(FAO Rick) Exhaust Finally Done

[Defender200Tdi]

After umming & aaahing for months, I finally took the plunge and did the 3" exhaust thing.

Having damaged the rear section of the original system a couple of times, I went through the initial idea of just fitting a 2½" tail section, then maybe going right back to somewhere near the engine sump. Finally I convinced myself that it was worth messing around with a 3" sytem right back to the end of the turbo dump pipe. It was only after I picked up a spare 200tdi Defender engine and taking the dump pipe off that, that I realised how restrctive the dump pipe actuallu is. Although it connects to a 2½" initial pipe, the outlet for the cast iron dump pipe has an I.D. of just 40mm!! The section where it connects to the turbo and drops down at a right angle is even more restrictive.

It was this piont which finally convinced me that I wouldn't get the best out of a 3" system without doing something about that dump pipe. The result is I had someone make up a new dump pipe from the flagne on the tubo back, all in 3" mild steel. In the best "in for a pound, in for a penny" fashion, I also had them fit a 3" stainless flexible section along the lines of a 300tdi (just bigger).

Well, here's a few photos:

Can't see much here but the bloke who made up the new 3" dump pipe did an excellent job, even managing to get the bend tight enough for the original heat shield to go back on:

https://www.aulro.com/afvb/images/imported/2007/04/283.jpg

The new stainless flexible coupling, just after the system straightens out by the engine sump:

https://www.aulro.com/afvb/images/imported/2007/04/284.jpg

Mid section on the way past the gearbox. I now have proper flange joints by the engine and after the transmissions, so that I can take out the centre section easily for the inevitable geabox/clutch swaps etc:

https://www.aulro.com/afvb/images/imported/2007/04/285.jpg

Just enough room to squeeze past the Maxidrive actuator on the rear axle housing:

https://www.aulro.com/afvb/images/imported/2007/04/286.jpg

The front section is all mandrel bends welded together, but the rear is just one pipe with normal bends (in the interests of economy). I figured with 3" pipe I wouldn't notice a slight drop in diameter at the bends with a 200tdi.

https://www.aulro.com/afvb/images/imported/2007/04/287.jpg

Tailpipe is tucked up quite tight, hopefully less likely for me to squish it in the future:

https://www.aulro.com/afvb/images/imported/2007/04/288.jpg

https://www.aulro.com/afvb/images/imported/2007/04/289.jpg


Paul:)

[DiscoDave]

Looks like a good mod (adding it to my wish-list now...) how does it drive?
Good post with quality photos too. :)

[Ken]

Very nice job that 3" will make heaps of difference to the way it perfoms especially down low out in the bush Have Fun

[County3.9]

Very nice. IF you don't mind me asking...how much did it cost in the end? Has it made a difference that's worth the cost?

[DarrenR]

Yeah looks good, good to see another project done that didn't happen without pics.

And do tell us how it runs?? and what type of muffler was used.

Best regards
DarrenR

[modman]

great pics but still waiting for seat of the pants dyno run.????
am considering this my self before i check boost and mod pump.
david.

[Defender200Tdi]

Well, after giving it all a flogging over the weekend, here are my thoughts:

1) Definitely makes boost more quickly off the mark and the engine does have a bit more acceleration. Noticeably more responsive to the throttle, although using responsive in describing a Tdi is probably not quite the right term, but you get my meaning.

2) The muffler is a straight through (3" bore) jobbie that is slightly larger overall than the original. However, I've done without the factory resonator at the back. The result is that I can now hear and exhaust sound that wasn't there originally. It's not loud, but it's there, and it's not something I particularly wanted. 4 cylinder diesels do not make a pleasant sound IMO, so I reckon they're better off not heard. I'll probably live with it, but I can always add on a small resonator later if it really craps me off.

3) There is definitely more noise from under the bonnet. I think this is because the old cast iron dump pipe, apart from being very restrictive, probably muffled a lot more of the noise out of the turbo than the 3" mild steel pipe does. It's not bad, just there, and it wasn't before. Also, the turbo has considerably more whistle than before, and 200tdi Defenders have much more whistle than 300tdis or Discos, simply from the location of the turbo. Once again, not particularly unpleasant, just more noticeable.

4) Cost all up was $950. Of this, $150 went on the stainless flexible coupling that was optional. Probably another $250 was taken up by the dump pipe replacement that could have been saved if I took the simple route of attaching the new 3" pipe to the existing cast iron dump pipe. Having looked inside the standard unit though, this would have been false economy IMO.

5) One of the things I was hoping might be affected, was the EGT. My engine is set on the fairly erm "aggressive" side with fueling, so I can see rather high EGTs if I'm heavy with the right foot for too long.:wasntme: I was wondering (hoping) that the new exhaust would have a beneficial effect in this area. Sadly, if there has been any effect, it's not of the magnitude that's got me excited. Howver, I'll be playing in the sand at Robe on the weekend, so that might give me a better indication.

There you have it. Was it worth the money? Hmmm... to be honest, I didn't drive it away thinking OMG this is fantastic! I've spent less money for much more significant results, and I'd rank this exercise behind upping the boost and fueling, both of which cost me nothing more than 20 minutes of my own time with a screwdriver (plus the cost of the boost & egt gauges I suppose). For me it came down to a dwindling list of mods I'd originally planned to do, and it was the next one to pop up. If I could be bothered with buying a pile of 3" bends and some straight pipe to knock up my own system for ½ the cost (which I certainly wouldn't), then yeah, it's worth it. To chuck a grand at it for the performance gain it produced, is probably only something I'd do if I couldn't find anything better to blow the cash on. Which I couldn't, so I did.:p

So, what shall I do next...:twisted:

Paul:)

[VladTepes]

Next ? You should tell me what I can do to my 200Tdi re boost and fuelling (or did I miss another thread somewhere) ?

[sclarke]

Paul,
Well done...
You have convinced me to do it myself and make it from normal pipe and not Stainless......

Steve

[rick130]

mate, a 12" resonator fits where the original one goes, costs around $70 and well worth it. I've been toying with fitting the flex pipe as there is a harshness/vibration right at 100km/h (or 80km/h in 4th) but at $150 it can wait a bit longer...

It does help EGT's, but it will only be marginal. With stock fuelling it reduces them by 20*C, so it gives a little up your sleeve when the pump's wound up, but I usually have to back off going up long inclines too...:angel:

FWIW, for the first time in a couple of years I actually drove the 130 over the long weekend without any gear except a couple of overnight bags in the back over the long weekend.
I hadn't realised how good the pump mods work. The 'fender is definitely quicker and holds on better than our (stock) Patrol, and still with much better fuel economy. NVH is another story ;)