t2 housings n/a internals

[86-rx7]

so i am wondering can i use t2 housing and put in n/a internals. I just bought a parts car that came with a extra t2 motor and i want to stick to n/a and was thinking about porting out the t2 motor hopefully for some more power out of a n/a. Also would i have to use the t2 tranny as well since i am using t2 housings as well. Any help of what i would need or should do would be great thanks

[vex]

Originally Posted by 86-rx7

so i am wondering can i use t2 housing and put in n/a internals. I just bought a parts car that came with a extra t2 motor and i want to stick to n/a and was thinking about porting out the t2 motor hopefully for some more power out of a n/a. Also would i have to use the t2 tranny as well since i am using t2 housings as well. Any help of what i would need or should do would be great thanks

Wait... Let me make sure I understand you correctly. You have a 6-port 13B (That's the N/A) and you have a 4-Port 13B (that's the Turbo). You are not planning on using a turbo, but want more power from your NA?

If that is the case, then no (-Ted). What you're attempting to do is asinine and will not yeild you dramatic results, if any improvement at all. One major reason is that your NA has 6-Port Induction (6PI). Two of which are put on a valve system (of sorts) that allows you to have low end torque without sacraficing your highend horsepower. If you switch over to the 4-port motor you will lose the 6PI which will result in a loss of low end torque and marginal if at all gains up top (depending on port job). There really is no improved benifit to switch the rotor housings, Irons, and the rest of the motor from a T2 onto an NA rotating assembly and remaining NA. If you were planning on turbo charging your engine, then that would be a different story. You'd have all the ability to run a turbo, and still have high compression rotors.

[Whizbang]

Originally Posted by vex

Wait... Let me make sure I understand you correctly. You have a 6-port 13B (That's the N/A) and you have a 4-Port 13B (that's the Turbo). You are not planning on using a turbo, but want more power from your NA?

If that is the case, then no (-Ted). What you're attempting to do is asinine and will not yeild you dramatic results, if any improvement at all. One major reason is that your NA has 6-Port Induction (6PI). Two of which are put on a valve system (of sorts) that allows you to have low end torque without sacraficing your highend horsepower. If you switch over to the 4-port motor you will lose the 6PI which will result in a loss of low end torque and marginal if at all gains up top (depending on port job). There really is no improved benifit to switch the rotor housings, Irons, and the rest of the motor from a T2 onto an NA rotating assembly and remaining NA. If you were planning on turbo charging your engine, then that would be a different story. You'd have all the ability to run a turbo, and still have high compression rotors.

Then explain Logan's 13b-Re n/a that makes more hp than any 6pi ever will.

[vex]

Originally Posted by Low Impedance

Then explain Logan's 13b-Re n/a that makes more hp than any 6pi ever will.

How's that tuning Think about it. Stock you have a rich and non-aggressive timing map. Looking strictly at the engines themselves:

The velocity at the low end will not leave a good torque curve let alone you had to port the 4-port to get to the same amount of intake area, right? Add to that if you're going to be porting the Tii you might as well port the 6-port and have a larger intake area with a finer control on volume (assuming you're leaving the 6pi intact).

Lets look at it another way. Assuming that the stats from the previous post are accurate at that the hp of the modified engine on a standalone is 186hp whp with S5 internals lets compare how they do to the S5 NA which produces 160hp, for sake of argument we'll assume that it loses 20hp and only produces 140whp. That's a 46hp defeciet that it would have to make up right? How much hp can you pick up by adjusting the fuel curve and spark? You can get a butt load. I can honestly see picking up 50-60hp with a standalone. Why? Because you lose some of the most restrictive portions of the intake and you can tune for power instead of fuel economy. 1) you lose the AFM providing less restriction on for the engines intake. 2) you can lean or richen the fuel to make the approriate AFR 3) you can retard and advance the spark to where the power is.

Is that not accurate?

[My5ABaby]

Originally Posted by vex

Lets look at it another way. Assuming that the stats from the previous post are accurate at that the hp of the modified engine on a standalone is 186hp whp with S5 internals lets compare how they do to the S5 NA which produces 160hp, for sake of argument we'll assume that it loses 20hp and only produces 140whp. That's a 46hp defeciet that it would have to make up right? How much hp can you pick up by adjusting the fuel curve and spark? You can get a butt load. I can honestly see picking up 50-60hp with a standalone. Why? Because you lose some of the most restrictive portions of the intake and you can tune for power instead of fuel economy. 1) you lose the AFM providing less restriction on for the engines intake. 2) you can lean or richen the fuel to make the approriate AFR 3) you can retard and advance the spark to where the power is.

