decat. yes or no ?
Discussion
Thinking about decatting my 4.3, are there any negatives to this? does it add any problems etc, and of course, how much louder will she be?
where are the cats situated and are they easy to get to ?
I have a guy that can make me replacement sections unless they are cheap enough to buy anyway
where are the cats situated and are they easy to get to ?
I have a guy that can make me replacement sections unless they are cheap enough to buy anyway
As I understand it the pre cats can be removed without to much effect on sound or emissions. (which live in the exhaust manifold on each side)
Removing the main will make it louder, but then will most likely fail the MOT on emissions. As the main cat lives in the dustbin like section of the Y piece I doubt many people could just knock up replacement being such a complicated fitting.
Maybe consider buying an off the shelf replacement and swap it at MOT time.
Removing the main will make it louder, but then will most likely fail the MOT on emissions. As the main cat lives in the dustbin like section of the Y piece I doubt many people could just knock up replacement being such a complicated fitting.
Maybe consider buying an off the shelf replacement and swap it at MOT time.
Edited by dogbucket on Thursday 10th January 07:50
Mine is now fully de-catted and yes, it is somewhat louder though the object wasn't to make it so. The biggest draw back I find is the smell of the exhaust when it gets drawn into the cockpit (which it invariably does with the lid on and the windows down). It's very acrid; not nice at all.
I'd say no - if you want a 'rawer' sound, sleeving the zorst and removing the pre-cats is plently loud enough. You get all the pops and bangs your heart could crave as well.
This route should not affect the MOT. I've never had any problems.
If you have the main cat removed, it will need to be replaced before each MOT which increases hassle and maybe cost (if you can't do it yourself)...
This route should not affect the MOT. I've never had any problems.
If you have the main cat removed, it will need to be replaced before each MOT which increases hassle and maybe cost (if you can't do it yourself)...
try to find out before purchase if your replacement manifolds which have been decatted still have provisions in for your lambda sensors.
My car has been decatted, all three, and the lambda sensors are removed by fitting these manifolds, effecting fuelling. I'm currently going through the motions of having them put into the decatted manifolds.
And my car isn't the only decatted car without lambdas, so check before you buy
Cheers
Matt
My car has been decatted, all three, and the lambda sensors are removed by fitting these manifolds, effecting fuelling. I'm currently going through the motions of having them put into the decatted manifolds.
And my car isn't the only decatted car without lambdas, so check before you buy
Cheers
Matt
I would support this argument, depending on what exhaust you plan to run with the decat. I have heard a decat car running on sleeved pipes and it sounded very tractor-like (the owner agreed). On mine though I have the ACT system with the twin cherrybomb exhaust so the whole thing is new, front to back (which incidently, the owner mentioned above has since switched to). The key I think is the manifolds, the ACT ones are smaller bore to retain back pressure and they do change the engine note quite a lot I noticed (for the better though IMHO). I had the cherrybomb system put on before decatting though and it didn't really get much louder but it did gain a deeper more throaty tone to the exhaust note. Coupled together this system doesn't sound at all tractor-like IMHO, sounding more like a muscle car. It is very loud, I will admit but I love it and it makes me grin like a loon whenever I drive it. It sends small children running, makes old people wave their fists and makes some people cheer! To me that doesn't matter as I did it because I love the sound and I wouldn't change it back if you paid me, but as with all things, its down to personal choice. My best advice would be to go and listen to one before you buy. I listened to Wildfire's ACT Griff (theres a vid on here somewhere) first and loved it so much I rang Tim the same day - fantastic bit of kit!
