White Bros E-series Carbon Fiber-Ti tapered header test
Posted June 29, 2000 - 05:45 AM
It is an E-series carbon fiber pro meg exhaust with a titanium tapered header. Clarks opinion was that the pro meg exhaust would help the WR400 top end and the tapered header would help the bottom end (as it is known to do). I now agree with this theory but more on that later.
After removing my old stock WR400 exhaust and header and comparing the weight between the two units, I was blown away on how light the White Bros felt. The Ti header is as light as a feather! I don't have a good scale at home. Just a people scale. So I held the stock unit and header and stood on the scale, then I held the new system and stood on the scale. There is a 4 to 4.5 pound difference between the two. At first I was disappointed by this difference. But then I stood on the scale without either exhaust. The stock exhaust weighs between 10 and 11 pounds. That's at least a 35% - 40% weight savings over the stock exhaust! Too bad the disks aren't titanium, that would save a lot more weight since they are so heavy.
Note: The unit tested in Dirt Bike was not the carbon fiber exhaust. I'm not sure how much more the aluminum version weighs.
After installing the new unit, I was also impressed on how well the header was tucked in under the radiator. I've seen other after market exhausts on the WR400 and the header sticks out quite a ways where it is vulnerable to diggers and causes burns on the riders boot.
Time to ride. I loaded up the WBE (White Brothers E-series) with 8 disks. This is probably less than I would normally ride but I wanted to compare performance on a quieter exhaust to my old stocker. At idle with 8 disks it is a lot quieter than the stock system with no baffle. It has a very nice but throaty exhaust note. When revved, it certainly gets louder. But I still think it is quieter than stock and it doesn't have that loud echoing booming sound as the stock system. I rode to a local field with straights and turns and a few fun jumps. When I punched the throttle in 3rd gear at low speed, it seemed to be a bit torquier than stock (I'm running a 52 tooth rear sprocket). However, I could feel a loss in the mid and top end. This isn't all bad news though. This might be a good setup for tight twisty forest trails. Its a very smooth power band with more torque on the bottom and quite a bit quieter than the stock no baffle setup.
Next I pulled over and installed all the disks I could cram into that sucker. I ended up getting 15 disks to fit. I could have done one more but didn't want to risk not having enough purchase on the threads that hold the disks in. I was already running longer bolts for this setup. I started the bike and noticed that it now sounded like the stock exhaust with no baffle. At idle and while revved. I don't know if it's any louder or not. But it certainly isn't quieter. I thought it might be a little louder but then realized that the sound isn't going out the back like the stock exhaust, but rather out the sides. So it might just seem a little louder. Some friends I met later (XR riders that hate loud Wr's) thought it was about the same as the annoying stock system with no baffle.
Now time to ride it. It was actually pretty strange. When I got on the gas, I noticed the power was a LOT smoother than the stocker. And I think it revs quicker to red line. The first time I gunned it, I was already going along at a good clip and I waited for the big 'hit' that I got from the stock pipe and it never came. However, when I came to a stop and then accelerated aggressively a few times, all my concerns went out the window. I don't know how or why, but with the new pipe the bike seems to accelerate better and hook up better in the dirt than with the stock pipe. In third gear in loose dirt with the stock pipe, the low end wasn't enough to wheelie (remember I'm riding at 6000 feet minimum) and when I got the mid range hit, the rear tire would just spin. But with this new WBE, when I crack the throttle at any low or mid rpm range in third gear, the wheel hooks up and the front end lofts easily. This is without leaning back on the seat, popping the clutch, or any other cheating.
Tell me if I'm full of crap here but what I think this is telling me is that the pipe is giving my more low end torque and smoothing out the power band to make the power more useable and the bike more tractable throughout its range. Plus the bike revving a little quicker helps compound those new traits. I absolutely loved it. It RIPS! And the upper end seems to be about the same or maybe a little revvier.
I can't wait to try it out on a real trail.
Posted June 29, 2000 - 06:12 AM
98WR WRtiming,Fineline sus;Scotts clamp and stabilizer,Pro-tapers,Pacemaker3,IMS 3.3,4.0,YZ seat,IMS pegs,Devol guards,YZ plastic,TM Designs chain slider,Factory Effex,Driven DS kit (sometimes)
Posted June 29, 2000 - 09:34 PM
Watch the CArbon Fibre pipe..
There was quite a few failures with the orginal ones..
The alloy mounting bracket on the back was only rivited (I think) on the early ones.
They pulled through.
White Bros replaced them due to a defect.. and then started building them with a plate inside the pipe that stopped the rivits pulling through.
Have a chat to Whitebros if you have any probs in the future.
**Ride it like you Stole it!**
Vist the Rubber Chicken Racing Online Shop
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Posted July 06, 2000 - 05:24 PM
Sounds like you performance experience was about the same as mine with 15 disks the WBE hauls timber and it does improve top end and low end torque as you described. Its hard to see these things on a dyno chart because they are running at WOT and a dyno cannot describe the type of throttle reponse between RPMs as you open the throttle. Sounds like another satisfied customer.
I recommend you purchse some the stainless steel rivits from White Brothers and repack the muffler every 3 months using the long stringey Silent Sport packing material, as it out lasts regular fiberglass packing about 3 to 1. You want to remove the end with the disks when repacking. If you need help call me and I will work you through the process you must be very carful not to damage the carbon fiber CAN.
Posted July 06, 2000 - 06:03 PM
I really liked the pipe at high altitude. The smoother response and increased low end helped my on the narly technical stuff at 13000 feet. I could still throttle wheelie in third gear and that surprised me. That's where I need the extra power the most and it came through for me.
My DRZ friend that always complains about my overly loud WR said that at idle and low throttle, the WB with 15 disks and tapered header is quieter than stock with no baffle.
But he thinks (and I agree) that at full throttle, it is a little louder.
I dread having to pull off those rivets. Too bad it's not a little easier to access. I see that WB offeres rivet sets for that pipe. I saw it in a magazine add somewhere. I'll probably have to do that right before Moab in October.