Discovery 2 exhaust upgrade

Ok, so I have a 53 plate discovery Td5 with a cat fitted. Im looking to upgrade the exhaust system mainly for performance/economy gains. Im planning to replace the cat with a straight pipe and I would be open to replacing the entire system but I really don’t want my Discovery to sound like a droney sports tractor, particularly on long journeys.

so my question(s) is, is it worth replacing the front pipe if I was to leave the centre and rear silencer? Should I consider replacing both front and rear sections but leave the mid or are there any companies which offer a more free flowing centre silencer as a quick google search seems only to bring up straight through systems?

Any opinions and feedback on your own exhaust systems regarding noise and performance would be greatly appreciated, too!

It won't make any difference

Removing the very large & heavy centre silencer can make the engine pick-up slightly faster - but can make the exhaust very "droney" at speed (unless you're already deaf - lol).
I replaced the centre section on ours with a straight through stainless section & it lasted 4 weeks before I decided it had to have a "cherry bomb" / small straight through silencer welded into it to make it acceptable for long journeys. It would have been great for the boy racers, but you couldn't make "good progress" without everybody in earshot looking at the car & wondering what you were doing.
Adding the straight through silencer had no negative effect on performance.

I replaced the exhaust system on my Disco 1 300tdi for an official LR performance system. Front to back, slightly wider bore, one silencer at the rear.
Transformed the performance and didn't affect fuel consumption at all, in fact probably improved it a bit.
you can only hear it if you are driving through a tunnel or around town with the window open and in traffic it just sounds lovely.
On the open road you can't really hear it.
It reduced the flat spot just above tick over that used to be a right pain when taking off onto a roundabout or whatever, to more or less zero. i.e. the turbo lag.
Best thing i did to my D1
On my D2 TD5, I replaced the front box with a straight pipe, same diameter obvs, and it made no bloody difference at all.
Moral of the story as far as I am concerned, don't feck about, replace the whole system with one dedicated to the car.
The wider bore reduces the back pressure, it makes it breathe easier and spools up the turbo faster.
There are other threads on here about all this.

Pawl said:

Removing the very large & heavy centre silencer can make the engine pick-up slightly faster - but can make the exhaust very "droney" at speed (unless you're already deaf - lol).
I replaced the centre section on ours with a straight through stainless section & it lasted 4 weeks before I decided it had to have a "cherry bomb" / small straight through silencer welded into it to make it acceptable for long journeys. It would have been great for the boy racers, but you couldn't make "good progress" without everybody in earshot looking at the car & wondering what you were doing.
Adding the straight through silencer had no negative effect on performance.

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You'll be able to read about my slightly different experience of doing exactly what you did, but then mine is a 2000 MY with no Cat, maybe that was the reason. I couldn't hear, or feel, any difference at all!

I dont find it loud at all, not over the noise of the mud terrains anyway. I think it sounds great. You need a remap to make it worth your while though

Thanks for all the feedback guys. I think I’m going to go for a full system replacement but will enquire more about some sort of cherry bomb for the centre section and possibly consider just leaving the rear resonator/silencer. I should have mentioned that the Disco has a stage 1 remap, already and I’ve removed the EGR valve. I’m also currently on Allisport’s backlog for an uprated intercooler!

The Allisport intercooler is a useful upgrade. Pick-up starts at slightly lower rpm & seems to add noticable torque + better top end

Pawl said:

The Allisport intercooler is a useful upgrade. Pick-up starts at slightly lower rpm & seems to add noticable torque + better top end

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That’s what I want to hear! I’ve also been considering a stage 2 but I’m not sure how much that would effect the longevity of the engine. It’s just ticked over 90,000 miles and has a FSH so I’d like to think
It’s still got plenty of life in her!

Mr bouze said:

That’s what I want to hear! I’ve also been considering a stage 2 but I’m not sure how much that would effect the longevity of the engine. It’s just ticked over 90,000 miles and has a FSH so I’d like to think
It’s still got plenty of life in her!

