I put an RKTek head on and didn't really notice anything on the top end, However the bottom and mid-range really made a difference. Would do it again.Hey everyone,
Its time to rebuild my 09 M8 I know that I can use 800 HO cylinders, head and pistons but what other mods to the motor would you do? Is an aftermarket head worth it, if so what brand. I'm looking for more power Thanks!
We never had a bog...actually runs perfect across the entire range in all conditions and hits hard off the bottom. I also was wrong on the secondary spring...that was left stock. The only thing I did was change the primary spring to one with a bit more preload (starting rate) with the same finishing rate. Same weights. You end up pulling 200-300 more RPMs with the added power and the stock weights are great for that. Honestly the best sled mod I've even done. Literally bolted everything on and never touched it again...has been 6+ years now. Never touched it. Belts last forever. Runs perfect everyday.I second the slp pipe kit.
The bottom end bog is a bit worse but the gains on top end are huge.