Thread: removing Centre muffler on a td5

The centre muffler is very restricted by removing it the motor can remove the exhaust gasses winch gives more power. I have no muffler on my td5 and a 3 inch system the turbo keeps it Fairley quite I have also found the car runs a little cooler hope this helps.

We had ours removed only cost $60, didn't make a big difference to the performance sounds a little better.

Auto's drone like a bastard in the cabin with no centre muffler. Ask me how I know? I replaced mine with a sports muffler. Sounds good and not droney like an 18 year olds commodore with 20 in rims

Pricey

Originally Posted by frostyblue

I've heard a lot of people who do this, what is the benefit to doing it

Cheers

ken

If you remove the cat converter (Just below the flex section) as well as the centre muffler so in effect, getting rid of 2 exhaust restrictions, you'll get a much more responsive engine and turbo response plus shedding quite a few kilos off the weight of the car. There have been some reports of a 'exhaust drone' at highway speed but I never encountered this on my D2 or my mate's Defender.

You will hear the turbo whistle more but in my opinion, it was never intrusive and sounded kinda cool :-)

And no one seems to mention removing the cat is technically illegal, not to mention potentially bad for the environment. If it's pre 2001, they don't have cats.

Pricey

Originally Posted by gusthedog

And no one seems to mention removing the cat is technically illegal, not to mention potentially bad for the environment. If it's pre 2001, they don't have cats.

Pricey

Fair point but it's actually it's a bit of a "furfy" - EU3 emission requirements needed all diesels manufactured in the EU to have a cat converter (Later came diesel particulate filters included with cat converters). Current ADR's (Australian Design Rules) are not compliant to EU3 and the later EU4 rules and this is why you should junk the cat converter.

(Check out our motorcyling brothers {And I'm one} who can buy an "Australian" model bike that has a completely different exhaust and ECU to an EU model bike that has cat converters and multiple Lambda probes fitted to pass strict EU4 regulations that are not needed under our ADR legislation)

But........ADR's do state you cannot modify the emission system of a vehicle without penalties regardless that the vehicle is not required to be complaint to an EU ruling.

So....I'm not alone in getting rid of EGR systems that coke up an engine as well as unnecessary cat converters for the benefit of a free breathing, better performing engine.

If you knew the price of replacement EGR valves on a D2 and worse - a D4 (It's financially staggering!!) then you would do what I and many smart D4 owners have done and got a software update on the D4 ECU that never allows the EGR valves to operate (Thus never having the problem of a coked up EGR valve sticking open and prompting "limp-home-mode")

Horses for courses unfortunately and I'm quite comfortable with my very, very small carbon footprint against a world environment!

Just another factor that may give you solace is that I read an interview with the chief engineer who developed the TD5 to EU3 spec in LRO a few years ago.
He stated that the TD5 actually met EU3 without the catalytic converter but as a safeguard to ensure that all engines met the spec, they added what he called a small cat.
He also gave a max safe horsepower for the engine which AFAIR was about 180BHP, which seems to be regularly exceeded by chip developers.
Regards Philip A

Something else that has not been clearly pointed out. If the exhaust gases can flow easier than the turbo lag in theory should be less and the EGT should be lower.

These are 2 pretty good reasons to remove the centre muffler.