Fuzzo

Hi,
Can you let me know what the ideal AFR reading should be when running boost of around 1.3 bar.

THanks
Farzan

D1CCY

Depends on the engine and who mapped it. My 2.0 03STi remapped by Pat at SC runs 11.5, a mate with a 2.5 06STi runs 10.5 to help cool the pistons, also mapped by Pat. Standard maps tend to be richer (ie 10.5 on a 2.0) to be ultra safe. Some tuners have strong views as to whats best, I'm only reporting known figures in two cases where I can say the engines work very well.

Fuzzo

the map is standard. we are turning up boost (1.2+ bar) on the standard map and checking the AFR readings.

When i increase boost, i'm in the 13's range. I am thinking of getting an external fuel pump. this should help correct?

oh and my car is a 98 wrx

AndrewC

Shouldn't go that lean on std ECU, could be fuelpump, fuel pressure reg, MAF, airleak or a whole host of little problems.

What's the AFR at normal boost levels.

Fuzzo

its between 11 and 11.5 on standard boost.

did the same thing on my friends sti4 last nigh and he was hitting the 13's as well.

he has since added an external fuel pump and now he is at 10.

dynamix

iTrader: (3)

Have you got a wideband fitted?

There's a lot more to it than AFR and boost - get a mapper that knows what he/she is doing to map it.

High 13's and you are g'teed to need a new engine shortly though.