turbo tuning suggestions
 

I just got my engine into my car. My buddy came over with his LM-1. We tuned idle to 13.5 and it seems to be running well except it's going lean on deceleration ( 15.7) is this normal he seems to think it's too lean. If so what can be done to correct it ??
Thanks
Todd

HI a little more info on the engine would not go a miss, as to just what you have and then we just may be able to help, thank you

regards mike

OOPs, it's a 79 3.3 turbo with a K27-7200 turbo.
SC Cams .. Hope that helps

some good info here:
http://forums.rennlist.com/rennforums/showthread.php?t=267790
I have mine tuned to 14.5 at idle. I also have an Imagine Auto fuel head that's capable of flowing more fuel. I'm still in the engine break-in period so I'm not pushing things too far. But at spirited runs (some boost), I'm at about 12.3 for AFRs

On deceleration, things do go lean

What's most important is the AFR under boost. Look for 12.5 or richer. Elsewhere it's more about driveability and emissions, so it's more or less your call.

On decel, it doesn't matter. In some cases (with EFI), you can shut the injectors off for greater decel - this will send the AFR off the scale.

On idle, my car likes 12.9 or so, and does not foul plugs. Give it what it wants.

It shhould go lean on deccel. Actually, it should shut down fueling completly. As CIS is old and crude, this is impossible so it still injects some gasoline into the engine which leads to backfire on deccel.

Nothing to worry about.