Finally got the 3" exh. just some questions.

[AndrewD]

I was finally able to get my 3" mandrel bent exhaust done but unfortunately the bloke coundn't bend the pipe to make a new dump pipe. However, he was able to "clean" out the original cat. Personally I wanted it from the turbo back but I'm not complaining as I believe it was a good price for what I got. I have already dropped 2 litres per 100km which is great and the response is unreal all the way through the rev range.
Just a couple of questions; does an aftermarket dump pipe and cat really make that much more difference for the extra cost involved? Please support your answer with facts, not just yes it will.
If I was able to get someone to make a dump pipe, does anyone know what the biggest dimensions are that can be used? I understand you would have to come off the turbo with the original dimensions so it would bolt onto the back of the turbo and then step it up to the desired size.
Finally, if I decided to keep the original dump pipe is it possible to remove the piece of cast iron at the beginning of the dump pipe that creates two chambers instead of one like the beaudesert dump pipe?
Appreciate any feed back

 

[superiorcruiser]

dont know why your guy couldnt make you a new dump pipe..
i had one made from 3 inch pipe when he made my 3 inch exhaust,but he did say it was a basterd of a job...
maybe your guy just cuoldnt be f#$@^d doing it..

 

[Lasoya]

Only a few shops will custom bend 3" pipe on the job.

 

[redman]

I have a 3' Mandrel bend.. If you compare it to the original one you would say Holy F***... The stock dump pipe is really restrictive...

My tip, Gettin a 3' exhaust, get it done properly the whole way! I had 3' with a straight through cat and no muffler... Nothing but positives comin from me!

 

[AndrewD]

cheers guys, may have soruced a dump pipe from suncoast exhaust.

 

[DieselTuner2]

I have made a few posts regarding the exhaust system including dump pipe change, 2.5-3" etc and everything in between. If you do a search for posts I have made you will be able to find it, with supporting dyno graphs showing the lack of any gains in doing so.

I think the gain going from std dump and cat with 3" system, up to custom 3" dump pipe & hi flow cat with the same rear section was about a 2kw loss up to 2200rpm and 2kw gain from there on.

 

[wilba]

no drama there old mate thats who did mine

cheers guys, may have soruced a dump pipe from suncoast exhaust.

 

[tweak'e]

I have made a few posts regarding the exhaust system including dump pipe change, 2.5-3" etc and everything in between. If you do a search for posts I have made you will be able to find it, with supporting dyno graphs showing the lack of any gains in doing so.

I think the gain going from std dump and cat with 3" system, up to custom 3" dump pipe & hi flow cat with the same rear section was about a 2kw loss up to 2200rpm and 2kw gain from there on.

your testing was on the D40 not the D22. different engines.

 

[redman]

I dont care what dyno's say or whats proven by digital systems, For my D22 I couldnt tow my 3 ton boat safely the way it was... Putting the 3' complete exhaust system on has made it much more pleasurable to drive and actually gain speed up hills and tow's heaps better, Actually overtaking cars while towing! I cant do 140km /hr But i can sit on 100 doin 2400rpm which is fine.. Happy 3' customer no matter what a Dyno says...

 

[DieselTuner2]

your testing was on the D40 not the D22. different engines.

Well, not to different if he has the YD25...
Alas I can dig up the testing from both YD&ZD on the D22's tomorrow if I have time for you guys.

I dont care what dyno's say or whats proven by digital systems, For my D22 I couldnt tow my 3 ton boat safely the way it was... Putting the 3' complete exhaust system on has made it much more pleasurable to drive and actually gain speed up hills and tow's heaps better, Actually overtaking cars while towing! I cant do 140km /hr But i can sit on 100 doin 2400rpm which is fine.. Happy 3' customer no matter what a Dyno says...

Dyno wont disagree with you. A 3" system is a huge step up from standard.
All I was saying is a 2.5" gives all the benefits of a 3" anyway, so its 6 of one half a dozzen of the other.

If its a ZD30, yes changing the dump pipe makes a difference, YD25, not so much.

 

[tweak'e]

Well, not to different if he has the YD25...
Alas I can dig up the testing from both YD&ZD on the D22's tomorrow if I have time for you guys.

well yes different. D22 YD25 is normal turbo not variable and a whole lot less power.
be really good if you have testing of the D22's.

 

[DieselTuner2]

well yes different. D22 YD25 is normal turbo not variable and a whole lot less power.
be really good if you have testing of the D22's.

