Ther has been some discussions on this topic, in other topics posted. I'd like to get some feedback from some of you and see if anyone else knows of others offering the kits.
I have been searching for some companies that offer high comp piston kits for the Raptor. So far I only see 2 reputable companies that offer them. What I have learned is that, under 1000' elevation, running a 11.0-1 compression or higher requires race fuel. I ride at 600' and am not a big fan of running race fuel, for many reasons. One company I have found is FST, advertising the kit being able to run on premium pump fuel. My guess is that it is either, they ride at a high elevation @(11.0-1) or it is a 10.5-1 ratio kit. The problem is getting in touch with them. They only take calls at a certain time of the day, for 2 hours and I have been unable to find a website, or anything specific about this kit. Does anyone know about Wiseco, JE, or anyone else other than Powroll and FST? I am ready for the power increase, just can't get answers and info. Anyone with help?

 

Well, I just got off the phone with Mickey at FST. Currently, all he offers right now is a 10.25-1 as a bored 40 over kit. He is working on a cam and the stand alone stock bore high comp piston kit will not be available for about 6 weeks. Mickey says the reason Powroll is recommending race fuel at under 1000' for the 11-1 kit, is because of poor gas in the area. He personally has run premium with no problems. FST is located at under 1000'. So?
If anyone hears about a 10.5-1, (i would like to be safe, no race fuel) Pleas let me know.

 

I have always liked the higher compression pistons, but with the same bore. I had a 440ex and have seen and ridden many other strokers and i would rather have a hgher comp piston and a cam than a stroker. The 440 especially would vibrate the hell out of you. You shouldnt have to run higher than 93 octane on anything lower than 11:1. my 440 was a 11.25:1 and it ran without flaw on 93. A buddy of mine had a 400 with just a 11:1 stock size poston in it and i liked it a lit better. I myself would wait until White Brothers came out with a kit, those are some oof the better ones

 

Lrd has some things in the works

they have a high-comp big bore piston (12.5:1 comp ~720cc ) it is 4" in dia huge.. I think they are looking into a stock high compression pistion to.... I know on mine, once the pipe is done, they are going to be doing some port/flowing on the head, and possible deck the cyl/head, they still have to check on the piston/vavle clearence....... but doing that you can bump comp a bit...