D&D Slip-on Canister - A Comprehensive Review

Hi folks,
As promised, here is my review of the D&D carbon slip-on for the '94-97 VFR750F. I'm gonna cover things in a fair amount of detail, to try to answer all the questions that several of you have been asking me. I will attempt (but not promise!!) to be as objective as possible, in order to help those of you who are in the process of making this most agonizing decision about which pipe to purchase for your beloved. ;-)

MY STORY...

After exhaustive research on aftermarket slip-on exhausts, I finally bought a D&D carbon fiber slip-on for my '95 Viffer back around Biketoberfest (mid-October). My goals, in order of priority, were:

1. Unleash some of that wonderful V4 sound!!
2. A bit more power / performance.
3. Appearance (I personally like the look of the carbon fiber cans).

I decided on the D&D because I perceived it to be a *serious* pipe, offering very high quality and good performance at a reasonable price. I was quite impressed by a phone conversation I had with David Dwayne (D&D) Rash, the owner of D&D Performance Enterprises. Dave is a "good 'ole boy" Texan, with such a friendly, down-to-earth manner that he seems at once like an old friend. We talked a long time. He claims to have been making pipes for the past 25 years, and is REALLY enthusiastic about his product. He went on and on about the quality of the materials he uses, about how all his pipes are hand-built, etc.. Talk about a small company -- he only has 9 employees!! When he's not manning the phones, he's in the back, running his dyno. Describing the design of his slip-on for the VFR, he said that he had spent 3 months just experimenting with different canister inlet and outlet tapers in order to get maximum useable power from the design. He claims the slip-on will add approximately 5 hp and 5 lb/ft of torque across the rev range.

PRICE AND AVAILABILITY

I got my local Honda dealer to order the pipe direct from D&D. I paid US $285 plus tax and shipping. Dave Rash offered to sell directly to me for $285 (he'd pick up the shipping), but I decided to give my dealer a little business. Besides, I figured he'd take care of me if there were any problems. Turns out, I should have just bought directly from the company and saved the tax and shipping (see FIT & FINISH below). You can also get the D&D pipes through many of the mail order houses that advertise in the bike rags. The Motorcycle Accessory Warehouse web page lists this slip-on for US $262.95, but wanted $20 to ship it to me. The aluminum can is about $80 less than the carbon.

INSTALLATION

Installing a slip-on on a '94-97 Viffer is REALLY easy, and should take most folks no more than 15 to 20 minutes to accomplish. Just unscrew the bolt from the passenger footpeg hanger, then unscrew the two bolts on the mid-pipe clamp. Remove the clamp and take the old muffler off (be careful not to drop it on your foot, it's heavy!!). Slide the chromed mid-pipe into the inlet end of the slip-on and tighten the supplied clamp loosely. Hang and fasten the new slip-on just like the stock can. One of the nice things about the D&D and its two-piece-w/ clamp design is that while all the fasteners are still loose, you can adjust the angle of the can to your liking. By rotating the mid-pipe, and/or sliding the mid-pipe back or forth in the can, you can vary the angle from almost parallel to the ground, to sharply upswept. When you get it where you want it, just tighten all the clamps and bolts, and it's as solid as a rock. I have mine upswept to an angle that basically parallels the rear bodywork.

FIT & FINISH

The first impression I got when I unpacked and inspected my new pipe was one of sturdiness and quality. Beautiful carbon fiber sleeve, brilliantly chromed mid-pipe, canister end caps, and exhaust tip. All in all, a very attractive package. On the bike, it looks quite different from the stock pipe, in that the can is relatively small, measuring only 16 inches in length (not including the exhaust tip) and 4 inches in diameter, versus 20 x 5 for the stocker.

One thing you have to remember is that these pipes are hand-made. That means that different samples of the same pipe may vary slightly, if only cosmetically. My pipe had one really noticeable cosmetic flaw. The exhaust tip was not rolled evenly all the way around. It had a bit of a twist, or warp, to it (kind of like a lock washer), and there was a messy weld at the bottom of the opening where the two uneven edges met. Though I considered this to be a flaw worth returning the pipe over, I went ahead and installed it on the bike to make sure that I would otherwise be happy with it. After riding around for a couple of weeks, I decided to stick with the D&D, but to return this particular sample because of the aforementioned problem. I called my dealer. He suggested I call the company and deal with them directly (gee, thanks a lot guys!!), so I did. D&D said to send it back and they would check it out. I did so, and enclosed a letter to Dave Rash explaining the problem. They replaced the pipe, no questions asked.

