[walterd]

I have a heavy car, 3600 w/me, currently I am spraying 150 shot at 37 timing with 5 pulled out. I am going to 200 and then 250, I am thinking about running 28 at both do you think this is too aggressive?

461 CI
10.5 Compression
Edlebrock heads ported 315 or so
Victor w/950
Turbo 350/10" stall 3700/brake
9" 3.70 rear, 28" tire

Would you run 93 octane or race gas, I have been running pump 93 on the 150 fine? Edlebrock recommends race gas on 200 or more
Thanks,
Walt

[Brian Baker]

28 total would likely be ok up to the 250 shot and aluminum heads, but it's better to sneak up on it. I ran 34 total naturally aspirated in my 467" combo with iron d-port heads and 11:1 CR, and would pull 8 degrees out for a total of 24 on a 250 shot (6 degrees and 26 total on a 200 shot). I kept it conservative and never bothered to sneak up on it and find the "sweet spot", largely because I didn't race it long enough on the bottle to want to tune it to that level.

Keep your bottle pressure consistent from run to run (always stage at the same bottle pressure). I always tried to stage at 1000-psi, which would drop to about 900-psi after a pass, and kept the fuel pressure at 6.5-psi (which was a little on the fat side for what NOS recommended for their plate kit I was using). I would run race fuel as well to be safe. I always ran C16 in mine when I was spraying, which was a little overkill, but again, I was playing it conservative. Tighten the plug gap up a bit (I tried them from .028"-.032" but never noticed much difference for my application between 23 or 32). I used NGK-8's which worked well up to a 200 shot, but showed signs of being too hot of a plug at the 250 shot, so I switched to 9's. VP Red is what I ran naturally aspirated.