what the hell?

http://members.aol.com/rooster433/alvinsmall.jpg

doesn't sound like its breaking up too bad.. just a little AFR is dead at 11.5 :1 boost is 10lbs.

 

Some info about the combo would be helpfull. Doesnt really look like any spark problems ive seen on a dyno sheet. Id look more towards fuel. Are you getting the volume and pressure you need at higher rpm's? Fuel maps ok? More fuel or less spark needed at higher rpm. Are they both programmed in?

 

show us the A/F ratio chart

 

Its a 10 lbs non intercooled car
with

MSD 6AL
.035 gapped NGK two steps colder
MSD coil
automatic
pulled timing down to 19 degrees and it still did it

umm thats about it.. The dyno guy couldn't print out the AFR so you'll just have to take my word it was between 11.5 and 12.0

 

Sounds alot like the problems I was having at the end of last year. Couldn't figure it out then the snow came and she's garaged untill spring. Not sure of the cause. She just fell flat on her face at 4000 with some light sputtering. At this stage I'm leaning towards spark on my problem. Felt alot like my Storm did when the pickup coil was going. Definately going through the distributor over the winter.

 

I had a similar problem on my 85. It turned out to be a series of problems with the ESC and knock sensor. first of all my knock sensor was tightened. they are supposed to be only so many inch pounds or they become hypersensative. the next problem was that my quicky dump was too close to the sensor and when running on nitrous it was too loud the vibrations made it pick up false knock. there is something about the 4000 rpm range that really kills a car when the computer is retarding. a simple test can be performed but must be done with care as you will have no detonation protection. I pulled the wire off the sensor and made my fastest pass. just something to consider.