Have not seen any dyno figures, dyno means absolutely nothing though. They are all good pipes, some louder and some fit better than others. Just get whatever brand you feel most comfortable with.

 

The pipes in the classifieds are Pro Circuit, not Pro Comp--never heard of Pro Comp. That is a fairly decent deal if they are in good shape. I'd like to know what dealer you could get them from for the high $400's--that's less than my dealer's cost. Retail on them is $679. You may want to look at the Big Gun if the crossover pipe is a big deal to you, they are producing a hair more peak than the Yosh pipes. On our local shop's dyno, the Yosh made the least peak HP of all the major pipe brands. The DMC's made the highest HP, but IMHO look cheap and are obnoxiosly loud. I haven't seen any results on either the HMF or Duncan's Fat Boy 4 system, but I hear those are both great systems as well. All of the pipes my local shop tested were within 3 horse of each other, so it all boils down to what you like the looks of the best.

 

Big Gun Exhaust

 

If you're saying the DMC's slowed the V down compared to the stock pipe, then you were either jetted incorrectly and/or clutched incorrectly. The power increase over the stock pipe was very, very noticeable on my V and my results speak for themselves.

 

zmann i bought the hmf duels and im very satisfied with um good high quality. and they do come with the jets if you order them strait threw the company like i did.

 

I assume you ordered them straight from HMF?

 

What type of finish is on the duncan pipes? I am juts asking since they are quite a bit more expensive than the HMF pipes. Did you have any problems getting the jetting worked out on them? Thanks for all the replies everyone.

 

Here's something I would think about before I made a choice. I feel pretty sure those tests were done with the stock spring and I think everyone knows by now the stock spring isn't even adequate for the stock pipe. A pipe making the best power with the stock spring is probably making its power much lower than other pipes. That would be good for GNCC or trail riding, but for some occasional straight-line racing I would want a pipe making its power as high as possible and then change my clutch setup to match.

 

That is probably true, but, I would hope that Team Green isn't running a stock spring. Who else on here runs a stock spring? It seems like the first thing that you would change on one of these.

 

I really must not understand what changing a spring would do for me unless I was into drag racing in a straight line. The V has more then enough power, and speed as is for the GNCC, trail riding. The only mod I have done is HMF duals. No jetting(and my plugs still look good), air box mod nothing. I don't want to move up in the higher rpm's at a slow speed, because I already have a hard time keeping the front end down. I doubt Greenteam changed his spring...he rides 4-stroke stock, and I bet other top GNCC riders are running stock spring. So where does the big benifit from the "spring" come from?