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Kicking the Cat

Fair enough.

The guy I spoke to was actually pretty enthusiastic and apologetic, he was searching through a copy of Autocar for 3rd party companies I could try!

Any comments re. affect on insurance?
 
BTB 500 said:
Any comments re. affect on insurance?
This is very much down to the insurance company.

I went to the trouble of declaring all the mods on my previous car and directline didn't seem interested, the premium went up by about £8 or something. They completely forgot all the mods when I renewed and I couldn't be bothered to re-inform them.

That included a C43 AMG exhaust box. I told them it was a factory item designed for another model and wouldn't affect the performance, the only visible difference was two small chrome tips. They asked how much it cost, I told them I had a hole in my current exhaust and that it was a straight swap (I've no idea what a standard backbox is for a C230k but the AMG box was about £450 after discounts). They did nothing with the premium.

If it makes your car look better or go faster then expect a premium hike of a seemingly random amount of money.
 
OK thanks. As I've mentioned before, I had the opposite experience with Direct Line when I told them my SL had 17" M-B wheels on it - mandatory £750 excess and £100 additional premium. Random seems to be the right word for it!
 
on the other hand, when I changed from 17" AMG to 18" AMG wheels, no difference in premium. I just wrote them a letter to tell them ...


BTB 500 said:
OK thanks. As I've mentioned before, I had the opposite experience with Direct Line when I told them my SL had 17" M-B wheels on it - mandatory £750 excess and £100 additional premium. Random seems to be the right word for it!
 
BTB 500 said:
OK thanks. As I've mentioned before, I had the opposite experience with Direct Line when I told them my SL had 17" M-B wheels on it - mandatory £750 excess and £100 additional premium. Random seems to be the right word for it!
I told them I fitted some 17" AMGs to replace the 16" oem wheels, they didn't care. Same goes for AMG bodykit, oem grill and a few other bits and pieces.

The insurance company? Directline.
 
all the vehicles i`ve seen it done on run better with no bad effects. you may notice a slight rasp which IMO sounds brilliant.
even if your car is newer than 92 you can still decat it if your running lpg, you just adjust the idle mixture using the software so it passes the emissions test. contrary to popular belief you dont actually need a cat to pass the mot, your emissions just need to pass the yest, which most cars cant do without a cat. with a vauxhall 20XE on throttlebodies with a mappable ecu you can pass the cat test without a cat if its mapped right.

Is it ok to de-cat a 1998 W210, 300TD?

Not worried about emissions as running svo which hardly registers on the test equipment.

Thinking about one of these puppies

Universal Exhaust De-cat pipe AUDI BMW MERCEDES JAGUAR on eBay (end time 20-Oct-09 09:01:42 BST)
 
Is it ok to de-cat a 1998 W210, 300TD?

Not worried about emissions as running svo which hardly registers on the test equipment.

You can de-cat any diesel as the cat function isn't tested, only a smoke test, which a 300TD always comes in very low due to the pre-chamber with hot spot causing very good vaporisation of the fuel.
 
300TDexhaust.jpg



It looks like it may actually be an option on our models according to EPC, the cat's number 11 right?
 
You can de-cat any diesel as the cat function isn't tested, only a smoke test, which a 300TD always comes in very low due to the pre-chamber with hot spot causing very good vaporisation of the fuel.

I took the Cat off my C220 and it went better but the noize from the turbo spooling was noticibly louder - Passed the MOT no questions asked :D
I didn't keep it long enought to notice any difference in fuel economy
 
When I took the undertray off the break was pretty obvious .

Fortunately there was half an inch left on the cat side of tube so used fire proof ally tape as a temp DIY fix.

I dont think it will be possible to put in a de-cat tube unless the cat was cut out from below the manifold join - looks like a big job tbh.

can probably make a permanent repair;

catbrokenpipe.jpg


If it needs replacing does it go half way to the back of the car and join here?

catbrokenpipejoin.jpg


Would need cutting here to install de-cat tube?

cutexhausttube.jpg
 
Cheers again DM,

Golf is the neighbours not mine.

I have cut a beer can in half and have two large jub clips, I'll put thay on tomorrow and see how long it lasts - drove around today with just the ally tape and it was fine.

I dont have a welder but its on the shopping list, will a small MIG be ok?
 
Mine as been welded already at the same spot ( and badly) by the previous owner, it look like its a "common" thing???

Just a thought, but while you are at it you might as well empty the cat... Nop?
 
Hey bud,

Yup, I did think about that but not sure of what to expect.

It's a bit cramped under there and not sure that the pipe/cat would move away to one side allowing adequate poking room :)

I saw on another forum they can be full of nasties as well :eek:
 
Well the ally tape held up ok, put the beer can on plus some more but didnt bother with the jub clips -

Can always get to it quite easily without removing the under trays although this time i drilled them and attached cable ties to stop the mid section drooping down :thumb:
 
I have 'decatted' my 96MY SL500 with a PowerFlow S/S system. I left the front downpipes/lambda sensors in place but have had flanges put on the old cats and on the new centre section so I can insert the cats back in to place easily again if I need to for emission on MOT.

