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-   -   Racing Fuel, Worth An Experiment? (https://www.fuelly.com/forums/f9/racing-fuel-worth-an-experiment-10287.html)

bowtieguy 10-28-2008 01:46 PM

Racing Fuel, Worth An Experiment?
my mechanic mentioned that a certain sunoco station sells racing fuel. is it worth experimenting with?

will it do damage to my car? it's 100 octane correct?

i'm curious what FE can be achieved on straight gas, but will this curiosity kill the cat(car)?

dkjones96 10-28-2008 01:58 PM

Just make sure that it isn't leaded race fuel. I think only the 104+ octane blends have a risk of being leaded but if it isn't than have at it.

I've considered adding white gas like a fellow member had mentioned to lower the octane level of my fuel. I have always been under the impression that you see the best economy from a fuel that has the lowest octane level the engine can run without becoming a diesel lol

Ford Man 10-28-2008 03:52 PM

When I had my motorcycle carbs worked on the person who did the work put racing fuel in it. You sure had to be careful on the throttle just cracking it open and the bike was gone. 30 years ago it would have been fun if I didn't kill myself. The extra power was the only benefit and on an 1100 I don't need that much extra power. A friend of mine that is a mechanic said running fuel with that high of octane in a stock engine could burn the pistons. That information came from a person who has been doing mechanic work for over 40 years. Just something I wanted to throw out there. I'd talk to someone who knows before trying it.

bowtieguy 10-28-2008 04:02 PM

yep, my mechanic said i'd get quite an explosion using it! :D

thought about filling only 1/2 race fuel to spare the pistons.

how do you lower the octane of a gas?

Jay2TheRescue 10-28-2008 05:02 PM

By mixing it with lower octane fuel...
When I worked for a fuel station when we wanted midgrade we'd order 1,000 gallons 87 octane and ~200 gallons 93 octane to make 89 octane.


StorminMatt 10-28-2008 05:16 PM

Burn holes in the pistons with high octane gas? I think the mechanic had this backwards: using LOW OCTANE fuel in a high compression engine will burn holes in the pistons from detonation. NOT the other way around. Also, contrary to popular belief, high octane fuel does NOT have a higher BTU content than lower octane fuels. The BTU content of all hydrocarbon fuels is about the same (more or less). High octane fuel will not give you more power UNLESS you have high compression, and the ECU retards timing if pinging occurs with lower octane fuel. So there really isn't anything to be gained by using racing fuel in a car with 9:1 compression. Unless, of course, you just like to brag about using race gas in your Metro or VX. Hell, even my B18C5 CRX (which has 11:1 compression) does not seem to benefit from using 100 octane gas over just plain old 91 octane gas.

I should add, though, that it IS possible for fuel to cause a hole to be burned in the piston if the volatility is low. This COULD be a problem with SOME racing gasolines. Specifically, it is possible that fuels designed for turbo or supercharged engines were not made with volatility in mind (since the hot intake charge in a forced induced motor will pretty much vaporize everything). But you will be fine with the 100 octane stuff you can buy at the pump (although you won't notice a difference). Anyway, a fuel of low volatility can cause a lean condition (by not completely vaporizing), which will lead to detonation AND give you lots of oxygen to burn away aluminum from the piston. This COULD be what the mechanic is talking about. But even if it is, it is not the high octane itself that is the problem.

suspendedhatch 10-28-2008 06:31 PM

Absolutely no benefit and besides the huge cost of running it, it can only have a negative impact. You're not going to be able to burn the fuel fast enough so most of it is going to come out your exhaust pipe.

Are you running super advanced ignition timing? (If so, why?) Is your car pinging on 91 octane?

GasSavers_JoeBob 10-28-2008 08:27 PM


Originally Posted by bowtieguy (Post 122673)
my mechanic mentioned that a certain sunoco station sells racing fuel. is it worth experimenting with?

will it do damage to my car? it's 100 octane correct?

i'm curious what FE can be achieved on straight gas, but will this curiosity kill the cat(car)?

I'll be curious to see your results as well...we have, of all things, an Alta Dena milkhouse with a gas station attached...they just started selling 93 and 100 octane "Streetblaze" fuel. At 6.99/gallon for 93 octane, and 7.59/gallon for 100.

zero_gravity 10-29-2008 04:52 AM

StorminMatt and suspendedhatch are correct here, you won't see any increase in fuel economy as both high octane and low octane contain the same amount of energy. high octane just resists detonation much better. so it would be great if your engine was modded with a silly high compression ratio - more compression = higher power and efficientcy. lower octane would ignite under the pressure potentially causing severe engine damage.

some race engines are designed like this and/or they use turbochargers at stupid high boost levels. compressing an extra 30-40 psi into your cylinders really raises the pressure in there. regular fuel would just detonate so race fuel is required. some will just lower the boost with a boost controller for lower grade fuel and bump it up for the track or when they are running the higher octane.

itjstagame 10-29-2008 11:29 AM

Yup, about the only place you would see improvement is if you had a turbo set up. Basically a way to change compression ratio on the fly.

My friend used to set his Turbo to 22-23psi on 93 Octane, but now and then would get 100 and increase it to 28psi. Running 100 at 22psi would do nothing, at 28psi you have a bit more 'compression ratio', that is more O2 forced into the engine in the same size space and then you get a use out of it.

100 Oct is the highest without lead, the only other Octane I've seen is 110 and was definately leaded. There's also Aircraft fuel, I've heard you can get it from most all small airports, I think it's 104 Octane and unleaded, but not sure, only guys I saw using it were some people on their heavily modified rally cars. Running 100 shouldn't hurt anything, but running leaded will destroy your cat pretty quickly, this is second hand info, but I was told it chemically reacts with the platinum in the cat and renders it inert.

If you want to experiement with high octane fuel why not try E85? Or 1/2 mix E85 and E10 for starters. I've thought about doing this, but without a turbo I'd have to custom build a 13-15:1 engine which would be infeasible.

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