I know you're all sick of discussing exhausts. But...

To buy or not to buy?

Right now I have a 1999 WR400 with the stock exhaust system. I run it without the baffle which seems to be basically an open pipe. As you all know, it's LOUD! But it runs GREAT!

I also have a Vortip exhaust insert which I hate! Although it is very quiet, it TOTALLY eliminates any low end torque which is what I need most!

Over the weekend, I took a hacksaw to my Vortip thinking that if I cut off the internals, I would be left with a slightly smaller openening than stock with a turned down tip that might just reduce the noise somewhat. I was right! It is still pretty loud but the hacked up internals takes the sharp bite off the exhaust note. It sounds real nice! So, I took my bike and the newly modified (hacked up) Vortip to a test field near my house. Although it is much better than the stock Vortip power wise and sounds great, it still slightly reduces low end torque. I rode with the Vortip, without, with, without and came to that obvious conclusion.

Am I fooling myself here? If I reduce noise with ANY after market pipe, won't I also be doing it at the expense of power? How can this not be?

More restriction = less power = less noise?

If I could have the perfect exhaust it would:

1) Allow me to keep the awesome middle and upper range I have with my WR w/ YZ timing.

2) Give me a little more low end torque.

3) Be slightly quieter than the stock open pipe (about like my modified Vortip would be nice since it takes the edge off the open pipe sound)

Does this pipe exist? Or does it only exist in the land of marketting and magazine adds?

I've considered the White Bros. e-series. But, it seems to me like the disk system, no matter how many disks are in place, would baffle the exhaust and cause blockage. So, I'm guessing it wouldn't run as good as my stock pipe. Plus, I'm not sure if I like the disk type system since it seems to burn plastic side plates.

I've considered the new Big Gun SDS. But, first I can't find anyone that has used it. Second, I'm sure it's about as loud as my stock set up with no way to temporarily quiet it when riding around my neighborhood like I have now. And third, I would think that second head pipe may add some weight?

I'm not convinced that he FMF really adds much performance over stock with open pipes and it's only BARELY quieter than stock (Dougie has one).

The Yoshi pipe seems to be more of a high end booster and that's not what I need.




This is such an exhausting subject!! You can always be like me and bide your time until Dirt Rider does an evaluation on FMF's Power Core IV-2 with the Power Bomb Header. I too require as quiet an exhaust as possible. After pulling my pipe's end cap resulting in an orgasm on the first ten feet I rode (and washing my leathers afterword! :) ), I cannot ride the bike w/ stock exhaust, even though I am forced to. I am just sitting and waiting Pal. It doesn't hurt as much now that we have ten inches of fresh snow on the ground. One week ago, it was 60F, now it's 34F.

Biding my time...biding my time...


[This message has been edited by Kevin in New Hampshire (edited 03-13-2000).]


Unless some magazine does an exhaust test where each exhaust is weighed, dyno'ed and Db's measured you don't really know.

Everybody that buys a product wants to confirm that they made the right decision by telling you that you should buy the pipe they bought. This is just human nature.

With this in mind, I will tell you about my experience with the DSP pipe and tapered header. My first guess is that it is made by Yoshimura, I am not sure if this is true, Moto-Greg mentioned it and it looks very much the same. As a side note Moto-greg uses a e-series (I think) and I had the good fortune to ride with Moto-Greg about 4 weeks ago. He may be able to tell you how loud he thought my pipe was compared to his. Just another opinion

The pipe is a straight through design, no restrictions.

I was pleasantly surpised by the noise level. Maybe I was expecting the worst, but it appears that the pipe is significantly quieter than the stock exhaust without baffle. With no Db meter I will just say that it sounds about 70-80% as loud as stock exhaust without baffle. This is coming from a person that hates most aftermarket exhausts because they are too loud. My 97 YZF1000 still has a stock exhaust and I will keep it that way. I will say that the sound is somewhat a Dr. Jekle and Mr. Hyde sound. I can cruise through the neighborhood quietly if the throttle is used judiciously, but if I wack the throttle, it does have a loud bark. But at idle and low throttle settings it is relatively quite. My personal opinion is that it has a great sound.

