3" vs 2 3/4" Exhausts

[Dueler120 Senior Member Find all posts View Profile Close Dueler120]

Hi All,
Now that allot of people have upgraded the 120 series 3.0 diesel exhausts I wouldn't mind hearing some feedback on how they are performing. In particular what is the conclusions on if a 3" is better suited than a 2 3/4" system or visa verse? Question was raised by a Steinbauer tech when I was playing around with my chip that they would not recommend the 3" system that I have and would opt for the 2 3/4" as a recommendation. At the time of my exhaust purchase it was all the rage/ advertisement for the 3.0 CRD's having the 3". I currently have a Manta system installed.

Any thoughts or conclusions much appreciated.

Cheers,
Matt

[djnapkin Junior Member Find all posts View Profile Close djnapkin]

Was said tech also a seller of Beaudesert exhausts by chance?

Sent from my GT-P5110 using Tapatalk

[Ghost Advanced Member Find all posts View Profile Close Ghost]

I've got a 2 3/4 on my buggy. But that was from a recommendation from beaudesert


Sent from my iPad using Tapatalk HD

[matt150 Avid PP Poster! Find all posts View Profile Close matt150]

I've got a 2 3/4 on my buggy. But that was from a recommendation from beaudesert


Sent from my iPad using Tapatalk HD

X 2. It's like having an extra gear in the gear box..

[winniliss Avid PP Poster! Find all posts View Profile Close winniliss]

I also have a manta 3in exhaust and very happy with it. Had excellent results with the limited time I had a chip fitted. Unless a direct comparison is conducted using both exhaust's on the same vehicle we will never know what is better unless someone has their unbiased info handy.

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

Surely, there's no real difference. I'd guess that most of the exhaust flow is limited by the turbo. Resistance to gas flow mostly would be at the mercy of the turbo followed by flow characteristics of the mufflers. Whether it's dumping into 2 & 3/4 or 3 inch is probably neither here nor there. I'm no exhaust guru. My Cobra has skinny primary extractors dumping into nearly 6 inch diameter side pipes and I know the windsors love little primaries. Companies, like Manta, do their research when they build a system so they should know.

[Dueler120 Senior Member Find all posts View Profile Close Dueler120]

Yeah the Tech was from Steinbauers contact list, possibly from the Diesel Center mob in Queensland but can be sure as they were responding under the Steinbauer signature. Anyhow it was just interesting to see how everyone's exhausts were working out for them over a longer term. Cheers.

[Ghost Advanced Member Find all posts View Profile Close Ghost]

Make sure they send out the new bracket/ mount they made which come off the back of the tranny! I got mine and they had never thought about this extra mount mine used to vibrate to hell so had a local exhaust mob make up a bracket for me

[Blue Box Lurker Find all posts View Profile Close Blue Box]

Back in the 90s I used to race a petrol turbo escort (when I lived in the UK) and the general consensus was with a turbo no back pressure is required (different for NA vehicles) so a short fat exhaust to let as much gas out as quickly as possible was the best way to go.... maybe the last 20 years things have changed, or maybe diesels are different... but in my experience bigger is better for performance.

[shodown Senior Member Find all posts View Profile Close shodown]

This is covered on the 150 exhaust thread http://www.pradopoint.com/showthread...-which-is-best

General consensus is:

• 2.75" better than 3"
• Torque loss when going to 3"
• Best bang for buck is muffler only replacement
• 2.75" is also kick ass

Kevin

[macaroon1 Advanced Member Find all posts View Profile Close macaroon1]

Agree with above but not point 3, esp for a 1KZ-TE. Most restrictive part is the dump pipe. Spending @$300 bucks is just not worth it..IMO. May as well get a whole new system??? If you get a chip...that may be OK but then you have to get those hot gases out quicker leading to a ...a/m exhaust.
No complaints with my BD 2.75" gives it a little more go and I can always add the chip at a later stage if I so wish...??? One of the best mods I've done so far...don't regret for 1 minute. If I'd have bought a d4d I would not have done it, I needed to pep the ole 1KZ-TE!

150 is a very diff beast....stock exhaust has been described as good....just my 2 cents!!!

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

Looks like we need Engine & Exhaust Myth Busters.

[Heath74 Senior Member Find all posts View Profile Close Heath74]

3" getting fitted on Thursday after much procrastinating, however the recent purchase of a caravan has pushed the decision. it's a turbo diesel- no loss in larger size, the principle is very simple-get the gas out and get it out quick. The concept of back pressure, which may in some engines, require a smaller exhaust is not relevant.

You may not gain much by going larger, however you certainly won't lose anything.

But each to their own.

[tassie tiger Advanced Member Find all posts View Profile Close tassie tiger]

I have the beaudesert 2.75". They said I could have either that or a 3" but recommended the smaller which was also cheaper.

[Pradonut Lurker Find all posts View Profile Close Pradonut]

This is covered on the 150 exhaust thread http://www.pradopoint.com/showthread...-which-is-best

General consensus is:

• 2.75" better than 3"
• Torque loss when going to 3"
• Best bang for buck is muffler only replacement
• 2.75" is also kick ass

Kevin

Hey Guys, I'm a longtime lurker and feel it's probably time to give something back.
My experience with the 1kz is first I changed the muffler with no noticeable difference I then tried 2.75" mandrel bent, plus dump pipe, with an improvement but nothing spectacular. I have recently changed to a 3'' mandrel bent (no name - it was cheap) and new dump pipe and it is a noticeable improvement. All 'seat of the pants' but no noticeable loss of torque, more free revving and with egt gauge fitted it seems to be running cooler with a definite improvement in run down cool time.