C5natie

iTrader: (1)

Just wanted your guys opinions on this. I just started testing with mixing xylene to 91 octane gas. Im using a 20% xylene mix (should bring it to around 100oct, havent done the math yet). The car (2002 C5) has 11.3:1 comp and it seemed to like it. The weather here has been hot and I have some races coming up so, I want to reduce knock and get better combustion in the hot weather. Here in SoCal it can get pretty humid, which kills good combustion, so I hope the high vaporization rate of xylene will help. I know a lot of FI and turbo guys use this stuff. Is 20% good (8gal. gas to 2gal of xylene)? Also, some guys I heard use that marvel mystery oil in the mix too, to help protect o-rings and such. If so, how much mystery oil should I use per 10gal? Thnx for any input.

DeltaT

iTrader: (5)

The MMO is used as a top end lube. 1-2oz. per 10 gallons is the normally cited amount. I would start with 1.

Do you have knock with pump gas? If not, higher octane gas has no payoff for you. Octane is merely a number indicating resistance to detonation, not power potential.

Jim

C5natie

iTrader: (1)

I know what octane means but if you have no knock and more complete combustion then, yes, it will give you more power. There are many dynos that show how race gas can give up to 10hp alone on a high comp motor. Anyway, I just want to reduce any knock caused by high temp conditions and incomplete combustion due to humidity(xylene helps with a high evap rate).

Soul Crusher

I used to have a turbo GTi running 30psi on a fairly small turbo, the IAT and knock retard was increadable (even on 94 octane). I ran a coupple gallons of Toluene (similar to xylene) one day at the track and it definitely helped (picked up a coupple 10ths).

However it was less cost effective than race gas after I did the math. So I stopped useing it.

DeltaT

iTrader: (5)

You might go a little faster since your wallet will be lighter.

Jim

98catfish

iTrader: (13)

You can get more out of tuning than just running more octane. If you make more power w/ just more octane then you have a tunning issue. eg. too much timing.

Higher octane fuel will have a slower burn rate. If you just tune some timing out you'll pick up more than 10 rwhp IMO

Doug

C5natie

iTrader: (1)

Any other opinions?

DeltaT

iTrader: (5)

Slower burn rate = Needs more timing in a NA setup

If you pull timing with high octane fuel on an NA setup, you will end up with an incomplete burn, expensive exhaust gases and less torque.

Jim

98catfish

iTrader: (13)

What I was saying was if your na car picks up power w/ just more octane then your tune is off. Most likely too much timing.

Doug

Cmarsh

Its good stuff to bump the octane up. I used it in my Turbo buick all the time when turning the boost up. If you are on the threshold of detination, then it will help for sure. I liked it so much I bought a 55 gallon drum of it from the local chemical supply company, was MUCH cheaper that way. I think I only payed like 125 bucks a few years ago for the drum, vs 10 dollars a gallon at the Home Depot.

Chris

maxgee

iTrader: (5)

I wonder how much it cost today. I wonder how much the VP race distrubutors pay for a 55 gallon drum.

Cmarsh

Quit wondering so much and call up your local chemical supply