Regarding the powerband, torque down low is not a problem. No mater how slow I lug the engine, as long as the motor is still spinning, I can crank on the throttle and the engine barks to life, with globs of torque. (This could be as much a result of my bike being a 2000 model - different carb). There isn't the slightest hint of peaky-ness

Regarding fit and finish and cost. The hole setup cost me $400. I understand the titanium is more costly. The weight savings is huge. The hole unit probably doesn't weigh more than 2 or 3 pounds, header and all. The stock unit is a boat anchor, maybe about 12 pounds, just a guess.

The fit through the frame area is tight since the header diameter is large at that point. Everything clears with one or two mm of clearance in every direction.

The unit I have is a spark arrestor type. This is a plus for me. I can't see the screen causing any reduction in flow. The power pulses literally make a clapping sound on my hand when the motor is idling.

The DSP pipe is the unit that the factory racing team uses.

Would I buy it again, yes. Is there another pipe out there that is as good or better. I am sure that all of the pipes are good quality peices. It is just a question of which one suits you. Did I evaluate any other exhausts before I bought, no.

Hopefully you will have the opportunity to see all of the pipes you are considering side by side and hear them side by side.

Hey if you really get desparate, I have a phone in the garage and can start the bike so you can hear it. Then you can get us all together. Put one of us on call waiting and switch back and forth between different bikes. Just a thought.


Is there somewhere on-line I can check out the DSP exhaust?

I've heard it is mostly for improving top end. But, it sounds like you think it gave improvements all the way through the power band?


Brian, remember the SDS has several tips that are cheap, and modify the noise radically.

I have a 99 WR. I use the tapered head pipe and E-Series silencer from White Bros. It is lighter than stock and much louder. It pulls hard all the way through the RPM range. The best thing about the pipe is the ability to change the oil filter without removing the exhaust.

Clark has tried every available exhaust on his bike andI think was selling what he did not want to keep...check w/him.

Have fun!

I went with the FMF PC IV SA and Hi Flo Moto header based on tests done by Dirtbike magazine specifically for the '99 WR.

The top performer was Big Gun followed by the FMF combo. I went with FMF becuase it was way cheaper. The article had power curves and dBs listed for many pipes.

This reminds me, I was supposed to go to the library and copy them for someone out there. I think you were from Indiana. I'm really sorry. If you still want the info, please let me know and I will see if they still have the back issue.


Dougie, '99 WR400

Mods: YZ timing, Race Tech Suspension, FMF PC IV, FMF Hi FLo Moto, YZ seat, IMS 3.3 tank, One Industries Graphics

The good thing about the E-series disc style is that its tunable. Its basically the same design as a SuperTrapp which has been around for years. Ive used SuperTrapps on all my thumpers over the years and have really liked them. They arent restrictive at all. The thing that always amazed me with Trapps is how much difference a few discs made in power range. When Id run 14 or more discs I had awesome top end but no engine braking or low end grunt. When I ran 8 or less it would be really down on power. The best all around compromise I always ran? 12 was the magic number. I had one on my Suzuki DR370, a couple Yamaha TT500's, a Yamaha TT600, An XR650L...well, you get the idea. The reason I havent put one on the WR is that I believe Yamaha earnestly did their best with a high performance free flowing exhaust stock. If you looked and heard the previously mentioned bikes you'd know how horrendous the exhaust was on them. Huge coffee can style mufflers weighing over ten to twenty pounds. Yeah, Yamaha didnt compromise on the stock pipe this time. Thats why its so loud, its built for high end performance with minimal restriction.

Supposedly, FMF’s new PowerCore Four Squared model comes out this week (4/17/00). They don’t have it on their site yet, but the PowerBomb is there. Be careful, they have a Cold Fusion problem, so here’s the link: http://www.fmfracing.com/y2k/wr400/powerbomb.cfm

Anyone have any input on whether this is marketing fluff or a real step forward in muzzling thumpers?

Doug, I'd love the info, if you still have it around. Fax 303-708-9558


The DSP unit is the way to go. I'm using the non-tapered header with the spark arrested can and I don't think it's any louder than the uncorked stock system, but it makes SICK midrange and top end power. If you want more bottom end, go with the tapered header. For desert and/or MX, the non-tapered unit rips.

About the air box lid removal making a difference or not debate, I was one of those "it won't make a difference" guys until I installed the new exhaust system. I had problems while trying to get my jetting dialed. Way too rich with the recommended jets. John in Long Beach convinced me to remove the lid and the thing turned into a monster. Thanks John!



