I've got a 2004 400EX and I've got a few questions. If I get a WB E-Series slip-on silencer would I get more performance with a header on it?What kind of pefrormance? Could I put the slip-on my stock header? If I got the WB E-Series slip-on could I put on a header later?Could I put on a WB E-Series slip-on and put on a FMF powerbomb header with it? Would a FMF Powerbomb or a WB header be better? Thankyou very much[img]i/expressions/face-icon-small-smile.gif[/img]

 

im not totally sure about the powerbomb mixing with the white bros silencer or vis versa, i seriously doubt it, but you can purchase a silencer a white bros silencer and get the header later

 

the power bomb will fit any SLIP-ON silencer. however, a silencer made for the white brothers header won't fit on to the powerbomb header.

 

so the slip-on is the same width as the full system?

 

For a basically stock engine you would be better with just the slip on silencer (brand of your preference) and the stock header.

From my personal experiences and talking with many engine builders the 400 doesnt see any real increases from a larger header unless its a big bore with lots of internal mods (porting, valves, cam etc) and then the advantage is debatable except for the higher rpms where this engine isnt really known to make tons of power anyhow.

Some builders like TC Racing even prefer to run the stock header on the higher hp big bore engines as it has shown to create better better bottom end power than the aftermarket headers.

So I cant tell you what to do etc but it seems that a lot of the stuff many of us have been brain washed into thinking are enhancing performance may only be lightening our pockets.

And for the record my 440 runs sweet with the stock header (modified) and a silencer so maybe tc is on to something, and I would have spent over twice the price for a complete system.