91 T2 street port + bolt ons dyno LEAN AS S**T
 

Hi guys, I have a 91 T2 with a fully rebuilt race motor.

Huge street port
dowel pinned
3mm apex seals
8.5 comp clearanced rotors from s4 turbo
1991 s5 plates which are the strongest
s5 turbo
ported wastegate 10psi or 0.7bar
Power FC
Walbro 255
stock 550cc tuned to 85% duty cycle (cleaned)
full exhaust decat
fmic
RB flywheel & clutch

I was told from the previous owner that the car was tuned very well to 296whp on the Power FC by Intec Racing in Kent, WA.
Went there today for 2 base runs, no tuning. The car made 260whp and 129ftlb.
A/F was in the 18's!!!!!!!!!!
Car has detonation at low and high rpm at WOT, and smooth in the mid range.

While he did the pull, I did notice a slight mist around the intake manifold......fuel leak??
Also, car had left a few tiny drops of fuel on the ground outside. Luckily it was raining out, so i saw them in the wet.

Whats causing me to run so lean when before it was tuned to 296whp???
I'm getting 1600cc tonight, in preparation for BNR stage 4 in the near future.
Also I'm getting all new fuel lines and putting them in next week. Then I'll take it for a proper tune. Lawrence there has 10 years of tuning PFC's

Here is the sheet:

RPMs on the sheet are messed up. It was revved to 6.5K, NOT 12.5K lol

Attachment 689115

550's at 10 psi and youre surprised it went lean??

Well I see your reasoning. I'm surprised that apparently it ran fine with them before.

....is it just me, or is does the TQ seem oddly low. Theres other slips here on stock motors making more.

It's low cause of the lean condition.

you were lied to, it never 296hp.

torque numbers are messed up because the rpm's are wrong

Yea I really doubt you'll get that much power on a stock turbo and 550's are way too small, you also will need to upgrade your fuel pump.

I wouldn't keep running it the way it is, you'll blow the motor with it detonating/running lean.

Rotary >Pistons

I already have a walbro 255. Are you suggesting I upgrade from it?

No that should be fine, I thought u were running the stock fuel pump , at minimum you'll want 720cc secondaries, or 720cc on all four for the boost and power you're wanting to to make

550cc is going to be beyond its limit. You'll need to lower your boost or you're going to risk engine failure--dont keep running it lean!

Rotary >Pistons

Yeah. I'm not even driving the car right now. I ordered ID 1600cc's and fuel lines. Then I'll take it straight to intec for a retune.

That stock turbo is at its limit at 12psi so don't push it any higher than that or it'll blow its seals.

Upgrade to the stage 4 bnr and it should push a significantly higher amount of boost and power. Not sure exactly what but I'm thinking 360-400 whp maxing out.

You'll need to upgrade more than just your fuel system, you'll now be needing to upgrade the stock top mount intercooler, and probably other things too.

Rotary >Pistons

LEAN=POP even a "built" motor will pop if tuned wrong