Exhaust For Yfz

[05yfz]

what does everyone tihnk a good exhaust is for yfz i was considering the new white brothers pipe the e2

With the way that engine produces power and the fact that there really isnt all that much difference between most of the silencers I would have to think its more of a personal prefference or price that should be considered.

I guess what I mean is that every rider I have talked with that has an aftermarker pipe on their YFZ likes whatever pipe they have, and all the mfg's show about the same dyno numbers (who believes those anyhow) so it doesnt look like there is all that much difference.

I think the reason for all this is that most of the silencers for that model seem to be overly free flowing and very loud, and with them not having any real back pressure etc they all do the job well. Maybe there are some that I have not seen that are different but so far thats my take on them (and its basicaly the same deal on the 450r pipes also).

[CronicArt]

I like FMF pipes. No perticular reason. They have been in the game a long time. Lennys right every pipe will make you happy its just personal preferance. If you really want to get technical I would think the best pipe would be a GYT-R pipe. Yamaha makes the motor so they should know what would work best right. Who has more knowledge on thier design but them.

[05yfz]

Originally posted by CronicArt@Oct 22 2004, 06:19 AM
I like FMF pipes. No perticular reason. They have been in the game a long time. Lennys right every pipe will make you happy its just personal preferance. If you really want to get technical I would think the best pipe would be a GYT-R pipe. Yamaha makes the motor so they should know what would work best right. Who has more knowledge on thier design but them.
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[05yfz]

o ok thx

[rpyfz450]

I didn't spend a lot of time deciding on a pipe, but I did wait a good 8 months before deciding to get one. The biggest decision you're probably faced with is, do you want a low rpm improvement or high rpm improvement?

You can expect a low rpm pipe to be more rideable in the woods and faster in a bunch of technical situations like comming out of a turn and gassing it up a hill without switching gears.

The high rpm pipes are probably more noticeble overall though. They should give you better performance on holeshot (drag racing) and flat out top speed (dunes and fire roads).

If you pull the spark arrestor from the stock pipe, remove the airbox lid and re-jet the carburetor accordingly, you'll see a big improvement in performance. I rode my YFZ like this for the 8 months up to the point I bought an LRD pipe (low rpm). Once I switched to the LRD pipe, a noticeable improvement in low end power was restored.

From what I gathered, the LRD is the best low rpm pipe that has a decent muffler and has a spark arrestor and quiet core as an option. There's at least one low rpm pipe that's supposed to have better performance than the LRD, but it's obnoxiously loud and doesn't offer a spark arrestor.

if I were looking at a high end pipe, I would probably start looking at the Curtis Sparks pipe. I believe this pipe has a tapered muffler interior which extends the taper far past most other pipes. I don't know much about 4-stroke pipe design, but I know the added expense of extending the taper into the muffler was likely done for a good reason.

[CronicArt]

Basically when it comes to pipe tuning your looking at torque curve. This can be adjusted with any pipe that offers multiple exhaust tip sizes.

4stroke bikes are very similar to auto engines in theory. The bigger the opening the faster the engine will rev. The faster you get the exhaust out the faster you can get the next intake stroke in. So your end cap opening will determine how you turn on the torque curve. Smaller opening slower curve.

4Stroke usually have plenty of top end. You want a snappy bottom end hit espescially for those Oh crapp situations. Unless you run in the desert top end is not much of an issue.

You can also adjust your hit playing with gearing. For example if you have a 14 tooth front sproket and you go to a 15 you will gain more on top and less on the bottom. A 13 tooth will give you more on the bottom and less on the top.

You first must determine what kind of riding you will be doing most of. If it is trails or track type riding you don't really need top end because you probably will never get to see those rpm ranges being as soon as your on the gas your back off of it.

How often are you really going to be topping out 5th gear. On a 450 not very much. If your hitting 5th then you are going over 70 mph. Where do you need that?

I would start off like rpyfz450 stated and take out the tip on the stock exhaust. That will give you a lot of punch to start with. An after market pipe won't give you too much more than that, but they look and sound cool.

[ridnwarrior]

I second RP450's decision on the LRD.
I chose it for all those reasons plus some of my own.
When I talked with Jason from LRD he was willing to work with me.
I bought my full system from LRD. Headpipe, silencer and
spark arrestor.
Other companies wanted to charge me for every carb jet I needed.
Jason from LRD was like "I'll send you what you need and call us if
it doesn't work" I called them back and with the proper jetting it works great.

All pipes are mostly the same but the customer service is where
you will notice the difference, not in the woods.

[rpyfz450]

Originally posted by rpyfz450@Oct 22 2004, 09:48 AM
From what I gathered, the LRD is the best low rpm pipe that has a decent muffler and has a spark arrestor and quiet core as an option.<div align='right'><{POST_SNAPBACK}>

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One other thing about your exhaust pipe decision...
The LRD pipe uses the stock pipe's heat shield. I'd recommend you give extra consideration to pipes that offer a heat shield.

Just a thought but do any of you guys know of there being any serious differences between the various set ups for the yfz?

RPY's comment on low end v/s top end power was what really go me to thinking about how there are apparantly more obvious differences between pipes and silencers for other machines than the new 450's, or maybe its just that I have not seriously looked into them and am going by the more popular ones I have seen.

Honestly the only one that has not looked like nothing more than a larger headpipe and a hollow canister for a silencer was the DrD and that one was just mostly the shape of the canister being that of a D. It also didnt seem as loud as some others, but thats about it on being different.

So what ones produce different power curves and why?