drumminforev

I have seen many people talk crap about rising rate regulators because its a "band air" fix. Now what the hell does that mean, and why is it not the "proper way" to handle boost. If its not, exactly what is the proper way, and does this mean stick with a 1:1 fpr?

drumminforev

um ok...how about a reply

drumminforev

b for reply

Jay_Sensing

a 1:1 FPR just raises fuel pressure one lb per lb of boost.

What everyone is calling a bandaid is an FMU (Fuel Management Unit). It can raise fuel pressure on stock injectors up to 12 lbs per lb of boost. They are not the proper way to tune a car simply because it's a linear rise in fuel pressure that you can't change with rpm. A car doesn't need the same amount of fuel all the way through the rev range so you can be super fat in some areas and dangerously lean in others.

The proper way to do it is to chip and OBD1 ECU and allow the computer to read boost and control a larger injector so you can actually get the AFR dialed in across the board.

drumminforev

Hmm, so lets see if i got this right...

A fmu will add up to 12:1 fuel pressure for boost pressure. Got that. But i dont understand how its bad for the AFR. I know fuel amounts vary at diff rpm, but isnt it the high rpm the more fuel (assuming wot). How is this going to ever be lean then?

ScorpioMk

with a greddy 15g kit and a 12:1 fmu on a d16a6 at 6psi, afr was 12.9-13.1 basically across the board. and thats a pretty small turbo. imagine a bigger turbo flowing more air at the same boost level. ya its gonna lean out even more. thats not good.

Marcus

khoalie

Ok lets say you already had hondata/crome/whatever. Couldn't you use an fmu in conjunction with that instead of actually buying injectors?

ndogg

no. like the guy just said, with a tiny *** greddy kit, the 12:1 fmu could not deliver enough fuel. So adding crome cannot magically make your injectors deliver more fuel because stock injectors on a stock map are already close to maxed.

khoalie

well i'm assuming ScorpioMk was running a stock ecu therefore having no control over injector pulse length and running some type of missing link/check valves. By using a 3 bar map sensor and using crome to tune injector pulse length, wouldn't this be a viable alternative?

edit: nvm, i just reread your post. didnt realize stock injectors were running at such i high duty cycle already

ScorpioMk

the simple solution is get some dsm 450's and use crome like you want, done deal and done the right way.


Marcus

drumminforev

thanks, makes sense now