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Modifying exhaust header for 2 into 1
Posted: Fri Feb 26, 2010 8:13 pm
by fredskidoo
Looking for some discussion about modifying stock exhaust header for 2 into 1.
1. Would simply cutting off one side (sealing the hole, of course) suffice?
2. How would the back pressure be effected? More or less muffler baffle?
3. Would changes to the carburetor be necessary? If so, what?
4. Any other considerations? Valves, timing, etc?
Easy - E
Re: Modifying exhaust header for 2 into 1
Posted: Fri Feb 26, 2010 9:26 pm
by jpitz31
The simple answer is that changing to a 2 - 1system is suppose to increase your torque. But the long answer is that there are a lot of variables to this answer.
Exhaust pipe diameter, exhaust pipe length all can induce changes to back pressure, and the scavenge effects of exhaust flow.
Just cutting off a pipe and running one exhaust pipe is not the answer.
AFR will be effected by change in back pressure and timing may be affected as well.
There are vendors who do offer a 2 into 1 system that changes back pressure. On the FI Ducati's this requires a chip change to compensate for the change in back pressure and exhaust flow which affects AFR.
higgy would know more about this, and could provide more particulars.
To do it right re-jetting is in order and maybe some dyno time to check for possible low, mid and high range changes in performance.
Just my two cents.
Cheers
Joe
Re: Modifying exhaust header for 2 into 1
Posted: Fri Feb 26, 2010 10:59 pm
by paso750
Re: Modifying exhaust header for 2 into 1
Posted: Sat Feb 27, 2010 3:00 am
by jcslocum
Pics of my 2:1 system
The 2 pipes need to be the same length for the flow and scavenging effect to be right and balanced.
Re: Modifying exhaust header for 2 into 1
Posted: Wed Mar 03, 2010 8:39 pm
by Tamburinifan
Real nice, jon!
