Race fuel

combustion · Apr 20, 2003

Hello, I would like to know if race fuel harms a engine or is good for it? I have a acura integra gsr with a b-series vtec engine and i like to run a mix of 100 and 94 octane, does this cause more carbon build up on the pistons? I tend to run either straight 100 or a mix 1 gallon to 6 gallon of 94.

[ April 20, 2003, 10:34 PM: Message edited by: combustion ]

GROUCHO MARX · Apr 20, 2003

I'll give it a shot: you don't need it. It might not harm the engine, but the compression of the engine is geared towards the recommended octane. Why would you fuss with something that is working?

[ April 21, 2003, 11:30 AM: Message edited by: GROUCHO MARX ]

Drew99GT · Apr 21, 2003

You don't need race fuel unless your running higher boost/timing/nos/compression etc. Most race fuels are unleaded. Never ever buy low lead or leaded for your GSR, you'll hurt your cat big time and possibly your 02 sensor. In fact, running a higher octane number than you truely need will often result in a power loss. Octane is simply a measure of the resistance of a gasoline to preigniting, so high octane race fuel burns more slowly, cooler, and in a more controlled fashion which will result in a power loss in a motor that doesn't need resistance to spark knock.

Patman · Apr 21, 2003

quote:

Originally posted by Butch 02 Sierra Denali:
Most Race fuel has heavy lead content and will harm/clog up your cats, but there are different grades. The compression is a factor, but mainly the timing curve determines octane requiremts. If your engine has a knock sensor, and it has a performance timing curve, than the octane will absolutly give you more power.

This isn't true in every case. In the case of the LS1 f-body and Corvette, their programming has two curves for their spark advance tables, a low octane curve and a high octane curve. When the computer senses too much detonation for a period of time, it drops back to the low octane curve until you add at least 5 gallons of gas, then it assumes you've gone to a more appropriate octane and goes back to the high table again. But my point is, if you're on the high octane table already, and are running 94 octane for instance, you won't really get much if any spark retard at all, so going to a higher octane yet again will not put the engine into an even higher octane curve, it simply stays where it is. With my old LS1, I ran the Autotap software on it and it showed zero spark retard all the way from a dead stop through to the redline in 4th when running 94 octane gas along with a bottle of octane boost. This was on a hot 90 degree day too.

So the only time race fuel will benefit someone will be if their car's computer continually goes to an even higher spark advance curve with higher octane fuels. If their computer isn't set up that way, and if they're not getting spark retard with 93-94 octane, then race fuel isn't going to give them more power.

[ April 21, 2003, 03:17 PM: Message edited by: Patman ]

digitaldrifter91 · Apr 21, 2003

doesnt race fuels come in blends? ahh GSR..memories.

Butch 02 Sierra Denali · Apr 21, 2003

Most Race fuel has heavy lead content and will harm/clog up your cats, but there are different grades. The compression is a factor, but mainly the timing curve determines octane requiremts. If your engine has a knock sensor, and it has a performance timing curve, than the octane will absolutly give you more power. I have never seen higher octane cause more carbon build-up, unless the timing won't advance enough to take advantage of it.

Butch 02 Sierra Denali

Spector · Apr 22, 2003

What about adding the Octane Booster additives that you see on the shelves? Also, Redline and Amosil also sell an octane boost. Has anyone had experience with these products.

I tried the Amsoil one recently, only noticeable diff I found (which is probably perception) is that the engine, after sitting for several days, started immediately which it never has in the past. Again, probably not a vlaid observation.

combustion · Apr 22, 2003

I tend to run a 6 to 1 mix of 94 and 100 or 104 because i can get it easily and no the race gas i run is never leaded. I do notice that throttle response is better.

Patman · Apr 22, 2003

quote:

Originally posted by Spector:
What about adding the Octane Booster additives that you see on the shelves? Also, Redline and Amosil also sell an octane boost. Has anyone had experience with these products.

You have to be careful, because a lot of the octane enhancing products out there don't raise the level by much more than 0.5 octane. Super 104+ was proven to raise it by 2.2 points, and based on my experiences using it in my 98 Formula, and seeing the level of knock retard go to zero according to Autotap, I know it works. Problem is that extended use of that stuff will foul out the plugs quicker, I found that out also.

combustion · Apr 22, 2003

Now when you say it will foul out the plugs faster, is this because the heat in the combustion chamber has risin from the heat of the higher octane?

Patman · Apr 23, 2003

quote:

Originally posted by combustion:
Now when you say it will foul out the plugs faster, is this because the heat in the combustion chamber has risin from the heat of the higher octane?

No, it's due to the chemicals used in the octane boost.

Remus · Apr 23, 2003

Toluene is a great octane booster. I use two gallons on track days. pump gas in my area is 91 w/ two gallons of this and a full tank I get about 94-96. So far I've had no side effects

http://performanceolds307.tripod.com/backup/id9.html

[ April 23, 2003, 05:35 PM: Message edited by: Remus ]

Jimbo · Apr 23, 2003

Interesting, toluene is one of the ingredients in 100 octane leaded avgas.

For very high compression street engines, 108 octane unleaded, oxygenated race fuel is made by Union 76 and probably other small suppliers. The cost is about $4 a gallon.

Race fuel

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