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Old 12-17-2003, 05:22 AM
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At what RPM should the total advance top out?

My question for you guys is the centrifical advance "Total In" RPM for my street rod. The distributer is a MSD and has vacuum. I'm told that with a street driver, all the advance should be in by 2800, but that seems too quick. What do you guys think the RPM should be?

DETAILS:
350 SBC
Edelbrock E-Tec heads, Performer Air-Gap manifold, Performer 800 CFM carb.
Comp Hyd roller cam; 280/280-.525
700R4 tranny; 3.70 rear axle ratio, 30" rear tires
Hooker headers
2600 lb car (curb weight)

I expect engine HP and torque to be about 435 or better
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Old 12-17-2003, 06:23 AM
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Total timing (initial plus mechanical) should be all in between 2500-3500 RPM. Experiment to find what works best for your combo. The Total should also be the highest you can achieve without any ping and should be set with the vacuum advance hose dis-connected and plugged. As to where to hook up the vacuum advance; this again will be decided by you by experimenting. Some will say that you should use the Ported connection and others (myself included) will suggest using the Full connection.

My setup that works very well for my combo is as follows. 18 degrees initial, 38 degrees Total (with vacuum advance hose disconnected and plugged) all in by 2700 RPM. I use the vacuum advance on the Full manifold vacuum. This is with a stock GM HEI on a 350 Chevy engine. Cam is a Comp 280H Magnum. Rear gears are 3.80-1 with 28" tall rear tires. Vehicle weight is 2660 lb.
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Old 12-17-2003, 06:34 AM
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I agree with Frisco. I have all my advance in by 2800 rpm (34 total, 18 initial) and my vacuum advance is connected to manifold (full) vacuum. This is on a 9.8:1 406 sbc with a Comp 280H cam. This was tested on an engine dyno. 3300 lb car

Steve
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