TwinTurbo93

Hi everyone!
I recently got a used Pettit racing ECU with two sets of diferent chips, the limited and the unlimited chips.
Now any of you that can identify these chips I would be greatly appreciative

I called Pettit, but since I didn't buy the ECU directly from them they couldn't or didn't wana help much, don't mean to knock on them.
The dude I got it from seems to be to busy to answer my pm's for over a month now.

My question is this: the two chips installed right now in the ECU say: WKS and EXE , and the other set of two say: RX71754.W 11.99BE and RX7084.EXC 11.99BE. Now which ones are the limited and which are the unlimited???
and if I wana change from limited to unlimited or vice versa, do I need to remove both of them and install the other two or how this thing works coz I got no clue about this crap. I got pics of them that may help a litle more.
Thanks in advance...John.

TwinTurbo93

here is the pic of the other two

bureau_c

I'm sure if you want to swap back and forth between them you'll need to change both of them to be safe. I don't know exactly what features are on which chip, but I don't think there's anything to be gained by mixing and matching. That said...its impossible to tell from the info you've given which is which. What exactly is the claimed difference between Unlimited and Limited, I've forgotten. Does the Unlimited allow higher boost? You may be able to figure it out through testing if that is the case, but I just don't remember.

jds

TwinTurbo93

For as fare as I know about these chips the limited should alow you to boost up to 14.7 PSI's and also change the timing as well.
The unlimited will allow much more boost but of course you must change the injectros and update lots of other crap to run that mode, I think Pettit dont sell the unlimited no more, because people think they got the unlimited chips and can runn as much PSI's they want and then blow the engine up without upgrading the injectors and so on.
All I need to know is these chips need to be changed both at the same time and wich one is which?

Thanks, John.

TwinTurbo93

Any one else

bureau_c

Well, if that's so then they just raised the boost limit in the ECU...are you planning on using ECU boost control or an external controller? There is certainly nothing about the Unlimited ECU that precludes running it at even stock levels of boost with an external controller. I've been getting a lot of spiking at the transition using the ECU boost control now that my exhaust is a bit more opened up, so I plan on bypassing the ECU entirely and using an external controller.

jds

TwinTurbo93

Most likely I will be running an external boost controller after I see how this thing works, (didn't install it yet)(what I'm waiting for ?) Don't have much time lately to play, it'll be soon thugh.

JDS you are sayng that the unlimited will rise the boost a bit? How about the limited will the limited raise the boost to?

RageRace

Dude the Pettit ECUs are identical except for the unl. allows unlimited boost and the other is up to 14.75. Neither one is "tuned" all they do is take a stock ecu and bypass the fuel cut defense, which saves your engine. At max on pump gas only run 12psi MAX!!

bureau_c

You are so wrong its not even funny. Seriously, if you don't know anything, why post? The ECUs are not *usually* tuned for a specific car or mod list, but they are most certainly not just a change to max boost and a removal of fuel cut.

jds

bureau_c

I believe both will change the duty cycles of the boost control solenoids so as to increase boost, but I'm not 100% sure what they are set to. My ECU which has since crapped out allegedly started life as an "Unlimited" but it was tuned a bit for improved boost at the transition...it definitely didn't act like the wastegate line was removed or anything, but it also definitely provided higher boost than stock.

jds

TwinTurbo93

I hope is going to be a nice saturday so I can do some work in my FD, I'm installing the Pettit ECU and gonna do some tests on both limited and ulimited.

Finaly the Dude I got the ECU from after 2 months allmost replied to me and said that the chips allready in, are the Unlimited which will be the first post.

I'll play around this saturday and se how's this **** going to work.

I'll let ya know,, thanks guys.

TwinTurbo93

OK, finaly got the ECU instaled today, tell you the truth I can't tell no freaking difference between the stock ECU limitited and even unlimited.

Isn't the unlimited or lim. supposet to raise the boost at least litle,,, hmmmm didn't do it for me neither one.

I dont know but it seems the same as stock to me, I don't feel any power difference,,, anyone knows about this ECU, any thoughts?

twokrx7

iTrader: (1)

I would expect more of a change, here was my experience.

It was many years ago when I ran a Pettit ecu but I recall changing the pill sizes on the wastegate line to get higher boost. The ecu allowed higher boost without the dreaded boost spike. You can also run an adjustable valve in lieu of changing pill sizes. Or just install a boost controller.

When I installed the ecu I also put in a downpipe so take that into account when I describe the difference. The difference with the ecu and a dp was astounding. A friend was driving his 7 along side and when I hit transition the car shot forward and the sound was unreal. We were both drop jawed.

Prior mods were open intake, stock mount ic, midpipe, catback, and I had played with pill size to increase boost (dyno'd about 278 to the wheels) ... started running into fuel cut and then decided to go with the ecu. With all the goodies I dyno'd 355 rwhp at 14 psi, it was dead reliable for several years till I fu##ed it all up going single turbo .

TwinTurbo93

I did the downpipe, open intake +(K&N filter) and catback awhile ago and I noticed every mode, catback was pretty noticable but downpipe was the most, intake not as much but OK, the ECU didn't give me any dofference not even as much as the Intake,,, funny right?

BTW the air/fuel ratio remains the same to, I don't se it running any richer either. I'm maybe going crazy here.

AnthonyNYC

iTrader: (3)

You will not notice a difference between the 2.

The 14.7 chip will NOT allow you to run anything more that 14/7 psi. The car will bog. When I tried, my car would bog.

Then I upgraded to the unlimited chip and was able to run a lot more boost with no bogging.

Both basically have the same fuel maps. At 15psi the injectors are maxed anyway. The difference between the 2 is the timing maps.

The unlimited chip has a timing map setup for over 15psi. If you run the unlimited chip you will need to add additional fuel somehow, AIC etc...

If you have questions, ask for Cameron. He is ALWAYS willing to help. They also still sell the unlimited chip as far as I know.

Anthony

bureau_c

I know this ECU allows higher boost by providing fuel and moving the fuel cut, and I know it is possible with these things to change the solenoid behavior and therefore boost but I don't know if its part of Pettit's standard programming. I had a Pettit ECU that someone had tweaked the programming for and boost was higher and smoother at the transition than in the stock unit...but it has since given up the ghost.

jds

TwinTurbo93

I started to notice now my car running more rich (A/F Ratio) with the unlimited (that's what I'm using for now) and no more red line beep and fuel cut (raced sunday with VW golf 300hp turbo ) hit 9K RPM's no prob, BTW smoked his ***...

Other than that I'm boosting stock 10-8-10 LBS as before Pettit ECU installation, I haven't notice any extra power.

My turbos are old now 105 K on them and if I raise the boost to 14 psi as I would love to I know that I would kiss them goodbye real soon m'I right or no?

Turbo upgrade is next on the list of mods , $$$ is low so I'll wait a litle before running higher boost, that's when the Pettit ECU will come more handy.