flow

Hi all ,
I'm thinking of buying a mugen ECU , but that will be the only mugen part on my car .
My mods are TODA header , 70mm TB , gruppe-m CF airbox and fujitsubo exhaust .
Do you guys think this will help gain some HP or not ?
Or should i go and tune a vafc on my car .
Is the ECU at his best with all mugen parts or doesn't that make a difference .

Hope you guys can help .

Hyper-X

There was mention that having the Mugen ECU, Toda header combo may lean the AF ratios a bit due to the increase airflow... but I don't know the effects of the gruppe-m cf airbox as I have no idea what that is (could you post a link or a pic?)

Anyhow, it was determined that it was a good idea to have an adjustable fuel pressure regulator to increase the fuel supply to prevent the engine from getting too lean. I know UL was involved with this but I can't recall who's car he was working on... perhaps Prolene?

flow

U can compare the gruppe-m airbox with the mugen one .
So u dont think this would be a good idea ?
I have a euro spec s2000 and i've seen that they run a litlle bit leaner than an USDM s2000. The guys that fitted a sc on an euro s2000 got a much leaner A/F ratio than others .
So i'll be better of tuning a vafc then ?

thanks

Stealth Operator

You should not have any mechanical problems gaining approximately HP with the setup, it's all bolt-on power as long as you match it with the appropriate cooling bits (1.3 radiator cap, Mugen or Spoon radiator fan switch, Mugen or Spoon thermostat) and most importantly 100 octane fuel.

Hyper-X

I forgot to ask, are you planning on keeping the cat or removing it? If you keep the cat, then I believe (more certain than not) that using a Mugen ECU with your mods will keep you right on the edge of being ideal with the AF ratios.

It's when another member who had an AEM V2 intake, Toda header, test pipe and exhaust with a Mugen ECU that it started to show a bit lean due to the increase in airflow (where the power increase is coming from). UL had a good article saying how adding an adjustable fuel pressure regulator was a required step to add fuel (to richen the AF to safe levels). The VAFC (1 or 2) isn't good to add fuel, but it is good to remove fuel (lean).

As someone said it, the ECU requires the cooling accessories to be effective, like the cap, t-stat and f-switch. You don't need to use 100 oct gas to use the ECU, but 91 probably won't cut it either. We have 92 here and I believe it's okay, and a local owner mixes 100 oct gas with 92 to make 93 octane, just to be safe.

Hyper-X

The VAFC is a good to do mod, but it requries tuning... not a true bolt-on mod IMO. It can alter your VTEC points and leaning out the AF ratios where it needs to, but the Mugen ECU does it well out-of-the-box, is true plug-n-play (no tuning needed) and runs more ignition timing, something that you can't do with a VAFC.

flow

I wont remove the cat . And i'l install the cooling mods .
But i wont be running 100oct gas , it will be 92 oct .
For now i have a vafc(untuned) but because i dont find someone here that can tune it properly , i'm looking for something else .

But i want to be sure that my car wont run too lean .

Hyper-X

You should be alright with the Mugen ECU as far as I can tell. It won't require tuning and you're going to be just as lean as you'd want to be anyway. If you do go with a straight pipe, that's when you're going to need to add some fuel to restore the AF balance.

With the Mugen ECU, there won't be a need for you to use that VAFC.

flow

Alright .

Thanks very much for your help

Kobe

I have run Mugen ECU, with Mugen header + basic cooling mods + decat pipe. When car was cold...no problems and felt very sharp.....however if water temp went into the 80C's...I felt I heard onset of some pinking....so removed ECU until I sorted the temps better...water + air inlet. This is JDM engine with the premium fuel.