I have posted about this situation several times, but no one seems to take me seriously. First off we own two identicle 2002 Vipers both with TPI's, 1.25" Camo tracks and Heavy Hitter clutch kits. I have tried the SLP, the Bender and the MBRP all on my Viper while leaving the other Viper untouched. All three silencers lost power. You could feel it in the seat of the pants and the rpm's dropped. That alone tells you something when the R's drop. With any of these silencers on, my sled lost 5-7 lengths in an 800-1000' drag race. When the stock silencer goes back on ,they are almost dead even. We own a heated shop with a drag strip right outside. We have owned 22 Yamaha's since 1982 and have alot of experience tuning them, so I am not "BS"ing here.
I do own another stock Viper silencer and for the heck of it I opened it up with a plasma cutter to see what's inside. If I get a chance ,I'll post a photo, but there wasn't much I could do in terms of trying to mod it. Obviously the baffles in the pipe itself is what is doing alot of the quieting of the engine. I would like a nicer triple sound too like the 700 SX motor had, but I am not willing to give up that much performance. If Power inc. still existed, now maybe they could achieve making one without losing power. As many know ,you need to keep a certain amount of backpressure and get the correct bounce back into the pipe to get the proper recharge effect on a 2-stroke motor. I personally think the baffles in the pipe have a different effect on the Viper than most sleds. I have had silencers on the 700SX and the 600 SX and never experienced power losses such as this.
