(click photos to enlarge)

 
We bought our 2008 Suzuki DRZ400SM project bike used, with a pretty ratty Supertrapp exhaust installed on it, so the bike was in dire need of a new exhaust system. We recently installed our Yoshimura RS-2 Performance Package, which consists of the full Yoshimura RS-2 exhaust system, a Dynojet Jet Kit, and No Toil Air Filter. We also did the 3×3 airbox mod commonly done on these bikes. After installation, we had the carburetor jetted at a local race shop (MPH Ohio) using the Dynojet Jet Kit. They did dyno runs before they installed the jet kit, and then again afterwards (see dyno chart below).

Review:
These simple mods made a huge difference in the bikes overall performance. The Yoshi exhaust system sounds and looks much better than the stock exhaust system, and the entire Yoshi Performance package has made the bike way more fun to ride. The bike pulls much harder than it did before, and the powerband feels more linear. The sound of the RS-2 exhaust is excellent… it’s just the right noise level in my opinion and not too loud like some exhaust systems can be.

Dyno Results:

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We didn’t have a stock exhaust system to do base runs with, so I pulled some info published by Motorcyclist Magazine for a stock DRZ400SM. Here are some actual numbers comparing a stock DRZ400SM to our DRZ400SM Project Bike after it was dyno tuned…

Stock 2008 Suzuki DRZ400SM (According to Motorcyclist Magazine)
Max horsepower: 32.5 bhp @ 7850 rpm
Max torque: 23.9 lb.-ft. @ 6750 rpm

Our 2008 Suzuki DRZ400SM Project Bike (without Dynojet Jet Kit)
– SRmoto.com Yoshimura RS-2 Performance Package
– 3×3 Airbox Mod
– Carburetor NOT re-jetted
Max horsepower: 34.01 bhp @ 7200 rpm
Max torque: 24.41 lb.-ft. @ 6400 rpm

Our 2008 Suzuki DRZ400SM Project Bike (with Dynojet Jet Kit)
– SRmoto.com Yoshimura RS-2 Performance Package
– 3×3 Airbox Mod
– Carburetor re-jetted with Dynojet Jet Kit
Max horsepower: 36.27 bhp @ 7200 rpm
Max torque: 28.57 lb.-ft. @ 5800 rpm

The results above show the importance of properly jetting the carburetor with the Dynojet Jet Kit. Without it, the bike ran poorly, and as you can see from the results (and the dyno chart above), we weren’t maximizing performance gains from the Yoshi exhaust, No Toil air filter, and 3×3 airbox mod.

Overall We are very pleased with these results considering how simple these modifications were to do to the bike. An increase of about 4 hp and 4.5 lb-ft of torque is pretty impressive and can definitely be felt. Our DRZ400SM is now much more fun to ride, and it finally sounds like a REAL motorcycle. We couldn’t be happier!

If you have a Suzuki DRZ400S Dual Sport or DRZ400SM Supermoto and are looking to improve its performance and sound, our Yoshimura RS-2 Performance Package is just a few clicks away…

Where To Buy:
– Suzuki DRZ400S/SM Yoshimura RS-2 Aluminum Package at SRmoto
– Suzuki DRZ400S/SM Yoshimura RS-2 Carbon Package at SRmoto