Compression ratio

[swedenturbo]

I know my post is in the wrong forum but at the snow bike section there's not lot of people who have much knowledge in boosted engines.
I'm also ridig a Nytro MCX270 ;-
Question:
Have a boosted KTM 500 snowbike. Built the turbo kit by myself. Using MCX piggyback fuel injection.
Running stock compression ratio at 11,8:1. Boosting 7,25 lbs with 102 RON fuel. Bike runs great, about 80-85 horses. (stock 55,6)
I would like to safely increase boost to 10 lbs with pump fuel.
Nobody seems to have any opinion about what compression ratio is safe with that fuel and boost.
What compression ratio would you guys recommend?

Here's my build http://www.snowestonline.com/forum/showthread.php?t=325741

 

[up-high]

There is an octane calculator around here somewhere. Just seat-of-the-pants I think 10.5 cr so be safe. What elevation are you usually at?

 

[swedenturbo]

Here in Sweden its different... I think I'm considered as a flatlander Max elevation 3000 ft.
KMS are boosting 10 lbs with avgas but I have my doubts about the reliability...
My fuel is Sunoco 102.

 

[up-high]

Under 3000 I think 9 cr maybe. Don't know. My Apex had 9:1 pistons. Good for 17# on 91 octane but I never rode under probably 3500'

 

[ondik]

is your bike xc or exc, xc ecu can be remaped, more ignition retarding could do the trick