gohorns

Ok I have done the research (mainly on the pettit) but I still can not decide which ECU to get. Please advise what would be good for my mods: Pettit intake, DP, CB. Motor is new and has 10K miles. Turbos are original and have 88K miles. I plan on staying with the stock fuel system. Future mods would include: IC, Y-pipe, Hi-flo cat and boost controller. I would not run more than 12 psi. When the stock turbos retire I plan on getting the 99 Jspec turbos. Based on this info what would you recommend. Pettit ECU or Apexi PFC? Please dont just say Pettit or Apexi because one is better but also tell me why.

Thanks

Snook

iTrader: (12)

the pfc is way better because you can tune it but since you just said that you aren't going to ever upgrade further than the stock twins and 12 psi you should get a used pettit ecu from someone to save money. I have the unlimited boost pettit ecu and I believe you can run up to 14.7 psi on it but I would call pettit to make sure.
I am going to have intake, dp, midpipe, cb, streetport, and run 13 psi and the pettit ecu can handle that fine.
The power fc is just awesome if you can afford it I would get it but if not the pettit ecu will do a good job too. The pfc also gives you some extra hp because you can tune the air fuel and therefore improves your gas mileage. The pettit ecu makes you run very rich. In the city I get way below 10 mpg and on the highway just a little above 10.

ttpowerd

go with the pfc, I should have 1 year ago. Instead I got the pettit and now my mods force me to have to upgrade again. With the pfc you just adjust via commander or datalogit.

nmo93

i agree w/ ttpowerd. if you have the money go w/ the pfc. you have alot more options w/ it. and i know you say that you won't upgrade any further, but everyone will tell you how addicting this car can be. i have the pettit ecu and i love it, but if i had the money i would have went w/ the pfc. nick

Mahjik

iTrader: (1)

Go with the Pettit.

If you aren't going to run more than 12 PSI and you are staying with the stock fuel system, it will be easier on your wallet and you.

Yes, the Pettit does run rich, but if you are getting below 10mpg, you should look at changing your O2 sensor. Also, the default maps of the PFC are leaner than the stock ECU, so you really need to get some tuning for the PFC *if* you get one.

ttpowerd

Very true! make sure you get it tuned if you get one. Cost is certainly more but well worth it IMO. Plus if you use the commander it has graphs and 'gauges' built in basically so you can monitor stuff like injector duty, boost, etc. without having to spend the extra money on all the seperate stuff.

rotorbrain

my pfc maps were way richer!!!!!!!!!!! it was rich as hell all the way through.

paul

Street King

People tend to blow a lot more engines with the PFC due to bad tunning or not knowing what you are getting into. A chip is "safer" if you can say that. A PFC is the better choice but you have to think wether or not you want those few extra ponies or not(with correct tunning). I think for right now you should get a USED Pettit chip and then when your ready for the PFC(if the time ever comes) you can sell it for what you bought it for. Used Pettit chips are always in demand, and save a little more and get the PFC.

gohorns

I was leaning towards the Pettit but if its going to effect gas milage that bad then I would rather pay the difference. I get really good mileage right now (15 city 22-25 Hwy). People who have the Pettit how did it change your gas mileage? Should'nt it be the same as stock when you are cruising?

If I get the Apex PFC: Can I use the base map with the mods I have currently or does it have to be tuned? Can you tune just with the commander or does its have to be on a dyno and wideband. This info will really help.

Thanks again.

GoodfellaFD3S

iTrader: (213)

I respectfully disgree . The Power FC has a million advantages over any stock ecu variant--

It gets rid of the 3k rpm hesitation.

It has a 16bit chip instead of 8.

It allows you to monitor vitals like boost, coolant temp, intake temp, knock, inj duty cycle, etc and it does it accurately, unlike many gauges I know of.

I went with the power fc when I had intake, dp and cb, and the difference was night and day. Running the base maps, drivability and acceleration was noticeably improved.

It's pay me now or pay me later. Bottom line--an upgraded stock ECU is a stop-gap measure for those who don't want the utmost performance out of their FD.

GsrSol

Agreed. You really don't need the PFC with your mods.

Street King

Correct on that, but not all people know how to get the most out of their FD or are satisfied with it in the stage it's currently in. I have a chip going in pretty soon and I do it because I don't want the hassel to deal with the tunning of it, have the cash to experiment, nor have it tuned by a rotary shop at this point. BUT, I will be getting one soon as my rx7 experiance grows larger.

Mahjik

iTrader: (1)

Who says he has the hesitation? I have a Pettit ECU with no 3K hesitation. The stock ECU does NOT cause the 3K hesitation. If it did, every FD would have had it when it rolled off the assembly line.

I never said that there weren't advantages to a PFC. However, for his application, it's overkill and not needed. Plus, how many people blow seals on Pettit ECU verses PFCs?

