Hi All,

I dont have experience but will that be okay to put in racing fuel into the car just for the track day? Can the engine adjust and back to normal after a day?
And (leaded and unleaded), does it matter?

 

Wow, um I'm not sure where to start with this. If you would like to immediately replace your catalytic converters, O2 sensors and most of the fuel system then by all means, use leaded race fuel. Otherwise, using (unleaded) race fuel on a stock tune will be of minimal benefit. If you have a GIAC tune with the race gas option then using race fuel will actually make a tangible difference. Hope that helps.

- Patrick

 

Sunoco offers 2 unleaded versions. 100 and 104 octane - 260 GT and 260 GT plus. I use them often as in a mix with pump Gas as the highest octane I can get at the pump in Idaho is 91.

It makes a difference... Significant in fact.

 

I fill up with 100 from time to time. I can't really say I noticed a difference. Maybe on a hot day at the dragstrip I would see better performance, but I am not sure it makes much of a noticeable difference without a tune. I run 93 always. I guess if you are stuck in a state where only 91 is available, you would feel a difference running 100.

 

The 991 Turbo S stock mapping is set to only advance ignition timing to its max at the detonation point of 98 RON = 87 MON = 93 AKI (roughly). Any RON rating above 98 (93 AKI), in a stock car, will make no difference as maximum advance occurs at 98 RON. This assumes the fuels are otherwise equal, which in EU USA etc they are (or should be), because fuel is so tightly regulated in its refining process and retail additives. If a tuning map has been applied that successfully can further advance ignition timing to a point just prior to the detonation point of a higher RON rating, that may give some additional power, but it wont be massive.

 

Well when I added the Sunoco 104 to my car on Friday night, I added as much as 3mph on trap speed and .2s ET compared to 93. I only added 3 gallons to a 1/4 tank and the FVD module picked it up resulting in much better performance. See my post on SS100 where I posted the slips.