Powerbomb downpipe

[MerlinUK]

Hey guys i'm new to the forum. I Just picked up a 03' WR450, and love it to bits, the power is awesome ? It has the FMF pipe fitted, but not the downpipe, can i expect to see a decent gain from fitting the powerbomb downpipe?

Some pics from todays adventures

1

2

3

[pjriss]

By downpipe I assume you mean what we yanks call "header". I noticed some gain with an FMF Powerbomb SX, especially on the low end on my '02 426.

[MerlinUK]

Yeah the header ? Its just listed on fleabay as the powerbomb downpipe Any gain is good

http://cgi.ebay.com/ebaymotors/NEW-FMF-Titanium-PowerBomb-for-Yamaha-YZ-450F-WR-450F_W0QQcmdZViewItemQQcategoryZ35596QQihZ002QQitemZ4620907709QQrdZ1QQsspagenameZWD1V

This the baby?

[clark4131]

There are two types of Powerbomb, the SX and MX versions. SX is supposed to give you more low end, while the MX works the top end. I honestly don't know how much of a difference is between the two, but I went with the SX as the bike's low end is more useful to me...SC

[pjriss]

Yeah the header ? Its just listed on fleabay as the powerbomb downpipe Any gain is good

http://cgi.ebay.com/ebaymotors/NEW-FMF-Titanium-PowerBomb-for-Yamaha-YZ-450F-WR-450F_W0QQcmdZViewItemQQcategoryZ35596QQihZ002QQitemZ4620907709QQrdZ1QQsspagenameZWD1V

This the baby?

Not enough detail in the listing to tell if it's an SX or a MX but it should bolt on. Titanium is way expensive though and only saves a few ounces on a header. I went with stainless.

[MerlinUK]

Thanks for the advice ? I'll look for a sx version me thinks, cheers again for the info guys

[SJMC_DON]

Make sure to get the Stainless Steel one, the TI headers (no matter what brand) are too soft and dent way easier. I have the SX Stainless, I had to go richer on the main after bolting it on but it works great and I actually dropped 2db's after mounting it on!!!

[MerlinUK]

Is there much difference in performance between the Megabomb, and the powerbomb ? ?

[johnnyjeep]

I may be wrong, but I thought I read somewhere that there is a clearance issue with these, or its hard to get to something like the oil filter?

John in Vegas

[Just_a_trail_rider]

I may be wrong, but I thought I read somewhere that there is a clearance issue with these, or its hard to get to something like the oil filter?

John in Vegas

I have the powerbomb with a factory4 pipe. I don't have a problem getting to anything.

[clark4131]

From FMF's site...

The Megabomb

-Well with Sound Restricting Mufflers

-Effectively Reduces Sound Output by as much as 1.5dB

-Less Susceptible to Damage than a Long Header

-Produces Low End of a Long Header and Top End of a Short Header

-Improved Bottom to Mid-Range Power

-Exclusive Ti-Metal Construction

The Powerbomb

The redesigned PowerBomb is a four-stroke header that incorporates FMF’s patented PowerBomb module at a precise location in the initial stage of the header. By positioning this “Bomb” at a key point in the system, increased performance and flow is achieved through the expansion and contraction of exhaust sonics through the system. Result is a flow increase of nearly 10%! The outer chamber in the Powerbomb allows the air to expand, cool and ramp back up at a higher velocity.

Additionally, the PowerBomb is a “pre-muffler” of sorts which helps to lower the bikes sound output by providing more sound absorbing surface area for the sound medium (exhaust gases). On some models, you can choose between a moto or supercross version. The supercross version is designed for more low to mid-range power where the moto version is focused in the mid to upper RPM range.

I didn't see a Megabomb application for the WR listed, but the definitive answer is just a phone call away (310) 631-4FMF (4363)...SC

[RC81]

Anyone ever put one of these on a dyno? If they work so great why dont they come stock? Always wondered about this.

[johnnyjeep]

Anyone ever put one of these on a dyno? If they work so great why dont they come stock? Always wondered about this.

It probably has to do with cost. For that matter, why do they come with the intake/exhaust clogged up, or a throttle that only opens 1/2 way?

[nitronaf]

Anyone ever put one of these on a dyno? If they work so great why dont they come stock? Always wondered about this.

they do come stock on the 06yzf

and most probably on the 07wrf =P

[RC81]

It probably has to do with cost. For that matter, why do they come with the intake/exhaust clogged up, or a throttle that only opens 1/2 way?[/QUO

This is how Yamaha qualifies it for a green sticker.

[johnnyjeep]

This is how Yamaha qualifies it for a green sticker.

yeah, I know. I guess what I was really saying is that companies put on it what will help sales, not what will help the bike.

[clark4131]

they do come stock on the 06yzf

and most probably on the 07wrf =P

Since when ? ?...SC

[nitronaf]

Since when ? ?...SC

since 2006 o_O

https://www.thumpertalk.com/forum/showthread.php?t=306351

edit: oops not in the US, my bad.....all aussie models got it anyways

[clark4131]

edit: oops not in the US, my bad.....all aussie models got it anyways

&%$#@!? Why don't they do that for us? I find it hard to believe that it would have any detrimental effect on emissions, so why the hell not? It's gotta be the greenies...hippie, mother:censored: ?...SC

[RC81]

This is how Yamaha qualifies it for a green sticker.

yeah, I know. I guess what I was really saying is that companies put on it what will help sales, not what will help the bike.

It would seem if it helped like claimed one of the mfrs would put one on. Still would like proof they work not seat of the pants feel. The moto guys run them so maybe there is something to them....or they just like the sponsor money.