If you're anywhere near Surrey, you're welcome to come and listen to mine but if not, i'm sure there are plenty of people around who would be glad to help
If you're anywhere near Surrey, you're welcome to come and listen to mine but if not, i'm sure there are plenty of people around who would be glad to help
Edited by thenick on Monday 14th January 00:11
This is the same system as mine on Wildfire's 4.0 Griff - his has better sound than my crappy cameraphone ones!
http://www.pistonheads.tv/clip961
http://www.pistonheads.tv/clip961
Edited by thenick on Monday 14th January 00:36
It's a no-brainer in my view just for the very significant improvement in under bonnet temperatures if for no other reason. With the cat maps still activated and lambdas present, the car drives nicer too ('though mine is a long way off standard now). With a sleeved or bombed exhaust, no cats will take you into F loud territory, which may or may not be a problem depending on where you live, your neighbours and how many multi-storey car parks you have to use (I can't get to where I have to park for work without setting at least 4 alarms off every time).
What I want to do, but haven't yet, is try a completely standard (ie silenced) exhaust on the decatted manifolds and Y piece... suspect this will be the best solution of the lot.
What I want to do, but haven't yet, is try a completely standard (ie silenced) exhaust on the decatted manifolds and Y piece... suspect this will be the best solution of the lot.
Decat: no.
My Chimaera sounds fantastic just the way it is. I've heard decatted cars and sometimes they are actually TOO loud. Now I know that the old rock'n'roll adage says "too much is not enough" but my car already sets off car alarms. I don't need it any louder - and it would be a lot less usable if it was. We go on long journeys in ours - touring holidays and the like and usability is a key factor for us.
Secondly - have you followed a pre-car car (of any type)? They STINK! Since I like to travel with the roof off as much as possible I have really become sensitive to the difference between modern cars fitted with Cats and older vehicles that are not. Frankly I hate the smell when following a pre-Cats vehicle - so to my mind I shouldn't subject traffic following me to my stinky discharges - and the smell of the car's exhaust.
Now - everyone is different, entitled to their opinion, and if decatting your car floats your boat well its up to you. But to my mind the downsides outweigh any percieved benefits.
My Chimaera sounds fantastic just the way it is. I've heard decatted cars and sometimes they are actually TOO loud. Now I know that the old rock'n'roll adage says "too much is not enough" but my car already sets off car alarms. I don't need it any louder - and it would be a lot less usable if it was. We go on long journeys in ours - touring holidays and the like and usability is a key factor for us.
Secondly - have you followed a pre-car car (of any type)? They STINK! Since I like to travel with the roof off as much as possible I have really become sensitive to the difference between modern cars fitted with Cats and older vehicles that are not. Frankly I hate the smell when following a pre-Cats vehicle - so to my mind I shouldn't subject traffic following me to my stinky discharges - and the smell of the car's exhaust.
Now - everyone is different, entitled to their opinion, and if decatting your car floats your boat well its up to you. But to my mind the downsides outweigh any percieved benefits.
Don said:
Secondly - have you followed a pre-car car (of any type)? They STINK!
I luuurve that smell! 
But Don does raise another good point, they do smell a bit more whether you like it or not, doesn't bother me even though it's my daily driver but it may bother you...And yeah they can set off car alarms, there are two in particular in my flat carpark which always seem to go off when I drive in at normal speed, but several more if I come in fast and tickle the throttle to get some pops and BANGS - makes for a rather good game!
Edited by thenick on Monday 14th January 14:06
Gents,
For your info and me just the messenger here, I also wanted to go down this route yesterday and checked with my insurers (Sunninghill) first, who were very helpful, I was informed that removal of the main cat is on the definitive list of frowned modifications that are not supported by their underwriters (Chaucer)and would my invalidate cover without question.
Obviously, I will be keeping my main cats in, pre cats removed and disclosed to insurers with no concerns, except an increase in premium and larger excess! But to be fair this was lumped in with other previous performance mods to which I ‘came clean on’.
Retro
For your info and me just the messenger here, I also wanted to go down this route yesterday and checked with my insurers (Sunninghill) first, who were very helpful, I was informed that removal of the main cat is on the definitive list of frowned modifications that are not supported by their underwriters (Chaucer)and would my invalidate cover without question.
Obviously, I will be keeping my main cats in, pre cats removed and disclosed to insurers with no concerns, except an increase in premium and larger excess! But to be fair this was lumped in with other previous performance mods to which I ‘came clean on’.
Retro
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