Exhaust upgrade 300Tdi, I read the posts

[simmo]

I read a lot of posts on different websites, but alro, is the best

I'm getting The Madman turbo on in June, it's sitting in the garage waiting to go, Disco transfer case is ready for dispatch from Bushy.

From my net surfing I have come up with the following exhaust options based on the experiences of the forum on various upgrades Td-5 & Tdi.

Almost all Forumians agrees some type of muffler is required and most agree it should be the "tail muffler " or resonator, other wise the car is too noisy. I'm good with that. Most agree going from 2.5 " to 3" on a Tdis of not much value, I'm going with that.

I have come up with following options that suit my need for; not to noisy, and not too expensive, but still give some performance advantages. ( a variation of cheap , fast and good) Standard 300 tdi Landrover pipe is 60mm or 2&3/8"

i) Remove the first muffler and replace with a straight pipe. (lots of good comments about this, cheap, noticeable performance and not too noisy)
ii) Get new 2.5" mandrel bent pipe from turbo outlet to join the exhaust pipe after the first muffler position , ( muffler removed.), connect to the standard "tail pipe and muffler dia 60 mm".
iii) Get new 2.5" mandrel bent pipe from turbo outlet to join the exhaust pipe after the first muffler position , ( muffler removed.) replace all of the remaining pipe with Td-5 2.5" including the tail pipe and muffler.

Does anyone have a 2.5" TD-5 tail muffler they wan to sell? or a Defender Td-5 exhaust system minus the first muffler, Brisbane area only

What do your think? Thanks for your thoughts cheers Simmo.

[redrovertdi]

2.5 inchs is 63.5mm so you will gain 3.5mm larger pipe, why bother. When i did my research the best was said to be 2.75 inchs but that is not a common size so 3inchs it was and is, the turbo spools much much faster with the larger exhaust, i have one large muffler in the center standard location and thats it, its no noisier than previous set up.
Just my opinion.....

[simmo]

Thanks Redrover, No droning, that's good news the landy is noisy enough as it is. I agree with you about sizing, from 60 mm to 63 mm is only 10% increase in flow area, but my figuring was if its good enough fora Td-5 it's ok for Tdi.

That could be another option, 3" all the way with big muffler in the std position, I din't see that option discussed much on the forums.

What type of muffler did you use a big Lukey, Hi flow?, Magna flow etc? I was worried about he cost of the 3", also the difficulty to make it fit well around the back axle.

thanks for sharing your experience. cheers simmo

[rick130]

You will need a main muffler plus resonator with a 3" system otherwise the noise and done will be unbearable on trips.
There is no difficulty getting the big pipe up and over the rear diff housing and around the chassis, it's harder getting it right when going past the t/case/cross member or the front engine mount without it hitting anywhere under load, but there's plenty of space if done well.

[noogie]

2.5 inchs is 63.5mm so you will gain 3.5mm larger pipe, why bother. When i did my research the best was said to be 2.75 inchs but that is not a common size so 3inchs it was and is, the turbo spools much much faster with the larger exhaust, i have one large muffler in the center standard location and thats it, its no noisier than previous set up.
Just my opinion.....

I went 3" also with a high flow muffler. The turbo spools really well and she goes real sweet.

[86mud]

I've got a 2 and a half inch system with no mufflers on my 300tdi 130. It has a nice note but can only hear it when the rear LH window is down. No noise otherwise.

[simmo]

Interesting, I checked the prices of the pipe that replaces the center muffler. In the UK 50 pounds. In aussie $185, more than double the cost.

It's not like you're buying it from china.

Can buy one and freight it half way round the world for half the price?

How much to get one made locally does anyone have experience ? cheers simmo

[Defendozer]

To give you an idea I got a new 2-3/8" (standard size) rear section of pipe made up complete with a stainless steel resonator for around the $250 - ish mark, give or take a little I can't remember exactly, a centre section would be far cheaper then that as it's more or less just a straight length of piping. I did also get the centre silencer removed for about $60, sounds better with that gone and I found it didn't increase that annoying drone.

The reason I only got the rear section replaced is that the first two sections are 2-3/8" but the standard rear section reduces down to somewhere just above 2", I did notice a difference to performance when I got it done.

Also it needs to be pointed out that there is a big difference in exhaust noise levels between a ute and a wagon, my brothers single cab 130 has a straight through system with no silencers and you can not hear it at all, whereas when my 110 wagon had an un-silenced system there was a near constant drone which might not bother some but I found it quite annoying!!

[simmo]

The reason I only got the rear section replaced is that the first two sections are 2-3/8" but the standard rear section reduces down to somewhere just above 2", I did notice a difference to performance when I got it done.

Dozer, thanks for that info, very interesting about the reduction to about 2" at the end. That would make a big difference, reducing from 60 mm to 50 mm.
Because I have bad hearing I'm trying to avoid increased cabin noise, so you comments about the rear resonator are helpful.

[mox]

It has been regularly claimed that replacing the front muffler with a piece if straight pipe improves performance. The muffler is basically straight through and the same internal diameter as the 60mm OD pipe. However, the pipe has been pushed into each end before welding, leaving a rough obstruction inside each end about 4mm in diameter smaller. I cut the welds on each end of my muffler, pulled these bits of scrunched up pipe out and rewelded everything using short bits of 2.5 inch pipe to get length the same.. So it is now straight through pipe with muffler. Same crude original fitting up process has been used on standard short rear muffler, which has a smaller pipe (2 inch OD?) out of it. However, after mine got bent by backing into something, I cut the pipe off just in front of the rear muffler and replaced it with a pipe going straight out the back. Had to cut hole in rear chassis outrigger to facilitate this. Presumably allows better gas flow than standard. Slightly bigger and shorter rear pipe with no restrictions inside muffler ends. Maybe small disadvantage is that LH rear lights tend to get dirty from smoke.