hey guys my tuner is working on my car right now and i'm real nervous in need of advice...
to start with i have a stock bottom end ls1 with 6.0 heads, ptk turbo kit with a TC76 and .98 a/r.
anyway he's having some problems with the car not boosting right, but my concern is he's shooting for 18 degrees of timing and 10-10.5 air to fuel. i personally have no idea what safe is but my builder said that's really pushing that bottom end and is too rich! my tuner said that's very concervative and he can boost timing even more while still staying safe. please help!

 

bump...anyone?

 

That's too rich... many tuners are under the impression that too rich is conservative - it is not... As far as the timing, that depends on how much boost you are making... you didn't mention that... do you have meth on it? only the dyno (or track) numbers will tell a tuner what timing it wants...

 

it was around 6lbs or boost and he was trying to get it to 8 lbs but having problems with the wastegate or something not making any more boost? no meth. on the dyno. at best it made 474 wheel.

 

What is your compression? 18 dgrees is not too much for 6#

 

FWIW - I ran ~16 degrees of timing on my stock internals LS1 at 11.7~12.0:1. It was a D1SC setup with a FMIC. The safety margin comes with setting the IAT timing table correctly. If you get a lot of hot air going into the motor, you'll want to pull timing.

I would suggest to your tuner that safety comes through timing, not AFR. Running the car that rich will wash out the cylinders and foul out the plugs. Besides, an extra rich AFR in effect increases the burn time in the cylinder, which essentially is just like retarding the timing. So, might as well just retard the timing to begin with and avoid the side effects I just mentioned.

 

sorry guys been out of town. thanks for the help. my compression is alittle lower then stock because of the 317 heads and gm thicker head gasket. my biggest fear is blowing the bottom end on the dyno...i'll probably have the car retuned but i want to make sure with these figures he's not risking blowing the motor is he? are the numbers that unsafe or just alittle agressive?

 

Not even close. The motor could let go anytime under boost though.

I'd be looking for 10-12lbs for that setup. 6-8 is too low to be efficient.

 

^^^^ ditto. Afr is way to rich.tuner should be targeting 11.6 and then add timing. another reason I have come across with a overly rich condition it you can brake a ringland due to excess fuel in the ring pack igniting