Custom Exhaust System

[Disco4SE]

Looking at a free flowing larger exhaust system for the D4.
There are companies like Beaudesert, Taipan and Roo Systems that do them, but too far from Vic.

Does anyone know of someone closer to Melbourne????

Cheers, Craig

[Tombie]

You will gain nothing from it.

[Disco4SE]

You will gain nothing from it.
Have fitted larger exhaust systems to other 4WD's I have had, and noticed a difference straight away.
Why would the D4 be any different????

Cheers, Craig

[101RRS]

Get that huge muffler out and put a smaller one in elsewhere and there will be enough room for an auxiliary tank where the muffler was.

[boofdtl]

Hi craig just get them to send it down and we can fit it at work got the new hoist in now so lifes good...

[Disco4SE]

Hi craig just get them to send it down and we can fit it at work got the new hoist in now so lifes good...
Thanks for the offer mate.
Turns out Taipan don't do one for the D4 yet, and the others want the vehicle to make it up.

Cheers, Craig

[discotwinturbo]

The exhaust looks a reasonable size on my D4. There is only so much gas that will come out. I don't think the 3 litre is being strangled by the exhaust, unlike modern Jap cars.
Just my opinion.
Brett....

[Graeme]

Get that huge muffler outLooking to reduce some weight?

[101RRS]

Looking to reduce some weight?

Would be a good spot for an auxiliary fuel tank - would be nearly the same size as the main. Then you would not have to pay out big dollars to get a wheel carrier.

Gary

[SuperMono]

Get that huge muffler out and put a smaller one in elsewhere and there will be enough room for an auxiliary tank where the muffler was.

My thoughts for the D3 exactly, I generally don't need more than standard capacity and a small auxiliary tank (even 20L) would be worthwhile for me.

[Tombie]

Have fitted larger exhaust systems to other 4WD's I have had, and noticed a difference straight away.
Why would the D4 be any different????

Cheers, Craig

The D4 system flows very very well.
It also avoids droning...

Changing it could introduce harmonics but I doubt you'll get any power benefits worth the cost.

[Stuart02]

Would be a good spot for an auxiliary fuel tank - would be nearly the same size as the main. Then you would not have to pay out big dollars to get a wheel carrier.

Gary

I suppose the aftermarket equipment ppl can't openly condone messing with the exhaust system?

[baldivistribe]

IM sure the 3litre would sound better with a larger free flowing system. IM waiting for the warranty to run out before I play.
Cheers
Steve

[Disco4SE]

IM sure the 3litre would sound better with a larger free flowing system. IM waiting for the warranty to run out before I play.
Cheers
Steve

Let us know how you go Steve.

Cheers, Craig

[isuzurover]

The D4 system flows very very well.
...

And you base this on???

Just fitting a less restrictive oxy-cat can produce a big performance increase, not to mention a less restrictive exhaust.

As has been discussed in other threads, the exhaust on a TD is where big gains can be made.

It is unlikely you will make a TD exhaust excessively noisy as the turbine removes most of the sound energy.

[Disco4SE]

Just fitting a less restrictive oxy-cat can produce a big performance increase

Do you know of such cat??

Cheers, Craig

[isuzurover]

Do you know of such cat??

Cheers, Craig

Easy - find the largest one you can fit - e.g. from a 4L or 5L diesel instead of a 3L.

(you could put some "speed holes" in yours, but that would be illegal).

[Tombie]

And you base this on???

Just fitting a less restrictive oxy-cat can produce a big performance increase, not to mention a less restrictive exhaust.

As has been discussed in other threads, the exhaust on a TD is where big gains can be made.

It is unlikely you will make a TD exhaust excessively noisy as the turbine removes most of the sound energy.

The exhaust on a strangled TD is where big gains can be made.

There's at least 2 near here that have aftermarket pipes due to offloading damage.

I've driven one of them, with dump pipes only fitted (front of rear diff area) and besides noise it runs almost to within 1/10 second 0-100 against my stocky.

