timing question

[dalwine250]

how much timing advance are you guys seeing at idle and at wot 4500 rpm ? i am seeing around 27 at idle and as low as 9 at 4500 wot.i'm just wondering if thats in line.
dave

 

[syclone0209]

Re: timing question

idle seems normal. 9 seems a little low. usually see about 14 on most trucks ive seen w/stock heads

 

[ghettosled]

Re: timing question

9 is definitely low, probably due to detonation which is pulling timing out through the computer. if using a scan tool look at the spark retard/ kock retard. You will probably see a number around 5 or 6 which means if it wasnt detonating it should be making 14-15 deg total advance (normal for pump gas)

Also FYI, the timing map varies with boost, so it pulls timing as boost increased. I always laugh when i see msd boost retard modules installed in these trucks..

 

[dalwine250]

Re: timing question

i had turerpro rt running.no knock,no timing being pulled.i had 100 oct in the tank.my iat's where at 120 at the end of the run.16 lbs of boost at 4300 rpm.my o2 voltage was in the 800 range.shows 9.2 degrees of advance.i thought it was low considering no knock.i have a gutted cat with a stock wastegate .i can control the boost,i'm just lucky it stops climbing at 16-17 lbs.i plan on knocking the puck out,porting the wastegate area big and making the big flange for the down pipe.i hope that will give me boost contol back and then i can go from there.
do ya think this timing issue is boost related ?
thanks ,dave

 

[syclone0209]

Re: timing question

what chip are u using

i had turerpro rt running.no knock,no timing being pulled.i had 100 oct in the tank.my iat's where at 120 at the end of the run.16 lbs of boost at 4300 rpm.my o2 voltage was in the 800 range.shows 9.2 degrees of advance.i thought it was low considering no knock.i have a gutted cat with a stock wastegate .i can control the boost,i'm just lucky it stops climbing at 16-17 lbs.i plan on knocking the puck out,porting the wastegate area big and making the big flange for the down pipe.i hope that will give me boost contol back and then i can go from there.
do ya think this timing issue is boost related ?
thanks ,dave

 

[dalwine250]

Re: timing question

a 3 bar burnt by jsm

 

[ghettosled]

Re: timing question

i'd check with JSM to verify they only program 9 degrees in upper RPM/boost. With 9 degrees of advance, only 16psi and 100 octane i would sure hope it isnt detonating...