Fatman0203

I have someone that may be selling me one, I really wanted an M2 Stage 3 but I cant seem to find one. So .. should I settle for this? Will it give me the same safety net of the Stage 3? I currently have a full exhaust (midpipe) , intake, and street ported motor with 1000 miles not in the mood to blow it so .. is it a good ecu? PLEASE dont say get a PFC because I can afford to shell out a grand for it right now after the cost of the car.
Thanks

Mahjik

iTrader: (1)

M2 has never recommended midpipes with their ECU's. However, Pettit has never had a problem.

Pettit ECU's are more agressive than the M2 ECU's. You'll make more power with the Pettit ECU than the M2's:

https://www.rx7club.com/time-slips-dyno-121/dynoed-my-car-today-259617/

The Pettit Limited and Unlimited have the same map. The difference is the Unlimited doesn't have any fuel cut.

Mr rx-7 tt

iTrader: (5)

I would get a PFS purple first. It's programable, get one with the latest upgrades. We used them for years and never had any problems.

Fatman0203

What do you suggest Mahjik, wait around for the M2 if I find it? I'll probably be pushing 12 psi with the midpipe.


$995?! At least brand new! Sorry thats still to pricey for me.

Mahjik

iTrader: (1)

I'm running the Pettit Limited and really like it (had it for about 4 years now). IMO, I would get the Pettit over the M2 any day. However, I would in the least upgrade to a M2 over the stock unit.

There are some happy people out their with the PFS unit, however it has some quirks.

birdy01

i think the m2 should be find but since u can't find one, jus get the pettit, i have both(only running one tho lol)

i have a pettit but its got an older chip tho so i'm not sure how different it is from the current ones so i'm not sure if i wanna get rid of it either if its an older chip(might not be worth it?)

Fatman0203

BTW im afraid of the additional flow I get from a ported motor.

Mahjik

iTrader: (1)

Search for username "RTS3GEN". He's running all bolt-on's (include midpipe) and a Pettit Race-Ported motor on the Pettit Unlimited ECU.

He dyno'd a little under 360rwhp at 15 PSI and has a 1/4 mile time of 11.77 on stock sequentials.

J_J

I am having this ECU shipped to me and will be posting a dyno chart with all the popular bolt-ons including water injection. I should have my car back this Sunday, so probably early next week or possibly this weekend I'll post the dyno sheets.

r0t0r-rooter

Fatman, taken from M2's website (prob abandoned by now):

"Note: We do not offer this service for vehicles equipped with automatic transmissions, or ported engines."

Fatman0203

Thats awsome, but Im more interested in AFRs and not blowing the motor. Know anyone with AFR charts with this ECU bolt on's and a ported motor?

Fatman0203

I was aware of that, but I heard their ECU is extremely conservative.

Mahjik

iTrader: (1)

oakridgerx7 listed his AFR's on his post that I linked above. Not a ported motor, but you'll get the idea.

Fatman0203

But doesnt a ported motor Flow ALOT more? Enough to detonate easily?

Fatman0203

He jumped to the 12's. in the AFRs.

Mahjik

iTrader: (1)

Depends on the port job. Running 12 PSI as you said won't be a problem. Porting doesn't add *that* much. Pettit trust their ECU's with their Race Porting.

As long as it's not some bridge or peripheral port, it's fine.

Yea, and his motor didn't blow (however if you read the thread, he spiked over 15 PSI).

If you are looking to run 15+ PSI daily, then you need to rethink your upgrade path. If you aren't going to run 15+ PSI daily, then there isn't a problem.

cruiser

Pettit is more agressive - meaning it either provides more agressive timing or less fuel.

In this regard I think M2 Stage3 is more safe, but it also dumps A LOT of fuel up top. I use it with a full 3" exhaust on non-ported WG without problems (read - spikes or creep).

And yes, I think Pettit should make more power. A friend of mine has it and when I take my car again to the dyno I will try it with M2 and then with Pettit ECU to see the HP difference.

cruiser

This is what I am experiencing also with my M2 ECU, so my next mod is either HKS TP or PFC or Pettit Unlimited.

Mr rx-7 tt

iTrader: (5)

Buy used. You can change the programing as you modify your car. Simple

http://cgi.ebay.com/ebaymotors/ws/eB...category=33596

https://www.rx7club.com/forum/showth...&highlight=pfs


https://www.rx7club.com/forum/showth...&highlight=pfs

Mahjik

iTrader: (1)

I don't think anyone but Pettit and/or M2 know their maps so no one on here can answer that question with any hard data as to exactly what is different. What is evident is that hardly any M2 ECU has dyno at 350rwhp (none to my knowledge) while Pettit ECU cars have seen those numbers regularly.

It seems M2 ECU's struggle to get over 300rwhp. If 300rwhp is your goal, then the M2 ECU's are a good and safe choice.

cruiser

I wholeheartedly agree. I will have solid proof this year, when I dyno on both ECUs on same day, same dyno.

But you do agree that if something is more agressive it either needs more agressive timing or less fuel ?

On the other hand - could it be that M2 ECU owners dont produce those numbers because they are afraid to run mild port and midpipe and thus run way lean ?

Fatman0203

Someone ran a 350 with an M2 ECU, and porting. I think the M2's timing is what makes the difference in power, plus it runs a tad richer, at least looking at the AFR numbers of a few Ive seen.

cruiser

In last sentence I ofcourse mean "rich" not "lean"

Fatman0203

I had a friend blow a ported motor though with the stock fuel system at 330 hp? So how are some people getting 350? Fuel pump Im guessing, but is that enough of a safety net for the 20 extra hp. Oh let me add he had a fully tuneable ECU, the Wolf I think its called.

cruiser

Bad tune. Bad injectors. Bad fuel filter. Bad fuel pump. Spike, creep, ...