I have the exact same gas mileage with the Pettit as I did with the stock ECU. Nothing has changed there.

If you are going to get a PFC, or any other reprogrammable ECU, get it tuned for your car by someone who knows how to tune it. If not, you are risking your seals, period.

ttpowerd

That is certainly not a fair statement to make. Its like saying "How many people blow seals stock vs 400+rwhp? Now you realize why you want to be stock."

For ease go with Pettit.
If you plan to continue upgrading save yourself the trouble and expense and go with the pfc.

the_glass_man

iTrader: (2)

PFC all the way. It doesn't cost much more then the Pettit. You don't need the commander, it helps buy you don't need it.
You can take it to someone with a datalogit to get it tuned and never have to worry about anything. You can also have it turn the fans on at a lowertemp. That adds reliability, you can use it to control boost and use it to prespool as well.

Mahjik

iTrader: (1)

Actually, it is a fair statement. Not everyone that blows seals are pushing 400+rwhp with the PFC. I would say very few are here in the forum are pushing that much rwhp (at least with stock twins and stock fuel system which is what he stated he was staying with in his first post).

gohorns

Although price is an issue, I rather spend once and get it over with. So keeping in mind that I will not be upgrading the fuel system and staying with the stock twins (or 99 Jspecs), is the Apex PFC going to be utilized to its capacity with the stock fuel system?

Mahjik

iTrader: (1)

It's used as well as your tuning allows. As I said, you don't have to be pushing 400+rwhp to run lean and blow a seal.

I wouldn't trust any base map for a re-programmable ECU in my car. As I stated earlier, if you are going to get a re-programmable ECU, get it tuned for your car by someone who knows how to tune it. If you aren't going to mod the car much, just get the Pettit, M2, GForce or other reprogramed ECU.

If you do plan on upgrading the fuel system or going single turbo, then definitely look into a reprogrammable ECU.

Don't worry. You can still make some serious power with a reprogrammed ECU. Check this thread with some more info:

https://www.rx7club.com/forum/showth...threadid=97425

pp13bnos

iTrader: (1)

I just sold my pettit. I like it alot. Only time that i had teh 3k rpm problem was when the car was cold. It did it from the first day I owned it....the pettit did'nt make it better or worse.

I sold my pettit because i plan on going single, big injectors, etc. etc. The p-fc is the gentalmens ecu....like Rocky at RP says. CJ

redrotorR1

Going a little off-topic, but the 3K rpm hesitation is a grounding issue. If anyone still has it, attaching an extra ground from the grounding harness (only on an RX-7 ... ) should relieve the problem.

A lot of people whine about the reprogrammed ECU's, but generally speaking they perform "as advertised". I personally am probably going to go with a reprogrammed ECU because I don't really want to play with the tuning that much; I don't want to blow up my car; and because I lack the funds. Fortunately, there is a huge amount of information about tuning the PFC .. so if you decide to go that route, it shouldn't be too terribly difficult.

Street King

It has also been said the fuel pump is the cause of the 3k hesitation. When it switches from medium into high mode around 3k rpm. This is where I think the problem lays.

Mahjik

iTrader: (1)

The problem with this is the same as blaming the stock ECU, which is:

Why didn't it happen right off the assembly line?

We all know the stock ECU didn't reprogram itself and create the hesitation, so that rules out the ECU. The fuel pump didn't change the way it's operating, so I don't see that being the problem. It also doesn't explain why some cars have it and some don't.

I believe it's something electrical, in which it just happens to affect the fuel system causing the hesitation.

Now, some people have removed the hesitation but upgrading to a different ECU, and I believe they don't see the hesitation anymore. However, I don't believe that fixes the problem, but bandaids it.

yzf-r1

iTrader: (1)

I have the Pettit with all the usual bolt-ons, and I love it

as far as I'm concerned, the PFC is still half ***....it's definitely nicer than the Pettit, sure, and the display options and increased processing speed are great, but it you have long term plans to go single, just get it over with and buy the Haltech now (or perhaps the new progammable ECM Jason is selling)....anything that utilizes the crap stock wiring harness and has limited tunability is still a stop-gap measure in terms of ultimate performance.....almost all the experienced, high hp single turbo guys (i.e. > 400 rwhp) run Haltech, by no coincidence

Mahjik

iTrader: (1)

Just linking a similar thread:

https://www.rx7club.com/forum/showth...hreadid=116858

jf4828

I have heard that the stock ecu ground circuit is not beefy enough. When the secondary injectors come online under light acceleration, the surge through the circuit causes the hesitation.... I don't really understand exactly how that all works, but that is what my mechanic told me is his best guess.... This might explain why regrounding or changing the ecu both seem to solve the problem....