my engine is pinking in 3-4......help

[jonnyboy]

hi im haveing a problem with my car pinking in third and fourth gear when on boost its runing 4psi at the mo. i was told to change the fuel pressure but i dont now what to can u guys help chears.

[fowler]

what mapping are you using more info required ??

[jonnyboy]

at the mo am using the stock airflow meter which is crap i know . i wana use megasquart but am not sure how to go about using it or where to get it from or price of it. ive got a t34 turbo which runs mint at 4psi apart from the pinking in 3 and 4th gear at high revs ive put a 3.0 fuel regular which helps alot. cheers any help will be mint. i will try and post some picture asoon as ive got my camra working.

[Kos]

what type of actane fuel are you using ?

how long has it been running with the turbo ?

has it happened before ?

[appletree]

Also has it been like that since you put the turbo on or has it got worse as youve been using it??

[Colonel Sanders]

have you played with the timing?

[jonnyboy]

hi, its been like it from day one ive not played with the timing so set at standed settings and am using super unleaded. i turboed a 320i and am moreless using the same set up and it pull like a train so dont know why am having problems with this 1

[Ant]

the pinking is either a mix thats too lean, or too rich, too much timing at peak torque( my bet given the high gears only situation as you've posted) or any combination of the above

a turbo will increas the effective CR of any engine, thats how the power gain is achieved so a std 8.8:1 CR M20B25K engine will have an effective CR of 11:1 or so @ the given boost level, too high for the stock timing map in any case.

Control is the key, and TBH at the moment you have none.

where is the AFM placed ? suck through or blow through ??

[jonnyboy]

hi,cheers for your reply . the afm is on the end of the turbo so it will be suck through.u said about the timing,do you know wat setting it will need to be set at.cheers

[Gunni]

#1 Check your AFR
#2 Find a way to retard timing if needed when you have rectified the lean AFR.