replacing the 08 exhaust

[Dirtbiker05]

http://www.fmfracing.com/products/catalog.aspx?CategoryID=281 does anyone have any experience with this exhaust system?? im looking at replacing my 08's to try and open it up a bit. could i get away with just using a slip on and still find an increase in performance? thanks.

[KJ790]

I highly recommend that exhaust. I have run it with the stock header, powerbomb header, and megabomb header. The slip on alone yields a large increase in power across the RPM range. For me I prefer the powerbomb combined with the factory 4.1 silencer on my 450. I am running the megabomb factory 4.1 combo on my 250F.

[Dirtbiker05]

thanks KJ790. is there a big increase in power when u installed the 4.1 muffler and powerbomb header? is this the best exhaust system out there for the 08 in your opinion? thanks for the help, Dirtbiker05.

[KJ790]

Yes, there is a big power increase with the factory 4.1 powerbomb combo. I personally feel it is the best pipe combo out there, but Dr. D and white brothers also make very good pipes for the YZ450F. In my opinion you can't go wrong with any of these pipes.

[grayracer513]

Let say here and now that there is no best exhaust, per se, for any bike. There may be a best for your bike, but what that is is going to depend on a set of criteria completely unique to you.

Having said that, Let me now say that in the case of the '08, the stock rxhaust is so restrictive to low end power that almost anything will produce a remarkable increase. Even the stock exhaust from an '06 or '07 will snap up the low end considerably compared with stock.

A good full system on an '08 will not yield much in terms of peak power gains at all; no more than one more at peak at the most. Where the boost will come is from 4000 to 8000 rpm. In that range, you can expect to gain as much as 7hp or more at different points along the curve.

FMF systems are good, light, well made, well supported products. But they are pricey, and the "bomb" headers are a concept that is designed to widen the power curve. The YZ450 from '06 on does not really need this as much as earlier models, because the engine has one of the widest power curves around as it is. To ride yours now, you'd disagree, but you're looking at your bike with the stock exhaust on it. The Factory 4.1 will work, but so will the DRD stainless system that costs just over half as much, or any number of other choices.

[KJ790]

Well said Gray. The "best" pipe comes down to how you ride, but as Gray mentioned, pretty much anything is better than stock on the 08 YZ450F. FMF pipes are a bit pricey, but not twice as much as Dr. D. A Dr. D stainless retails for $549.95 and an FMF stainless powerbomb with a factory 4.1 with stainless midpipe is $579.99, so there is only a $30 difference. If you get any of the pipes that I mentioned before you will most likely be very happy.

[Ga426owner]

A buddy of mine had one of the brand new GYTR full systems on his 08 last weekend. It is the header that has the PowerCan mounted on the header aka FMF/Arapovic etc...He told me the power is just incredible that this pipe makes and it was quite compared to others. The length of the cannister is very similar to the stock 08 pipe length.

Bottomline...any aftermkt is better than the stock 08 pipe and there a a bunch of choices out there:thumbsup:

[grayracer513]

an FMF stainless powerbomb with a factory 4.1 with stainless midpipe is $579.99,

They're finally offering them in stainless, eh? Didn't used to, That's the difference. The original Ti4/F4's were all ti, and around $7-800

[DPW]

A buddy of mine had one of the brand new GYTR full systems on his 08 last weekend.

Part #?

This one??

[Ga426owner]

Part #?

This one??

yep that is the one - he luvs it

[grayracer513]

A different take on the principal used in the FMF 'Bomb headers.

[DPW]

hmmm...where is the best place to buy GYTR parts online..just thinkin ;-)

[Ga426owner]

yes it is similar the the power bomb and the Arapovic Pro pipe GL and Reed use. There is a can under that CF cover. A rather large can that is....

I did not ride the bike with it but the owner has used other aftermkt pipes said the power is phenominal using this GYTR....whatever this means

[wolfie12]

Has anyone had any experience with Two Brothers Exhausts?

[bnyfe]

Has anyone had any experience with Two Brothers Exhausts?

The Two Brothers complete exhaust for the 08 YZ450F rocks! I got a full Ti system off ebay for 365.00 shipping included because Two bros. is not going to offer the Ti system anymore. A full 7.1 HP increase @ 5600 rpm. Here's the Dyno Sheet.

http://www.twobros.com/cgi-bin/shopper?search=action&keywords=07_yz450F_full&searchstart=0&template=Templates/TBRSearchResult-Simple-Yam-YZ450F-FULL_07.html

click on dyno to see results....

[DPW]

yep that is the one - he luvs it

can you get a picture of the exhaust on the bike? I've searched high and low and can not find a picture of that exhaust mounted on a bike.

[angellmxer]

The 08 header is already Ti and came stock with a larger diameter hi-flow design to try and compensate for their restrictive silencer. I bet by just adding a new silencer, you would gain 99% of what any new full system will accomplish.

I love my 08 stock exhaust, but I will be dissecting it soon to try and remove one or two of the internal cones. I want to keep that hot new “shorty” look.

[grayracer513]

The larger header diameter is a compensation for the shorter overall length, and a design concession to the bias toward top end power.

I think the 99.9% estimate is out of line, but very nearly any freer-flowing muffler would alleviate most of the soft spot the engine has between 4000-6500, which is the source of most of the complaints about the '08's performance. A truly good system could be capable of adding to the peak power as well, where many of the simpler solutions don't do that.

[wolfie12]

The 08 header is already Ti and came stock with a larger diameter hi-flow design to try and compensate for their restrictive silencer. I bet by just adding a new silencer, you would gain 99% of what any new full system will accomplish.

I love my 08 stock exhaust, but I will be dissecting it soon to try and remove one or two of the internal cones. I want to keep that hot new “shorty” look.

I like your rationale, and was thinking about the same thing, for the same reasons.

[rickallen124]

yes it is similar the the power bomb and the Arapovic Pro pipe GL and Reed use. There is a can under that CF cover. A rather large can that is....

I did not ride the bike with it but the owner has used other aftermkt pipes said the power is phenominal using this GYTR....whatever this means

I'm sure that akrapovic makes the gyt-r pipe just like muzzy made them the past few years. It looks identical to the akrapovic, just re-badg.