exhausts...

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A

Austin Shackles

Guest

having just been reading the MOT tester's manual...

it doesn't say anything about cats on compression ignition engines - the
vehicle has to pass the appropriate smoke test, is all.

new system put on the 300 TDi - both boxes are "straight-through" and as
such don't restrict flow.

Put a non-cat front pipe on, mainly 'cos it's about 250 quid cheaper... I
think it makes slightly more black smoke on fire-up, but overall, it's
running better and smoking less, if anything, than before. It's definitely
responding better, especially at low-medium revs. Next time it gets MOTed,
I'll see if I've got leeway to turn the pump up a bit more :)


Someone mentioned a bit back that on a turbo engine, the silencer is almost
redundant, so in a spirit of scientific enquiry, after fitting the front
pipe but no silencers (and of course no cat) I fired the engine up and
revved it a bit. It *is* noisier than normal, but not much. Certainly
nowhere near as noisy as a normal CI engine with no silencer on it.

so I reckon if you wanted, you could just run a pipe out the side or back.
However, since the silencers supplied for the disco are non-restrictive (or
the ones I got are) there's not a lot of point.
--
Austin Shackles. www.ddol-las.net my opinions are just that
"'Tis a mad world, my masters" John Taylor (1580-1633) Western Voyage, 1
 
Austin Shackles came up with the following;:
> having just been reading the MOT tester's manual...
>
> it doesn't say anything about cats on compression ignition engines - the
> vehicle has to pass the appropriate smoke test, is all.
>
> new system put on the 300 TDi - both boxes are "straight-through" and as
> such don't restrict flow.
>
> Put a non-cat front pipe on, mainly 'cos it's about 250 quid cheaper... I
> think it makes slightly more black smoke on fire-up, but overall, it's
> running better and smoking less, if anything, than before. It's
> definitely responding better, especially at low-medium revs. Next time
> it gets MOTed, I'll see if I've got leeway to turn the pump up a bit more
> :)

Our local MOT centre (well, the one I use) is a large Goods Vehicle test
centre too, and if you bung them a fiver they'll check the emissions etc for
you. Money well-spent as a diagnostics I think.

> Someone mentioned a bit back that on a turbo engine, the silencer is
> almost redundant, so in a spirit of scientific enquiry, after fitting the
> front pipe but no silencers (and of course no cat) I fired the engine up
> and revved it a bit. It *is* noisier than normal, but not much.
> Certainly nowhere near as noisy as a normal CI engine with no silencer on
> it.
>
> so I reckon if you wanted, you could just run a pipe out the side or back.
> However, since the silencers supplied for the disco are non-restrictive
> (or the ones I got are) there's not a lot of point.

Indeed. When our rear box 'fell-off' the only way we knew it was gone was
when we got out and saw it hanging down. When the centre box went it was
noisier, as you say, but only enough to make me think there was a problem,
maybe a hole, not that there was no silencer at all. ;)

My next change wil be for a non-cat front bit.

--
Paul ...
(8(|) Homer Rules ..... Doh !!!
ebay 5852306602

 
On Thu, 12 Jan 2006 10:18:44 +0000, Austin Shackles
<[email protected]> wrote:

>Someone mentioned a bit back that on a turbo engine, the silencer is almost
>redundant, so in a spirit of scientific enquiry, after fitting the front
>pipe but no silencers (and of course no cat) I fired the engine up and
>revved it a bit. It *is* noisier than normal, but not much. Certainly
>nowhere near as noisy as a normal CI engine with no silencer on it.

I toyed with making a straight through exhaust for my car (also a
turbo), but I spoke to somebody else who did the same thing and he has
put a silencer back in as the car didnt sound as nice without
anything. This is a petrol though so may differ slightly from a
diesel.
I've just gone for one silencer rather than the stock 2 for the moment
and am on the lookout for a less restrictive silencer to use as my
only one.

