Quote:
Originally Posted by Packard V8
Since you've got the A-trim, use it to set up and get running. If it only makes 6PSI, that will be a huge horsepower increase. I know a guy who is a TBI-blow-through-guru. Send me your e-mail off list and I'll ask him to contact you.
big_g is the exception. No one else I know has been able to run 16PSI of boost through a regular NA ignition timing. Usually that boost level would require half the ignition advance of the NA, say 18 or 20 degrees versus 36 NA. This month's Car Craft had a supercharged draw-through article and they said the max on 91-octane was 19 degrees. Yes, a blow-through with an intercooler will have a cooler charge, but are you really running 36-38 degrees of ignition advance with 16PSI?
thnx, jack vines
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No, I am running 32*...have tried 34* and no detonation, verified by plug examination. Keep in mind this was with a big overlap cam and 8.3 scr. 93 octane is available here in Austin, Texas. Engine Masters did a write-up a few years ago with almost the exact engine build I have. They also ran a D1SC at 16 lbs. They ran as as much as 30* timing, no retard. This was with 9.5:1 scr motor.
FWIW, fron the ProCharger site:
"For engines that are experiencing detonation problems, the primary options are the use of ignition/timing retard systems, higher octane fuel, or intercooling. While ignition retard systems can be helpful in certain situations, they can also greatly reduce the horsepower output of an engine, as any reduction in timing will reduce horsepower. And while a reduction in timing can save a motor from detonation, the excessive heat which was causing the detonation is still present.
Intercooling, on the other hand, actually removes the heat which causes detonation, and allows higher boost levels to be safely run with full timing on pump gas. This produces the maximum benefit in terms of both horsepower gains and engine protection, without any additional maintenance or hassle."