WR Exhaust imput requested

Hi All,

I have a 02 WR426, currently have uncorked stock exhaust and am looking to go aftermarket. I am specifically trying to improve the low to mid end power band. I have heard that the "BIG GUN" race series exhaust would be a good move, but I am not familiar with them. Anyone have experience with this exhaust or any other that maybe give the results I'm looking for?

Thanks for the help,


Starting with an FMF Powerbomb SX header would be a good way to improve low to mid range punch. It'll fit your stock muffler or you can add one of FMF 's (or other) muffler of your choice. A louder, less restrictive muffler will improve top end power, while sacrificing some low end grunt.

I'm not sure about the BIG GUN...I heard it's on the cheap and flimsy side.

I just received my White Bros E series pipe for my WR 400. I had the stock but snapped it so I bought the E to replace. I haven't bolted it on yet but it looks like quality workmanship and it's a lot lighter. It also has a stackable disc system like the old Supertrap systems so you can tune it to your liking, although the note with the pipe says that their race team have found that running it open with no discs gave the best results, and it's a bit lighter.

I have the FMF Powercore IV (with S/A) on my '02. Love it. Have been sound tested twice, both times at 96db which kind of surprised me, I thought it might be louder. The bike pulls solid from idle all the way up, and sounds great while doing it. I have smacked the pipe around for almost three years now, and the only problem I had was when the 3 rivets holding the endcap on broke, and I blew the end cap off. No biggie though, I repacked it (time anyway) and put it back together with better rivits. Good as new. The new ones don't use the rivits anymore, they are bolted. :)

I wouldn't hesitate to buy this pipe again.

Thanks for the ideas. I ended up going with the FMF powerbomb header and Q. Waiting for the shipment.

Thanks again!

It must've been a bad Monday morning when the guy at the FMF plant put my Powercore IV together. Sucker's about 104db. I could almost break 100 at idle. Maybe the guy's meter was wrong at the unsaid race I was at a couple weeks ago. He let me go through anyways, :thumbsup:, but dang, might not always get that chance.

Anybody else see these high of numbers on their Powercore IV?

mine was recently tested at 101 at a local poker run, they allowed me partcipate thankfully. I bought a quiet core for it which made it a lot quieter (probably closer to 90 or 92db)but at a cost in loss of performance. I will use when I have to, otherwise leave it out.Anyone have any ideas on how to make this unit a little quieter without killing performance, I would love to hear about it.

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