Total spark timing
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Total spark timing
Trying to dial in the spark timing (unfortunately without a dyno).
On a ZZ4, GM suggests running 10° BTDC at idle with the vacuum disconnected and 32° total at 4000 rpm with the vacuum disconnected. Would it be reasonable to put those two values into the table and try to work from there (i.e. 10° at 650 rpm and 100 kPa; 32° at 4000 rpm and 100 kpa)? Or is the EFI factor something that invalidates the ZZ4 spark advance R&D that GM did with the carb?
Thanks.
On a ZZ4, GM suggests running 10° BTDC at idle with the vacuum disconnected and 32° total at 4000 rpm with the vacuum disconnected. Would it be reasonable to put those two values into the table and try to work from there (i.e. 10° at 650 rpm and 100 kPa; 32° at 4000 rpm and 100 kpa)? Or is the EFI factor something that invalidates the ZZ4 spark advance R&D that GM did with the carb?
Thanks.
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From: In reality
Car: An Ol Buick
Engine: Vsick
Transmission: Janis Tranny Yank Converter
Re: Total spark timing
Originally posted by ULTM8Z
Or is the EFI factor something that invalidates the ZZ4 spark advance R&D that GM did with the carb?
Or is the EFI factor something that invalidates the ZZ4 spark advance R&D that GM did with the carb?
~20 at idle
~30 cruise
WOT whatever works best for your combo.
You want to run the least consistant with max performance. Gotta be careful about running too much timing and too much fuel at WOT.
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