YZ Timing spec

180 main, 48 pilot, 2.2 turns out

No lid :)

DSP SS Non-Tapered w/ SA

15 tooth c/s sprocket

Pro-Tapers & Scott's Crown

Elevation Range & Average Temp: 3500 - 7000 feet at 75 degrees

Terrain: 60% Desert 40% Mountain Single Track

Range with Stock Fuel Tank: Reserve @ 102 miles

Fun Factor: Off the Scale

I'm looking at the Big Gun SDS but the price is what is holding me back.

The exhaust is $410 + shipping + $96 for the spark arrester. And that still may not be quiet enough so I'd have to add a quieter insert for even more $$. That's well over half what a full exhaust with titanium can cost me for my '98 VFR!

I agree with Ron.

I have the DSP with a tapered header on a 2000wr.

I drove a friends 2000 YZ426 and his bike didn't feel any faster.

Loads of power, and quieter than an FMF PCIV, and quieter than stock without baffle.

The new White Bros "S ?" series looks just like the DSP. Is it the same.


Hey Brian I got 2 weeks on my dsp stainless and its awsome but it is loud good low end wild mid and great top end but loud.

I have the e series with 12 disks and just inserted the quiet core insert because of the decibel level here in Nor Ca. Saturday was the first day on the track and trails with the insert. It is ALOT quieter and a lot less powerful. Just wasnt the same. My WR would hit real hard in third going around the track and now it just rolls. It appeared to me that I got more power out of 4th then 3rd. There are places on the track that 3rd would just rip for me, but I know had to find 4th build up that speed. I am not the best mechanic in the world so I am probably missing something that would help. Any recommendations? Also the ranger that was supposed to be their to test my bike was not. The workers out their said I should pass, "It is the quietest E series they have ever heard" but I could not actually test on the DB reader. I road with John from Granite Bay for the first time. He also has the E series and his power was far better then mine with the quite core insert. Incidently, John can rip on a bike. Blew me away. Good riding John.


Bryan, the answer is so simple it's staring you right in the face. YOU NEED TO MOVE!!! You aren't ever going to make any power riding up there in the clouds :)


'99 WR400

'92 GSXR 7/11

Visit my photo album AT YOUR OWN RISK!! My photo album

Anyone here a sportbike fan also? Then visit us here at www.insanespeed.com

I did a modification to my stock WR muffler that worked well with WR or YZ valve timing. Recently I upgraded to White Brothers "e" series and tapered header for the adjustability and weight savings. The weight objective was a success, but I don't think much was gained with the adjustability. Here is what I did for a cost of $5.00:

1. Buy an automotive 1 3/4"-90 degree exhaust bend. The size is important; it fits perfectly over a sleeve inside the end cap.

2. With the muffler and end cap on the bike, slip the female end into the muffler end cap until it stops, angling the bend down.

3. Through the original insert screw hole in the end cap, drill a small hole into the extension Install a short self tapping sheet metal screw.

4. Using a hacksaw, cut off the new extension to suit your preference of down angle. Cut square to the pipe centerline at the cutting plane. Debur the cut with a file and emery paper. My turndown extended about 3" from the end cap.

5. Seal the extension outer diameter to the muffler cap with black silicone.

6. Raddle-can paint the extension and sealer black. Not required to be heat rated.

This install looked good and did the following for my bike:

A. Provided water protection to the upturned stock cap opening.

B. Significantly lowered the sound level at low throttle.

C. Preserved all the power characteristics of the open WR end cap. This is true for all the "dial in" combinations discussed in this forum.

D. Leaves the spark arrester screen in place.

CGH imports in England do a carbon fibre canned DSP pipe which is slightly larger than the metal one and quieter, it has a spark arrestor and is sound tested at 96dbls.

FWIW, the Big Gun exhaust has changable cores with varying loudness.

From their web site:

Competition core-98-100 db (No power loss) Quiet Core- 96-97 db (No power loss) Super Quiet Core- 93-94 db (Slight power loss with this core)

With the spark arrestor they list the Race Core at 96 db and the Quiet Core at 93 db.

[This message has been edited by JamesD (edited 04-18-2000).]

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