2.5 NA versus 200TDI Exhaust Internal Diameter

[Prith]

Guys

I have a 1991 Defender 110 which  had a 2.5NA Engine, which I later changed to a Defender 200TDI engine. Except the exhaust downpipe from the exhaust manifold which came with the 200tdi engine the remaining exhaust is of the 2.5NA.

Correct me if I am wrong, but I feel she is very sluggish and its because of the restriction of the old 2.5NA Exhaust pipes. 

Does anyone know the internal diameter for the 200tdi exhausts? I am sure its bigger than the 2.5na's.  Here in my city an Exhaust manufacturer can make me a new one and wants the internal diameter of the pipe for the 200TDI. Should I retain the middle box or go for a straight through pipe. 

Would appreciate some help.

THanks a ton

[monkie]

My understanding is that most people who convert from a 12J to Tdi use the 19J (2.5TD) exhaust system as it fixes to the chassis off the same mounting points but is wider diameter to cope with more gas flow from a turbo.

I'm sure this off the shelf option would be the most cost effective way to do it if you just want a standard system.

 

[miketomcat]

Pretty much all exhaust td and on are the same shape excluding the down pipe for the 110. There is some differences to the tail pipe and mounts. I have a v8 system on our 200tdi converted 110. 

90s on the other hand varies considerably. We have a td system on our 90. The 200tdi system is hideous and I wouldn't use it on a 90.

Our 90 has the middle box deleted sounds good without being stupid loud. Straight through is to loud for regular use unless your deaf and you don't like your neighbours.

Mike

[Prith]

59 minutes ago, monkie said:

My understanding is that most people who convert from a 12J to Tdi use the 19J (2.5TD) exhaust system as it fixes to the chassis off the same mounting points but is wider diameter to cope with more gas flow from a turbo.

I'm sure this off the shelf option would be the most cost effective way to do it if you just want a standard system.

 

Thanks a ton for your reply. As I am based in India its cheaper to get an exhaust made rather than importing a 19J exhaust to India. The Exhaust manufacturer said he can replicate the exact mounting points which are there for the 2.5na right now. What is the internal diameter for the 2.5TD? Someone else on the forum called Paul used a 3 inch ID pipe for his 200tdi. IF I at least know the ID of the 2.5TD then I can ask this guy to make the same here.

Thanks a ton

 

[Prith]

7 minutes ago, miketomcat said:

Pretty much all exhaust td and on are the same shape excluding the down pipe for the 110. There is some differences to the tail pipe and mounts. I have a v8 system on our 200tdi converted 110. 

90s on the other hand varies considerably. We have a td system on our 90. The 200tdi system is hideous and I wouldn't use it on a 90.

Our 90 has the middle box deleted sounds good without being stupid loud. Straight through is to loud for regular use unless your deaf and you don't like your neighbours.

Mike

Mike thanks for your reply. If removing the middle box improves the performance of my Def 200tdi then it makes sense. If it is going to be too loud with a straight through middle section then I will drop the idea. I hate it being loud. Nice for a few minutes later its a headache. 

Hence want to make a new exhaust with the correct ID pipe required for the Def 200tdi 110 and can go with a straight through middle section an retain the last box or the rear section so that the noise is less and performance is more. Or 2nd option is to go with all the middle and rear boxes but with a bigger pipe.

 

[Jocklandjohn]

I've got an old stainless exhaust in the garage awaiting some new joint clamps. It's 20 years old, was designed for a 2.5 19J as a direct replacement. It was attached to the straight-down downpipe from the 19J which I used on the 200Tdi I replaced the old engine with (part NTC4426) as seen here

I've just measured the stainless one and its just under 2" ID and 2 1/8th" OD.

[Prith]

2 hours ago, Jocklandjohn said:

I've got an old stainless exhaust in the garage awaiting some new joint clamps. It's 20 years old, was designed for a 2.5 19J as a direct replacement. It was attached to the straight-down downpipe from the 19J which I used on the 200Tdi I replaced the old engine with (part NTC4426) as seen here

I've just measured the stainless one and its just under 2" ID and 2 1/8th" OD.

John I was just at the garage and he showed me the dowpipe from the turbo and its a little less than 2.5". this is the pipe that fits the Def 200TDI Turbo. 

Thanks for doing the needful. Wondering how Paul used a 3 inch pipe when the it will be too wide for the turbo?

[Anderzander]

3” is wider than stock - it’s a performance exhaust.

I think the 200TDI is 2.5” for the whole system, sometimes quoted as 60mm.

I believe the 2.5TD is 55mm - so perhaps 2”.

[Prith]

6 minutes ago, Anderzander said:

3” is wider than stock - it’s a performance exhaust.

I think the 200TDI is 2.5” for the whole system, sometimes quoted as 60mm.

I believe the 2.5TD is 55mm - so perhaps 2”.

Correct then it is, as the downpipe was supplied with the Def 200TDI engine and its 2.5" but it get lesser from there on to the 2.5NA exhausts. So now I think the blockage is in the mid & rear section of the exhaust. Will have to remove them to check the internal diameter of the pipe. 

