Suzuki TL1000R bike - exhaust restriction

[amorrison]

Suzuki seem to have deliberately put an "crimp" in the bikes left exhaust pipe. As there is a "cross pipe" there will be more flow through the right exhaust than through the left.
What is the reasoning for this?
Thanks

 

[bradrs]

This could be a matter of trying to tweak scavenging somehow. On 4 cylinders, the crossover is more symetric, but with a V twin, they might have done something odd to account for the uneven pulses.

Or it could be their method of quieting the exhaust on one side, to change the exhaust noise level at a certain position behind the bike to meet noise emission requirements.

Do the aftermarket full systems have something similar? IIRC, they were run in Superbike for a year or two, so there probably was some testing done on this.

 

[pyro]

The bikes that ran in Superbike used a Yoshimura exhaust which doesn't have the "crimp". The cross-sectional area is roughly the same as the rest of the mid-pipe and exists solely for clearance of the chain and therefore to allow enough ground clearance of the retracted sidestand as it sits against the bottom of the pipe.

 

[sbozy25]

Interesting... I have a TL 1000S and it does not have this crimp. I have the stock exhaust and an aftermarket Yoshimura, both of which are round the whole way.

I wonder if this is what keeps the R at slightly lower performance. If you compare the specs, the S has slightly higher HP and other characteristics due to the open body design.

Cabbages, knickers, It hasn't got A BEAK!

 

[pyro]

I have a US-spec 97 TLS and the stock header did have that squashed section. The Yoshimura system it has now obviously doesn't. Prior to the Yosh system I installed a Two Brothers full system and before any fueling changes were made the extra torque was enough to cause the clutch to slip as soon as it passed 5k rpm. That was fixed with some heavier Barnett springs, but it indicates that the stock header definitely has some significant restriction.