fd3s_rx7

iTrader: (13)

Well boost problem has always been an issue to me on the stock twins, so I don't really know what my steady pattern is., For that I decided to go with the 99 spec turbos. And what do you know, I'm boosting at 13 psi, it'll gradually drop to 11 psi to 10psi, and quickly recover on the secondary to 12psi to 11psi. So I call up the previous owner about my boost pattern, and he explains to me that he took the car to tune it at a performance shop to run 13 psi on the Pettit ECU with stock mods. (the stock intake and exhaust.)

He claims that It is actually safer to run high boost on the stock intake and exhaust because they will limit the amount of air moving through the engine, making the A/F ratio richer. So by upgrading intake and exhaust and etc. = Opening up air paths can increase performance, but also risk running lean and pre-ignition which means blown rotor seals.

So tell me what do you guys think on this.?? Is it true that running higher boost on stock car is better.?? Or is it a bunch of BS...I mean I could see where he is going, but just can't believe that stock IC, and no open cold air intake could handle 13psi, even if the Pettit ECU is tuned to run 13 psi.

ptrhahn

iTrader: (9)

Running high boost through the stock intake, IC, and downpipe will mean your turbos will have to work awfully hard to produce that boost (many stock cars can't manage past 8-9 psi on the secondary), creating alot of heat that will in turn be fed through that cracker-jack box stock intercooler....

You'd be better off breathing the car out and running 10 psi.

adam c

iTrader: (2)

The stock intercooler can handle 13 psi, but it's not a good idea. To get 13 psi at the manifold, the turbos are probably pushing 15 1/2 psi. That's not so good. An intercooler upgrade should be done, if you want to boost to 13.

clayne

Can we PLEASE stop referring to boost as a measurement of potential power?

CFM
CFM
CFM
CFM
CFM

With flow modifications, you increase potential CFM - which means 10 psi with intake/exhaust/dp/etc is NOT the same CFM as 10 psi with OEM components.

fd3s_rx7

iTrader: (13)

Yeah,
My mods are:
HKS mega Flow Intake
HkS Dragger Exhaust
Downpipe
and Blitz SMIC

hopefully these mods will still make the car run rich and not lean.

PVerdieck

Sounds like a bunch of crap, but at least give the guy kudos for getting the ECU taken care of with those mods.

Kento

I don't know why he'd want to "run richer" when he's got a Pettit ECU in there; the Pettit is already set up to run pretty rich with the usual intake/exhaust mods. If those really are '99-spec turbos, I wouldn't make them work harder by plugging up the intake and exhaust with the stock components; you'll just shorten their life span considerably, and as clayne pointed out, you'll get more power due to increased efficiency with the usual intake/exhaust mods.

Montego

iTrader: (1)

No, No... It's true just read my sig!!!!

SVT Squasher

BS. Its all about fuel managment. Upgrade the **** out of it, just make sure you have the fuel you need. If you want more boost you need more fuel.

More power comes from more fuel, this is comon sence. The more air you but in a motor the more fuel you can but in there wich means more power. The best way to put more air in the motor is to increase the boost. Some factory parts cant handle the cfm of increased boost so they ned to be changed. JUST MAKE SURE YOU HAVE THE RIGHT AMOUNT OF FUEL.

lopedl

iTrader: (1)

So what is the power difference??

Mahjik

iTrader: (1)

Someone made around 266rwhp with full bolt-ons using the stock ECU at 10 PSI. A healthy stock FD will be around 220-225rwhp so 266 is not a bad jump for the same boost level but more CFM.

That's where the CFM difference comes into play as clayne was mentioning.

RotorJoe

CFM, thats the only reason my buddies car is fater then mine. Single turbo here I come. non-seq twins are nice but they act too much like a single without the major kick. Both my buddy and I have very close set ups running 1 bar.