Want to "De-Cat" my K8

Just want to say the mesh like thing in the pipe is the pre-cat, I'm told it pre-heats the gas on the way to the main cat in the exhaust system. Problem is if you remove it you'll change the way the system is set up and possibly fail the MOT emissions test, when the time comes. I've popped a Scoripon Street extreme on my K8 and kept the lamda sensor and pre-cat, ready for when I have to put the old system back on of the MOT. Seems to work well with a few pops and bangs on overun, definitely not for quiet retiring types.........

[Rich]

I didn't think the SV had a CAT, well nothing like my gsxr did have, now even a car would have been proud of that. The mesh is just holding sound dampening wadding in place. A CAT converts emmisions to bring them down to standard, all i see in the SV's system is sound dampening!!!

Hi Rich,

I can only quote what the techincal expert at Scorpion said - their initial instructions for the K8 were incorrect by 10cm's and I ended up cutting part way through this "pre-cat". So, as far as he was concerned the two parts were needed for an MOT; that's why a connector is provided in the kit so the bike can pass it's emssions test by refitting the old silencer.

[Rich]

Originally Posted by Respray SV

Hi Rich,

I can only quote what the techincal expert at Scorpion said - their initial instructions for the K8 were incorrect by 10cm's and I ended up cutting part way through this "pre-cat". So, as far as he was concerned the two parts were needed for an MOT; that's why a connector is provided in the kit so the bike can pass it's emssions test by refitting the old silencer.

Ahh ok, but i still can't see how that reduces emisions i thought they had to pass through a series of filters. From the SV system i can't remember any real restriction other than abit of mesh and wadding!!!

Originally Posted by xXBADGERXx

De-Catting for wheelies .... heard it all now , you wanna pop the front end up then travel at 30 in second , slam the throttle shut then whack it open again , that will lift the front end up on a bit of private ground . #.

Ill try this...
Just dont want to be doing them off the clutch... Just throttle.

Originally Posted by fizzwheel

TBH you'd get more benefit wheelie wise by altering the gearing than you will chasing power gains IMHO.

Getting tuned next week,
If she is not right ill drop a tooth on the front sprocket

Originally Posted by sv650nutter149

just get a 52 rear sprocket for wheelies

Im under the influence that dropping a tooth on the front sprocket is easier and cheaper..

Wont it fail the MOT if you take the CAT out?
Steve

[BoltonSte]

The mesh is only for sound, unless they changed it for the pointy's as it's there in the curvey pipework as well, and they don't have cats.

[yorkie_chris]

What are you on about fellas? The only emissions test for bikes is they can fail you for excessive smoke.
There is no requirement to keep any silly cats on the bike. F##k them off and get a proper system on it. While you're at it fit some dirty gret petrol snorting carbs.

The problem with all this slightly homosexual EFI b0llocks, is the lambda sensor, which is part of the ECUs closed loop control over the injection which means you either have to fit an earlier open loop injection system, or find a way to make the ECU ignore it. You MIGHT be able to do this through the TEKA/yoshi box software. Or, you need to weld a boss into your new system to keep the sensor.

The mesh stuff in the collector is just for sound dampening. Feel free to remove.


Respray SV, there is no emissions test in bike MOT. Your pops and bangs on the overrun are from the PAIR system, which bleeds air into the exhaust to burn off excess fuel on the overrun... in turn the excess fuel needs to be there, I believe, to smooth off the transition back onto throttle. Also has a nice cooling effect on stuff (not really a consideration here though, SV motor is in a low state of tune)

Originally Posted by Rhys

Your O2 sensor is attached to your injection so you are going to have to keep that, unless someone has a way round it. To fit it, just cut it back in.

you can loose the O2 sensor.
My thou has a full system on and no O2 sensor.
you unplug the electrical connector attached to the sensor then you get a blanking connector with a feed back loop and all is well.

Originally Posted by stevebetts

you can loose the O2 sensor.
My thou has a full system on and no O2 sensor.
you unplug the electrical connector attached to the sensor then you get a blanking connector with a feed back loop and all is well.

Will that not confuse the ECU in telling it the emissions are wrong and so instruct it to adjust accordingly?