 
In message <[email protected]>
"Paul - xxx" <[email protected]> wrote:

> Austin Shackles came up with the following;:
> > having just been reading the MOT tester's manual...
> >
> > it doesn't say anything about cats on compression ignition engines - the
> > vehicle has to pass the appropriate smoke test, is all.
> >
> > new system put on the 300 TDi - both boxes are "straight-through" and as
> > such don't restrict flow.
> >
> > Put a non-cat front pipe on, mainly 'cos it's about 250 quid cheaper... I
> > think it makes slightly more black smoke on fire-up, but overall, it's
> > running better and smoking less, if anything, than before. It's
> > definitely responding better, especially at low-medium revs. Next time
> > it gets MOTed, I'll see if I've got leeway to turn the pump up a bit more
> > :)
>
> Our local MOT centre (well, the one I use) is a large Goods Vehicle test
> centre too, and if you bung them a fiver they'll check the emissions etc for
> you. Money well-spent as a diagnostics I think.
>
> > Someone mentioned a bit back that on a turbo engine, the silencer is
> > almost redundant, so in a spirit of scientific enquiry, after fitting the
> > front pipe but no silencers (and of course no cat) I fired the engine up
> > and revved it a bit. It *is* noisier than normal, but not much.
> > Certainly nowhere near as noisy as a normal CI engine with no silencer on
> > it.
> >
> > so I reckon if you wanted, you could just run a pipe out the side or back.
> > However, since the silencers supplied for the disco are non-restrictive
> > (or the ones I got are) there's not a lot of point.
>
> Indeed. When our rear box 'fell-off' the only way we knew it was gone was
> when we got out and saw it hanging down. When the centre box went it was
> noisier, as you say, but only enough to make me think there was a problem,
> maybe a hole, not that there was no silencer at all. ;)
>
> My next change wil be for a non-cat front bit.
>

You need to change the down pipe & middle box/tail pipe as one, but still
a hell of a lot cheaper than a cat.

Richard
--
www.beamends-lrspares.co.uk [email protected]
Running a business in a Microsoft free environment - it can be done
Powered by Risc-OS - you won't get a virus from us!!
Boycott the Yorkshire Dales - No Play, No Pay
 
beamendsltd came up with the following;:
> In message <[email protected]>
> "Paul - xxx" <[email protected]> wrote:
>
>> Austin Shackles came up with the following;:
>>> having just been reading the MOT tester's manual...
>>>
>>> it doesn't say anything about cats on compression ignition engines - the
>>> vehicle has to pass the appropriate smoke test, is all.
>>>
>>> new system put on the 300 TDi - both boxes are "straight-through" and as
>>> such don't restrict flow.
>>>
>>> Put a non-cat front pipe on, mainly 'cos it's about 250 quid cheaper...
>>> I think it makes slightly more black smoke on fire-up, but overall, it's
>>> running better and smoking less, if anything, than before. It's
>>> definitely responding better, especially at low-medium revs. Next time
>>> it gets MOTed, I'll see if I've got leeway to turn the pump up a bit
>>> more :)
>>
>> Our local MOT centre (well, the one I use) is a large Goods Vehicle test
>> centre too, and if you bung them a fiver they'll check the emissions etc
>> for you. Money well-spent as a diagnostics I think.
>>
>>> Someone mentioned a bit back that on a turbo engine, the silencer is
>>> almost redundant, so in a spirit of scientific enquiry, after fitting
>>> the front pipe but no silencers (and of course no cat) I fired the
>>> engine up and revved it a bit. It *is* noisier than normal, but not
>>> much. Certainly nowhere near as noisy as a normal CI engine with no
>>> silencer on it.
>>>
>>> so I reckon if you wanted, you could just run a pipe out the side or
>>> back. However, since the silencers supplied for the disco are
>>> non-restrictive (or the ones I got are) there's not a lot of point.
>>
>> Indeed. When our rear box 'fell-off' the only way we knew it was gone
>> was when we got out and saw it hanging down. When the centre box went
>> it was noisier, as you say, but only enough to make me think there was a
>> problem, maybe a hole, not that there was no silencer at all. ;)
>>
>> My next change wil be for a non-cat front bit.
>>
>
> You need to change the down pipe & middle box/tail pipe as one, but still
> a hell of a lot cheaper than a cat.

Yes, if using LR original parts. Our local Kwik Fit did me a great job with
pattern parts, just replacing bits rather than a full exhaust.

--
Paul ...
(8(|) Homer Rules ..... Doh !!!
ebay 5852306602

 
On or around Thu, 12 Jan 2006 11:18:38 +0000 (UTC), beamendsltd
<[email protected]> enlightened us thusly:

>>
>
>You need to change the down pipe & middle box/tail pipe as one, but still
>a hell of a lot cheaper than a cat.

looks like the "300 TDI non-cat" front pipe would be a direct replacement
using an existing centre box and rear pipe. It's also possible to fit it
without removing either half the suspension or the gearbox crossmember,
which looked like it would be the case with a cat one. I decided it was
easier to hacksaw through the old one to get it off. Judging by how
difficult fitting the non-cat pipe was, there's no way the cat one would
have gone on without removing something. This one has a front anti-roll
bar, should be said.

