Hello Bs and Gs,

Just wondering if anybody has decatted their Superb? I'm asking because mine rattles at idle revs and annoys the hell out of me. The 130PD sounds agricultural enough without adding a bloody annoying rattle to matters. I was thinking of just binning the damned thing if it wasn't too much hassle. I'm guessing an exhuast would need to be fabricated with the correct flow dynamics, unless anyone knows of an off-the-shelf part that can be bought?

Also does it require any adaption via Vag-Com / VCDS?

Just looking for info really, would be good to hear first hand experience.

Cheers.

Edited 11 July, 201213 yr by allclownsareevi

There is no VAG mod needed, that i am 100% sure off. I've got the same problem, but don't have money to fix it. Removing the cat will definitely increase exhaust noise.

Removing the cat will definitely increase exhaust noise.

That did occur to me also. Good news that it doesn't need adaption though. I'll have a chat with an exhuast bloke I know and see how much a decat box would likely cost. Cheers for the reply.

Ok so rather than removing the cat I managed to get a few minutes with the car on the trolley jack and check out where the rattle was coming from. It is the cat rattling but it's an internal rattle (not the heat shielding or clamps). A little further inspection revealed that the mid-section vibrating causes the rattle. It's a long peice so I'm guessing a small vibration at one end amplifies as it travels along the box.

Figured I'd try and cobble together a vibration dampner with a few bits I had laying around. A 58mm exhuast clamp, a few cable ties and a peice of timber to spread the load and hey presto we had ourselves something that works. Pictures below, and yeah I'm ready for a host of laughs on this one, I deserve them. I mean look at it!

... but it was more of a proof of concept to be fair.

It works a treat, no more annoying low-rev rattle. I'm going to fabricate a plate for the clamp so I can hang a poly-rubber belt from it and do away with cable ties. The poly belt should have a little give in it and soak up any vibrations without putting any strain on the exhuast.The peice of wood was only there to test the load on the lower metal bracket and will be lauched towards the nearest bin.

btw check out my garage leds. It's depressing when your garage is cooler than you car.

Edited 11 July, 201213 yr by allclownsareevi

Love your garage dude

BTW what floor do you have there, is it just paint or some sort of seal?

Edited 12 July, 201213 yr by oh_superb

Heath Robinson lives!

Seriously though nice work, I might give this a go, I have a slight annoying rattle I think is coming from there...

Thanks man, it's a standard concrete floor which was then sealed. Let it cure for at least 6 months then cover with floor paint. It's good, It really keeps the dust down and oil spillages aren't an issue anymore. When it gets dirty just throw a bucket of soapy water over it and squeegey it off. B&Q sell the stuff for £37 for 2.5l. Do a search on eBay though and you'll find the same stuff for around £25 for 5l. I got 10 litres for £25 delivered.

Just don't seal it with the stuff that you put on driveways because if you ever come to paint it it can inhibit the paint adhering to the floor.

It needs a recoat every 3 or 4 years I guess but it's far easier than the first coat. About an hour job. Did it end of last year. Being as it's about the only room in the house that I'm allowed to call my own when I finished recoating it I thought this was so beautiful I almost cried.

I know it's shameless but I'm using this opportunity to post up a picture of my cabin leds. (If asked I'll lie and say I posted them up because we were talking about floor paint.) I finally got around to switching out the yellow standard bulbs with some high rated LEDs last month.

Heath Robinson lives!

Seriously though nice work, I might give this a go, I have a slight annoying rattle I think is coming from there...

You're bloody right it's Heath Robinson mate but don't worry I'm suitable ashamed of my mock-up. It's half the reason I posted it up, figured it may get a laugh.

Whilst it's cured the very low-rev rattle it does transmit some vibration at around 1800 revs. This weekend I'm going to switch out the cable ties with a poly-rubber belt. (taken from a vacuum cleaner of all places) The polyrubber should absorb vibrations without transmitting them directly into the floor pan. I'll let you know how I get on.

Edited 12 July, 201213 yr by allclownsareevi

Well as I posted above my first attempt mock-up to cure my infuriating exhaust rattle met with mixed results. Whilst it cured the low-rev rattle, it produced reverberations at almost every other rev-range. I guess it's because the cable ties, when under tension, become almost rigid and transmit the vibration to the floor pan.

So I fashioned a metal brace to fit on the base of the exhaust clamp.Very easy to do, took less than 5 minutes. The brace just holds a rubber belt securely in place, away from the heat of the exhaust. The rubber belt is tensioned enough to apply a little pressure to the exhaust (stopping it vibrating), but there's enough slack in it so that it doesn't transmit vibrations to the rest of the car.

In case anyone is interested, the belt was a 6" replacement part for our old Dyson vacuum cleaner and cost a few quid maybe? The exhaust clamp was 58mm diameter and cost about £1 from partco. I'm still painfully aware this is Heath Robinson solution, but to be fair, it does cure the problem without having to shell out for new cat.

The car still sounds like a Series II Land Rover, but so does every other PD engine. I doubt anyone else will find this useful, but it may get a laugh or two.

I took pre-cat and cat off, used metal bar to get all staff out

then fitted it back on

no huge power gains but it still passed mot

soon will pop in to my local powerflow-exhaust specialist and get all custom done in stainless still with straight through with one backbox

I have to say my one is 2.5tdi Auto