How much boost should I run on Pettit ECU
 

How much boost should I run on the Pettit ECU?

i think you can 14.7...

search around and youll find your answer

14.7 with unlimited version

never run 14.7 thats what its advertized as but your injectors cant pump enough fuel if you have a ported engine intake and good flowing exhaust.

Cameron Worth from pettit told me 12psi MAX on pumpgas and 14max on good racegas and upgraded intercooler.

Agreed. I would keep the boost down to 13 psi max, as the stock fuel system will have difficulties keeping up with fuel demands beyond that point. And the Pettit (or any stock remapped ECU) will not support larger injectors.

Make sure you read the whole thread. Don't read the first post and think you can run 16 psi boost all day long with the stock injectors...

While I don't suggest running 16 PSI all day long, the stock fuel system can push a lot more than what people are doing today.

The PFC hasn't been around since the car was created and people did modify their cars LONG before it came about. And yes, people were putting down some serious numbers:

fuel system aside, i would not recommend running more than 12 psi on a stock intercooler. just thought i'd ad that since you didn't list your mods.

I rane 14+ psi on the unlimited for almoast a year on pump 93 oct. on stock injectors and pump... Maybe wasn't the safest to run that much boost with stock IC but I did it with no ill efects ever.

The unlimited will provide enough fuel (IMO) for 14 psi, on my air/fuel ratio gauge (I know you gonna say they not accurate 100% but they are somewhat close) showed that I could crank it up a bit more to run perfect stoichometric mixture.




John Gazivoda.

Unlimited version has no fuel cut but it's a oxymoron so to speak. You will need and fuel computer over 1 bar, so the unlimited version means "nothing"! The limited version hit's fuel cut at 1bar, but so does your fuel system. Why do people think unlimited is better?

Anyhow, I ran 1bar and was fine but I don't recomend more then 14lbs. If you don't have the injectors and fuel pump to support it then keep at limited to 12lbs.

You're best bet if you really want power and assuming you upgraded the IC, intake, exhaust, etc is the dual boost controller. Set normal for 10 or 12 lbs and race for 14lbs.

What do you guys run on your Pettit ECU, or even the Power fc?

You can always try to find the limit yourself or stick to proven 12-13psi.

I run my boost controller at .75 bar (~11psi) while running around town and .85 (~12.5psi) during autocross. Depending on temps and how my turbos feel like spooling through transition I'll sometimes see up to .91 bar (~13.3psi). I'm running M2 Stage 3 which is very similar to the Pettit (perhaps a bit more conservative fuel delivery on the M2). I'm somewhat worried about the efficiency of my turbos with the stock IC at boost levels much higher than they are now. If you have a FMIC or something around the size of M2 medium/large you should be able to go up to .95 (~14psi) safely on stock fuel delivery.

As you start turning up the boost I recommend getting the car dynoed to make sure you aren't having high RPM ignition breakup. The HP/Torque lines should be smooth (i.e. they should not look like a mountain range or heart rate monitor) all the way through to redline. If you are getting this check your spark plugs, turn down your boost until it goes away, or look into something like HKS twin-power to resolve it.

Word
 

I run 89.3 on mine with pump gas and I run 7 @178... that should do it

M2 Stage 3 ECU is actually less conservative compared to Pettit. At or over 12psi it just dumps all the fuel into the engine, running 10 or lower AFRs in high RPMs.

That's where the ignition breakup comes from or from a restriction in flow.

Actually, I'd call that more conservative, as they're dumping more fuel to ward off detonation. M2 also uses a more conservative ignition advance curve for the same reason.

The difference, however, is that those people pushing 400 hp on the stock injectors surely had all the right conditions that Wade stated, including much better pump gas quality.

I wouldn't say that. Getting 92 octane in my area is still a chore, let alone anything around that octane 7-8 years ago all over the place. 15 PSI is most certainly doable on the stock injectors as long as everything else is "in the right conditions".

Keep in mind that "in the right conditions" matters with all boost conditions, not just pushing the stock injectors (as in you can have problems with high charge temps and low injector duty cycles as well).

Yea... you're right :)

I went and they set the primary turbo at 10psi and the secondary at 8psi, they said that anymore than that could be dangerous. They also said that the boost would creep more than that sometimes anyway. I trust Pettit. Tyler and Cam are awesome, tell you what you need to know.