In this case the whole back half of the system was shot - the rear box fell
off some time ago and the pipe was rotten all the way through. The centre
box is actually OK but the pipe had detached itself from the back end of it.
But provided you eschew the cat the whole system is not expensive enough to
be worth putting half a new one on it.

--
Austin Shackles. www.ddol-las.net my opinions are just that
"Would to God that we might spend a single day really well!"
Thomas À Kempis (1380 - 1471) Imitation of Christ, I.xxiii.
 
dosn't matter if it's petrol or desil there is no requirement for a cat,
unless the engine needs it to meet the emission standards, which is unlikely
on a desil. Have seen the straight through exhaust system fitted to 2 turbo
desils so far and at tickover is only slightly louder, although the tone of
the exhaust changes, in all other respects the vehicle remains roadworthy
ie. emissions and noise
"Tom Woods" <[email protected]> wrote in message
news:[email protected]...
> On Thu, 12 Jan 2006 10:18:44 +0000, Austin Shackles
> <[email protected]> wrote:
>
>>Someone mentioned a bit back that on a turbo engine, the silencer is
>>almost
>>redundant, so in a spirit of scientific enquiry, after fitting the front
>>pipe but no silencers (and of course no cat) I fired the engine up and
>>revved it a bit. It *is* noisier than normal, but not much. Certainly
>>nowhere near as noisy as a normal CI engine with no silencer on it.
>
> I toyed with making a straight through exhaust for my car (also a
> turbo), but I spoke to somebody else who did the same thing and he has
> put a silencer back in as the car didnt sound as nice without
> anything. This is a petrol though so may differ slightly from a
> diesel.
> I've just gone for one silencer rather than the stock 2 for the moment
> and am on the lookout for a less restrictive silencer to use as my
> only one.
>


 
Dad wrote:
> dosn't matter if it's petrol or desil there is no requirement for a cat,
> unless the engine needs it to meet the emission standards, which is unlikely
> on a desil. Have seen the straight through exhaust system fitted to 2 turbo
> desils so far and at tickover is only slightly louder, although the tone of
> the exhaust changes, in all other respects the vehicle remains roadworthy
> ie. emissions and noise

As I understood it, there is a requirement for a cat on vehicles on /
after a K plate. I had a J-plate Audi and was told by a specialist
exhaust manufacturer that if it had been a K-plate I wouldn't have been
able to remove the cat legally, but as it was I could, and I did! I'm
not sure about requirements for diesel vehicles though.

Only thing you need to be careful about when removing the cat is that it
can cause vibration problems/noise within the exhaust at certain RPM
unless it is replaced with a silencer box, but that's all down the the
particular vehicle.

Matt.
 
Matthew Maddock wrote:
> Dad wrote:
>> dosn't matter if it's petrol or desil there is no requirement for a
>> cat, unless the engine needs it to meet the emission standards,
>> which is unlikely on a desil. Have seen the straight through exhaust
>> system fitted to 2 turbo desils so far and at tickover is only
>> slightly louder, although the tone of the exhaust changes, in all
>> other respects the vehicle remains roadworthy ie. emissions and noise
>
> As I understood it, there is a requirement for a cat on vehicles on /
> after a K plate. I had a J-plate Audi and was told by a specialist
> exhaust manufacturer that if it had been a K-plate I wouldn't have
> been able to remove the cat legally, but as it was I could, and I
> did! I'm not sure about requirements for diesel vehicles though.
>
> Only thing you need to be careful about when removing the cat is that
> it can cause vibration problems/noise within the exhaust at certain
> RPM unless it is replaced with a silencer box, but that's all down
> the the particular vehicle.
>
> Matt.

No requirement on diesels as long as emissions are met. Binned the one on
our defender (P reg) years ago. Middle box went next. Back box will follow.
Coupled with the full width intercooler it flies!

--
Graham

101 GS
101 Radio Body


 
On or around Thu, 12 Jan 2006 16:29:40 +0000 (UTC), Matthew Maddock
<[email protected]> enlightened us thusly:

>Dad wrote:
>> dosn't matter if it's petrol or desil there is no requirement for a cat,
>> unless the engine needs it to meet the emission standards, which is unlikely
>> on a desil. Have seen the straight through exhaust system fitted to 2 turbo
>> desils so far and at tickover is only slightly louder, although the tone of
>> the exhaust changes, in all other respects the vehicle remains roadworthy
>> ie. emissions and noise
>
>As I understood it, there is a requirement for a cat on vehicles on /
>after a K plate. I had a J-plate Audi and was told by a specialist
>exhaust manufacturer that if it had been a K-plate I wouldn't have been
>able to remove the cat legally, but as it was I could, and I did! I'm
>not sure about requirements for diesel vehicles though.
>
>Only thing you need to be careful about when removing the cat is that it
>can cause vibration problems/noise within the exhaust at certain RPM
>unless it is replaced with a silencer box, but that's all down the the
>particular vehicle.

