Running rich.

[funkihamsta]

Am I right to say that a very common way to gain bhp, especially with japanese turbo cars, is to fit larger injectors/raise fuel pressure and basically crudely overfuel to match increased demands/boost and not detonate.

I know a SLIGHTLY richer than stoichometric fuel/air mix gains more power, but just how much of a compromise is this in comparison to proper fuel remapping?

[funkihamsta]

More of curiosity really. I've just noticed that a lot of DIY modding on turbos is to wack in an enormous turbo, run boost at 25psi and chuck in loads of fuel (larger injectors, no remap) to prevent leanout. Overfuelling? Yes but apparently flames coming out of your tailpipe on overrun is a good thing apparently.

I'm going to be spending rather a lot of time and money in the presence of a lumenition EMS for my car. I just wondered just how much better a proper remap is over using OE engine management and kludging higher fuel supply across the board.

[funkihamsta]

A slightly rich ~12:1 mixture yields more power, but richer still leads to stumbling, plug and chamber fouling and generally less power.

Therefore a properly matched and mapped fuelling supply will always give better results. Its not just a case of wasting a bit of fuel 'out the tailpipe'.