Want to "De-Cat" my K8

[Fazerkid]

Hey Guys,

Been searching all over the net in search of De-cat pipes and the only result has been MiVV Collectors for £125 from brspecialtuning.co.uk

Anyone have these or any other solutions?
How do you deal with the Lamba sensor when putting on a full system? :???:

Im de-catting the bike, whipping in a pipercross filter and getting her teka tuned :rolleyes:

Thanks

Rhys

[Paul the 6th]

think the catalytic convertor is actually in the can part of the exhaust system, so an aftermarket can removes the cat and makes it louder/breathe a little easier :)

[Geoffrey]

i agree with the post above, the cat is in the silencer not the downpipe

[sam_p2000]

Yep...in fact when you cut the stock system to fit the new can and link pipe you can see it in the standard pipe. Get onto the carbon can Co. and order one of their pipes, they are meaty sounding with the baffle in and roar like a lion wthout! Even without mine passed its mot. I dont know if they even have a lambda sensor do they? My '04 doesnt anyway.

[Whitehouse]

i think the k8 has two cats, one in the can and one near the collector, because when i cut my pipe there was the corrugated material just infront of the cut pipe and it was also in the can when i had a look in there. I think if you wanted to totally decat it you would have to get either a full or 3/4 system

[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.

[Fazerkid]

i think the k8 has two cats, one in the can and one near the collector, because when i cut my pipe there was the corrugated material just infront of the cut pipe and it was also in the can when i had a look in there. I think if you wanted to totally decat it you would have to get either a full or 3/4 system

Whitehouse your right..
There is a cat (wire meshy thingey lol) just at the collector.. Never looked in the can though.
Maybe this is only for the K8 i dunno :???:

[Paul the 6th]

Forgot to say mate, welcome to the forums :)

Are you turning it into a track bike? Or just wanting to make it amazingly loud? If you're just after the sound & to free up some gas flow, an end can will do a good job with screwing the emissions etc... I bought a £150 beowulf can which does a cracking job, but there's plenty of others available: scorpion, blue flame, carbon can companyto name a few :)

[FG1]

When I put the Street Extreme on my K8 I just hacked the corrugated mesh out of the collector with a flat blade screwdriver. It is pretty soft and breaks up easily.
Mine runs ok without it.

[Paul the 6th]

When I fitted my can to my sk5, it has corrugated mesh in there as well? Didn't think there was a cat in there as well, since it was louder than the sound of atoms splitting... Hey ho :)

[Paul the 6th]

Forgot to say mate, welcome to the forums :)

Are you turning it into a track bike? Or just wanting to make it amazingly loud? If you're just after the sound & to free up some gas flow, an end can will do a good job with screwing the emissions etc... I bought a £150 beowulf can which does a cracking job, but there's plenty of others available: scorpion, blue flame, carbon can companyto name a few :)

and further to an end can, there are full systems available which I'd have thought would do away with any cat's full stop

[Fazerkid]

No not for the Track..

I had a FZ6 before and could wheelie it all day... SV not a hope!
So tuning it!!

Teka tuning the ECU
De-Cat along with Carbon Fibre Scorpion Street Extreme
Pipercross Filter (K&N is too restrictive still)
TRE

If that wire meshy thing comes out with a screwdriver does that mean no cat is in there????
Whats the point of that mesh!!!

[Paul the 6th]

No not for the Track..

I had a FZ6 before and could wheelie it all day... SV not a hope!
So tuning it!!

Teka tuning the ECU
De-Cat along with Carbon Fibre Scorpion Street Extreme
Pipercross Filter (K&N is too restrictive still)
TRE

If that wire meshy thing comes out with a screwdriver does that mean no cat is in there????
Whats the point of that mesh!!!

Well I'm not a mechanic or anything but I'd have thought the mesh was there to mess with gas flow before going into the cat or summink?

Also, have you looked into the oil starvation issues which come with wheelie-ing sv's? I've only ever heard it mentioned but it seems quite a common thing

[fizzwheel]

I had a FZ6 before and could wheelie it all day... SV not a hope!

Then with respect your technique is wrong. I could wheelie my completely standard apart from an end can SV with no trouble at all.

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

[glang]

i think the k8 has two cats, one in the can and one near the collector, because when i cut my pipe there was the corrugated material just infront of the cut pipe and it was also in the can when i had a look in there. I think if you wanted to totally decat it you would have to get either a full or 3/4 system
My K6 had the corrugated material and no CAT so I pretty sure its for sound deadening. The actual CAT should be well buried inside the can but changing the can wont affect the O2 sensor in the collector or the injection system.

[Whitehouse]

I thought the corrugated material was the cat? i thought the can was used just for sound deadening, especially considering how big it is!! :D

[dual-power sv]

Then with respect your technique is wrong. I could wheelie my completely standard apart from an end can SV with no trouble at all.

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


i can wheelie my restricted sv easy through second and sometime if i try really hard in third, its all down to technique

[glang]

I thought the corrugated material was the cat? i thought the can was used just for sound deadening, especially considering how big it is!! :D
no CAts are made of platinum or something equally expensive so wherever it is it's going to be bloody small. I think thats how they sneak it in the can with no one noticin!

[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 . Oil Starvation can occur , knackered head stock bearing will probably be eventual if you land a bit heavy too , then again you did them on the other bike so you know the drill . Sprocket size would be easiest option in the long run , welcome to the site by the way :) .

[sv650nutter149]

just get a 52 rear sprocket for wheelies

[Respray SV]

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!!! :smt102

[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.

[Rich]

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!!!

[Fazerkid]

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 . #.

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


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

just get a 52 rear sprocket for wheelies

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

[startrek.steve]

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)

[stevebetts]

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.

[Fazerkid]

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?

[stevebetts]

Will that not confuse the ECU in telling it the emissions are wrong and so instruct it to adjust accordingly?
I dont know 100%, this was done when i purchased the bike.
I have read threads on the SV1000 site where people have removed the O2 sensor and just removed wire number 45 from the ECU (this is for K5 onwards, i believe it is wire 23 pre K5).
This stops the ECU throwing up a FI fault.
All info i have found says removing O2 sensor has no effect on performance.
This is why i looked into it when i found my bike had no O2 sensor.
The blanking connector on mine i believe comes with the exhaust system - hopefully this means it does the job properly ( i would hope on a +£1100 exhaust system it would!)
If anyone else knows different please let me know.