Exhaust inserts



36 replies to this topic
  • SmallMonkey

Posted September 19, 2005 - 10:12 AM

#21

I just got the PMB insert....it actually made my bike run BETTER than uncorked.
It's nice and quiet too :banghead:

  • bg10459

Posted September 19, 2005 - 10:40 AM

#22

Originally Posted by bg10459
You should get louder and more power with the insert than with the stock baffle, but quieter and less power than completely uncorked.

This is not correct, the noise is more of a placebo effect and does not make the bike any faster or have more HP (If tuned incorrectly, it may have less). Read the June 05 issue of Dirt Rider magazine, and they will cover that. All of the inserts will be an inprovement, some are just better than others. :banghead:


First, let me say I never intended to correlate the power output to the sound output, BUT, (PMB, please answer this for me)

1 - Can one expect a louder exhaust with an insert (PMB or other) than with the stock baffle?
2 - Can one expect a quieter exhaust with the an insert than with the completely uncorked stock muffler?
3 - Can one expect less restriction on the exhaust with an insert than with the stock baffle?
4 - Can one expect more restriction on the exhaust with an insert than with the completely uncorked stock muffler?

The answer to all of these questions is yes. With regard to the last 2, less restriction means the engine is capable of "breathing" more air, which means it is capable of creating more power. (of course assuming properly tuned in each case). With the stock WR muffler, you will be able to get the most power if it is completely uncorked (and tuned for it, i.e. carb, airbox, etc.), simply because it creates the least restriction.
That all said, the differences may be negligible.
Someone please show me dyno results to the contrary and I'll shut up.

  • 96warrior

Posted September 20, 2005 - 10:47 PM

#23

Is the differences in the inserts really that noticable? Like if you already have one?

When the fmf q 2 proves to be reliable and pass the michigan sound test, I will probrably get one of those. :banghead:

  • foxtailleader

Posted September 21, 2005 - 04:20 AM

#24

I got the Pro Moto Billet insert after the stock part broke at the nut plate.

The bolt fell out of mine but it happened in a slow section so I went back and found it. Lock-tight on the threads and it's staying put.

  • hankdog

Posted September 21, 2005 - 12:13 PM

#25

less restriction means the engine is capable of "breathing" more air, which means it is capable of creating more power.



In a modern 4-stroke engine this is not necessesarily true...there are lots of complex things going on like scavenging and pressure wave reflections. For a given length of exhaust, less restriction does not always result in more power. I'd like to see the dyno curves also, as I've got a brand new stock WR and currently contemplating what mods make sense, and which don't.

  • Joe Reitman

Posted September 21, 2005 - 01:23 PM

#26

Sorry, quietiscool, thanks :banghead:


Forget #, will see if I have packaging. If not, try quietproducts@cox.net

  • bg10459

Posted September 21, 2005 - 01:37 PM

#27

Maybe Radrick will re-post what got deleted last night. The basic jist was, as you say, 4 strokes benefit more from a tuned exhaust than simply the highest flowing exhaust. Bikes with the inserts made better power at lower and mid RPM's, but the open exhaust made the most power at or nearing redline, which is what I meant by capable. Maybe more beneficial though, is the sound reduction that the inserts provide, while maintaining high performance.

In my deleted post, I conceded to the fact that my statements were generalized and over-simplified.

As far as which mods make sense and which don't, an insert will provide a power increase over stock while remaining relatively quiet. However, if power is your main concern and sound is not, there are better options available, just more costly. In my opinion, the free mods are a must. Combined with jetting and exhaust (I went with a YZ pipe) the bike has plenty of power for me...at least for now :banghead: .

  • RADRick

Posted September 22, 2005 - 12:21 PM

#28

Maybe Radrick will re-post what got deleted last night.

