Well I was planning on running 12 pounds on stock fuel along with an intake, DP, cat-back, larger SMIC and potentially upgrading to a FMIC this summer. Every indication I have says that the ECU will handle a high-flow cat as well at that level of boost. Especially considering that there are a number of people running MPs with the ECU. But I just wanted some final clarification before I purchase one.

 

Well, we're not supposed to. But, I have been running the following for a year @ 12-13psi:

M2 Stage 3 Ecu, CAI, DP, N-tech Hi-flow cat, HKS Cat Back, M2/Asp Large SMIC, , Supra Fuel Pump, HKS Twin Power Ignition Amp*

BTW, I get bad boost creep in 5th gear at WOT

*When I added the bigger Fuel Pump, I got hesitaton between 5-6k rpm. I assumed that I was running overly rich due to the M2 ECU being tuned "rich" for saftey. So I added the HKS twin power and the hestiation went away. I also aded extra grounding straps. I was also having low voltage issues which might have been causing the hestiation.

 

John,
You left out your home depo boost control valves.
M2 says that it becomes difficult to control boost spikes and creep after the stock cat is removed. They tune their ECU with the stock cat in place. They recommend limiting boost to 12 psi to be safe but with good gas it should work to about 14.5 psi.
Tom

 

I added an Ntech high flow cat to my M2 stage 3 setup, and the A/F reading stayed about the same (mid 10s on a WB)..the only difference I saw was that with the high flow cat the boost held at 13 psi all the way to redline, rather than the 1-1.5 psi drop I would get before.

 

Considering that the stock ECU will allow for a few mods I can't imagine that running a HFC with the Stage III will really change anything significant. I saw car Stage III car with a HFC running that way for 8K miles.

I know some people run a mid-pipe with a Stage III ECU.

 

Hmmm...pretty risky, IMO...Go Power FC and have wide-band tuned. Definitely recommend more fuel upgrades with a high-flow cat and steady 12 lbs

 

you should be fine, the M2 is tuned rather rich. i ran with the N-tech for a while then switched over to a mid-pipe boosting 1 bar and the A/F was still below 12.

 

Not trying to jinx myself here, but why do you say this? Is your concern due to potential boost spikes, or just running leaner with the HFC? I see 10.6 AFR with this setup at 13 psi.

 

hey id say its ok... jus dont be racin around everywhere... but im the guy that ran a single turbo.. with the stock fuel system and ic... at 12 psi.... im also on engine #3 now... soo dont be a dougie... play it safe.. and keep off that gas pedal

 

i've been running m3 stage 3 for about 2 years now and when i first installed the ecu, i notice that when i came to a full stop, it took a couple of seconds for the idle to drop from about 1k to 700 rpm. i thought it was just my car. but i got another FD and installed the same m2 unit and it behaved the same way.

any of you guys have the same problem?


thanks.

 

Each car is different. I don't have spikes with J-spec twins and high flow, but another guy does...boost spikes are not good, and high flow cats can cause them (less exhaust restriction). See my sig for my mods.

 

I thought the back pressure of a high flow cat makes it easy to limit the boost? You can't creep with a high flow cat.

And if held to 10 psi, you can run all the bolt on's except for a midpipe (because of boost creep), shouldn't the m2 ECU easily be able to handle atleast 12 lbs??