Fuel these days...

[pk2]

Originally Posted by blue2000s

I don't know exactly what's in Race Fuels like Sunco that makes them different,.... The higher percentage of fuel allows it to have more energy content. It also keeps it from cleaning your engine and shortens it's shelf life.

If all else were equal, there's no point in buying a gas for a higher octane rating than 93 (or 91 for us at higher altitude). ...Using a fuel with a higher octane rating doesn't gain anything... You will also increase stresses on components and increase the temperature of the engine and cooling system.

The additives in a particular gasoline are what make up the different grades/octanes. BP, for example, starts with the same base and adds different things to it to make it low, mid, or high grade. In fact, mid grade is a 50/50 mixture of low and high grade often mixed at the pump.

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I have forced induction and a piggyback AIC (or call it a DME-lite) that leaves whatever Porches intent was as far as induction & ignition goes, somewhere back along the road.

Your right I suppose that more energy might create more heat but, a blower adds alot more though, an easy 125+ degrees to the intake temp. The hotter the charge the more it is likely to detonate.. Knock sensors will solve that by retarding the timing but, start Kissing performance away to.

The setup as designed is really pushing the limit on 93 octane (probably pre ethanol 93). We only have 91 oct. (except for 2 or 3 places across town) So, just to get it to that minimal 93, I have to brew my own from 91 and 100. I can't pretend to notice the dif between 93 or 91. I've been leed to beleive higher octane it a cooler burn. Keeping my piston from burning (they can) is my only concern. This thread complicates things a bit.

PK