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Discussion Starter · #1 · (Edited)
Has anybody just cutoff the EXUP? If you were to have slip-ons/race baffles and a Y-pipe/gutted cat, would it help to just cut-off the actual shaft on the butteryfly valve? Leaving the exterior portion of the EXUP as a block-off plate and of course removing the cables, but keeping the servomotor to avoid throwing a code.

If you have done this, did you loose any low or midrange power and would a full system map work (ie..full graves map), until you got a custom map?

I know a full system would be the way to go, but already have race baffles, y-pipe and PCIII. Trying to save a buck and was wondering if there is anything to gain (or lose) by getting rid of the EXUP.
 

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Discussion Starter · #4 ·
I'm not planning on cutting the cables. If I were to remove the EXUP, I would remove the cables. I would then take the valve out of the collector and actually cut the metal portion of the valve where it is narrow (shaft) just before it enters the portion that goes outside. The actual butterfly portion would be gone, but a small portion 1/2in. would be on the inside. I would keep all the crap (spring, washers , nut, and cover) on the outside. The solenoid would still have the electrical connection so there would be no codes on the instrument panel. I don't want to have an engine light on all the time incase something else (more serious problem) occurs and I just blow it off just thinking it the same old EXUP code .
 

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Discussion Starter · #6 ·
Thanks for your input. I was just asking anybody who has an "07" who may have taken out the EXUP (doesn't matter to me how it's done) to see how it ran down low. And also to see what map they used. I'm debating if I should leave it or remove it. As per the weight savings, I just need to look in the mirror to see where I could lose 30 lbs.
 

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Discussion Starter · #9 ·
That is exactly what I was thinking of doing, cool. Yea, tell us about any changes in power and are you using a PCIII, and if so, which map? Also, do you still have the cats?

I might just make a cover plate and keep the EXUP in one piece. That way I might do my own testing to see which way feels better to me. On the same day I could test ride it without the EXUP and then yank it out and see what kind of effect it made and maybe try other maps. If there is no question (yours and others input) that taking the EXUP out helps, I'll just cut the thing off.
 

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Discussion Starter · #12 · (Edited)
I'm with you on that thought. The whole EXUP thing has me baffled (pun intended). I know some times that increasing muffler volume (not restriction), stepped headers, "D" shaped exhaust ports can all help in ant-reversion thus helping torque in the lower rpms. But sticking a big ole' restriction in the collector? The whole idea of having exhaust tubing mandrel bent is to keep the restriction down to a minmum. I have never seen one in a car?

I'm going to take that "thing" out!
 

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Discussion Starter · #13 ·
I guess I'm just wondering why it seems so hard to get rock solid info on the EXUP. I read somewhere on this forum that on the 07 they don't need it anymore since the intake is so finely tuned now and Yamaha just uses it for noise regs. I couldn't say if that is true or false. It would be nice to see a side by side dyno run..one with the EXUP and one where it was removed (with stock headers). Does anybody know if anything like that exists?
 

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Discussion Starter · #21 ·
Hey British Bulldog, great job on the tractor!!! Noticed you have filters (breather) in place of the smog system (AIS). Just wondering why you didn't just use block-off plates? Obviously it looks like you know what you are doing.
 
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