Wondering how can a 3" ID pipe fit on the Turbo outlet when itself is a little smaller than 2.5"? Am I correct that the downpipe fits to the output of the turbo ?

Ander, if you are saying 3" is a performance exhaust then how will it fit the Def 200TDI as the 3" pipe is bigger than the output pipe of the Turbo? Is there some ind of 3" to 2.5" pipe adapter?

 

[RedLineMike]

i would use 2.5" turbo back, its a decent size & aslong as you dont have any tight bends it will be ok, had a 2.5" system on my old tdi 90

[Ex Member]

They were both 2.25".  They went to 2.5" with the 300TDI.  It will not affect anything.

Timing and fueling are what will give you power.  The exhaust will not be the problem.

Edited June 22, 2018 by Red90

[Stambecco]

Internal diameter of mine at the tail pipr (200Tdi) is 50 mm. External 54 mm

Engine external is 57 mm do 2 mm thick would be around 53 ish

Edited June 22, 2018 by Stambecco
Cortection

[Ex Member]

Tubing is sized by the outside diameter.

[western]

Prith, as you know my '89 110 was a TD, it's had a 200tdi since mid '94, I use a stainless steel TD system [brackets/hangers are different on genuine 200tdi defenders] I haven't had any lack of power issues problems with my system, I also removed the centre silencer some years ago.

[Prith]

11 hours ago, western said:

Prith, as you know my '89 110 was a TD, it's had a 200tdi since mid '94, I use a stainless steel TD system [brackets/hangers are different on genuine 200tdi defenders] I haven't had any lack of power issues problems with my system, I also removed the centre silencer some years ago.

Thanks a ton Ralph! As your exhaust was already for a TD, the new 200TDI engine could manage. Where as mine was a 2.5NA and then I swapped it for the Def 200TDI with the mid & rear section exhaust of a 2.5NA only. 

Except the downpipe from the turbo is from the 200tdi. 

[Chambo110]

On 6/22/2018 at 5:36 PM, western said:

Prith, as you know my '89 110 was a TD, it's had a 200tdi since mid '94, I use a stainless steel TD system [brackets/hangers are different on genuine 200tdi defenders] I haven't had any lack of power issues problems with my system, I also removed the centre silencer some years ago.

Sorry to jump in but I’m in similar situation

Ralph I think we have the same set up. Ex TD but now 200tdi.

i have just purchased a new stainless mani to first box section and rear box removal, side exit section .. both for 200tdi.

however , looking at my centre section I’m going to have to replace that aswell.

Question is, will it be too loud if I remove that first silencer. As it will then be straight thru all the way .

 Also, what centre section should I get (thinking about hangers) ?? 200tdi or TD ? Are they the same diameter 

appreciate any assistance, and apologies for hi jacking, but it made sense in my head to revive an older post with lots of helpful info already there

 

cheers chaps 

 

Edited March 12, 2019 by Chambo110

[western]

Been without my centre box for some years now, haven't had any compliants of being to loud inside the cab while driving. I kept the rear box, TD hangers use rubber bushes/bolts/nuts, 200tdi use rubber rings on pins. I prefer the older type fixings.

[Anderzander]

My 80” has a 200tdi and just the back box - and isn’t loud at all. I’m still suprised by how unobtrusive it is.

[Chambo110]

Thanks for replies fellas.

so, I just been outside.. it seems new pipe from turbo down is approx 2.5” dia but on vehicle at the minute the pipe is approx 2” 

200tdi conversion from 2.5td was not done by me, I inherited it. So I’m struggling to figure out what I have. 

So my new 200tdi exhaust will not fit ( unless I reduce it to 2”) is this something I should do ?

my downpipe has a hole either side of exhaust for bolting to block, and hangers on the original exhaust ( by that I mean the one that’s on there now??) are rubber ring type things and pins where the ends flap over to stop slipping off 

question is what do I actually have?

engine deffo 200tdi

turbo ?? Wrong one ?

exhaust ??

hellllp please 

thanks

[monkie]

There are 2 configurations of the 200 tdi: The Defender version (turbo up high like the 2.5 TD) and the Discovery (Turbo low down like a 300 Tdi). Which do you have fitted?

 

[Chambo110]

Not 100% but I think it’s the defender type. It is high up. Heat shield above looks like it’s nearly touching the bonnet and turbo directly below that 

 

thanks

 

[western]

high mounted turbo is the Defender spec like mine, use the TD exhaust with the 200tdi downpipe, thats what I have [Double S] stainless steel right through.

[Chambo110]

Apologies 

the downpipe is 2.5”. 

I measured “the pipe” not the bit that flares out to go over the turbo pipe

appreciate the help chaps

 

[Snagger]

12J engines used 2" pipe as far as I know.  That was the diameter of the Steve Parker special exhaust made for my 109 with that engine.  19J and Tdi use 2.5".

Running with one muffler omitted, and even with the remaining muffler as a "straight through" type doesn't create excessive noise because the turbo charger regulates and dampens the pulses in the exhaust, doing far more sound suppression than the rest of the exhaust all together.

[Ex Member]

12J, TD and 200TDI used 2.25".  300TDI used 2.5".