The other owner says "it sounds better" but no noticeable gains...

The system is nice factory.

I'm not saying dont change - just don't expect big gains... But if you keep it legally routed to the rear - expect larger pipes to get banged up quicker!!!!

[Disco4SE]

Hi all,
Had some exhaust mods done the other day in preperation for some ECU upgrades. They installed a larger (largest legal) free flowing cat & a free flowing muffler.
Had it dynoed before and after. The power gain is about 5Kw at the wheels (about 8Kw at the flywheel).
Sounds throaty, but not too loud.
I am told that my exhaust gas temperatures will have dropped , especially under load.
Will keep an eye on the fuel economy to see what impact it has made.

Cheers, Craig

[discotwinturbo]

Craig, did you only have the cat and muffler replaced or all pipework ?

Do you mind if I ask for the approximate cost ?

Brett.....,

[Disco4SE]

Craig, did you only have the cat and muffler replaced or all pipework ?

Do you mind if I ask for the approximate cost ?

Brett.....,
Hi Brett ,
There was a little pipework done as well.
I'll post some pics when I get a chance.

Cheers, Craig

[Disco4SE]

Towed two different trailers yesterday and found that the new exhaust modifications are more noticeable when towing.
You can tell that it's breathing better, especially up hills. Very happy.
Still have to post some photos.

Cheers, Craig

[~Rich~]

I've managed to dislodge a baffle in my main muffler on my Simpson trip it now has a rattle / vibration at idle, so I'm looking at the best option to replace mine. Details please Craig?

[Disco4SE]

Finally got around to posting some photos of my less restrictive muffler & cat
https://www.aulro.com/afvb/images/imported/2014/08/604.jpg
https://www.aulro.com/afvb/images/imported/2014/08/604.jpg

Cheers, Craig

[boofdtl]

Nice work shop mate

[Tombie]

Must say thats a neat job!!!

Glad you're happy with it..

Hows the fuel use going?

[Disco4SE]

Must say thats a neat job!!!

Glad you're happy with it..

Hows the fuel use going?
Hard to guage the fuel at this stage Tombie. When I took the D4 in to get the exhaust done, I wrote down the Trip A speedo reading (bit over 4,000Klms). I intend to check the fuel usage once I get to the same 4,000 odd Klm mark.
Its hard with me, because I have 3 trailers and a boat. Some days I'll be towing a heavy with a load, others days, none.
I will say that it seems to pull better with the trailers.

Let you know, Craig

[~Rich~]

Hi Craig,
Has the note from the exhaust change either on the inside or outside of the car?

[Disco4SE]

Hi Craig,
Has the note from the exhaust change either on the inside or outside of the car?
Hi Rich,
You can definately hear the rumble Rich.....sounds good. Especially under load.
The noise inside is barely noticeable at some speeds / revs. It is more or less a competition between the exhaust & the Cooper LTZ's. Nothing annoying though.

Cheers, Craig

[~Rich~]

Just had a quote on replacing the main muffler & cat from the bottom of the flex just behind the turbo to mate up with the existing rear pipes, 3" stainless steel mandrel bent, bullet cat and Magnaflow muffler. $900 fitted.
How does that compare to yours Craig?

[Disco4SE]

Just had a quote on replacing the main muffler & cat from the bottom of the flex just behind the turbo to mate up with the existing rear pipes, 3" stainless steel mandrel bent, bullet cat and Magnaflow muffler. $900 fitted.
How does that compare to yours Craig?
Few hundred cheaper than mine Rich.
Sounds good.
Cheers, Craig

[Disco4SE]

Just clocked over 4,500 Klm's with the new exhaust modifications and my lie-o-meter shows that I am 0.2 Lt per 100 Klm's better off than the previous 4,500 Klm's without the mods.

If you are doing it for the economy gains.......forget it.
The power gains are noticable under load (especially towing), but not as much under normal use.
I didn't check the exhaust gas temperatures before & after, however I am tipping they should be down enough to warrant the modifications, seeing as though I tow a fair bit.

