Octane Question

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Mar 24, 2004 | 03:51 PM

Crunch

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From: Columbia, MD

Octane Question

My car is currently tuned for 93 octane.

But if I filled up the gas tank with 100% Sunoco GT100/CAM2 (100 octane R+M /2), and retuned with the most aggressive tune possible without detonating, How much of an increase in horsepower could I expect? I put down around 530 on 93.

Is there any benefit to increasing the octane if I do not increase boost?

Last edited by Crunch; Mar 24, 2004 at 04:38 PM.

Mar 24, 2004 | 04:47 PM

InvisibleSun

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From: Redondo Beach, CA

I would think that if you do not increase boost, then increasing the ocatane wouldn't do a whole lot. If you go up to 100 octane, then I would guess that you would be able to increase your boost by 3 or 4 psi, which obviously, would give you more hp. Of course, I don't know your setup so I'm not sure. I know for my original setup when I was going to do an F1R, we were talking about using 91 octane and running 10 psi and with 105 octane, we were going to go up to around 15psi.

Mar 24, 2004 | 04:57 PM

Crunch

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From: Columbia, MD

I run the 2.75" blower pulley which shows 10PSI at 6500RPMs.
I have no plans to change pulleys just to run at the track.
I just thought that running higher octane and retuning with crazy timing would net huge gains, but apparently not.

Thanks, I'll stick with 93.

Mar 24, 2004 | 05:14 PM

Zo6Killer

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From: Cincinnati, OH

Don't think I'm a dick, but if you previously put down 530, you SHOULD KNOW what your combo would do w/ different octane. 530 rwhp doesn't come cheap. Nor do the engine combos that can net them. That never came into your mind when you were on the dyno?????

Mar 24, 2004 | 06:01 PM

Crunch

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Quote:

Originally Posted by Zo6Killer

So, because my car put down 530 on 93, then I automatically know what it will do on 100 through osmosis.

How the hell do I know what my car will do with higher octane without actually tuning it with higher octane in the gas tank? I have no experience tuning LS1's, let alone with race fuel. If I knew that, I wouldn't have posted this thread.

I had 93 in the tank when they dynoed my car last. I suppose I could have paused the tuning session, drove for an hour and burnt off the rest of the 93, find a Sunoco with GT100, refuel, and drive back to the dyno. But then I would had to pay those guys to sit there for another two hours at the dyno while I go and find race gas.

This time I planned on filling up prior to the dyno session, getting the dyno tune on race fuel, and saving the program on my laptop so I can enter the program into the PCM at the track.

Sorry I asked. Jeeeze.

Mar 24, 2004 | 06:04 PM

InvisibleSun

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From: Redondo Beach, CA

YOu may want to check out the Torco race fuel concentrate. It will turn 93 into 105. It isw supposed to work really well and be quite accurate. That way you could tune your car on 93, toss sme Torco in the tank and then tune again. That is what we plan on doing in a few weeks with my car...