what's the perfect pipe?

How do you ever go about choosing the right pipe for the wr426? there is too many choices and all claim to be the best for 4-strokes. Has there ever been a test? The decision is the only thing keeping me from buying.

pro circuit t-4 LOUD-powerful-$370-pretty light-mostly upper rpm power with large dia. endcap.

I really like my YZF pipe, wide powerband, and fits awesome. No huge bulge. Not to mention the MX'ers are alway's selling them for very reasonable. $125-$150 for comp sys.


The WB e series is quieter than stock and tunable. Haven't messed with the disks yet. I used to have a set of Supertrapps on my old street bike and I loved them.

Dan :)

In the last 2 months one of the Dirt Bike Mags ran a pipe article. I see most of the riders on this forum like the White Bros with 12 dics. I chose the DSP because Yahmaha factory racing uses it. If you change the complete system you will notice the improvement especially if you take advantage of the new jetting options you will have.

Latest DirtBike Magazine has a positive article on the new FMF Q pipe. It's a quiet pipe for woods type riding, but definately boosts power significantly.

I have a white bros. tapered head pipe and a pro meg w/6 discs and spark arrestor on my yz'd wr. This system is real loud, it's always the loudest bike in the bunch. With the spark arrestor out the sound is unbearable. I really like the mid-to-upper hit the bike has once I got used to it. I ride everything from tight woods to big motorcross tracks, but mostly in the woods.

I have the White Brothers E-series with the WB header. I have been running it with 7 disk. Before that I ran with 12. It totally shreds. The only problem is that I ride a lot in the woods where noise is an issue. I can quiet it down by removing disk but that seems to affect performance quite a bit. I have been considering going to the FMF Q. I have the Big Gun with the quiet core on my DR but they are more expensive and I'm not convinced worth the extra money. After I try the FMF Q I will be able to make a better comparison. Performance wise they will both be judged by the WB. Which so far has been the best except that its too loud. P


Right now I am running with 7 disks and it is much more quiet than my friends 02 WR426. He has the stock pipe. Now that I have done the BK mod I will try messing with the number of disks but I like more low to mid power than high. I do mostly trail riding. I am not sure about the quiet core, I bought the bike used.


[ February 06, 2002: Message edited by: Dan Lawrence ]

Hey Dan, How many disks are you running to make the E-series quieter than stock? Mine with 12 disks is way louder than my stock yzf pipe? Do you have the quiet-core?


I have a WB E series with the quiet core and a FMF power bomb (also I have a FMF megamax 2, not much different, just larger)

The quiet core does change the tone of the BBBBRRRAAAPPPPPP!!

My grandma says its quieter.. ( Q core w/ 10 discs, VS 8 discs and NO core) just about the same power..VERY CLOSE. it sounds a little more throaty.. deeper, less scream, more bark.

I like it.. just switched back, after a full comparison with the FMF mega max for the last 6 months.

So- in conclusion... the Quiet core lowers the db

level a little, with the same discs. (minor power drain)

Q core + a few discs = same power, and delivery... deeper, less ear piercing shreak


have fun playing in the mud!!

Thanks for the info guys. When I ride I'm usually on a track, but once a year we go to Oregon Dunes where they have a sound limit of 93db. Yea right! I think I'll try the quiet core and a few less disks, but I like the top end in the sand.


Has anyone tried the FMF 17" Titanium 4? Also, Crazyadam, does the power bomb header really act like a second muffler, making the bike somewhat quieter? And does the Power Bomb really make a difference in power compared to the stock header?

Thanks for any info you can offer.


The Power bomb is nice... noise levels are tuff.. I would say it adds life to the low- mid, and has a slight muffling effect. like the quiet core, it makes the tone a little deeper, with could be quieter.. or less abusive to the ear drum.

:D then the fine line of how many more discs until the effects of the core are nill. :D

I live in the woods (200 acres woods, 3/4 mile from the nearest road, 2 minute 4-wheeler ride to the cabin from my truck) that my Grandfather bought in the 50's, and grandma is strict.. NO 2 STROKES! She will hop on her 230E Suzuki (Shes 80!!) and chase down 2 smokers... "Please Be Quiet, or leave." And with the Power Bomb & quiet core (10 discs, good power) she will come out and watch me ride! Instead of just plugging her ears and screaming!

So it works for me!!!

Granny says..."thats not nearlly as bad as the yellow one!" (stock RM 125) :)

[ February 08, 2002: Message edited by: crazyadam ]

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now