ignition · FF-0506

Why did the supercharged ARDUN run better at 26 degrees than 20?

The rule of thumb is to take out one degree of advance per pound of boost, so expecting about six pounds they set it close to 20. The engine sounded lazy to the experienced ears in the room. They were on 112 octane race fuel for detonation safety, and the general opinion was that it burns slower and needs more advance. Back at 26 degrees it picked up about 20 horsepower.

Expert

Steve Coppock

Evidence

expert attributed

Component

ignition timing

Applicable scope

Steve Coppock's ARDUN Flathead, supercharged dyno test on 112 octane race fuel