Yes i could do a search and get some information on this but i would rather hear from some of you that have a 720 for answers.It is common knowledge that anything over 11:1 requires octane levels higher than pump premium but i would like to know what compression some of you have ran for any length of time and on what fuel.I am in the process of researching a build for my baja and i want to make as many informed decisions as possible to get it right the first time.I guess i should be more specific and ask what brand of piston has shown itself to be dependable for the 720 because that is the way i am most interested in going.Some of you may remember that i was going to build my baja some time ago but i decided to have my raptor built at that time but now it is time for the baja.This forum is a very good resource to obtain the kind of information i am looking for and i am looking forward to hearing some opinions.Thanks.

 

i run 112 with a 13.5-1 piston from tvi. there are quite a few others that run 11-1 on premium with out any problems...maybe someone will chime in....

 

11.5 is great on 91 Oct. What kind of CDI you run is important.Also I assume you are riding on the coast.

 

Yea what he said...11.1 is great with 91 octane..... but it also has to do with which cams and what CDI. Not to mention any other modifications such as Exhaust. Also your weight will have a slight factor as well. HPR indicates 11:1 compression using 91 Octane pump gas is ideal 11:5 needs 93 Octane under most circumstances.

 

I have the 11.2:1 je piston from mrhp and love it, I do run 91 octane and I have the stock cdi, I am witing for scoundrel to tell me how his aftermarket cdi is doing before I buy one lol

 

I'm running a MrHP 14:1 piston with thicker base and head gaskets. According to my spec sheet I am running 11.7:1 overall compression on recommended 91 octane pump gas. I also have a Vortex CDI and HR3 cams. I am probably on the very edge but she seems to run fine on pump gas.

What are some of the signs besides knocking that you need to go up in compression?

 

Oops, meant to say "up in octane"

 

well actually I have the je 12.1:1 piston from mrhp with the thicker base gasket and head gasket to bring it down to 11.2:1 sorry with stock cams and race ported intake

 

I have the 11:1 Pami piston. My head has been decked slightly so according to Knutz, I'm at 11.3:1 now.

I used to run 100 or 110 but now run strictly 91.

Ask anyone whose raced me since I switched.

It's made my engine run MUCH stronger![img]i/expressions/face-icon-small-happy.gif[/img]

 

Thanks for the replies so far and i am hearing what i wanted to hear about compression levels and the fuels you are using.It seems that the rated compression given for a particular piston can vary once installed (due to different gaskets)and that is why i am curious about the octane levels some of you have actually used with success.My Baja will be used for the majority of my dune riding so i really dont want to worry about having to run "race fuels" so i am wanting to go as high as possible on the compression while still being able to run pump gas.