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iTrader: (8)

did some searching..

I would like to see some dyno AFRs graphs for the Pettit and M2 ECUs. I am interested in how rich their AFRs are under load. If you do post, please indicate what level of boost you were running.

thanks

ExpensiveHobby22

I'd also like to know.

solo1seven

I will be dynoing back to back Pettit Vs. Stock today, will post numbers.

Andrew Wojteczko

dis1

I have some graphs on my site but it does depend on how the computer is tuned compared to what you are running. I told Pettit to tune mine as if I had a mid-pipe, which I don't. It runs a bit rich but is safe that way. I'm running between 10 and 11 psi @ around 300 hp.

solo1seven

Pettit only has one set of chips, the don't calibrate it for your car. The only option is no fuel cut or fuel cut at 14.7lbs.
The car I was going to dyno has a leak at the hard coolant line into the turbo, not at the banjo bolt but actually in the hard line, so unfortunately will not be on the dyno today.

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iTrader: (8)

dis1...thanks for your link...I believe I had visited your site previously...couldn't recall where I saw those graphs

solo1seven...sorry to hear about your car, if you dyno later... please post

anybody elese have graphs at boost other than 10.5 psi?

dis1

Incorrect, they have two sets of chips, true, but each can be tuned for the various basic setups. You tell them I have intake, dp and they will give you the right chip. If you upgrade, a replacement chip is $50. Too bad they do not yet have a chip for 1300 cc injectors, but they say they are working on it.

Directly from Pettit's website:

Pettit Racing has several stages of computer modifications now available. Each stage is matched to different engine modifications. Countless hours of dyno and track testing with many different performance levels were used to develop these programs. Once modified, program chips plug in and can be easily changed providing you with the best combination of reliability and performance available. This ECU will have a boost limit of 14psi. Core charge extra, or use your own.

solo1seven

I have read the website, I have also spoken with them, the only questions they had were do you want unlimited or limited boost.

HeatTreated

I went unlimited and got a profec B to keep the boost in check.

as with the other Pettit ECU, I got mine setup for the mods plus an IC which I dont have and it was 10:1 a/f from 4k to redline.

a great ECU and the only reason I might go PowerFC is for the good deal Im getting on one.

DCrosby

Fuel Cut sounds dangerous, you might want to ask them as to what they cut ?

Fuel Cut = Lean Mixture = apex seal...
Sparc Cut = Rich mixture = fuel economy (who cares)
Boost Cut = Horsepower / 911 passes you

Kento

It's a momentary fuel/ignition cut, like the stock setup.

artguy

these chips are nothing but guesses and are no substitute for tuning...since EVERY rx7 is different...even those with exactly the same mods..it is impossible to guage others afrs and such in order to compare them to how it might work on your machine....at least to the precision that the rotary truly requires. they can come kinda close...but kinda close can cost ya a motor..rich or lean.

honestly i think those ecus are a complete waste of money. you can not guess tune if you want a car that runs right.

good luckwith those hack ecu's...if you want it done right..get a pfc and get it tuned on a wide band or the dyno...or go haltech or motec if you can afford it.

the only way to run an ecu properly is to tune for proper afr's on YOUR CAR...no guessing...adjustments have to be made for it to be done properly.


j

Kento

I'd have to disagree with your statement that "they're a complete waste of money." For those that do not have the money (you're talking about $1200 for the PFC w/controller, plus more $$$ for datalogit software and a wideband O2 sensor) and/or a reliable tuner with dyno nearby (more $$$), the plug-n-play reprogrammed ECUs are an economical alternative. Yes, the engine will not run as good as it would with a properly tuned PFC, but I've seen plenty of cars with M2 and Pettit ECUs run strong, smooth, and idle fine-- my FD included.

I will most likely purchase a PFC along with the necessary peripheral accessories in the future, but in the meantime, the Pettit ECU is doing just fine for me.

artguy

well it comes down to my feelings on the fd...being as delicate as they are...there is only one way to do it..and that is doing it right.

half assed tuning so you can push a couple lbs of boost more (probably gunking up the bumper from running pig rich...fouling plugs etc...) is exactly that.

I just prefer to do it right...or not at all. I ran one of those upgraded ecus....i saw them changing the fuel curves with my own eyes...with no knowledge of the actual afr's. i also saw that it is a total guess job. I didnt know any better back then.

there are plenty of people who have datalogits nowadays...its not like the organized tuning sessions are all that expensive at three hundred bucks a person...

continue to fly blind....or not.



j

dis1

Yes, these ecus are guess jobs but they are educated guesses by very experienced shops. I'd say the ratios are only off by a bit car to car based on the mods Pettit/M2 tune for. Before the PFC you basically had two choices, ECUs like Pettit's or the PFS PMS. (Sure you could get a haltech but the cost was insane and the tuning wasn't known by many.) I went with Pettit because of all the problems the PFS system had. Sure you could tune it but what a POS. I'd say that at least 1/2 to 2/3 of the people I have talked to with PFS systems (and that is a lot of people) had some sort of problem with it. Today I'd get a PFC but I already have a Pettit and it is a great unit.

PFC = The best
Pettit = Not the best but great
PFS PMS = Paper weight

artguy

well with all the money ive put in my car, there is not a chance i would let someone do any guessing at all.

each car has different issues etc...i ran three different educated guess fuel maps from top shops on my car and each one was a mess when i actually datalogged it.

the only way to do it right is to do it right....but to each their own.

best


j