The exhaust to beat the FMF

Message

wistech · #71 Post by **wistech** » Thu Nov 19, 2009 1:07 am

Ok stepped duals galore. Ive been burning the midnight and morning oil to get these last two engines ready . I have 2 new designs to try out for the duals once again. One has a slightly bigger step with more volume in the mid and the other is progressive with each step. I dont think there will be much difference. I think both will perform better than the first couple of sets but at a cost of clearance for chain slap if motocrossing. It shouldnt be an issue with these as they are both for drag racing and tt. I have several sets of cans to choose from now . FMF Ti's ,stock hayabusa ,and a couple of D@D cans that look promising.
Exhaust is done and now to finish up on the other stroker.

kevin444 · #72 Post by **kevin444** » Thu Nov 19, 2009 4:39 am

little off the subject, but am i loosing or gaining power "in theory" with my FMF Ti completely gutted? it was not done on purpose, i lost the tip and had to pull the insides out and lost them during the trip. its very, very loud but im sure i loss bottom but gained top end. this happened right b4 my last rebuild so i dont have much to compare to. 432 with no air box 106/106, reprogrammed ecu, and ported / cleaned up head...etc

just curious of everyones opinion. i got a replacement pipe that im gonna grab, but was thinking about cutting this down?

thanks

cannondale27 · #73 Post by **cannondale27** » Thu Nov 19, 2009 5:20 am

You are losing power. Packing and the core are both critical for power. A open pipe doesnt perform. Been tested.

kevin444 · #74 Post by **kevin444** » Thu Nov 19, 2009 5:55 am

im sure i am, just happy the way she's running now after a fresh rebuild from the bottom up; looking forward to the new pipe

wistech · #75 Post by **wistech** » Thu Nov 19, 2009 4:56 pm

The fmf needs to be properly packed to retain power. Also shortening them to 10 inches seems to be the perfect length for max power as well.

kevin444 · #76 Post by **kevin444** » Thu Nov 19, 2009 6:55 pm

hate to ask, but what is the proper way to pack the fmf....

wistech · #77 Post by **wistech** » Thu Nov 26, 2009 6:04 pm

Fmf packing comes with instructions.
When installing duals its a good idea to install heat resistant material over the 2 hoses coming out of the frame.

wistech · #78 Post by **wistech** » Thu Nov 26, 2009 6:25 pm

Plenty of shock clearance . It took a while to find the right setup for a decent rear shock setup and after switching from a zps to dual rate wow what a difference in ride . I have several springs depending on rider. This is the light one for Karen since she is just over a hundred pouds. My spring is considerably thicker LOL. . Dirty Tony whipped up several sets of sliding sleeves and Brian Kinney added the hose and adjustable rezzy with slight valve change for trail riding. I shortened the main spring a little bit for the dual rate setup . This is by far the best riding shock Ive found plus it can be dropped for a super low ride height.

wistech · #79 Post by **wistech** » Thu Nov 26, 2009 7:31 pm

When installing the duals just like the fmf its very important to seat the headers in the head first and then shim the midpipe brackets to where they want to be without bending them into place . After they are secured then go ahead and install the mufflers. That way there is no tension to cause cracks while riding. I have washers and WWE wrist pins for spacers trimmed to length before cutting the actual spacers.

UpsMan · #80 Post by **UpsMan** » Thu Nov 26, 2009 8:47 pm

Sweet, chicks just over a hundred pounds are my favorite. And the Packers win. Yes!!!!