needanrx7

Could someone please explain the differences and advantages of either the unlimited or limited ecu?

With the unlimited do you need to buy chips to match your mods or does the unlimited chip take care of supplying the necessary fuel up to a certain psi(14.7 psi maybe)?

What is the max psi on the limited ecu?

MODS:
cb, dp, mp, ic...may add a used intake when buying an ecu

I'm spiking up to about 15psi at transition in the cold so for now I haven't been driving the car hard at all.

I need something than can hold that kind of psi and maintain the proper a/f ratio.

I'm considering Pettit because I don't have the money to buy an Apexi PFC or anything of that price.

THANKS

Mahjik

iTrader: (1)

The only difference (as far as I know) is that the limited has fuel cut around 15 PSI, where as the unlimited doesn't. However, I don't believe Pettit recommends running their unlimited beyond 15 PSI anyways.

GsrSol

If you have a midpipe they highly recommend the UNlimited. The UNlimited is a universal chip, they don't set it to your mods. It's defiantly worth the $50.

rxrotary2_7

for what its worth...two motors were popped on my unlimited.

JONSKI

I just checked out Pettit's website. It looks like this is a chip that you plug into their $700 ECU. Is this correct?

bureau_c

You can pop a motor on any ECU on the planet. ECU mods like that done by Pettit are a fairly course tool for modifying fuel and timing to account for mods. I don't know what else you had going on with your car, but its not hard to imagine a list of mods for which the Pettit ECU (or any ECU) alone would be woefully inadequate.

jds

bureau_c

The Pettit/M2/G-Force/Techtom/whatever ECU is really just a mod to the stock ECU, where they add two sockets (and some logic to make it possible to add one of those sockets). They've got a couple different programs they can load onto those chips that do different things. The maps *can* be tuned on these things, but its a pain and you have to have the right tools and you have to know what you're doing. Generally speaking, they create a couple of fairly coarse adjustments to fuel and timing, do something like remove rev limiters or fuel cut, and that's that. Once you have a Pettit ECU you can swap in any of the various programs that you want simply be replacing the two EPROMS.

jds

rxrotary2_7

thanks frot he heads-up. i now run an e6k.

GoRacer

iTrader: (2)

The "ONLY" difference is the the unlimeted does "not" have the fuel cut at 14.7lbs max boost whic the limited has. <--that's it, nothing else!

There is "NO" advantage to the unlimited! As you will need to upgrade your fuel system, since it maxes out at 14.7lbs.

If you are going to upgrade your fuel system, then there is "no" reason to buy a Pettit. You should be buying a Apexi or other stand alone.

This information is from Pettit. End of story. You can close the thread now.

CantGoStraight

I could be wrong but the unlimited also drops the rev limiter. Where as there modded ECU is pretty much a stock ECU that map fuel for the boost psi of upto 14.7 and mods of DP,MP, catback and cold air intake. Unlimited is just that (no limiters) I think they also recomend a higher output fuel pump for above 15 psi. PS. the 14.7 is not a rating used on pump gas (12.5) is there suggested limit on pump gas. The 14.7 is for racing gas.