I know you aren't supposed to run leaded race gas in the car if you have a stock cat and because of the O2, but after talking with a guy here in colorado(where there is 91 pump $ 3.15 gl) at a local fuel company, and decided to get 2 gallons of 111 race fuel leaded($5.75 gl), I know. I mixed in with about 8 gallons of 91 and 4oz of MMO. I am going to take the chance because the O2 I can replace if I have to and the cat is going soon for a high flow and resonator pipe and racing beat dual tip exhaust. so what do you guys think?

 

I don't think its going to do anything really. With mixing the 2 together you might have like a 100oct mix right now.

 

thats what I want for right now. I just want a higher octane then 91 so I can help with the knock, what you said is what the guy at the fuel company said to me. He said the lead content after being diluted with uleaded would simple boost the octane a bit and wouldn't cause harm, so thats what I did. I was just wondering what people thought it would do? and what octane I could expec t from that mixture?

 

the octane rating isn't gonna hurt it by being too high. But leaded race fuels gum up your cat i believe and can actually cause a big restriction. But i'm not sure.

 

Why are you knocking with 91 oct? Thats a more serious issue esp. on a FD. I have no idea what the mixture would run to get a 94-100 oct. I bet you could find some kind of calculator on google.

 

There is absolutely no reason to run "racing fuel" on a car running a stock cat on the street. I do run 100 unleaded when I am tracking the car for just an extra edge of safety with the motor running so hot.

Unless you are trying to run over 15 psi on your car (not likely with a stock cat!), there is no need to run racing gas. Any amount of leaded gas is going to clog up your cat, eventually. Save your money and stick with pump fuel. Just my 2 cents.

BTW, that mixture is 95 octane. If you don't want to follow my advice, I would just order a drum of 100 octane unleaded from VP or ERC Racing Fuels and use that....

 

I use the 100 octane gas when I go to the strip. I have used it for years. Wow $5.75 for 111 isn't bad, my Supra friends get C16 for 7.39 a gallon.

 

yeah I understand. I would love to do that, and I just might. I just don't have many options. I dont know if I am knocking or not (no gauge), I am just trying to play it more safe, I did see a few boost spikes when I was on the freeway so I wanted to make sure I don't get any detonation until I can control the boost, I am saving for a Power Fc for x-mas so I don't want to also get a e-boost controller right now, I might do a manual one. correct me if I am wrong on this theory. so the mix I got I thought would help, it seems to run real nice so far. just testing it out. Rynberg do you got a website for either one of those fuel companies? I would appreciate it.

 

thanx anyway on the sites but I got them.

 

I found on the VP racing fuel site, the vp ms 109. It is an unleaded fuel and the MON is 101 and the RON is 109. has anybody had any experience with Vp fuels. I might order some.

 

It's my understanding that the ECU will compensate for higher octane and advance the timming when it's used. But it won't change the timming back when you put in a lower octane fuel after running the higher version. I was told you had to disconnect the battery and rest the ECU to correct for the lower octane fuel. If I was told wrong please advise me other wise. This may account for your knock if you've run higher octane then gone back Sonix7. How was the B'd ay ? ? ? ?

 

b'day was good, that is very interesting info, I just did it so I could up my pump crack for better piece of mind. I am also very curious if this theory is correct? What kind of problems will I need to be concerned with, I plan on mixing the 111 with the 91 at a 20/80 mix until I can afford some unleaded fuel in a drum. I hope I am not ******* it up, I just can't deal with the low octane pump crack, it could be only like 87 ron in reality(also you got grocery store pumps that dominate the market here), I usually have to go to Texaco for quality gas(more expensive too), I found the 111 at a fuel company, this 111 is a pure 111, not something they boost up to 111. I am just learning all this stuff as of late, I have been reading a lot about this lately and am trying to grasp the right way of doing this. help is much appreciated.