Ignition Timing

[guycrosby]

Can someone please adivise me on setting ignition timing at different RPMs for optimum performance of a stock 1972 911S engine with MFI, Bosch distributor, and dual-pipe 911 sport exhaust. How much advance should be set to achieve optimum performance at the low (3-4K), mid (4-5K), and high (5-7k) RPM ranges?

Thanks for your help.

Guy

[Tom F.]

Can someone please adivise me on setting ignition timing at different RPMs for optimum performance of a stock 1972 911S engine with MFI, Bosch distributor, and dual-pipe 911 sport exhaust. How much advance should be set to achieve optimum performance at the low (3-4K), mid (4-5K), and high (5-7k) RPM ranges?

Thanks for your help.

Guy

Guy,

Did you check the advance curves in the shop manual? That's a good place to start. If you don't have them, send me a pm, and you can borrow/copy mine - we're close by one another, I think.

Tom

[911pcars]

Unless you have method of varying the curve from 0-6000 rpm, you'll probably have to live with the factory specs (see referenced manual). The best you can hope for is that your distributor advance is within spec and that you set timing at 5000-6000 rpm. Max. advance is more critical than static timing, it having a large role in creating or preventing detonation.

You can test your distributor with a timing light and a helper to adjust throttle speed and rpm.

Sherwood