I know these are an up and coming system for sportbikes but how do they go on the Raptor? i really need to get rid of the stock boat anchor. Is it worth popping for a full system or are the stock headers agood design? I like the look of theHMF but im afraidit will be too loud and being a non disc pipe, untunable.

 

You need to talk with Explor. He has one on his Raptor.
I have a HMF slip-on my DS. Here is what I think. The fit is very good. No leaks. I did go to ACE & buy rubber washers to help mount it though so it wasn't metal to metal. It is lighter than the stock exhaust. It looks nice. The sound is very deep. It is much quieter than the FMF on my friends 400EX & even a little quieter than the Big Gun on my grilfriends 400EX. The sound is so deep it sounds it doesn't seem that loud. Unless your in the garage !
The sound isn't edgy like a FMF either. Their spark arrestor design is kind of cheap & not really worth $30 but I bought one anyway just in case.
Performance wise on the DS it mostly added bottom end (Where the DS needs more power). It's more fun to ride now out of corners. With the Turf Tamers & HMF it will yank the front wheels much easier. Nothing like my girls 400EX but still suprisely well for a heavy quad.
I've only raced one guy since my tires & exhaust purchase. He was on a 400EX so you know what happened.... but he asked. I'm riding Saturday so hopefully out on the drag strip there are some Raptors & Banshee's to race[img]i/expressions/face-icon-small-wink.gif[/img]
If so, I'll let you know how much of a gain it was.

 

I run an HMF slipon, to answer your questions:

1/ The slip on gives a great power and torque improvement. To get the most out of the unit get it dyno tuned after installation.

2/ if you have a stock bike just go for the slip on and save the bucks on the headers.

3/ It is LOUD. If you have noise issues where you ride then look elsewhere (disc type mufflers). In saying it is loud it is a nice deep bark though.

The HMF is probably the best value for money slip on out there. Myabe some units might have a slight top end power edge, probably at the expense of low end power (this unit is very good in that regard).

kiwi

 

Kiwi,
You really think it's loud? They told me the HMF Db was 96-98. Compare that to a Big Gun race or CT at 100+Db.
What are you comparing it to noise wise? Maybe the Raptor motor breathes deeper & makes the pipe louder though???
All I know is it's better than an Big Gun or FMF on a 400.
Knutz from the Bombardier board had dyno tested disc type mufflers & said he didn't think they were that great. (just his findings) He runs a Big Gun on his DS-760.

 

Kiwi,
I rode my DS this weekend & gave your thoughts another listen. Maybe the HMF is louder than I originally thought. After riding back in the trees and hearing the echo. No it's still not as loud as my friends 400EX with his FMF, It's about the same as my girls Big Gun race, but louder than the Big Gun quiet. Not bad, but not the quietest either. The low end grunt is awesome though.

 

Guys, don't get me wrong I love the sound but it ain't stealthy, guess you can always scare the opposition into making a mistake as your breathe down their necks on a trail.............. hehehehe ......thunder bikes, have to admit I love the sound compared.........

If you are going to the trouble of getting a pipe and rejetting then also get a proflo in there with the big uni filter, this really opens up the beasts breathing and rpm ability. I'd almost recommend the filter first, it's a must for these engines.

What ever you slip on in terms of an exhaust you'll like the power gain.

Kiwi

 

Has anyone seen the HMF full system on ebay? seems like a good deal

 

whipit, the HMF is a great pipe. I got the whole set-up including the DynaJet kit and this thing rocks. It is a bit loud...like thunder rolling by. It's fun when "play-racing" to get up behind someone and just thunder by them with the increased horse-power. Power is great especially in the midrange. For now it is all the power I need for my Raptor. Pipe looks amazing also and is super-light weight.

Brian [img]i/expressions/face-icon-small-smile.gif[/img]

 

hye man what size jets are you using with your raptor setup??? with the hmf? mine is sorta missing in the mid range i have 25 pilot jets, 160 and 165 mains and air screw turned out 3