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As the bigger/better intercooler will be giving the engine more dense air which will then be hopefully fuelled properly as well, without a decent exhaust to help the engine pump the extra burnt gases out, you'll be wasting quite a bit of the advantage of the new intercooler unless you get the better exhaust.
Simples! not worth getting one without the other!

Mr bouze said:

That’s what I want to hear! I’ve also been considering a stage 2 but I’m not sure how much that would effect the longevity of the engine. It’s just ticked over 90,000 miles and has a FSH so I’d like to think
It’s still got plenty of life in her!

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.
My 2001 10P probably somewhere between stage 1 & 2 in terms of re-map, has the straight through centre silencer, standard rear silencer, Allisport intercooler & is on 201,000 miles without issues so far.
However, I've got an additional "real temperature" guage to monitor water temp & I typically only use full power for 10 ~ 15 seconds max while off-roading & monitor the temp continuously while cruising at speed on road.
If you don't monitor egr temps, you at least need a more accurate temp gauge.

Stanleysteamer said:

As the bigger/better intercooler will be giving the engine more dense air which will then be hopefully fuelled properly as well, without a decent exhaust to help the engine pump the extra burnt gases out, you'll be wasting quite a bit of the advantage of the new intercooler unless you get the better exhaust.
Simples! not worth getting one without the other!

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That’s very useful to know, thanks! Just got back from JSF 4x4 with a quote for a new system and I’m going to give them the go ahead. Think I’m just going to have to feather the throttle when going through a built up area.

Pawl said:

.
My 2001 10P probably somewhere between stage 1 & 2 in terms of re-map, has the straight through centre silencer, standard rear silencer, Allisport intercooler & is on 201,000 miles without issues so far.
However, I've got an additional "real temperature" guage to monitor water temp & I typically only use full power for 10 ~ 15 seconds max while off-roading & monitor the temp continuously while cruising at speed on road.
If you don't monitor egr temps, you at least need a more accurate temp gauge.

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EGR has been removed but I’ll certainly look into a more accurate temperature gauge. The larger intercooler can only lower engine/combustion temperature if anything, right?

Mr bouze said:

EGR has been removed but I’ll certainly look into a more accurate temperature gauge. The larger intercooler can only lower engine/combustion temperature if anything, right?

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Yep, and nope. Shoving more air and fuel, even cooler air, into the same volume then igniting it may well lead to higher temps cos you is getting a bigger bang.
If you left everything as standard but just changed the intercooler and the exhaust, you'd notice the improvement, but as with whenever you tune a car you often end up with knock on effects that need compensating for, which is why peeps remap, to maximise the use of other mods.
If you didn't remap you'd still be better off, just not AS better off as you could be. and of course the tuning/remap peeps like your money!

Stanleysteamer said:

Yep, and nope. Shoving more air and fuel, even cooler air, into the same volume then igniting it may well lead to higher temps cos you is getting a bigger bang.
If you left everything as standard but just changed the intercooler and the exhaust, you'd notice the improvement, but as with whenever you tune a car you often end up with knock on effects that need compensating for, which is why peeps remap, to maximise the use of other mods.
If you didn't remap you'd still be better off, just not AS better off as you could be. and of course the tuning/remap peeps like your money!

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Thank you for your insight. As my vehicle has already been remapped, do you think some benefits may be lost by the subsequent fitting of exhaust and intercooler?

Mr bouze said:

Thank you for your insight. As my vehicle has already been remapped, do you think some benefits may be lost by the subsequent fitting of exhaust and intercooler?

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Doubt it, if it were me I'd do it the other way round and would not even bother with the remap possibly. but in the end, if you are worried you could get the remap remapped!

Get the IC and exhaust, then get it remapped to make the most of them.

ronsealdeath said:

Get the IC and exhaust, then get it remapped to make the most of them.

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Ah, sweet, you're playing my tune!!