I mentioned in another post that I wanted to hit 100 in the 1/4 on pump gas and without slicks. It came up that I don't need race gas unless the engine is pinging. It's not. Wouldn't race gas burn better, and make more power, than pump gas? I was thinking about 100 or 105 Octane, not the crazy expensive stuff.
I don't know about making more power, I think it just allows you to make more power by utilizing higher compression ratios or forced induction. I'm under the impression that you want to use the lowest octane you can get away with without pinging or knocking, not only because its cheaper but also because it burns easier and quicker (hence the problems with detonation in higher compression ration engines)* *disclaimer - I'm no expert, this is just what I've heard from others, I'm interested to hear what other people have to say.
I agree...race gas lets you run more compression by burning slower. If you want to go quicker, and are willing to run race gas all the time, then put in some 13:1 pistons. Personally I'd rather lose the performance and keep the driveability of lower compression.
Yeah, I'm somewhere around 9.3:1 compression. I want to continue running pump gas on the street. I just didn't know if race gas would help on the occ***ional trip to the track.
Race fuel will allow you to run a few more degrees of timing advance before it starts pinging at the track. -Jeff
I'm not changing the cam or anything in the motor. Except for new lifters. Will I go faster with race gas?
[ QUOTE ] Will I go faster with race gas? [/ QUOTE ] maybe look for some alternatives other than the motor... perhaps lighten the car up a bit... you are very close to 100mph. only problem is, i know youve got a coupe but know nothing about its interior or what can or cannot be yanked off
I could tell the differece when I forgot to purchase my normal 114 octane turbo blue and bought 110 octane Sunoco at the track. I've got enough compression, that I can't run pump gas though. I was missing the extra grunt off of the corner. I didn't think that I would be able to notice the difference when I switched. The specific gravity, and other characteristics of the fuel make a bigger difference than it's octane rating though. My lawnmower doesn't bogg on the tall stuff as much as it does on pump gas either!!
I bought the $4 a gallon 101 octane last Saturday and I could not tell any difference over pump gas. Your engine my require it but I do not think I will spend the money again. I am in the same fix as you but with a different number. I want to break into the 12's and I am just .2 away.
I work at a big Chevy store. The guys have been ribbin' me about all the time I spend on my car and I still can't outrun a new Vette. So my new goal is 12.6. That's what the '05 Corvette does. I'm a ways off, but I don't expect to attain a goal in a week. It's something to work towards. I actually have two seats ****ed together, so the p***enger seat comes out next time. And I'll pay more attention to how much weight I have in gasoline. Heck, the first run I had my tool box in the trunk!
I work at a drag strip. I have raced on pump gas and race gas and i dont see much difference. Its not worth 4 bucks more. Try racing with 1/4 tank full. and go on a diet if you cant loose car weight. Hell go ****! You dont need to wear those heavy 3 pound jeans!
Only if you want your exhaust to smell good. I saw no increase in performance over pump gas with lower compression. Compression is one of the things that builds horsepower. Higher compression needs higher octane gas to avoid detonation - and the fuel burns slower. If your car runs fine on 92 octane, a slower burning fuel will not give you any more horsepower. http://auto.howstuffworks.com/gasoline3.htm Mutt
I don't think 9.3:1 is high enough to warrant race gas unless you are really advancing the spark or unless you have forced induction.
I am glad that several people have backed up my original statement. Race gas will only cost you money if your engine does not require it. Save the money you would spend on race gas and get a new cam and bigger carb, then see what you pick up in the quarter. If not enough, look into better heads. With cast iron heads you don;t want much more than 9.5 compression to still allow pump gas. Those new vettes are f***t, but your coupe looks better....
What is your rear end ratio? If you don't want to touch the motor, maybe slightly lower gears are in order.
Don't those new Vets run $45,000 or more? Have you spent that much on your coupe yet? Didn't think so, maybe those guy's would be willing to put up a few grand to help in your effort? I don't thing race gas would make you go faster unless your on the verge of pinging and can't tell. Guess it wouldn't be that big of a deal to try it once, then you would know what it does in your car. Sure would kinda **** to find out that would be all it took to get you over your edge, but never tried it.... I say shell out a few bucks and give it a try, then you will know. gene
Gears are 3.55's. I have another chunk that I was going to set up as a 4.11 spool, for the track. But I've been thinking and looking at some numbers. With 3.55's and my tires(28.3), I should be able to hit 105 at just under 6500 in 3rd gear. That saves me one of my shifts. So there almost second saved right there!
Here's some more info for you.... http://theserviceadvisor.com/octane.htm http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm Mutt
Get the engine and trans out of a new Vette.That will get you close real quick. What size is your motor ? And don't tell me you want to go that fast with a 283.
Well, whether you need it or not, the fumes do not burn your eyes like pump gas does! My cam has quite a bit of overlap, and when sitting in traffic for a few it starts to choke you out a little... your eyes get all watery and stuff.... that doesn't happen with the good stuff!
Damn, HRTH, so that's my problem in my 38's 454. The cam is too ****in big and that makes it smell bad when it idles Guess i will just have to suffer edit: I know my cam is big, I was trying to be joking
Did you play around with this one? I'm not sure what you are running for HP in the motor or how much your ride weighs but it supposedly tells you your ideal ratio for 1/4 mile. I think that with the added "get up and go" you should be able to at least compensate for that other shift to fourth if you go lower. http://www.richmondgear.com/112901.html
Good question buzzard, the replies were not what I had expected. Im learnin all kinds of stuff today!
I've found that the rear gear ratio has very little to do with top quarter mile speed and a lot to do with et. Good fuel will allow you to advance the timing and that sometimes but not always helps the et and mph. We used to advance it in low gear and retard it some in high when we were racing with a dual point.
[ QUOTE ] I work at a big Chevy store. The guys have been ribbin' me about all the time I spend on my car and I still can't outrun a new Vette. So my new goal is 12.6. [/ QUOTE ] Tell them to take the tires you have on your coup and see if a Vette will still run 12.6. Your car is way cooler than a Vette and sounds better. Screw em. There just jealouse still cause you got to see that Golf match that weekend on TV and they worked.
[ QUOTE ] Tell them to take the tires you have on your coup and see if a Vette will still run 12.6. [/ QUOTE ] Damn straight! Try moving your ****** to the back of the car, that may help a bit too.
[ QUOTE ] Did you play around with this one? I'm not sure what you are running for HP in the motor or how much your ride weighs but it supposedly tells you your ideal ratio for 1/4 mile. I think that with the added "get up and go" you should be able to at least compensate for that other shift to fourth if you go lower. http://www.richmondgear.com/112901.html [/ QUOTE ] I don't think I trust these calculators. I just plugged in the numbers for the Vette. Running 12.6, at 3100lbs, it says the horsepower is 265.
[ QUOTE ] [ QUOTE ] Did you play around with this one? I'm not sure what you are running for HP in the motor or how much your ride weighs but it supposedly tells you your ideal ratio for 1/4 mile. I think that with the added "get up and go" you should be able to at least compensate for that other shift to fourth if you go lower. http://www.richmondgear.com/112901.html [/ QUOTE ] I don't think I trust these calculators. I just plugged in the numbers for the Vette. Running 12.6, at 3100lbs, it says the horsepower is 265. [/ QUOTE ] At the rear wheels, I'll bet you'd find you're not too far off! My chevy II made 400 HP at the wheels the first year I had it out... 1 week later I took it to the track and it ran a traction limited 11.15 @ 124. The calcualtor says it should've gone 11.06 @ 118, so it's not that far off...
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