what is the best pipe for a stock 400ex.most horsepower and performance.

 

There are a million posts on this subject, just check the recent posts of the last few weeks and you will find many opinions. DMC and WB are favorites, I personally think 4 stroke pipes are a little overhyped for the cost and the gains they give compared to the noise.

 

DMC

 

DMC

 

Are the DMC and duncan Racing double barrel exhaust the same? They sure look like it. The new white bros. R series looks like a polished Pro-circuit pipe too.

Before my 400 I had a 300ex I put on an FMF mega max and jet kit couldn't tell much difference not for the money. Biggest bang for the buck is drop a tooth on your front sprocket. This makes your engine turn more rpm at the same speed, more rpm more power, up to a point. It will slow your top end speed down a little but I never rode 60 mph in the woods or climbing hills

 

The DMC and Duncan Double Barrel are the same pipes. The difference is the DMC has a stainless steel headpipe and the Duncan has a chrome plated steel headpipe. You gain alot more power with a piston and cam than you do the pipe, but if your going to really modify it and get the most out of the bike, sooner or later you will need a hi flowing pipe.