HOME ARTICLES JOIN GALLERY STORE SPONSORS MARKETPLACE CONTACT US  
Register | FAQ | Search | Memberlist
Username:    Password:       Forgot your password?
BIKELAND > FORUMS > ZX10R ZONE.com > Thread: 08ZX10R - butterfly valve isn't working after you put slip-on? AreaP? NEW TOPIC NEW POLL POST REPLY
YZF


Expert Class
Posts: 144
posted April 10, 2008 12:37 PM        
08ZX10R - butterfly valve isn't working after you put slip-on? AreaP?

Hi, as i Understand, the exhaust valve ("exup" or butterfly valve) is always disconnected (fully open) after you put any aftermarket slip-on. Is that true?

What about torque and power at lowers rpms? It should be pretty weak there? kbryant? What is the situation about this matter?

Dyno graphs do not seem to show any loss, but then again all of them are "from 3000rpm and up" ?


  Ignore this member   
k bryant


Needs a job
Sponsor
Posts: 2893
posted April 10, 2008 01:51 PM        Edited By: k bryant on 10 Apr 2008 13:55
The exhaust valve is removed completely with our Slip-On, as is the pre-muffler/boom box. The valve is located at the mid-pipe on the muffler. So even if you only replaced the muffler (and not the compete muffler and boom box as we do), you would remove the valve. So yes, any aftermarket Slip-On removes the valve.

It is primarily there as a sound attenuator for passing EC/EPA sound regs, as it is on most other models as well. I can only speak for our design and as you can see from our dyno charts, there are no losses from bottom to top. We happen to start our run parameters on this model at 3000 rpm. Most of them are 2500 - 3000 rpm. On in-line 4's, not much point starting lower. I can tell you it makes less than 25 hp below 3000 rpm

  Ignore this member    Click here to visit K Bryant's homepage. 
YZF


Expert Class
Posts: 144
posted April 10, 2008 10:33 PM        Edited By: YZF on 10 Apr 2008 22:36
Thanks for reply. I wonder if you try to ride half throttle with valve from 1500 to 3000rpm and without it (again, at half throttle), would there be any noticable difference in torque...?

Did anyone try this practicaly?

Thanks


P.S. Kbryant> when you test your bikes with slip-on, do you use PCIII or not?

  Ignore this member   
k bryant


Needs a job
Sponsor
Posts: 2893
posted April 11, 2008 01:49 PM        Edited By: k bryant on 11 Apr 2008 13:53
No perceivable difference. Again, just no sense of feel at all below 3000 rpm. And honestly, can't imagine ever really being too worried about anything below 3000 rpm (from a performance standpoint). Don't think it would be possible to gather much tangible data trying to go "half throttle" at 1500 - 3000 rpm. Maybe I'm misunderstanding your question?

We use a PC3 when available and/or if necessary. Most of the time just to gather additional data. Most of the bikes we get into R&D are very early pre-production bikes and there is almost never a PC3 available. But anytime we think there may be a viable benefit in fueling and/or performance, we will note that on our website in the notes section along side the Dyno Graph. There are times we may actually alter the mid-pipe design, core, muffler length, etc., to help it operate at peak efficency with the oem A/F curve. We always try to work around the min/max acceptable tables so our customers are not forced to purchase a PC3 if at all possible.

  Ignore this member    Click here to visit K Bryant's homepage. 
YZF


Expert Class
Posts: 144
posted April 12, 2008 01:12 AM        Edited By: YZF on 12 Apr 2008 01:12
Yes, you rarely use bike from 15000 to 3000rpms when riding, but still there are some moments when you do that on the street.

Still it was more a theoretical question rather than practical, its interesting to know if that valve makes any difference beside noise.

  Ignore this member   
All times are America/Va < Previous Thread     Next Thread >
BIKELAND > FORUMS > ZX10R ZONE.com > Thread: 08ZX10R - butterfly valve isn\'t working after you put slip-on? AreaP? NEW TOPIC NEW POLL POST REPLY

FEATURED NEWS   Bikeland News RSS Feed

HEADLINES   Bikeland News RSS Feed


Copyright 2000-2011 Bikeland Media
Please refer to our terms of service for further information
0.725044965744 seconds processing time