Guys, it seems like no matter what I do, I can't get past 400rwhp. Looking at
my setup as a whole, the only thing stock is the exhaust ports. What are they
capable of- from your own experience- [not what your buddy's cousin's beeyotch
made].It's a13b rew engine. Thanks guys and merry Christmas.

 

sk8world on this forum made around 425 on stock ports at 20 PSI on a GT40R turbo.

What turbo are you running and how much boost?

 

doesn't matter what turbo, hot side etc... 400ishrwhp- currently pt74gts 1.5 bar on.84hotside. Also, that was at 3200ft- around4000 ft corrected.

 

the .84 hot side is not the best choice for huge power. Have any 2.5 sections in your exhaust?

things like that will cut some hp.

 

i have stock intake and exhaust ports. 425 @19psi on a 1.00 divided hotside

 

yeah, .84 is small, but s wheel flows big. 3 inch exhaust, unhooked on dyno a couple hp
gain. Hell, I put a1.00q trim on a t70, no peak gain. I'm real close to going 20b if
nothing changes. I'm 99% sure I'm gonna port my exhaust and do a monster
street or half bridge.

 

The PT74 is a monstrous wheel... this compressor measures 2.92 inducer and 4.03 exducer according to their website. That wheel is on par with a T76, which as far as I know, nobody has ever put on any even remotely streetable RX-7.

Your turbine is on par with a Q trim wheel.

You have the completely wrong turbo on this car I'm sorry to say... I am amazed you can spool it at all with stock ports.

If you want big power, you need a street port I think. That turbo is huge and I think you should use a smaller one unless you're just going for pure drag racing.

 

It spools like crazy at about 4000rpm, hits 22psi instantly, I guess b/c of the .84.
I love the turbo- spools waaaaay faster than a t70 1.00q. I also have a 62-1
on a p trim 1.00 housing- great street turbo but same thing, not able to get
over 375-400 out of it. Again, does anyone see 500-600whp out of stock exhaust
ports? And yes, I want to run 10s. BTW isn't aHKS t51kai a 76mm wheel?

 

Finally, spoke to a guy who races rotaries, and sounds like I'm on to something-

 

So is this true that a stock port motor will not make more than 4XX HP regardless of the turbo?

 

I'm not about to say that. I think ErnieT ran 10's on a stock reman, and
my friend ran 10's on stock ports. I'm saying I can't seem to get where
they are with stock ports. Maybe I am missing something, I don't think
it's a lack of driving/shifting 'cause I 60ft 1.6s and shift well enough.
I run 10's easily in my blown 98 cobra- won the fastest street shootoff
in it. Just looking at the setup as an air pump and I think the exhaust
ports are a possible restriction. I will do some testing and let you
know. I have a buddy with a shop/ turbo know how.
Plan is to flow the intake and exhaust, then port if needed. then
get a manifold to intake ratio on pressure under boost. Then select
hotside housing to get a good ratio. I think he said 2 to 1 is good-
that is intake to exhaust. We will tune to 25-30 psi. If not happy,
then we will spray that beetotch until our facial muscles contract,
producing a curvature known as a smile

 

im gonna shoot for 500whp on stock ports and race fuel with my new setup. d-r af61r turbo

 

Looking into this, a close friend of mine made 540 hp to the wheels on a stock port turboII motor, but he was running 25-28 psi with a PT74 turbo.

 

so could you expect high 500s with a REW?

 

I am also shooting for over 400 on stock ports. This thread interests me...bump

 

I put down around 533 whp with stock exhaust ports. Looking for over 600 in february.

 

Will your 3" exhaust system be too restrictive for over 400rwhp? Mandrel bends or normal "squash" bends on it? Are you using straight flow-thru or "turbo" type chamber mufflers? Cat too small?

 

No cats 3 inch w/ greddy sp we took muffler off on dyno, only a few extra hp.
I really doubt it is the exhaust.