well i just completed the stock grizzly exhaust modification and, well the only way to describe the diffrence is HOLY ****. i can't believe the hoarse power gain and aceleration diffrence. I just have to re-jet and adjust the valves now. is it ok to take it to the shop and have them do it. i don't want them to adjust it so much that i looses all the power i gained. they can only adjust it one way correct? I also added the K&N air filter to the modification. any help would be appreciated.

 

What exactly did you do to modify it. I've been beating around the bush on getting an HMF pipe and the whole K&N package, but never have gone through with it. Do you think it would be worth it? I mean, are the gains significant enough? Silverbear seemed to think so, but then he went and turned his into a beheamoth 686 soon after.

 

How did you modify the exhaust? Drill out holes in the baffle and put a new end cap on? How many holes do you drill? Is it a lot louder? If you put the spark arrester back in, does it quiet it back down to where it was stock, or is it still louder?

Thanks

 

to modify the exhaust:
1) take the exhaust pipe "cap" off the end of the muffler
2) drill holes in the baffle with a long drill bit, i used a 3/4" bit and drilled 7 of them evenly spaced in the baffle
3) take the spark arrestor off the cap by using a drill bit to drill it off (but not through)
4) use either a hole saw, or whatever the hell you want to cut the wimpy 3/4" stock exhaust piece
5) get a 1 1/2" o.d. pipe ( i know it sounds stupid but i cut a peice off a bathroom handicapped hand rail, already has the bend and all)
6) use stainless weld to weld the new piece in
7) put back in place on muffler
8) have a good time after re-jetting.

doing it this way saves a lot of money and works just as well. and is worth the 2 hours it takes to to the mod.

 

when i did the stock exhaust mod i found it hard to dial in with the jet kit. right now your quad is running quite lean without a jet kit, and that is why all the power. i ended up going with a complete kit from highlifter, pipe and all. using the supertrapp( witch i love) i got her dialed in real good. here is my set up.
155 main jet
screw at 3 1/2 turns out
12 plates in the supertrapp exhaust
stock air box lid
k&n filter
needle on the 4th groove.
the power differance was odvious!!! in low, i can stand her streight up with no effort while i have on my titan 589 and itp rims. with the stock tires on, i can stand her up in high, let her back down, and re stand her up going 10 mph!!! worth every dollar for the h.p. gain.

 

I thought that most everyone agreed that if you are doing the exhaust mod only, and have no other mods done, you shouldn't have to rejet? Is this incorrect?