in the search for more power i have been looking in to a 13:5:1 compression piston and the HRC cam... My issue here is fuel quality... I do not in anyway want to run race fuel, its too expensice and unavailable.... What are your thoughts on this can I run that hihg of compression and still run 93 octane. Also what other modifications should I run for example what jet should I use Etc. thanks for the info

 

No way in he11 are you going to run a 13.5 to 1 engine on pump gas. Don't even think about this if you don't want to run race gas.
Unless the cam has some sort of weird bleed off rate there is no way. Then you going to have to drop all of the timing out of it. By the time you do all of this an 11 to 1 pump gas quad will be able to beat it.

 

I have an 11.5:1 Wiseco in mine, with a stage2 Hotcam. We have 92 not 93, but it doesn't run right on 92. If I cheap out, it is hard starting,and is a pig. Mix in some 110, 75/25 and it runs great.

I would not try a 13.5:1, on the pump like already mentioned.

 

i run 110 octane in my 450r......

and i have not had any problems

and do not use pump gas

110 is pretty expensive also..

 

pump gas builds more power, high octane is to cool the piston. The dome gets hot and lightes the fuel to soon by heat, compression gives you throttle responce. it will hurt you on top end , if looking for more bottom good mid then the high compression is good . Porting the head with the right combo of cams and the correct jetting and timing will be the answer.