How much WOT ignition timing are you boosted (5~8 psi) LT1 cars running on 91~93 octane and stock compression ratio?

 

When I ran mine stock, I ran 20-25 deg's. I run a little more now though, but not much.

Bill

 

Most boosted LT1's make max hp at 24-26 degrees. If you are asking about detonation, it's safest to be conservative on timing (try 22-24 degrees) and run it quite rich (in the 11.5-12.0:1 range.

Rich

 

I'm just starting to retune a boosted LT1 and that is a bit more than I've tuned boosted LS1s at. I'm looking at a mail order tune someone had done for their STS turbo kit LT1 that is running pretty bad and the tuner has it at 28* in the tables, and I know the LT1 computers add a few degrees over what is in the tables too. That seemed a bit too much, The most timing I've ever put in a boosted LS1 car is 20* and most of the other boosted LS1 cars a little less. We can only get 91 octane gas around here though.

 

Seems like the LT1's like more timing the the LS's. Mid 20's is probably safe with a good A/F like rich had said. 11.5:1 is good. I was running around 27 to 28 on 8psi with my old s-trim with no water/methanol. Ran fine with no detonation. I think i can get away with a little more at my altitude though. With my water/methanol and on 10psi with my t-trim, we had it up to 31 deg on the dyno and still no detonation. We just stopped there cause we weren't willing to find out where it would start detonating. Now at 14psi and i run at 27deg on the street with water/methanol.

Ken R.