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Effect of aftermarket exhaust (spec. vtr250)

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by rdkls, Jul 13, 2009.

  1. First, forgive my noobishness, still learning about all this, corrections welcome.

    I'm thinking about getting an aftermarket exhaust for the vtr250, mainly for the sound.
    However talking to someone today, mentioned watch out for drop in compression (back pressure?)
    Also - I read that without rejetting (or shimming) carbs the mixture's too lean and you get a flat spot in the torque curve round 4,000rpm.
    Both of these seem to make sense, to me.



    If you get the exhaust and rejet would all be good?
    Or is the exhaust one of those things that is engineered just fine and should be left as-is?
     
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  2. Utter bollocks

    You may or may not need to reject your carbies. Traditionally Hondas run on the rich side. So freeing up the exhaust brings them back to about tight.

    Try the exhaust and see how it runs. if it does develop a flat spot then you will need to look at jetting.

    You do have to consider whether it is worth it, given the price of the bike and the amount you would need to invest in a new exhaust and carbie rejetting.
     
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  3. Great will do
    I also asked Ken from Megacycle (where I plan on getting the exhaust)
    Said from all his sales he hasn't had any complaints, and for a very reasonable price he offered to dyno the bike afterwards. Should do it just for kicks.

    Also - the post I read about the flat spot was after having a Roo pipe fitted, which apparently are larger (too large) core for the vtr250.
    So I think I'll go ahead and see.
    Worst case I'll have to shim the needle, which apart from the work to get in there doesn't look super complex.
     
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  4. Thanks for preserving my typo, now it sounds like I have some sort of personal issues with my bike :)
     
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  5. You won't need to do anything, get the exhaust and be happy.
     
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  6. im gonna get a stocky from the wreckers and have a play with it, rip the shit out of the middle and see what notes i can get from it hehehe.

    i cant personally justify $500+ on a can which gives only extra audio performance, when i'll probably graze the crap out of it sometime down the road :)
     
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  7. yeahhh i know, $425 for something I'll be getting rid of in a year is a borderline call too (i know they do almost nothing for resale ....)
    liq's drilling the baffle sounded like it went .... louder :]
     
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  8. Seeing as i gotta have my LAMS bike for 3 years now im gunna get my slightly dinged stock and replace it with a new one. Now which one to get....
     
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  9. Looking around i couldn't find cheaper than the megacycles for $425
    Staintune are around there too.
    Haven't heard anything bad about any particular brand; people who get em seem to like em.
     
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  10. I agree. The only reason my old bike had an aftermarket exhaust was because the previous owner put one on.
    On a 250, they don't make a noticeable difference in power (couple of HP *if* tuned), but they do make a noticeable difference in noise.

    I'd save the cash for your next bike imo. $500 is a lot.
     
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  11. I know, you're right, that's sensible
    Please stop being sensible, I'm going in tomorrow morning to get it put on :]
     
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  12. Pipe

    Get the Megacycle. Ken's stuff is great & if it needs tuning he'll know about it.
     
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  13. If you do eventually get one let me know how it goes please :p
     
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  14. Ken at Megacycle put it on this morning and it's fn awesome, sounds a LOT bigger and meaner, makes riding even more enjoyable.
    I now enjoy engine breaking much more :]
    Didn't get it dynoed but seems to get to redline easier on my SOTP dyno.
    I'm happy :]
     
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  15. May i suggest grabbing a drill bit and going through the baffle a few times? If you dont like the sound its a few cheap self-tapping bolts to seal it again.

    FWIW it sounds great to me :p
     
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  16. lol
    something about the well-mannered suggestion to make my bike more obnoxious :]
    liq you did that on the stock right?
    if i didn't go the megacycle, i would have done that too.
    good idea with the screws, nice trick.

    but you mean drill out the megacycle?
    not sure, would ask Ken before doing that.
    i'm pretty happy with it atm
    i even got some cars to move over for me when engine braking :]
     
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  17. Which one did you get from Ken? The $425 alloy one?? Good that your happy with it mate :p

    Now i just gotta get one for mine..... I live in Canberra so id have to get it shipped up and then pay another $150 to have it fitted so i think its time to start looking for stores that make exhuasts here. Will see how i go but everyone recomends Ken.

    :grin: You got cars to move over, nice! :p
     
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  18. Yeppo, round alloy
     
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  19. Pics or vid now please :grin: Gotta show off your new can!!!! :p
     
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  20. No fear, will tonight :]
     
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