT until full boost my observations are just that...observations, nothing concrete or substantial til then.

Do you know what he's running for a turbo? I've seen an A-Spec 500R kit do damn close to 500 with a little windshield washer fluid injection

Originally Posted by MaczPayne

^You wouldn't happen to be talking about Howard Coleman? He's a BIG advocate of Auxiliary Injection, and his research has gotten me interested in it as well.

I like Aux injection, with the exception of two points.
1) No-One can definately speak about the wear that the injection causes by washing the oil off the housings etc etc
2) I have yet to see one kit that is fail proof. I am not completely up to date with Howards setup, but I am with BDC's..... now... you're using this piggyback system to inject whatever, and if you look at the fuel maps, you're pulling fuel, and ALOT of it out as soon as the boost comes on hard. Now, if ANYTHING goes wrong with the aux injection, it seems to me that it would cost you and engine right then and there. I'd gladly rock an aux system if I could run it off the Motec and have a few failsafes.

[NoDOHC]

What do you have for heat shielding in your engine bay?

Right now, nothing but a cold air intake (I am still NA)

In the future, I intend to have:
A cold air turbo intake.
An excellent intercooler.
Turbo heat shields.
Polished inside and outside of intake manifold (reflect radiant heat on outside, avoid turbulence that transfers heat to air on inside).
No coolant flowing through the intake manifold (I will tie the turbo in to the heater circuit).
Insulating manifold gaskets, lower temperature thermostat (cooler engine = cooler engine bay).
I might do the blanket on the turbo too, but that increases turbo temperature.

Keeping IAT low is critical in running lean, as detonation requires a certain activation energy. Even more awesome is that cool charge air actually makes the air more dense and makes more power at the same AFR and boost.

I like Aux injection, with the exception of two points.
1) No-One can definately speak about the wear that the injection causes by washing the oil off the housings etc etc
2) I have yet to see one kit that is fail proof. I am not completely up to date with Howards setup, but I am with BDC's..... now... you're using this piggyback system to inject whatever, and if you look at the fuel maps, you're pulling fuel, and ALOT of it out as soon as the boost comes on hard. Now, if ANYTHING goes wrong with the aux injection, it seems to me that it would cost you and engine right then and there. I'd gladly rock an aux system if I could run it off the Motec and have a few failsafes.

I am not sure about aux injection (I don't what it is), But I intend to drill the front and rear plate for injector bungs at the ports. I don't like how far the secondary injectors are from the ports (uneven fuel distribution from going around the turns).

[EJayCe996]

Originally Posted by NoDOHC

I am not sure about aux injection (I don't what it is), But I intend to drill the front and rear plate for injector bungs at the ports. I don't like how far the secondary injectors are from the ports (uneven fuel distribution from going around the turns).

Aux(iliary) injection is just having a second injection system, consisting of water, alcohol, or both, upstream in the intake system to cool the intake charge significantly. BDC, that TTT mentioned, is running two methanol "injectors" in his system (One right after the turbo and the other at the bend before the piping goes to the Throttle body)and it has been proven efficient enough (when in boost) to not even require an intercooler. I got to co-pilot in a few of his test sessions so I got to stare at the laptop with a strained neck, lol.

Brian's setup


I think the last thing you have to worry about is uneven fuel to your engine. Your front secondary injector supplies fuel to just your front rotor and the rear injector for your rear rotor
Air distribution on the other hand...

[TitaniumTT]

I think he's more worried about the fuel sticking to one runner more than the other, or the air distribution that we know is uneven causing uneven fuel distribution.

BDC's setup uses nozzles which I think are a little less accurate than injectors. If I were to do a aux injector system I would have everything controled via the Motec so you're not having a piggyback system working against the main efi setup. Just my analness I guess but I'd be paranoid of one of the gain or boost settings getting a little messed up and popping an engine.

Aux injection does have it's place though and I like the benefits that it gives.