04/05 header pipe worth the $?

[bk111]

I've already got hrc kit and hmf BB slip on. If I added the hmf header would I have noticeable gain and is it worth the $?

[jhtrx250r]

I would say yes off the top of my head, I had the HRC kit on my O5 when I went to a LRD pro 4 full ,I gained a very noticable power increase the head pipe was a larger diameter with a diffrent bend and made a world of diffrence.

[bk111]

Thanks for the post. I wasn't sure if there were noticable gains from the header for the 450. I also have a 400ex and was told not to waste $ on head pipe for the ex. Anyone else have opinions?

[maticus]

in the new atvsport mag hans from hmf said that for an un built engine he said all the power gained through an exhaust is in the slip on it was something like 1-2 more hp with full exhaust over slip on.

[jhtrx250r]

I dont know who told you a header on a 400ex is a waste of time.
but back when I had a 400ex it started out with a white bros slip on , I thought that was ok but then I up graded to a yosi full system and wow it came alive the head pipe makes a bigger diffrence than the end of the pipe or slip on.
all slip on will do is open it up more flow, after market headers are usualy a larger diameter for quicker and greater voluume and flow and usualy have a difrent bend or curve that changes power flow
add a cam to that 400 and you will have a decent runner
my old 400ex with a yoshi full exhaust hot cams stage 2 cam and open air box white bros rev box was as snappy as my 05 450r with the HRC kit befor the full exhaust and it would smoke my girlfriends stock 07 450er

I dont know if you stated what year your 450r is but if its a 04-05 do a full exhaust HRC cam have the carb boared and that will wake it up and keep it reliable jetting is also key on the older 450r's