400ex Modification (pipe/intake)

[FoxProRacing]

My 400ex is stock for now but I have a White Brother R4 slip-on that I want to put on my ex.I want to know if Wb R4 is a good pipe for a 400ex?

I want to put a dynojet kit,Uni Filter and open box,do you think that I will see a difference between this mods and stock?How Hp do you think that I will have with this mods?

And finaly,do you think that with all this mods,I will be correct with the jetting that Dynojet instruction say? (main jet?)

Thanks

[zlam27]

the R-4 isnt the highest HP pipe but it will wake it up some. also, you will notice a nice boost with an aftermarket intake setup and an open airbox.

i dont know dynojet jetting very well but i would start with what they say and then go from there. most people on here will say get rid of the jet kit and just buy the keihn jets from the dealer because they are easier to work with and everyone knows the sizes.

all in all, you will be happy with the outcome of what you are doing. should add probably 2 or 3 HP (not gonna get much more out of a stock motored 400). good luck.

zach

[FoxProRacing]

thanks to answer me

A yoshimura off road slip-on is better for a 400ex then WbR4?