Does anyone know about how many degrees of spark advance is normal in the upper rpm range? I've got a misfire at around 6K rpm in my Y8 with Edelbrock turbo kit (Link box has been changed out for a reprogrammed one), and I am getting about 18 degrees of timing at full throttle around 6krpm. Isn't this pretty low? I am just wondering if my timing is being retarded way too much causing the misifre? I've been through the entire ignition system, it's not loosing spark and fuel adjustments richer and leaner don't make a difference.

 

I believe it should be 26 to 28 degrees by 6k. I have my turbo setup with 4 degrees timing retarded by 5k.

 

Hmmm....so then 18 shouldn't be retarded so much that it would cause a misfire then. It feels like I have an MSD BTM that is just retarded way too much.....just pops and sputters around 6Krpm. I've changed plugs, wires, coil, cap & rotor. Changed out the fuel pump, added and subtracted fuel with my VAFC in that rpm range....and nothing has worked.

 

28 degrees at 6k is a lot. Be careful if you're shooting that high.

18 is a little on the low side, in general, but it's definately not low enough to cause problems. It's more than a lot of factory turbo cars run, so that's not the issue.

Is your spark plug gap small enough?

 

check your plug gaps and take them down to .030"

 

I've dropped the plug gap down, and it made no difference. I've tried 2 step colder plugs, 1 step colder, stock plugs, and now Iridiums....no difference. The only other mods on my car is a BBK 62mm t/b, and a test pipe. No chance that not having the 2nd O2 sensor in would cause this problem would it?