Is that not accurate?

Apparently the 186whp was on a conservative tune. If that makes a difference.

[vex]

Originally Posted by My5ABaby

Apparently the 186whp was on a conservative tune. If that makes a difference.

Do we know if he was using the S5 intake manifold or was it custom? (I haven't even factored in the other modifications that may have been done to the motor)

[My5ABaby]

Kahren on the other forum ran a S4 TII block with S5 TII internals to 186whp as an N/A setup. Of course it was on a standalone, exhaust, etc.

http://www.rx7club.com/showthread.ph...ht=port+kahren

So it's possible, but I wouldn't. I would just trade/sell the TII engine for an N/A one.

[Whizbang]

actually, i have to "beg to differ".

We just finished assembly of a 13b with S4 9.4:1 rotors and S4 turbo irons. Running on an Megasquirt unit and a distributor.

The thing is, the 6pi end plates can not make the power a 4 port ones can. Porting everything to flow well and maintain a desirable velocity and have your choice of port timing is easily done on the 4 port. But the 6 ports are basically the opposite of this.

I say go for it! I'm starting to stray away from turbochargers when i can. Its a huge step up in complexity and money with the benefits of a shorter life span.

[classicauto]

well, if by housings you mean just hte housings themselves and not the irons, the nsure, you'll make more power on the TII housings given that they don't have the divider/diffuser in the exhaust ports (the diffuser can be removed from the N/A housing BTW....)

Using the TII housings and irons you'll still end up with nearly the same peak horsepower as demonstrated by a few different cars in the past, Karhen's mostly. Either way, either N/A setup is going to come in under 200whp in most cases. Logan from defined autoworks cranked out a little over 200whp after alot of tweaking, but still to assume less than or in/around 200whp is reasonable.

Only way to really push much beyond that is with some more radical porting, or the addition of extra oxygen to the chamber (N20 or boost). It just seems to be the limitation of the volume of combustion....even look at renesis engines. Stock Mazda claimed "240bhp" but testing proved that to be inflated. IIRC the highest renesis dyno I've seen is a little over 200whp..........still within a mere few ponies of the setups discussed earlier.

Having full control over the engine is great, but still won't be enough to overcome the physics of the amount of air and fuel requried for number much beyond 200 without (as mentioned) bridge/p poritng or nitrous/turbo

EDIT: You won't need the TII transmission unless you use the TII flywheel. You'll need to make a choice on that one as if you decide to use the TII flywheel.trans you'll either need the adapter (TII Trans ---> N/A diff) driveshaft from Mazdatrix or the rest of the TII drivetrain.

[86-rx7]

well my motor runs strong in the car i was just thinking about it because i have 3 other motors and was asking if it woulld be even worth it. i know that the max power i can even hope for would be under 200 hp more like 180 or so. I was just thinking about it and thought i would toss my idea out there because some one might have done it and could shed some light for me. If i would need a standalone i will stay away from it because of money reasons maybe later. Like i said i was just curious about the idea.

[Whizbang]

i believe it was the RE manifolds.

[My5ABaby]

http://www.rx7club.com/showthread.php?t=380348

Stock intake with filter on TB

[vex]

Doing a quick glance over his set up, he's not using NA rotating internals. He's pushing 9.0:1 (S5 Tii) and making the 186hp with a full exhaust, intake, and tune. Not to mention larger injectors and a bigger pump.

knowing that he's not using NA rotors then he's obviously making up for the power in other locations, IE: Fuel, Timing, Intake Manifold, Porting, Exhaust, etc. He's not going to make that kind of power without a tune or the supporting modifications, so what I said still holds true. You will see little if at all increase in HP and a worse torque curve only swapping the Housings and Irons (leaving the rest stock. That includes: Fuel, Timing, Exhaust, and Intake).

[Whizbang]

well i pm'ed GTo7 to give his thoughts on the 13b-re setup he has. Better to just hear it from the horse's mouth.

[vex]

Originally Posted by Low Impedance

well i pm'ed GTo7 to give his thoughts on the 13b-re setup he has. Better to just hear it from the horse's mouth.

Very true. Better than my in-experienced ass trying to figure it out.