GU III 3.0 TD 3" Exhaust?

Submitted: Sunday, Nov 26, 2006 at 10:58

ThreadID: 39779 Views:2735 Replies:2 FollowUps:5

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P.G. (Tas)

Hi all,

My GU III 3.0TD is nearly out of warranty and I was considering fitting a DTronic and 3" mandrel bend exhaust. I went to an exhaust shop in Hobart and was told the 3" mandrel was the way to go and had glowing reports from owners with the conversion done. Not being one to take the first quote, I went to my local exhaust shop and he almost laughed and informed me he has had a few people ask for the same thing and then went on to tell me what a waste of time it was.

His reasoning is that the turbo outlet is only 2.5" and anyting bigger would be a waste of time and money, unless I modify the turbo. He recommmended fitting a 2.5" straight through with a resonator in the middle with the DTronic. He didn't tell me if it was mandrel bent or not.

What have other folks done, and what is your opinion?

Cheers,

Peter

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Reply By: Snowy 3.0iTD - Sunday, Nov 26, 2006 at 11:35

Sunday, Nov 26, 2006 at 11:35

Peter

Not sure how relevant it is but, when I was doing my research on buying a DTronic I came across a story of a guy who wanted a DTronic fitted but already had a 3" exhaust fitted, Safari apparently ended up modifying the settings on the DTronic for him so that it would work properly, it may be the same with the standard engine computer settings. If you are after more power, I would highly recommend a DTronic, $1200-$1400, 10mins for you to install yourself and you will notice the difference straight away

Snowy

AnswerID: 206936

Follow Up By: Member - Patrick (QLD) - Sunday, Nov 26, 2006 at 16:42

Sunday, Nov 26, 2006 at 16:42

Hi Peter,

I have been after the low down power on mine since I bought it without success. I have fitted the D-Tronic which works ok and then went to Beaudesert Mufflers for a quote on a 2.5 system. They told me that if I fitted one that it would reduce the effectiveness of the D-Tronic which had already set me back $1400. So I called Safari and they said the same.

If I were to do it all over again I think I would invest in the 2.5 exhaust first to see how much extra grunt it provided. It would be great not to have to slip the bloody clutch every time I have to pull the 2 ton van off a small incline.

Just me thoughts but I have been driving mu GU for three years.

Of interest, I took out the extra three year warranty as I have heard of some nasty things happening after a vehicle comes out of warranty. I have already had the turbo replaced inside 50,000 so I'm being very cautious.

Do the home work before making any decisions.

Cheers, Patrick

FollowupID: 466940

Follow Up By: hoffy - Sunday, Nov 26, 2006 at 17:07

Sunday, Nov 26, 2006 at 17:07

Check out Beaudesert Exhausts on the web. They recomend 2 3/4 in mandrel bend.
I had their system fitted to my 2001 3.0l Patrol along with a DTronic and it worked very well. Turbo spooled up earlier and made the vechile much more driveable.
Beaudesert do kits and exchange the cat to suit the bigger pipe.
I had mine shipped tp me and the fit was perfect; took about 2 hours to do the changeover.
Cheers
Graeme

FollowupID: 466943

Follow Up By: P.G. (Tas) - Sunday, Nov 26, 2006 at 19:23

Sunday, Nov 26, 2006 at 19:23

Thank you very much, there is some good information here :-)

FollowupID: 466974

Reply By: Chaz - Sunday, Nov 26, 2006 at 20:14

Sunday, Nov 26, 2006 at 20:14

Hi P.G.
I have a 3” mandrel system fitted to my 02 GUIII and also have a Dtronic along with a few other modifications that go toward improving performance and reliability.
I can tell you that there was a slight performance increase in the lower rpm range with the exhaust system on top of that given by the dtronic.
My system retained the original dump pipe and cat converter, but is 3” from the cat to the tailpipe with no mufflers. The noise levels didn’t increase much and the engine is still noisier than the tailpipe note, although it is a bit louder at idle.
There is an issue with doing this because the standard system needs some back pressure for EGR and an unrestricted system could cause the turbo to spool up quicker and cause high boost spikes. My car has had the EGR blocked and the boost reduced to 18psi max, so it all works together ok.
On the dyno, I’m making 127.7hp at the wheels (standard is 95hp) and torque is good enough to accelerate from 1300rpm.
The main reason I went for the 3” system was to help reduce EGT’s and it did help slightly, so my next step will be to replace the dump with a 2.5” to 3” flair pipe and remove the cat.
Chaz

AnswerID: 206993