revo, do you happen to have the pipe that comes with the promo kit? They have tested alot, that's pretty much the best pipe for the job. You will have great smooth power and very good runtime if tuned properly.


http://www.carolinasrc.com/Webstore/...idproduct=8940


It's honestly not restricitve at all for the engine. If that had been the case I assure you none of the top guys would have it on the engines. I think anyone that ran the worlds used that pipe/grp .21 tuned.