Just went to Jack Lilleys in my lunchtime and heard one of the best sounding bikes ever. A standard new Thruxton with custom paint job and SC Project exhausts. Relatively subdued on tickover but outrageous when revved. Talking to the technician and it had the catalytic converter removed which makes a big difference. The bike was very nice, and definitely would make me think about getting the standard one and using the savings for some personalisation. Some kind of dealer do this weekend, open Sat and Sun.
I personally would not remove the catalytic converter as it measures exhaust via the sensor and relays message to the ecu which controlls the fuel and air metering, the slight exhaust noise increase is not worth compromising the integrity of the engine management system. I have a set of "remus" mufflers fitted to my "R" and feel the sound is great ( restrictors removed). Just my thoughts!!
I removed the cat on my TTR and helped a mate do the same on his R almost 3 months ago. Replaced with the BC x pipe. Both bikes are running perfectly with beautifully louder but not obnoxious growls upon acceleration. Many folks have removed the cat and reported no issues. The Australia guy who makes and sells his Merkat x pipe ( pretty much the same as the BC pipe) has done extensive dyno tests and comparisons for air/ fuel measurements and they are well within safe parameters. The ECU has adapted to the X pipe.
I agree, the de-cat may be within the parameters but "not too lean or rich" is as well. Removal of the cat negates the "closed loop" mode of the ecu which then affects the monitoring of exhaust gasses. I figure engine manufacturers spend millions on R&D yet the "office worker" knows better!!
There isn't before and after cat sensors, removing the cat wouldn't upset the ecu as it only uses front lambda sensors. A lot of engines use a before and after reading to adjust fuel air but the Thruxton doesn't.
Yes I would agree all the monitoring for the ecu is done from the front lambda on a twin lambda system the rear lambda is only there to monitor the efficiency of the cat and throw up a warning light if it stops doing its job. An interesting point is triumph really struggled when they brought in cats as it raised the engine temps by up to 10 deg which as we all know is not good for power. I removed one from a 800 tiger and the first thing I noticed was the extra 3 or 4 minutes it took to warm up from cold
I bought my Thruxton R 2016 second hand with SC exhausts on it. They were one of the reasons I wanted this bike an not another average Thrux. The sound is fabulous, with or without the restrictors (here we call them 'db-killers'), never heard anything like that deep dark rumble!