Cheers, Craig

[~Rich~]

Much to my surprise I got a quote for a OEM replacement muffler, thought it was going to be a ridiculous price but it is only $546! I think I will stick with standard system.

[Erro]

I see TAIPAN XP in QLD are looking for a vehicle to use to develop a system for the D4, anyone near Gold coast interested? They say they offer a deal to use the vehicle.

[TerryO]

After the weekends off road outing up around Lithgow it looks like I will be needing a new exhaust in part ...:angel:

So I was wondering if anyone in Sydney or Canberra has had a aftermarket exhaust fitted to either their D3 or D4?

[~Rich~]

After the weekends off road outing up around Lithgow it looks like I will be needing a new exhaust in part ...:angel:

So I was wondering if anyone in Sydney or Canberra has had a aftermarket exhaust fitted to either their D3 or D4?

Hehe Terry, that rock is normally a "diff rock" you planted your exhaust on!

Any decent exhaust place that does custom work should be able to whip one up for you. Check out the earlier example and take photo's to the exhaust shop for them to quote you on. That's how I got my quote.

[Boofla]

I recently got a quote of $480 for a cat back system on my RRS sport.
2.5inch mild steel, split system.

[Tombie]

I recently got a quote of $480 for a cat back system on my RRS sport.
2.5inch mild steel, split system.

For that price it would likely be press bends.
And to be avoided at all costs ;)

You want mandrel bends, stainless...
A fit and forget job.

[Boofla]

That was mandrel bends.
Stainless is good but I've had several mild steel and stainless systems over the years and mild steel is fine IMO.

[Tombie]

My last quote for turbo back in stainless was $2k

[TerryO]

For now I have had the flattened tail pipes from roughly about a foot behind the muffler replaced and tucked up closer to the diff, cost $130 so not complaining.

They must have been damaged well before last weekend though given how the old girl was going, then after heading up from the base of Mt Walker through the rock garden they were truly stuffed.

Anyway it is like a rocket compared to how it was going, so feeling very pleased with the repairs and the cost.

I still am interested in getting a full Cat back better breathing exhaust but until I get the long range tank fitted its a bit pointless as they will not know exactly where everthing fits.

[Redback]

Finally got around to posting some photos of my less restrictive muffler & cat
http://www.aulro.com/afvb/members/disco4se-albums-my+disco+4-picture3666-imag1053.jpg
http://www.aulro.com/afvb/members/disco4se-albums-my+disco+4-picture3665-imag1051.jpg

Cheers, Craig


Just had a quote on replacing the main muffler & cat from the bottom of the flex just behind the turbo to mate up with the existing rear pipes, 3" stainless steel mandrel bent, bullet cat and Magnaflow muffler. $900 fitted.
How does that compare to yours Craig?

Sorry for dredging up this old post, but we are up for a new rear section of the exhaust system, just wondering how Disco4SE (Craig) and Rich are going with theirs and where you got yours done Rich.

Baz.

[~Rich~]

I found the factory replacement muffler and rear pipe which have to be welded to the existing vertical section that is on the angle just behind the rear axle was only $500, so thats the way I went. Still standard.

[Epic pooh]

Although for a petrol, when mine became a victim of age and damage from carelessness (crushed bits and loose baffles) - I replaced the section from the first flange back to the rear axle (i.e.. two mufflers and a lot of pipe) with genuine LR bits sourced from the local dealer. Fitted it cost just shy of $900. Which I though was ok considering the aftermarket options were either more expensive (magna flow) or dodgy looking and not stainless and not much cheaper. TBH, I was quite surprised at the relatively reasonable price ... (there's my perspective problem again ... haha) !

[Redback]

Thanks guys, I've suffered the same damage as TerryO, so needs replacing from the large centre muffler back.

Baz.

[tiddy]

Hi craig just get them to send it down and we can fit it at work got the new hoist in now so lifes good...

Got a new hoist, well it was when originally posted, but you are still.....a lucky bugger