which should i get if im gonna also drill holes in my airbox and put filterd plugs in the holes.... i want to get and improvement on bottom, mid and top end if possible.... thanx
these three pipes (yoshi, dmc, and wb) are the three im interested in.... please reply

 

My WB R4 is a straight through pipe, I think Yosh are to, which will help with any future mods. Allows more air to pump through the engine. WB dyno sheet that came with pipe claimed little under 2 hp gain over stock. Don't know about the other two. I do know that Big Gun will kill top end.

 

The yoshi system is restricting on any built engine, but it works fine on a stock bike. The WhiteBros. Promeg and the DMC are the best pipes you could get for your 400, they flow awesome on stock bikes and even full race ones. I like the DMC because of the looks, but they perform so closely. If you want a little bit more top end get the DMC, but the WB is not far behind in that department.

 

I have the yosimura on my 2001 400ex....It put out more hp and more torque than the dmc did ....
And i like the look better ......
But everyone has there opinions ..Also the yosh was cheaper than the dmc......

 

Get the DMC and remove your airbox lid. She'll go.

 

DMC,airbox lid removed (if you don't ride in alota water),K&N filter,and dyno jet kit. the DMC is good witha stock motor but it gets even better with motor mods......

 

AMMEN!!

 

Email Gabe about the small holes in the airbox. He has a nice mod that works alot better. he'll send you some pics. it works great and still filters better than the 1" drilled holes with the paper filters. As far as exhausts. It's your own pref. Any of the exhausts will work. IF you like how the dmc looks, then buy it. If you just want a straight thru design, go for the Yosh., if your after a tunable disc system then buy the WB. Each of the pipes you've narrowed it down too are miles apart in design. I'd look at it some more. Check out GTthunder, they've got some dyno runs and comments on pipes for the 400ex. Go to dealers also. Sometimes you can find a 400ex sitting in a dealer with the pipe already on it. Take it for a ride, listen to it. See how it has held up. Good luck

Jim

 

Just a DMC pipe and correct jetting will give you another 5mph on top-end. The DMC gives you gains all the way through the powerband. My dealer has a 400ex with a Pro Circuit pipe and he rides with like 7 other 400EXs that all have different brands of pipes, and he told me that the DMC 400EX was the fastest. I never raced piped 400EX when i just had my pipe on, but i raced my friends stock 400EX(after we adjusted his throttle to open up all the way) and blew him away.

 

I have a really neat muffler/pipe on mine. It has great torque and is quiet as hell. Didn't require any rejetting either. It also has a chrome tip and it comes free of charge with every 400ex sold. HeHe