some little question about f/i

gben_qc · May 22, 2014

Hi guys,
I've been looking on the forum since 1 month looking all thread about f/i. I found 95% of wath i was searching but could not found many info on witch ecu to use? Im looking for what is the best for turbo's f23a5 with a gt25 at 8-10 psi for now im gonna be stock internal until i finish to rebuilt my second f23. I know some of you running aem ems or p28 with s300. I work with turbo all week long but witch ecu to use is the only thing im not sure about. Does the stock ecu can take low boost ? Does the aem is better than a p28 tuned ?

Thanks for all advice and please dont comment search i've already did it

danmccormick87 · May 22, 2014

If you are serious about a F/I build, get a Hondata 300, and if you are just looking for a small PSI system, go with the P28 chipped. Just my opinion :beer:

Either way, I'd convert to OBDI, unless you need to worry about emissions, then AEM will probably be your best bet.

xci.ed6 · May 22, 2014

Stock ecu ~1psi. Replace stock map sensor w/ ~3 bar ecu sees lower volts, no boost. Or cut map volts. If you set VAFC that will do basic tune, a few other options here.

chaby_91 · May 22, 2014

I'm in a similar situation to yours. For a while I thought about buying the plug and play OBDII AEM EMS, but I'm going to look for other options. In the end, I'm probably going to find a good tuner and work with whatever he's skilled with. The stock map can take up to 10.94 psi so you'll be fine running 10 psi without CEL.

xci.ed6 · May 22, 2014

Stock map sensor does, ecm only programed for ~1 psi or get cel.

chaby_91 · May 22, 2014

xci.ed6 said:
Stock map sensor does, ecm only programed for ~1 psi or get cel.

That's very interesting. I'd still get paranoid running even 1 psi on stock ECM though. Personally, I'd install the turbo and leave the wastegate open until I have a proper tune. It's not like 1 psi on an ecm that's tuned for fuel economy is going to add much power anyway.

xci.ed6 · May 22, 2014

Yeah 1psi sometimes might happen w/o forced air, that's why ecm is programmed for it.

You could go way old school with check valves to map to vent boost and fpr rising reg set at ~10:1 to run boost (did this on friends CRX dx w/ mpfi for a bit, vids on youtube name 'krustindumm'). mostly mechanical fuel control. Also went spring instead of wastegate so entirly on exhaust mani pressure with better responce.

gben_qc · May 24, 2014

Where you get your information about the f23a5 ? Did someone try it or you says that cause one ecu you had try on the crx was 1psi ? Just anwsering if it was a fact or suposition ?

But here we dont have smog test or anything like it ... Some car inspection if cops don't like your car but i was inspector for federal inspection

then the best way to go might be the p28 with s300 ?

Thanks for the anwser !
Ho and im only be low boost on the engine that was in the car the other one gonna be a beast

xci.ed6 · May 24, 2014

gben_qc said:
Where you get your information about the f23a5 ? Did someone try it or you says that cause one ecu you had try on the crx was 1psi ? Just anwsering if it was a fact or suposition ?

But here we dont have smog test or anything like it ... Some car inspection if cops don't like your car but i was inspector for federal inspection then the best way to go might be the p28 with s300 ?

Thanks for the anwser !
Ho and im only be low boost on the engine that was in the car the other one gonna be a beast

1psi should be impossible, but at sea level, with a brand new air filter it may be possible. Thats why honda did it. look at oem fuel maps.