Cat free exhaust parts???

[nishikigoi]

I'm going to remove the cat 8)

I don't want a rear box, that will just hit the mud :oops:

What I want is a cheap factory part solution, with a middle box but no rear box (probably going for side exit with flexi-pipe).

Should I/can I buy a CAT bypass (seen on ebay for about £60...ouch! :shock: ) I have a centre box but no rear box (factory) at the moment and just redirrect the tail out the side?

Or buy an early 300Tdi system with no cat BUT these look like they all have a rear box :x

I don't mind the extra noise, so what are my options?

 :(thinkhard):

[ChrisW]

Mine is an early 300 system with no CAT. It has a centre box and a rear box if that's what you're after (without the rear box)?

I've also changed the front down pipe for a 110 300Tdi downpipe as this does not have the flexible section that only lasts six months  :twisted:
It's a straight swap for the Discovery pipe although it's a bit more of a fiddle to fit without the flexy bit!

Only thing you'd need to do is get someone to sort you out with the pipework for the side exit.

[nishikigoi]

Only thing you'd need to do is get someone to sort you out with the pipework for the side exit.

That will be flexible stainless like for boats  

[DiscoJim]

I have done a similar thing with mine. I removed the centre silencer a few months ago in the hope of releasing a bit more power. I have already upgraded the intercooler so thought this would be worth doing. It made little or no difference to the power or noise.

Recently my front pipe suffered some damage so it was a good opportunity to do away with the CAT. I bought part number ESR2740, a non CAT replacement front pipe with flexi section, it is a straight swap.

The difference is good, it revs more freely, is much happier to pull away and accelerates better but I do feel that top end power is lacking now.

It sounds nice too, a little bit chav in built up areas but quite nice.

[Skibum346]

Doensn't removing the cat have an MOT emmissions implication?  As in the standards are higher... remove the cat and you fail those standards as your vehicle SHOULD have a cat?

Skibum

[DiscoJim]

Doensn't removing the cat have an MOT emmissions implication?  As in the standards are higher... remove the cat and you fail those standards as your vehicle SHOULD have a cat?

Skibum

No, the regulations do not apply to diesel engined cars. Petrol cars built after 1993 do require a CAT to be fitted.

I am not sure what the emmisions test is on diesels but I think the smoke test is more important. Smoke levels are not effected by the CAT being fitted, thats a particulate filter that only very new and mostly German cars have fitted.

[Skibum346]

Ah....  That'll be ANOTHER reason to not have a V8 then.... or should I say three?   :roll:

Skibum

[floyd fan]

I've just bought the non cat downpipe from here....

http://www.dls-uk.co.uk/disco300exhaust.htm

48 quid & 7 quid p&p. Arived next morning, brill service.

[Horness]

No cat, and a defender down pipe fitted - passed MOT on the 1st with flying colours.  Emissions passed fine too.

Just want a side exit now.   :twisted:

[Cal]

Do you notice much difference without the cat Horness?

[barny]

Does anyone know when diesel cat law came in ? Mines had a new un fitted recently, but in the interest of squeezing more power from the 300tdi engine i'll quite happily swap it for something more willing !  8)

[DiscoJim]

Does anyone know when diesel cat law came in ? Mines had a new un fitted recently, but in the interest of squeezing more power from the 300tdi engine i'll quite happily swap it for something more willing !  8)

I am not sure that CATs are required on any diesels, if they are it will be fairly recent maybe 1998-2000 something like that.

[rangerider]

Bullfrog has done a few discos with no rear box & a side exit, mine will be visiting him before the year end for the mod.

I think he hangs around on here, if not http://htp://www.bullfrog4x4.co.uk

[Horness]

Do you notice much difference without the cat Horness?

None at all Cal, except my exhaust cost dropped to less than £125 end-to-end, fitted.  

I'm interested in taking mine to Bullfrog, but want to make sure I have the paint and rubber gromit to prep the hole when it's done, otherwise I'll never get round to doing it!  :lol:

Need a fuel tank guard first... don't fancy another dent in the tank.

[Cal]

None at all Cal

That's interesting - on the DOC forum, one of the guys said removing the cat would give better gains than getting rid of the mid section silencer.

I was thinking about getting one of the sports exhausts from Rimmer Bros which is from the cat back, but don't know how noisy it would be.

Also think that if I can afford it then a side exit makes much more sense for offroading.

Looks like we've got a similar list of planned mods Horness - HD rear bumper and fuel tank guard on mine too, and DP sliders waiting to be fitted (still!)

[barny]

Does anyone know when diesel cat law came in ? Mines had a new un fitted recently, but in the interest of squeezing more power from the 300tdi engine i'll quite happily swap it for something more willing !  8)

I am not sure that CATs are required on any diesels, if they are it will be fairly recent maybe 1998-2000 something like that.

Marvelous, that can be binned then ! Theres a stainless steel exhaust maker near here, i'll have a wander over some time and get some prices  8)

[Jake]

I'll be doing the same with my exhaust soon.
The flexy section is shot and the partical converter is killing my power and i want a side exit pipe too.
I had some flexy pipe on my V8 and it ran out the side (which was much neater and never got smashed)
 8)

[Porny]

You do not need a CAT on any diesel, regardless of age...

A Catalytic Converter test only applies to Spark Ignition Engines (i.e. Petrol's) not Compression Ignition (i.e. Diesel).
The catalyst test is part of the MOT test for most class IV spark ignition petrol engined passenger cars with four or more wheels first used on and after 1 August 1992.

