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Aftermarket exhaust

John Bass

New member
Am I doing any harm to my engine by using an aftermarket exhaust that eliminates the Cat converter ? The one I have (Ztech) claims it is the only one that will not negate the warranty but I am concerned that the bike was developed for a cat converter in the first place. Any advise please.:confused:
 
Hello; The Cat (catalytic converter) doesn't add or remove anything from the exhaust content. The oxygen sensor is upstream of the Cat anyhow, and measures the Oxygen before the Cat. Removeing the Cat will reduce back pressure, and allow freer exhaust breathing, I was (painfully) criticized for advocating gutting the Cat, but I have recovered from that, and am still enjoying the advantages in all my cars, trucks and motorcycles.
 
Do I know what the hell I'm talking about?
NO..............
- But -
I have tried the following combinations in the last 42,000 miles on my '02 R1150RA:

Complete factory exhaust system with the Cat' Code Plug removed. It seemed to minumize surging, but it robbed my bike of some of it's top-end.

Remus "Race" 'Y' Pipe (Cat' eliminator). With the stock muffler in place, the Y Pipe eliminated the weight of the cat' (so what), and made the bike sound a little less like a sewing machine. Performance at the top-end was anemic until I replaced the stock air cleaner with a K&N. Otherwise, nothing special.....

Cat' converter in place, but with the muffler taken off. If you want the least expensive conversion that allows you: Full size system case on the left side of the bike, a VERY NICE SOUND that is virtually no louder than the stock muffler, great mid-range, and a top speed that is at least 5 mph faster than with the muffler in place.... I have a K&N in place, and this set-up seems more effective at performance enhancement in the colder weather. (Don't knock it 'till you try it!)

Remus Y Pipe, K&N, straight through can that needs frequent re-packing: Sounded damn good, better top-end as the packing burned out, tripped all over itself at 'in-town' speeds; I loved it!

Remus Y Pipe, K&N, Super Trapp with 4" internal discs. Dhaaaaaamn, sweeeeeeet! With 9 discs, this puppy ran well at the lower-end, had great mid-range, and walked quickly/easily up to 120 mph. I think this would be ideal for the sane 'normal' rider.
But I wanted stronger upper-mid-range and a more aggressive top-end, so I added 6 more discs..... Dhaaam, SWEETER STILL! 15 Discs, and this puppy makes a very pleasant, albeit "aggressive" BARK! It now runs out where I like to play, and climbs right up to red-line.... begging that the rev' limmiter be removed!

Note:
After 25,000 miles of running w/o the CCP, I put it back into place..... the "Limp-home mode" that removing the CCP results in, compromises your engine's overall performance.
Whenever I made a change to the intake/exhaust system, I "reset the motronics" (remove #5 fuse, twist throttle twice).
My rear wheel horsepower with Remus/K&N/Straight through, produced 81hp, and damn good air/fuel ratio!
I plan to put the bike on a Dyno' again with it's current Super Trapp set-up and check out the air/fuel ratio. I intuitively believe that removing three discs from the current 15 could result in a more linear power band, but I ain't doing a thang until I see the Dyno results! 'Cause it runs sooooo good, sooooo hooligan, soooo loud, SO WHAT! I feel soooooo naughty..... :p
 
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