Yes, but less power means less airflow. Making the 3" even more unnecessary than it is in a D40.

I will see what I can find.

 

[redman]

Ahhh Comparing 2.5' to 3'?? Maybe not a great deal difference... Temps?? Over a distance or long haul could prove to be some differences??
Sorry I thought you were saying the Stock setup is just as good as the 3' setup...
Over stock though - Big Difference...

 

[Navvic]

I've been watching these threads (inc the D40 one) with interest. I do mostly highway driving (no load) and plan on doing some touring with SWMBO in the future and I get theres not much of a difference between 2.5 & 3 but yet I still struggle with it all.

I appreciate the input everybody has put in (inc 4x4) and it has helped clarify some of it for me .... the rest went over the top contributing to the thinning of the hair level

So I think I get it, I have a ZD30 so whichever way I go, 2.5"/3" ($ dependant) I should look at beefing up the dump pipe too.

The next question (for the victorians) is know anyone good to get it from ?

 

[ljacko78]

you should be able to get a dump back 3" for about $1200 + install. Have a look in my garage for pic of old vs new dump - the tight bends cause the restriction. Is worth changing and the guys above have said. Worth having a crack at install yourself. Dump pipe can be a bit tight to get off, but worth the effort when done. Short of a Vic member helping you, also check here for suppliers:
http://www.navara.asia/melbourne-vic/3160-trustworthy-mechanics.html

 

[superiorcruiser]

you should be able to get a dump back 3" for about $1200 + install. Have a look in my garage for pic of old vs new dump - the tight bends cause the restriction. Is worth changing and the guys above have said. Worth having a crack at install yourself. Dump pipe can be a bit tight to get off, but worth the effort when done. Short of a Vic member helping you, also check here for suppliers:
http://www.navara.asia/melbourne-vic/3160-trustworthy-mechanics.html

find a local exhaust shop thats done these before and get them to make one for u.
i got a custom 3 inch dump pipe,hi flow cat.and straight thru 3 inch exhaust FITTED for $900... in croydon

 

[tweak'e]

Yes, but less power means less airflow. Making the 3" even more unnecessary than it is in a D40.

I will see what I can find.

yes/no.

less power also means any change is more noticeable
the main thing is that the D22 doesn't have variable turbo so will respond differently to exhaust mods than a variable turbo motor.

 

[DieselTuner2]

yes/no.

less power also means any change is more noticeable
the main thing is that the D22 doesn't have variable turbo so will respond differently to exhaust mods than a variable turbo motor.

That part is very true.
The turbulence caused by the mixing of gated gas to turbine gas is very important to minimize on an wastegated turbo.

This is what has all the other shops confused when I post actual data and testing of smaller systems with no change in dump pipe 'd40 for example'
They are all still in the oldschool mindframe, instead of testing it they just keep selling what used to be the right thing.

 

[the_bluester]

I've been watching these threads (inc the D40 one) with interest. I do mostly highway driving (no load) and plan on doing some touring with SWMBO in the future and I get theres not much of a difference between 2.5 & 3 but yet I still struggle with it all.

I appreciate the input everybody has put in (inc 4x4) and it has helped clarify some of it for me .... the rest went over the top contributing to the thinning of the hair level

So I think I get it, I have a ZD30 so whichever way I go, 2.5"/3" ($ dependant) I should look at beefing up the dump pipe too.

The next question (for the victorians) is know anyone good to get it from ?

I built a 2.5" pipe for my ZD30 powered Nav from the flex joint back for about $350. Not as much benefit perhaps as a full blown system, but I did my experiments by dropping off the main muffler, the resonator (Which is the source of the demented piccolo noises that a ZD30 powered Nav tipically makes) and then by dropping the exhaust off from the cat and test driving under all of those conditions. There was a noticeable seat of the pants improvement in midrange torque, high RPM performance and a slight gain in response by dropping the main muffler but no noticeable gain with the rest. I went from the flex join back instead of just the main muffler as the car was much nicer to use when towing without the symphony of whistles from the exhaust tip under load.

I reckoned if you can not feel a seat of the pants difference between flex back and turbo back, why spend the money?

 

[Sparra]

I put a 3" system on mine right from turbo...There was a huge difference in power but the fuel economy is the same which surprised me as I was hoping to get a bit better...Next step is to chip it but not sure if this will improve the economy...

Cheers...Sparra