It's not in the MOT regulations. The exhaust has only to be secure, not too
loud and not leak. If the vehicle can pass the appropriate emissions test
(which a good engine with a good LPG system can, if you're lucky) then the
cat doesn't have to work. Not sure if it's an offence under C&U to remove
the cat, if the emissions are OK without it.

--
Austin Shackles. www.ddol-las.net my opinions are just that
"Something there is that doesn't love a wall."
Robert Frost (1874-1963)
 
On 2006-01-12, Austin Shackles <[email protected]> wrote:

> If the vehicle can pass the appropriate emissions test (which a good
> engine with a good LPG system can, if you're lucky) then the cat
> doesn't have to work. Not sure if it's an offence under C&U to
> remove the cat, if the emissions are OK without it.

My plastic rocket is too old to need a cat, but owners of later models
sometimes bash the cat innards out as the engine is clean enough to
pass the emissions standards without it. They're hoping that if they
get caught they can claim that they didn't know, although whether
that'll stand up or not is another matter. Their understanding is
that a cat is required whether it's needed or not, however given the
confusion amongst MOT testers I think they're assuming that on the
basis that the MOT tester will fail them anyhow even if it's not
required.

--
Blast off and strike the evil Bydo empire!
 
Matthew Maddock <[email protected]> wrote:

> Dad wrote:
>> dosn't matter if it's petrol or desil there is no requirement for a
>> cat, unless the engine needs it to meet the emission standards, which
>> is unlikely on a desil. Have seen the straight through exhaust system
>> fitted to 2 turbo desils so far and at tickover is only slightly
>> louder, although the tone of the exhaust changes, in all other respects
>> the vehicle remains roadworthy ie. emissions and noise
>
> As I understood it, there is a requirement for a cat on vehicles on /
> after a K plate. I had a J-plate Audi and was told by a specialist
> exhaust manufacturer that if it had been a K-plate I wouldn't have been
> able to remove the cat legally, but as it was I could, and I did!

Think it must be a date related thing. No cat on my k-plate 110 - ever,
so far as I cat tell.

FWIW: we also have l-plate box that does have a cat and the
restrictor/reducer in the fuel filler pipe.

--
William Tasso

110 V8 (white)
 
On 2006-01-12, William Tasso <[email protected]> wrote:

> Think it must be a date related thing. No cat on my k-plate 110 - ever,
> so far as I cat tell.

Pre-1993 IIRC, no cat on my '89 petrol-engined car.

--
Blast off and strike the evil Bydo empire!
 
On 2006-01-12, Ian Rawlings <[email protected]> wrote:

> Pre-1993 IIRC, no cat on my '89 petrol-engined car.

Ooops, I mean there was a cat, but no requirement for it on the MOT,
so I took it off as it was screwed, no problems at MOT time.

--
Blast off and strike the evil Bydo empire!
 
On or around Thu, 12 Jan 2006 19:03:02 +0000, Ian Rawlings
<[email protected]> enlightened us thusly:

>My plastic rocket is too old to need a cat, but owners of later models
>sometimes bash the cat innards out as the engine is clean enough to
>pass the emissions standards without it. They're hoping that if they
>get caught they can claim that they didn't know, although whether
>that'll stand up or not is another matter. Their understanding is
>that a cat is required whether it's needed or not, however given the
>confusion amongst MOT testers I think they're assuming that on the
>basis that the MOT tester will fail them anyhow even if it's not
>required.

but not required to test for cat function. The test is for emissions, and
if your engine can pass with a cat with a hole through the middle, you can
disclaim all knowledge of the hole. Nor will you get pulled up on it; if it
fails the emissions test it'll be put down to a defective cat and it'll get
replaced.

there's nothing in the test manual says the cat has to work, only that it
has to pass the test. I'll have a look in C&U sometime.
--
Austin Shackles. www.ddol-las.net my opinions are just that
"For when the One Great Scorer comes to write against your name,
He marks - not that you won or lost - but how you played the game"
Grantland Rice (1880-1954). my opinions are just that
 
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