I wish I could, but it appears to be lost in the ether. :applause:

The basic jist was, as you say, 4 strokes benefit more from a tuned exhaust than simply the highest flowing exhaust. Bikes with the inserts made better power at lower and mid RPM's, but the open exhaust made the most power at or nearing redline, which is what I meant by capable. Maybe more beneficial though, is the sound reduction that the inserts provide, while maintaining high performance.

Fairly accurate representation, thank you, although the performance gains of an insert over stock are not trivial. The stock system is just so poorly designed on so many levels. It's amazing such a small change can make such a huge difference, at least in performance. On the bright side, look at all the extra performance and weight savings you'll get when you finally decide to spend the $$$ and buy a complete system. And that used insert will likely sell quickly on eBay. :banghead:

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • 96warrior

Posted September 22, 2005 - 09:30 PM

#29

RadRick, could you pm me what you got deleted on you? I'm considereing a change from what I currently have, only if the gain is VERY noticable and I'll pass the michigan sound test.

Why did it get deleted anyways if it was useful info? :banghead:

  • RADRick

Posted September 23, 2005 - 09:15 AM

#30

RadRick, could you pm me what you got deleted on you? I'm considereing a change from what I currently have, only if the gain is VERY noticable and I'll pass the michigan sound test.

Why did it get deleted anyways if it was useful info? :banghead:

There was a problem with the TT servers and they had to restore a backup made prior to my post. Everything posted on TT after that point was deleted, not just my post. I have no way to retrieve the post that I know of. :applause:

  • 96warrior

Posted September 23, 2005 - 08:45 PM

#31

repost it :banghead:

  • RADRick

Posted September 24, 2005 - 01:32 PM

#32

repost it :banghead:

Dude, are you retarded? I already said twice that my original post was lost by TT due to a server problem on their end. I have no way to "repost it" as it has disappeared. Posts aren't archived on the user's system. It's gone forever unless someone from TT can find it and resurrect it. :applause:

  • 96warrior

Posted September 25, 2005 - 02:51 PM

#33

Nvm dick head, figured you'd just re type the info off the top of you head. Forget it. :banghead: :applause: :lol:

  • RADRick

Posted September 25, 2005 - 05:02 PM

#34

Nvm dick head, figured you'd just re type the info off the top of you head. Forget it. :banghead: :applause: :lol:

Yo, clueless, the post was very long and detailed. Much of it was summed up already by another poster. You didn't ask me for a retype, you kept asking me to repost the post that was lost. I can't, and with your attitude I wouldn't if I could. Sorry you missed it, was one of my better posts in a long time. :lol:

  • 96warrior

Posted September 25, 2005 - 06:40 PM

#35

Yo, clueless, the post was very long and detailed. Much of it was summed up already by another poster. You didn't ask me for a retype, you kept asking me to repost the post that was lost. I can't, and with your attitude I wouldn't if I could. Sorry you missed it, was one of my better posts in a long time. :applause:



I wasn't really giving an attitude, but oh well. Calling me a retard will cause me to fire back in one way or another,and like I said forget it. Kiss my Ass too.


The more you post the less I think of you, have a good day your royal heiness :banghead:

  • Kev_XR

Posted September 26, 2005 - 08:20 AM

#36

You two have caught the attention of the moderators.

If you two can't play nice, someone is going to get suspended. :banghead:

The database "burped" and we lost all posts for a day. Things happen with high tech servers.


As for Pro Moto Billet, when I was getting my XR400 tested two years ago, I asked about what worked for a YZ250F. The Rangers testing the bikes said the PMB insert was the way to go. Sound was their major concern, but if you don't pass the sound test, you risk getting sent home or getting ticketed in more and more places.

Once again, I see a reference to gains in low-end and mid-range horsepower vs peak HP. I'd rather have gains where I use the power more often.

  • 96warrior

Posted September 26, 2005 - 09:13 AM

#37

I was wondering the power difference between the gytr and the pmb insert. I'll just keep what I have, and bag it next season when I buy a quiet slip on I suppose. :banghead: :applause:




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.