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Rerouted 200tdi 90 exhaust


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Well the rear silencer has just about given up the will to live and with an up coming MOT it was time to do something about it, plus the fact that the FEDIMAs catch on it when the tyre moves up into the tub.

So using an new (ish) 300tdi rear 90 section I decided to chop it about to use the pipe work and bends to make something a little more geared towards the vehicles requirements.

The old pipe was cut off just after the mid box and some 300 sections fabricated together and welded on. This made a straight pipe up and over the axle to terminate in the 300 end clamp just above the chassis legs.


The aim was to then fabricate another tail pipe (with no rear box) to mate to the 300 end clamp and then exit just in front of the rear cross member. It cross over the rear chassis arms instead of the std underneath option to reduce the chance of it getting knocked.


This way there was no rear box to catch the tyres, the std rear winch spot was left free in case its needed in the future and the exhaust can’t be squashed by the crossmember on sharp drops plus its it has better protection coming over the top of the chassis rail.

The tail pipe is held in place using 300 hangers and rubber bushes, this then mounts to an adjustable arm coming vertically from the loadbay.


And from side:


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The exhaust you have fiited does not appear to be a genuine 200tdi exhaust.

Both the exhaust fitted to my old 90 (factory 200tdi) and the one bought for my new 90 (Disco 200 conversion) have the back box between the chassis rails in the place where the fuel tank is located on a TD5. The pipe enters from the front of the car on the passenger side of the box and then exits just behind this also on the passenger side of the box and passes beneath the chassis rail to exit behind the rear wheel, it does not pass under the rear cross-member at any time.

The arrangement of this allows an easy conversion to a high level exit through the bodywork, simply by cutting and rotating the elbow from the main pipe as it enters the back box, then welding this to the tailpipe (also cut from the back box). This can be made to pass through the stilt above the main chassis rail that supports the tub just in front of the rear crossmember. This completly removes the backbox and with careful positioning allows an exhaust that does not protrude beneath the chassis rails at any point.

I will post pictures when I get hold of a camera :)

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i thought the rear box in the middle or the rear load bay (common rear winch position) was the std 300tdi 90 exhaust.

anyway not to worry, i wanted to keep that load space free in case a winch ends up going in there so chopped up on of those to make what i now have. woudl welcome your pics though.

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Lewis, just picked up a std TD (19J) and from the looks of the exhasut on that maybe mine was the TD one not a 200tdi one. not sure now what a proper 200tdi one looks like.

Yeah i had one of these on the car before the tdi conversion, i thought yours looked similar, the bore is slightly smaller. Might be worth changing for the price, complete 200tdi def system was around 90 quid IIRC :)

Did you have trouble with mating it to the Steve Parker downpipe? (sorry dont know the history of your truck so ignore me if you do not in fact have a disco engine) I have heard from other people that there are issues with mating a TD exhaust to the Steve Parker, but the standard def 200 tdi exhaust will mate straight up. I dont know any of this from personal experiemce - my exhaust is yet to be fitted as i still havent bought the downpipe - but have heard it from friends

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mine came already fitted with LR gen parts retrofit def 200tdi engine kit,

i did a disco 200 into a def last Chrsitmas though and we used the steve parker down pipe into the original TD exhaust.

there a write up the tech archive at the end of Les' thread, Dan did the exhaust bit so read what he did there, dotn think he had any problems, i will ask him though. Def worth the money as we didnt have the time (or skills) to fabricate one

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  • 2 months later...

Okay, its been two months but i finally got around to doing photos of both mine and a mates rerouted exhausts on disco tdi engined 90s

Apologies for the poor quality - most photos were taken at night and i have had to massively resize them for uploading, if anyone wants the raw image PM me

First: Jakes side exit made entirely from the standard exhaust


From in the arch




From between the chassis rails from the rear



Next: My slightly downward pointing mid/side exit - if it causes problems then i'll route it up through the bodywork like Jakes


View of over axle routing


This picture shows it hangs very little below the chassis rails which is what i wanted. The tailpipe can be rotated in any direction by slackening the two bolts at the flange and twisting the end piece


If anyone has questions just ask

Lewis :)

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i thought there was a MOT/C&U reg that said zorsts had to extend outside the bodywork to stop fumes getting sucked back in? i could well be wrong though. looks a lot neater job than the rerouting i did on my disco zorst though.

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MOT requirement is exhaust exits in line with or proud of the bodywork, so a couple of mm outside should be ok.

I made my own exhaust for catflap, and what a little swine it was. :angry: 3-attempts at the downpipe, and then it wasn't too bad. Wish I had thought ahead a bit though and altered the flywheel crossmember to keep the downpipe high.


The 2.5TD exhaust joint collars are too big and awkward.


Jaguar ones are thinner, same diameter, and make the joint a lot tidier.


First join is over gearbox mount, passeneger side.


The exhaust is supported on one of the gearbox mounting bolts.


200TDi rear box. Not too sure about the rear mounting, I think it might make a racket inside the back.


Finally exits centre of the PTO hole.


Lewis/JST - do you notice much noise difference with the rear box missing?

I vaguely remember someone posting that the noise is irritating at higher revs.


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Lewis/JST - do you notice much noise difference with the rear box missing?

I vaguely remember someone posting that the noise is irritating at higher revs.


On the red 90 (first lot of photos) it now has only the small box shown over the rear axle in the pictures, this isnt too loud although it is noticeably louder - the tyre whine covers most of the noise. It is more of a diesel exhaust noise than a turbo spool

On my 90 in the second lot of photos I have only the standard 200tdi centre box, from the bonnet end you can here the turbo more but from the rear it just sounds like a standard defender on idle, raise the revs and it gets louder but is never uncomfortable, i think the volume is more of a function of the short tailpipe length than lack of boxes. Again most exhaust noise is covered by engine/tyre noise

Neither vehicle is fitted with any mats, carpet or sound-deadening in the cab

Lewis :)

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Les, absolutely no noise difference with the rear box removed on mine. and i wouldnt say the car is loud. on td5 taking the mid box out made hell of a difference in noise. but this tdi one and no rear box - no difference in noise, mpg, performance nothing, i put it donw to the extra bends etc.

mine doesnt protrude from the body work, OK so far with MOT though

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  • 1 month later...

Hi lewis

I did a similar thing about 3 weeks ago

but I get rid of the front Cat and replaced it as mentioned in the Tech section

I plumbed for Defender middle box (no back box)

having had somesort of flatfish oval middle box in the past - which reduce the tail section to about 50-55mm

for the tail section I cannibalised the old cat to first box section I had removed, leaving me with a sleeve to put a 40 cm tail pipe exiting just left of the rear tow bracket pointing down & slighly to the left (ensuring it isnt in the line of any wheel spray)

previously i has a large 90deg bend just behind the middle box leading to a raised side entry just behind the passenger door. impressive but not too practical as when booted the soot would soot the side of the vehicle.

This weekend the vehicle will be in a trial and so will test the straight through-to-the-back configuration.

removing the cat & upping the exhaust pipe throughout to 60mm has made a diff

happy trails

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