Any performance difference in Sunoco Purple?

[rboyle]

Has anyone seen any differences with the new fuel this year? Performance or other wise effected? Do you need to rejet or modify timing in anyway? Any help or advice is appreciated

[Myron Piatek]

You need to be a little more specific. Sunoco is the official fuel of NHRA and IHRA, but any performance changes or jetting adjustments may depend on which brand and octane one used before as well as the engine combo. All of the same fuels are still legal as before in the sportsman classes. One doesn't have to change brands, but Sunoco will probably be easier to get.


I've used Sunoco Purple.....about forever, in brackets and IHRA, and have been happy with the performance and consistency. I'll stick with it when I get into NHRA as well.

[Mike Croley]

Depends on which brand and octane you were running. Jetting should not be an issue going from one 110 brand to another. Or timing either. The only big difference between leading 110 octane fuels is the Motor Octane.
Sunoco 110 is 106
Vp 110 is 107
Renegade 110 is 108.5

[Run to Rund]

Rockett 110 also has motor octane 106.

[Adger Smith]

Better take a look at the specific gravity of each before you conclude no jetting changes are needed.

[Mike Croley]

Going from last years official brand of 110 to this years official brand shouldn't require major changes. But here's a rule of thumb for jetting when changing brands or blends of race fuel. The rule of 10.

Example... moving from a fuel that has a SG of .710 to a fuel that has a SG of .718 would require no change in jetting.
Moving from a fuel with .710 SG to a fuel with SG of .721 would require a jet change of 1 jet size.
Moving from a fuel with a SG of .710 to a fuel with a SG of .730 would require a change of 2 jet sizes.
The same rule would apply going from a larger SG to a smaller SG.

[Robert Simpson]

Mike in your description, would you go up or down a jet size with the SG lowering? From Say a .760 to a .740?

Thanks

Robert

[Mike Croley]

When going from a higher SG to a lower, you would increase the jet size 1 number for every .010 change. In your example you would increase jet size by 2 numbers.
As i said, this is a rule of thumb and assumes that your tune up was pretty close to begin with.

[ken robinson]

I loss my list of nhra accepted fuels , had all the s.g. and octanes on the list has well . Its got to be on nhra.com ?

[ken robinson]

accepted ducts list in rule book .....page 101 thanks