shawn_c992001

I'm running ~5psi with a ratio of 14.7 is this good or bad? Would around 12 be better?

ujslost2

iTrader: (27)

Yes i would definetly run at least 12.0 a/f at wot. 14.7 is way to lean for a boosted car...

slow

iTrader: (7)

you want to be richer when at wot, but part throttle, the pcm will command stoich, which is around 14.7

Ryan

soundengineer

iTrader: (16)

unless you put the car in Full time Open Loop
then it will command exactly what you tune it to
I liek to tell the pcm 13:1 for Part throttle and then 11.5:1 or 11:1 for WOT...... sometimes richer depending on Boost

ESR

iTrader: (7)

the car will try to maintain 14.7 during regular driving...........you want no higher than 11.8 ...........11.5 on a dynojet 11.8 on a mustang.

slow

iTrader: (7)

There is no benefit to being richer at part throttle that I have ever seen on a newer vehicle I'll do that on a fox body, to make then run smoother.

Ryan

soundengineer

iTrader: (16)

can help with tip in knock by having part throttle richer

LS1-450

iTrader: (33)

What I like to do is tune for 14.7 under part throttle while in vacuum to maybe -5 inches of water. Once @ -4 in. through 0 psi & up to 4,000 RPM maybe 13.5 & from above 0 psi through 5 psi no more than 13:1 as long as there's no ping (knock) & the car is making power. Somewhere between 12.5 & 13:1 should be OK as long as timing is not advanced enough too cause knock @ WOT. It's a balance between timing & pre-detonation under boost. For sure 14.7 @ WOT under boost is way too lean. Good-luck.

hellbents10

iTrader: (10)

Right I tune afr to cylinder pressure. At around 0 boost I like to see 12.8-13.0:1 at wot. Then as boost comes in I will go down to about 11.8:1, for a lot of boost on pump fuel I will go even richer.

shawn_c992001

What about the timing 28* at WOT too much?

hellbents10

iTrader: (10)

I would sy thats a bit much for even 5psi. Now lets say your iat was like 60deg with race fuel then it may be fine. How much kr are you seeing. 28 is good in vacume or up to 0psi but coming into boost you should be seeing a little less then that.

slow

iTrader: (7)

28 at wot, on street gas is very agressive imho on a lsx engine.

Ryan

shawn_c992001

What would be a good starting point?

John_D.

iTrader: (2)

I was running 28 (accidentally) and blew 3 pistons in about 3 seconds. You should be somewhere around 14-16 degrees, then adjust up or down from there.