There is a x-pipe/balancing pipe in the centre section. I have also had custom S/S tips made exactly the same as the stock exhaust tips so you cannot tell the difference by looks from the back. I wantedto keep my car stock looking.

It is a fair bit louder than before but that is not bad thing as I think the stock system is too quiet. There is a rasp/ringing noise at half to full throttle I believe due to the cats not being there anymore. At full 110% beans the sounds is not far off a top fuel dragster so it changes the car massively. Sounds much more like a muscle V8 now and more in tune with the later high performance V8 Mercs.

I was going back to the shop as initially I thought it was too loud but I am actually growing to like it now. It seems to 'breathe' much better now and the small lag that there seemed to be for example from 2nd to 3rd is now gone and the gearchanges are followed by instant acceleration in a very urgent fashion. Feels quicker and much more responsive to me so a good result. Expensive but worth it and much cheaper than buying a pair of stock cats and stock cat back exhaust system.

Highly recommended in my book but I guess it is subjective and really depends if you want a quiet refined SL500 or one with a bit more bite to it!
 
I agree the stock exhaust is far too quiet ... M-B must have thought so too, as '99 onward ones have a louder system. Also re. keeping the stock appearance - my one pet hate about s/s systems is seing an 'off the shelf' oval section rear box hanging down.

Have you removed all the cats, or left the front ones on (I'm 99.9% sure there are 2 each side)? If you've taken them all off there is no way IMHO it will get through the MOT so be prepared for some spannering then.

There was a recent change re. noise regs. which means your car can be failed on the MOT if the tester considers
Exhaust noise is in excess of that emitted by similar vehicle fitted with a standard silencer in average condition.
Rather subjective, but I understand that cars with modded exhausts are being failed quite regularly now. So putting the cats back might help in that respect too!

I would love to hear your system - how about some video?

I would like mine to be a little louder but I don't want to be messing around come MOT time. It only has the cats and AMG rear box (s/s/ piping where the centre muffler was) now ... one possible option is to get the back box opened up, some of the baffling removed, then welded up again.
 
Ah..I see...would be interested to hear a '99 model as I was looking for a bit more noise but think I have a bit too much now. I agree about keeping it stock. I am not much of a showman and thought the SL500 would be a bit too pretentious to non-car people if you know what I mean. I know car people would get an understand and SL500 but some not aware may see it is a bit showy and pretentious. I haven't had any hand gestures waved at me in the last 6 months since I have had it so it must be OK.

I was hoping I had 2 pre-cats on the front downpipes in addition to the rears but alas I haven't. I was therefore left with a bit of a quandary as one cat had gone and the second was starting to breakdown. It was either go for stock MB cats at about £1200 for the pair, non-MB for about £500 a pair or hi-flow sports cats at £600 for the pair. Last option was a decat with flanges to insert removed old cats for about £250. I went for decat option as if it backfires I am only £250 worse off if I then popped in hi-flow cats later down the line.

I have heard many people seeming to have passed MOT emission just one the 2 front pre-cats with rears removed. Not come across anyone yet with a pass on no cats on a post-93 model! Here's hoping!! I will do a pre-MOT emission check in 12 months to see if it will and if not will pop the old cats back in before its MOT. I got a new MOT done just before doing the exhaust/cats work even though I still had 6 months left. Meant I knew there were no problems with the car as it passed fine and also proved it was worth keeping the old cats for re-use if needed later as they would pass emission fine. It flew threw on emissions no problem even though there is barely anything left on the inside of the completely broken cat. The difference in weight of the two now is quite amazing so not sure if the broken one is doing much anyway.

Interestingly the week before the car went in for the work the car was seemingly strangled over 4k rpm which gave symptoms of a dirty or faulty MAF sensor (had this on my BMW 540i). However after the exhaust change and cats removed it was perfect proving it was likely the broken cat causing the issue.

Anyone know what the noise emissions limit or regulations are as I would like to do a noise test with a db meter to see if I am happy with it? I have agreed to take it back to the shop to have them look at the noise issue but haven't been able to get there yet as our 2nd child decided to make an appearance last week so not had the time.

I will do some video footage and post in some fashion as soon as I can. If it is the kind of thing you want it really sounds very good. It has a small deceleration burble a solid idle and light throttle note and a quite amazing full tilt crescendo! The only thing I am not sure about is the light/medium throttle is a bit too loud IMHO some might really like it though.

When I did a fair bit of reading to find out about the make up of silencers it seems there is a box with aired/holed baffle centre and wadding around the outside that does the silencing bit. Depending on the amount and acoustic silencing properties of the wadding used gives you the level of noise of the system. It seems to have no effect on back pressure/performance etc. but purely the noise level.

I would prefer mine 25% quieter so not an awful lot less. Would prefer too much noise rather than not enough though as I don't use the car tons and that was the point of it to be enjoyed. The noise really has helped it to feel a little more special and different.

I will post some pics as well showing the stock tips. Sorry for the long post!:o
 

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