Timing Advance vs Octane Rating

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CdnNavybob

New Member

Nov 24, 2003

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Sep 12, 2004

#1

• Sep 12, 2004

• #1

I'll soon be installing a timing adjuster and I'm trying to determine how much I can advance my timing with the 89 octane fuel that's available to me.

I read about some guys with alot of timing advance, but they also run 90+ octane fuel, which I can't get in this part of Canada.

How much timing advance does everybody run wit what octane.

Also, does a/f ratio have an effect on how much advance you can run? As a side, what's a safe a/f ratio for a mildly modified GT?

Thanks

 

mogs01gt

Founding Member

Jul 22, 2002

3,113

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119

Ohio

Sep 12, 2004

#2

• Sep 12, 2004

• #2

A higher octane fuel helps in prevention of Detonation. Start your timing at around 15. You may hear detonation, keep lowering the timing adjuster until it stops. Average is around 13.

 

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CdnNavybob

New Member

Nov 24, 2003

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Sep 12, 2004

#3

• Sep 12, 2004

• #3

Even with 89 octane fuel? I was thinking more like 8-10. I thought you needed 94 (or whatever the high octane you get in thew US is) to run that high without detonation.

 

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codyGT

New Member

Apr 11, 2004

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Nebraska

Sep 12, 2004

#4

• Sep 12, 2004

• #4

10 is stock setting

 

Redfire03GT

New Member

Sep 10, 2003

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Newark, CA.

Sep 12, 2004

#5

• Sep 12, 2004

• #5

I'm running 16 on 91. If 89 is the highest you can get, it doubt it'll be worth it. Even with 91 and 16deg of timing, I hardly noticed a difference.

 

Go HoTO!

New Member

Apr 11, 2004

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Mountaintop, PA

Sep 12, 2004

#6

• Sep 12, 2004

• #6

A TA is a waste of time with 89 octane most likely. Stock timing (as already stated) is at 10. With 89 octane, I doubt you can advance it much at all. Try it. Add octane booster is you want. Advance the timing as much as you can until you get pinging.