Boost / Fuel Octane Figures

[Ratpack]

I ran 7 pounds on 93 octane pump fuel for 3 years without a problem. Now I am running 10 pounds with 93 Octane and Torco also with no problems. We bought 5 gallons of Torco and saved a lot of money. I tried running leaded race gas 50/50 and cooked a o2 sensor fast. Unleaded race gas is $17 a gallon here so the Torco was an easy choice.

 

[rxrider]

Ratpack - at what altitude do you ride?
What compression do you run?

 

[SLEDSTART]

Ratpack - at what altitude do you ride?
What compression do you run?

That was my question. Stock motor or shimmed? I think I am just going to drop the compression. I want to run 10 pounds safe at sea level on pump fuel. I don't want to mess with race fuel or swapping pullys. I want to be able to swap clutching and head west with it. What head shim do I need. Anyone know? I was thinking of having Ulmer just set it up if I can get it there. I heard he does good with them. Anyone else I can use close to northern IL or Wisconsin? Would like to get in on a dyno. Anyone use Goodwin in Zion IL? He set up a few of my 2 strokes (viper and SRX) and they ran really really good. Don't know if he has done these though...gotta ring him

 

[Ratpack]

Most of my riding is between 1500'-2000'. When I was at 10,000' at 7 pounds I just ran 91 octane. Last year at 10,000' at 10 pounds I brought 93 octane and mixed it with Torco. The next time at 10,000' I will just mix 91/Torco. The compression is stock. I would like to shim it but my summers are just to busy with kids and baseball.

 

[SLEDSTART]

Rang Goodwin. he don't do much with 4 stroke Turbo or SC set ups. I did talk to Allen Ulmer yesterday. Sounds like he has set up more than a few of these MPI's and has a decent set up for them. May be meeting him in Milwaukee in a few weeks and just let him have the sled. I simply don't have the time to pull the head and mess with clutching myself, but I want it done. Talked to a few members on here that have his set up and they say they run really good...

 

[kinger]

He has it nailed, mine has been trouble free for quite some time now. Throw a fuel pump at it as well, maybe a brand new stocker can keep up but if you have a 2006 mine couldn't keep up. I used a walboro 255LPH from flebay and had to mod it to fit but works great and plenty of fuel for my 243hp.

Picts of the fuel pump mods are in this forum posted by speed and myself.

I honestly would make the sled a crossover if you shim it, your not going to want your stock sled after you get on a supercharged one. Afte owning everything I used to say I want a boosted one for the fun days and stock one for the long trail days and mine has proven to be good at both and reliable. No issues taking it on a 1000 mile a week trail getaway, I never even check it over each day just turn the key or because of you push the button on my remote and add fuel. As good as the 2011 apexs are nothing compares to boost. Running that only in the mountains or in big powder days would KILL me.

Good luck.

 

[rxrider]

Right on kinger

 

[snoseeker]

any body know if you have a sled that makes 7 # of boost and only need 94 oct and you have 110 oct to mix how much 110 to say 87 oct and how much with 89 or 90 so I guess what I am asking is how many gal of 110 to make the right oct to run thies fuels

 

[rxrider]

It's only math, but only approximately as some fuels will give you less than the math suggests.

50% 110 + 50% 87 would be 197/2=98.5 approx.

Run a few octane numbers higher than you need for your piece of mind. Better running safe than on the ragged edge.