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latest moto gp inspired exhaust

Posted:
Wed Jul 26, 2006 2:27 pm
by hidepenny
hi all, with all the new models of 600cc bikes, they tend to have this small exhast on the side, are they any different as in structural to existing exhaust setup?
anyone thinks that they will be available or compaitble with any bikes with side exhaust? or they can just be replaced with these new small exhausts/mufflers?

Posted:
Wed Jul 26, 2006 2:29 pm
by FrogZ
Some appear to have a collector under them but others appear to just be an exhaust.
As long as you dont alter your header or collector length I sure HOPE you can put them on, cause I want one on NKD12...
see Blueflame....

Posted:
Wed Jul 26, 2006 2:33 pm
by hidepenny
As long as you dont alter your header or collector length
why can't we alter the headers' length?

Posted:
Wed Jul 26, 2006 3:11 pm
by FrogZ
DAMN mate how long you got
I will keep it short and only give 1 reason of many.
The manufacturer came to that length as the best compromise for the rev range where they figure the bike will be used.
As a rough rule long headers for low revs and short for high.
The length of the header determines when the exhaust pulse returns and (with radical timing for example only) stops the inlet charge coming out (relative to cam timing, inlet and exhaust size etc. etc. etc.).
This is 4 or 2 stroke excepting valves of course.
In the old days we would get a bit of pipe that was slightly larger than the header and holding the bike at a constant throttle (where you are mostly likely to ue it i.e. mid range, top end whatever) and move that pipe in and out until the bike revs the most (only way I can think to say it)
My ol' da' reckons in 'is day they would just put a long bit of header on and cut it where it discoloured.
This goes for the collector (the bit between the header and the end can) as well.
For a FULL explanation get a copy of Irvings Tuning for Speed.
STILL relevant in this day and age....

Posted:
Wed Jul 26, 2006 4:33 pm
by javaman
That exhaust on the gsxr750 at broadford was really nice was it? MP4 or something? Never seen one quite like it.

Posted:
Wed Jul 26, 2006 4:39 pm
by hidepenny
That exhaust on the gsxr750 at broadford was really nice was it? MP4 or something? Never seen one quite like it.
hahaah Andi that's exactly what i'm think, may be i could change mine if it's only the muffler
like this
http://www.gravesport.com/cgi-bin/shopp ... =EX__033ST

Posted:
Sun Jul 30, 2006 9:27 pm
by Neka79
basicaly mate, the bikes are designed with certain length headers etc...changing them can/will affect power,noise, torque, ur bank balance... not always for the better either...
oh..and those GP bikes look cool, but they are tuned for that exhuast..oh and the cops dont harrass them abt noise..altho scruteneers do!

Posted:
Mon Jul 31, 2006 11:20 am
by FrogZ
After talking with my guru on the w/e he said to make sure that everyone understood that the HEADER length/diameter is V important, the collector part important and the end can the least important.
He said, loose tappets would prob. effect it more than cutting the exhaust due to the timing change (loose tappets effectively alter timing).