Apex MCX 260 kit what boost on premium

[DooAssassin]

Guys what do you think. . I know the original is 12 psi. But, my sled has a remaped mcx box for 14 psi?? Whatever that means. I bought this sled 1 month ago so I dont know alot about it. 12PSI is great but it was awesome @ 15-18PSI on 100LL......
This is what it has:
-LC pistions
-thick nik?
-large head bolts
-balanced crank
-carilio rods
-boost controller
-MCX box remaped for 14psi ? But can go up to 20 psi?

What boost should it be able to run @ on 91? Thanks, love to here your knowledgeable opinion from your own experience regarding this topic.

 

[powder muncher]

KEEP GIVING HERE AV GAS AND BE SAFE NO POINT BLOWING A MOTOR FOR A FEW DOLLARS OF SAVINGS ON FUEL.

 

[helmic]

Guys what do you think. . I know the original is 12 psi. But, my sled has a remaped mcx box for 14 psi?? Whatever that means. I bought this sled 1 month ago so I dont know alot about it. 12PSI is great but it was awesome @ 15-18PSI on 100LL......
This is what it has:
-LC pistions
-thick nik?
-large head bolts
-balanced crank
-carilio rods
-boost controller
-MCX box remaped for 14psi ? But can go up to 20 psi?

What boost should it be able to run @ on 91? Thanks, love to here your knowledgeable opinion from your own experience regarding this topic.

91 at 14psi with your set-up but no more not even .5lb more...MCxpress
as the new ones set at 14lb on 91..

 

[DooAssassin]

Guys what do you think. . I know the original is 12 psi. But, my sled has a remaped mcx box for 14 psi?? Whatever that means. I bought this sled 1 month ago so I dont know alot about it. 12PSI is great but it was awesome @ 15-18PSI on 100LL......
This is what it has:
-LC pistions
-thick nik?
-large head bolts
-balanced crank
-carilio rods
-boost controller
-MCX box remaped for 14psi ? But can go up to 20 psi?

What boost should it be able to run @ on 91? Thanks, love to here your knowledgeable opinion from your own experience regarding this topic.

91 at 14psi with your set-up but no more not even .5lb more...MCxpress
as the new ones set at 14lb on 91..

Because the mcx box was reflashed for 14psi, does that also remap the ignition timing?

 

[helmic]

boost

If the box was done at MCXpress for you it's been remap just like the new ones at 14psi and everything was done so you can run with 91 at 14psi.

 

[DooAssassin]

Thanks for the info! Hey I pay 1.68L for 100LL, I was watching slednecks last night and saw a price of 2.60L WOW. What do you pay?

 

[gsxr]

14 LBS on the 2011-2012 Apex 290 kit with 91

 

[DooAssassin]

14 LBS on the 2011-2012 Apex 290 kit with 91

Mine is the 260 kit @ 12psi. But with all the internal mods and mcx computer upgrade to run 14 psi. I wanted to know if I can use 91.

 

[TT]

Mcx kit are setup with their headshim to run with 91 octane @ 14psi. If you want to run 14 psi you need to have the same comp. ratio as mcx headshim provides to get away with 91 octane.

If you want to run 20 psi you need a higher ocatne, bigger turbo (thought I read in an other post you had the 16t), upgrade your mcx injectors together with a reflash of your mcx fuelmap.

Watch your AFR when turning up the boost

 

[quebecmoutainrider]

ran my mountain at 14psi all last year 3000 k...and it runs great..ran on 91 or 94...avy only when I run it higher..running at sealevel to 34000...wouldnt go higher cause have to ride down every day..if it was always above 30000 would run it higher...stage 2b

 

[DooAssassin]

Mine can handle 20 psi on avgas. I dont have a head shim anymore because I run LC pistions now. compression is 127 psi. My MCX box is reflashed. But its the 260 kit not hte 290 kit. Please read the first post before replying. And thanks for your opinions.