Anybody running FI 400+ CI and 700+ RWHP having trouble with putting out the fire at high RPMs? If so, are you running stock GM ignition, coils? Anyone try truck coils? MSD will have an new sys after the first of the year so it must be a problem in certain applications.

 

I'm not 400+ cu in but...

I run truck coils, spin to 8k RPM, 10:1 to 10.3:1 A/F, .030 gap on heat range 7 NGK's, and make enough grunt to go 170 in a 3350lb car.

No ignition issues. It will rich misfire about 9.5:1 however.

 

i have been thru a top end miss problem. my set up is 600+rwhp, leaded fuel, open loop, 6500rpm, 11.0-11.5a/f ratio, 15+psi, mostly stock 6.0, truck coils. tried 6 and 7 heat range ngk plugs.

i get a top end miss after about 500miles on the plugs, seems to be a "lead fouling" problem. i put around for 100 or so easy miles and then hammer on it, then do it again. from what i have read the lead builds up but doesn't have time to burn off when i hammer it, it gets too hot too fast and melts the deposits all together(yellow glaze on the plug).

i am one of the few people that have ever seemed to have igniton problems with the truck coil set up and it looks to be lead related, not coils.

 

Could be. I'm on new plugs every 6 passes or so

 

What is the difference in truck coils?

 

I run the Melco truck coils up to 7200 with TR8's or Autolites and the plugs have been okay and there has been no miss. I have had to clear the plugs up once or twice.

 

someone told me they put our more voltage or current, physicaly they are a little larger too.