My new pipe looks great. There was one small problem with it, however. The end of the mid-pipe that slips into the can was not perfectly round, but rather slightly oval-shaped. I was able to force it into the can without too much trouble however, and the pressure from the clamp has squeezed it nice 'n round. This one's a keeper.

PERFORMANCE

I honestly didn't expect to gain much power by installing just a slip-on and keeping the stock jetting and air filter. And it was not my intention to fiddle with changing anything else unless I had to. I wanted to keep things simple. Now, I can't be too objective here, cause I've never had the Viffer on a dyno. But let me tell you, I can really FEEL a difference!! The Viffer almost feels like another motorcycle now. Throttle response is a bit more crisp. The engine seems to pull stronger from the bottom up, but I really notice a big difference in the mid-range, particularly between 5 and 6 grand. Though the Viffer always had a healthy mid-range, things didn't used to really get interesting until the tach swung past 6 grand. The power curve feels flatter now. The engine is pulling really strong by 5K now, and I no longer feel a noticeable step up at 6K. I really enjoy running it between 5 and 6K now, where I never did before. And as the revs build, it just keeps getting better and better. Before, I was never really excited by running the bike hard through a few gears (it just wasn't much fun compared to my old CB1100F, or even my old Nighthawk S). Now, it's a real kick!!

Although the bike seems to run great at all engine speeds, I am experiencing just a bit of deceleration popping, so I may end up fiddling with the jetting after all. I'm at sea-level, BTW. FWIW, one of the reps. at D&D recommended setting the fuel screws at 3 turns out, and shimming the stock needles .020 (twenty thousandths). Any comments / opinions from listers with experience in this area would be welcomed.

Weight savings was 8 lbs. over the stock can (4.5 vs. 12.5 lbs.)

SOUND

Oh boy, this is such a subjective thing!! I wish we all had sound meters so that we could exchange some meaningful information!! Oh well, here's my opinion on the D&D: It's FRIGGIN' MEAN SOUNDIN', man!!! Somebody described it as having a "hairy-chested NASCAR sound," which I thought was pretty accurate.

I initially wanted a bassy, mellow sounding pipe much like the Yosh Zyclone with competition baffle (the only other slip-on I've ever heard on a Viffer). Actually, I even wanted something just a bit quieter than that. Well, the D&D is definitely bassy but, IMHO, is anything but mellow!! There is a very slight inlet and outlet taper along one side of the length of the inner tube, but essentially, it is a straight-through design you could roll a golf ball through. I believe that the shortness of the can, along with the straight-through design probably make the D&D one of the louder slip-ons on the market. At idle it is quite a bit louder than the stock pipe, and has a kind of angry growl that is only slightly muted. If you're easy on the throttle, though, it's still neighborhood friendly below 4K. As the revs rise it really howls, but maintains its composure, never getting raspy. Actually, it sounds quite wonderful, and I find that I'm becoming addicted to it! My only wish is that it were just a wee bit quieter....

Yes, it does stay cooler than an aluminum pipe. After a ride, the can is cool enough to grab hold of without getting burned.

SUMMARY

Other than my wish for just a tad less volume, I am very satisfied with the D&D. It's a beautiful pipe, the performance is very pleasing, and the price is definitely right. For those of you with "stock" late model Viffers, I think adding a slip-on is one of the easiest, most effective ways of dressing up and improving your bike. Now I understand what Fred Z. meant when he said something to the effect that he felt something was *missing* with his Viffer until he installed his pipe (full TBR system, BTW). I've never read a review on this list by anyone who was disappointed with the slip-on (or full system, for that matter) they purchased. The bottom line is: do your shopping, pick one out, then go for it. You'll be glad you did.

Gerry Allison
'95 VFR750F

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This article was written by Gerry Allison, a VFR Lister and he has graciously allowed me to post it here.