TC shorty with powerbomb?

[hondarider2006]

Well I was thinking about getting the FMF powerbomb header and trying to shorten it and make it fit my TC shorty. Anyone have it done, or can it not be done??

[NacsMXer]

So if I understand you right, you have the TC shorty on your modified stock header right? And you want to get a better header than the stock one because you don't think it flows as well as an aftermarket one?
The way I see it is, the TC is a super-short silencer mated to a stock diameter header. I would think the backpressure would be similar to an aftermarket header mated to a longer silencer.
If you want more flow, maybe try grinding the welds on the header down. But maybe I don't understand why you want to do this. :confused:

[hondarider2006]

I already have my welds grinded down. I just figured the powerbomb would flow even more over that. I know its universal, and will fit with the stock silencer, so if I cut it down like the stocker, would it be any better than what I have?

[khen]

The powerbomb headers diameter steps down at the end to fit the stock silencer.. if you just cut it down the silencer will no longer fit over it. You would have to cut out a section and reweld the end back on or figure out a way to taper it to the smaller diameter.

I did the powerbomb header at the same time as my exhaust so I'm not sure how much it improved performance by itself.. I know the combo of the two was a big improvement.

[NacsMXer]

Originally posted by hondarider2006
I already have my welds grinded down. I just figured the powerbomb would flow even more over that. I know its universal, and will fit with the stock silencer, so if I cut it down like the stocker, would it be any better than what I have?
If you did get it to work, you would probably gain some midrange to top end power at the sacrifice of some low end power. Opening up your exhaust more would reduce backpressure, and therefore, reduce some torque. You also might gain some HP back in the top end but it might not be noticable. But who's to know unless you compare the two setups on a dyno? I'd try calling Tom at TC and see what he thinks. On the 400EX, I think the TC was designed to accept the stock header for a reason.

[hondarider2006]

Alright thanks for the info guys. Sounds like I will just stick with the stock header for now. Maybe if I can fine a cheap FMF on e-bay or somthing I Will try fabbing somthing up. For now...this set-up works for me:)

[drthrottle]

actually khen I put the calipers on my powerbomb last night and it's the opposite of what you got. it's 1.45 in at the head. 2.0 in at the expansion chamber. 1.60 to the bend. 1.75 behind the bend. 1.90 at the end. that's the same size at the front as the stocker, and steadily increasing all the way to the back

[drthrottle]

when you guys say grind the welds, are you talking about the interior flange to header welds?

[khen]

Originally posted by drthrottle
actually khen I put the calipers on my powerbomb last night and it's the opposite of what you got. it's 1.45 in at the head. 2.0 in at the expansion chamber. 1.60 to the bend. 1.75 behind the bend. 1.90 at the end. that's the same size at the front as the stocker, and steadily increasing all the way to the back Is that on your 450R? My 400ex one steps down smaller at the end, here is a picture of what mine looks like:

http://img.villagephotos.com/p/2004-11/886144/powerbomb.jpg

[drthrottle]

I see they are definately different header pipes. Mine comes w/2" o.d. slip on adapter to match HMF or Titanium 4 slip-on. It took several calls to FMF @ 310.631.4363 to find out exactly what to get and what fits different applications. Yours looks like the one I put on my 440 in 03. Wasn't trying to make you look bad.

[khen]

drthrottle, oh no problem. I got on the internet and saw all the pictures of the powerbomb had straight pipes with no taper. So I had to go out to see if I was losing my mind at a faster pace than normal. :D