evoIX15

if you had the chance to fill your tank FULL of race gas i.e. over 100 octane, would you do it, even if the car is only used for daily driving/ a few races at the track on the weekend? bc i notice most people say mix it in with 91 or w/e you usually use, why not just fill the whole tank?

SwiftEVO

iTrader: (32)

I dont do it because of the cost. But yea I would run it if is was the same price as pump gas.

--Josh

Warrtalon

iTrader: (6)

Strictly cost reasons. If I had reliable access to 100oct, I'd run a 50/50 mix of 91/100 all day long and not even use my alky injection. Straight 100 can probably make a little more power, but in all my racing, I've just mixed 100-104 with whatever is in the tank and gone nuts. Refilling with straight 100 on a daily driven car would be expensive, though.

evoIX15

thanks for the replies, i was just curious

Turbo Meg

iTrader: (5)

I run a 50/50 mix of 100 octane and pump all the time.

Dnealy

iTrader: (1)

What are some of the disadvantages of running race gas alot? Ive read that it messes the injectors up blah blah blah. I mean i know its not the best for the 02 sensors but what else could it hurt, because not to far from my apartment we have 110 at the pump and i run it alot lol.

Turbo Meg

iTrader: (5)

Not sure? I have had no problem with the mix. I have been running it for over 5k miles. The reason I run it is to safely run 25lbs of boost. I also had my car tuned on the same mix.

Warrtalon

iTrader: (6)

Ah, you're confused, because not all race gas is the same. There is unleaded race gas, which is just a higher octane version of what you get at the pump, and there is leaded race gas, which is much different. The unleaded octanes are usually seen as 98/100/104 while leaded is usually 110/112/116. Race gas doesn't hurt injectors, but the leaded race gas does eventually foul out the o2 sensor and destroys the cat if you have one. Unleaded gas doesn't harm anything and has no disadvantage.

It's unlikely to find 110 "at the pump," because it's illegal for street use, so they usually make you pump it into a container in order to buy it. If they let you pump leaded race gas into the car, then they would get shutdown by the fire marshal.

bvdawg13

iTrader: (3)

is it ok to put in, say 104 octane without retuning it? Also how much of advantage is it to just put in the race gas and not turn the boost up?

evo637

Waste of money..I only use straight 100 only when I am at the track..@7.50per gallon its to much to use everyday..

Warrtalon

iTrader: (6)

With race gas:

1) Retune leaner with more timing and raise boost = most power potential
2) Same tune with boost cranked = next most power potential
3) Retune leaner with more timing and keep boost the same = some power potential
4) Same tune and same boost = waste of money. No gains to be seen unless the current tune and boost are already at the limit and causing knock

Warrtalon

iTrader: (6)

Luckily, I can get 112 for $4.40/gal, so I mix 2 gallons with every refill of 91, then for the drag strip, I have a separate custom tune for straight 112 + alky injection to see if I can drop a tenth or two. $7.50 for lowly 100 sux0rz.

deadbeatrec

iTrader: (9)

first off, yes its ok to run 104 if u have a good tune already. there is no reason to retune. second y would u run race gas without uping the boost? thats just silly. the only advantage it would have is garenteing that u will have no knock from low octane gas, thats about it. the reason we use race gas or a higher octane is to keep the knock down. thats all octane is, a measure of knock. the higher octane is more detonation resistant there for we can up the compression with more boost.

UT_Evo

iTrader: (5)

Except for racing instances, because the race gas is cleaner and more efficient, it is safer and kinder on your internals. Otherwise, why don't we all use 83 octane?

And to the above post... Octane is a measure of how easily a chemical component will burn and how hot it can get. That's why it reduces knock on a leaner tune because you need less gas to reach ideal levels of heat. And again, with it being cleaner.

Warrtalon

iTrader: (6)

No, your tune would be for pump gas, so it definitely would be beneficial to retune. You can go much leaner and be much more aggressive with timing.

Compression does not change with more boost.