A Diesel Engine only undergoes a smoke test… which a CAT will not effect anyway. A CAT does not stop Diesel smoke.

Vehicles first used before after 1 August 1979 – only have to undergo a visual smoke test

Vehicles first used on or after 1 August 1979 – are tested with a probe.


But either way a CAT is not tested regardless of whether it is fitted or not.

And a 300Tdi is not a proper CAT anyway, only a particulate filter.

The reason a CAT and EGR where fitted when new was to ensure that Land Rover met EU emission regulations for that model year. This is needed to gain type approval for that vehicle.

However, what the owner does to the vehicle once they have bought it is up to them…. The only test it will undo again is an MOT. It never needs to meet the EU legislation. So as long as it passes an MOT then an owner can do what they like.

Hence why people remove CATS and EGR without a problem.

Neither my 90, my parents Disco or my brothers Disco (all 300Tdi) have CATs or EGR fitted, and have never once had a problem. (and my 90 exhaust is far from standard!!!)

When the TD5 was launched it didn't need a CAT either, but one was fitted latter in it's life to meet EU4 legislation. (but again an owner can remove it!!)

Do you notice much difference without the cat

A minor difference, less back pressure means the turbo will spin up slightly quicker... more noticeable mid range.
Removing the large centre silencer box also makes a difference, again you will notice a slight improvement mid range.

As for noise - with just the rear small silencer:

if the system stays a standard length, then it doesn't get too load (the turbo acts as a silencer anyway).  
It is louder outside the car (and you will get an exhaust burble at idle) - and a whistle when on boost, but you can't really notice it that much from the drivers seat.

The noise only increase if you shorten the overall exhaust length; like the exhaust on my 90


Ian

[barny]

Excellant, you've sorted all my thoughts for me !

Now if you could just find a way for £75k per year .....  

[nishikigoi]

Excellant, you've sorted all my thoughts for me !

Now if you could just find a way for £75k per year .....  

Rent boy :smack:

 :(mad):

[davidlandy]

I have took the CAT from my 90 300tdi and replaced it with a straight thru pipe - it made a very noticable difference to low end pullaway throught to mid range. You can now hear the turbo singing more happily.  I would recommend it.  Took it for MOT passed ok.

blanked off the EGR last weekend after I finally got those fiddly allen bolts out of the manifold. Was gonna let Mr. Angle Grinder in on the action to speed up the job, but perserved and got there in the end with my allen keys and a ring spanner for a bit of leverage. :D

Havent driven it yet to see if there any difference.

only thing left to do now is cure the black smoke I get when before the turbo spools up.

[nishikigoi]

.

only thing left to do now is cure the black smoke I get when before the turbo spools up.

use 2 'ickle screw drivers to remove the 1" plug on top of the diaphram on the pump, turn it in 1/4 turn at a time, lock nut is 110 Flb tight 8)

[Cal]

I need to adjust my smoke screw as well - just to make sure I'm reading it right - do you mean do 1/4 turns clockwise, or anti-clockwise?  :?

Cheers  :D

[nishikigoi]

Probably best to post the links so you can read for yourselves. The best improvment was to turn the fuel supply screw in on the back of the pump, much better (ask Jake   )

http://dodgeram.org/tech/dsl/more_power/Power_ve.htm

http://www.cs.rochester.edu/u/jag/vw/engine/fi/injpump.html

[Jake]

The best improvment was to turn the fuel supply screw in on the back of the pump, much better (ask Jake   )

What a difference this made to mine!
Smokes like the red arrows on hard acceleration but beats boy racers off the lights!!
If i drive it sensibly it smokes no more than usual.
 8)

[nishikigoi]

The best improvment was to turn the fuel supply screw in on the back of the pump, much better (ask Jake   )

What a difference this made to mine!
Smokes like the red arrows on hard acceleration but beats boy racers off the lights!!
If i drive it sensibly it smokes no more than usual.
 8)

Just need to get £3.50 worth of Parafin to sort the intercooler now :D

This BHP is expensive  :(kerching):

Must have been 20p worth of diesel lost so far, the weight save from lobbing the collar in the bushes should pay that back in 10,000 years or so :lol:

[Jake]

Parafin will be brought when the car comes back
 

[barny]

Excellant, you've sorted all my thoughts for me !

Now if you could just find a way for £75k per year .....  

Rent boy :smack:

 :(mad):

Cheeky  :twisted:

[Mace]

If I replace the CAT down pipe on my 300tdi with a NON-CAT down pipe, should I then fit a CENTRE silencer for a CAT model or a NON-CAT model ? There are 2 different part numbers. Basically the CAT centre box might have less back pressure than the NON-CAT centre box, correct ?

[Porny]

If I replace the CAT down pipe on my 300tdi with a NON-CAT down pipe, should I then fit a CENTRE silencer for a CAT model or a NON-CAT model ? There are 2 different part numbers. Basically the CAT centre box might have less back pressure than the NON-CAT centre box, correct ?

Most places only list ESR2391 (which is the non CAT pipe) - but they say to use it for both models (A CAT equipped model is actually ESR2390 AFAIK).

Either way, I doubt there is that much (if any) difference between the two.  I bet both use the same silencers so one will not be less restrictive than the other.  Genuine parts may be fractionally different, but I doubt it.

I think you’re confusing Land Rover with a performance car manufacturer, who may be worried about losing a few bhp......  


Ian