high compression piston & what octane gas to run??

[ho416mx]

I just installed a 13:1 wiseco piston in my 450R, can i stick to 93 octane or do i need to move up to like cam 2 @ 110 octane??

[RedRacer44]

You cant run pump gas with the 13:1 piston, I have the JE 13:1 piston and I use TrackTek 111 octane. You could get away with a 50/50 mix of Premium/Race. Using the 93 octane will cause your motor to "ping" and run crappy too. It will run tons better with the race gas because it will detonate correctly with the race fuel. Race fuel also burns cleaner and 'cause your motor to run cooler.

[jeepnrocks]

do you have a cam ?
13:1 and the hrc cam could be safe with 93 or 94 pump fuel but I wouldn't risk it. I mix 50/50 pump and 110 sunoco.

[ho416mx]

i have the hrc cam but i think im going to go with straight cam2. thanks for the info!

[WhiteZee]

you will be fine with fresh 93 with the HRC cam.

[depotman19]

I agree 93 octane should be fine. If you wanted run 93 octane and see if you ping/detonate.

Jake

[drthrottle]

I hate how this question always gets conflicting answers everytime it is posted. What does the gas and piston company recommend? I had a 440ex 14.0:1 wiseco. I ran 114 octane always. It was stolen and long story short, run for a long time on pump gas. I would have never tried it, but they got away w/it for a while. What's it take to get a definate answer?

[Bling]

There's really is no definitive answer to that. COULD you run 91-93 octane with 13-1++ C/R???? Yes. SHOULD you run it??? Probably not. The increased overlap of the HRC cam helps fend off detonation somewhat. But if you went through all the trouble of installing the piston/cam, just to get those extra ponies, why would you run crappy fuel and wipe out your gains? Leave the pump gas for us stockers. You big CR guys step up to the good stuff.;)

[brandonpeake]

i can run 93 in my 13-1 Je and hotcams stage 2 with porting but i had the piston thermal coated, but i run 1/2 race gas and 1/2 93

[kgbg]

why would you run crappy fuel and wipe out your gains
A god quality, fresh pump gas is a very high quality fuel. It also is a waste only to run too high of an octane. Not a huge deal, but an engine will actually perform the most efficiently it can with the absolute least amount of octane rating without the pings. It will never hurt an engine to hve too much octane, and it can to run too little, so most error ont he higher side of octane.
Elevation, cam lift/durtation, TPS correctly working or not, all have quite an effect as well.
For instance a 14:1 with a HRC or larger at my (5000ft) elevation will make the most power and not ruin it self with a lesser octane than it woudl if it :
had smaller lift cam
was at sea level
had the TPS unhooked
I live in the mountains, so we can run big compression with our big cams and run a lower octane than a sea level guy.

In your situation, I would say that with your TPS working right, and hooked up, and a HRC cam, you can run fresh pump gas. Fresh is important, if you don't use all you bought, throw it in the truck and buy new everytime.

[chad502ex]

Originally posted by kgbg
A god quality, fresh pump gas is a very high quality fuel. It also is a waste only to run too high of an octane. Not a huge deal, but an engine will actually perform the most efficiently it can with the absolute least amount of octane rating without the pings. It will never hurt an engine to hve too much octane, and it can to run too little, so most error ont he higher side of octane.
Elevation, cam lift/durtation, TPS correctly working or not, all have quite an effect as well.
For instance a 14:1 with a HRC or larger at my (5000ft) elevation will make the most power and not ruin it self with a lesser octane than it woudl if it :
had smaller lift cam
was at sea level
had the TPS unhooked
I live in the mountains, so we can run big compression with our big cams and run a lower octane than a sea level guy.

In your situation, I would say that with your TPS working right, and hooked up, and a HRC cam, you can run fresh pump gas. Fresh is important, if you don't use all you bought, throw it in the truck and buy new everytime.

Kam, you lost me :confused:

i think i know what your trying to say tho

[ho416mx]

how do you know if your tps is working correctly or not? I found a post that gave the wiring cross reference from crf to trx, is that what you are refering to?

[MR.BIG]

Run 50/50 then you won't have to worry about.

[kgbg]

LOL @ Chad,
Thats what I get for typing after a few too many Rum and Cokes!

If your at sea level, with a smaller cam, you need high octane.
High elevation with a bigger cam, you can run pump gas if its fresh.
Whew.....
Sorry for the weird post.

[chad502ex]

Originally posted by kgbg
LOL @ Chad,
Thats what I get for typing after a few too many Rum and Cokes!

If your at sea level, with a smaller cam, you need high octane.
High elevation with a bigger cam, you can run pump gas if its fresh.
Whew.....
Sorry for the weird post.

:D I knew what you meant and could tell you were not yourself- it's kewl!

:cool: