I have a 2002 400 4x4 with a HSP speed kit + billet premium head and I want more power. I am going to get a pwk 39mm carb, HPD aluminum air box, and V force reeds. then this fall I was going to get a bubba port & .20 wiseco piston. I was just wondering if I could get the race port with the HSP pipe and clutch I already have (blue primary, white secondary in the # 2 holes, 45/40 secondary helix, T 15 weights I think ) I do mostly trail riding but also ride the dunes alot. how does the race porting do on slower rides ? any info on the differences between the two would be helpful??? thanks for the help folks

 

The 400's will respond alot better with race porting than trailporting. Bubba does a great job. He did mine as well.

 

Thanks does the different sprocket s make a big difference? I like to get to top speed as fast as possible but top speed isnt as important

 

The sprockets will help a bit. Milling the flywheel, and upgrading the carb are also get there quicker mods. The HSP pipe is o.k. for trails.....but if you want hp, and you want hp now, get the HPD ATV8 pipe.

 

Heck yeah, you could probaly sell the HSP pipe for almost as much as what you could buy a used race pipe, or at least take a big chunk out of a new one. Bubba