Advancing the Timing???



2 replies to this topic
  • javelinmxer

Posted April 15, 2002 - 05:34 PM

#1

I was wondering if any of you had advanced the timing on your 426. I was thinking of doing it since I have TA pipe, and the jetting is increased and I run 115 octane fuel. What do you think, and have you tried it, what were your results?

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  • Mark_Cantrell

Posted April 16, 2002 - 05:21 AM

#2

Sorry, no info, just questions.

How are you going to adjust it. The only two ways I can think of (without a science project bolted onto the bike) is to move the pickup coil CCW on the stator or to have the CDI reprogrammed.

If you get a Vortex from the authorized dealer, they will program it to your specs. One option would be to have a 'normal' map, say the power map, and the other switch position would be the 'advanced' map that you specify, maybe 3 to 5 degrees advanced at speed.

We're all curious now. Hope you get to try it.

mwc

  • Shawn_Mc

Posted April 18, 2002 - 08:25 AM

#3

Advancing the timing is a dicey deal. But running the fuel you do, you could get away with it.

Problem: In high RPM application, you dont want a lot of timing.
Coming off corners, having the timing advanced will help with bottom end grunt.

Back when I was drag racing a pro gas car, I had my ignition set like this.
Off the line 50 degrees of advance, at the 40 foot mark, it would back down to 42, then as the engine would come all the way up to full RPM, 8200, we had the timing backed all the way off to 37, basically through the lights.
The problem with what you want to do is, the stock ignition is mapped three dimentionally. So any static adjustment will impact everything over the entire map, and you may not want that.

The fuel your running at 115 octane seems to me to be too much, you would more than likely make more horsepower with a milder fuel, depending on your compression. If its stock you simply dont need 115 octane gas. 108 is plenty and common. Ive run into situations where super high octane fuels make the motor run flat.
When I was racing boats, my buddies dad went and bought the fuel for us once, he came back with 115 octane blower gas. We ran it, and the motor wounldnt rev up. It hit about 6300 and just went flat. I cut the fuel with some reg. pump gas for the next heat, and we got back to 7600 rpm.
Food for thought.





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