3" exhaust on td5

[noogie]

Hi all

I had my 3 " exhaust put in today on my td5.
There was a bit of a communication problem as the exhaust place has put a straight thru exhaust system in.
I did mention to him that I just wanted the centre muffler removed, but he has put a straight thru system in with a small resonator where the small front resonator was.

It sounds good and you can hear the turbo whistle, but it is a little too noisy when you put the foot down and when excellerating/cruising on freeway. It goes better with less turbo lag noticed but I need to quieten it down.
Does a straight thru system have any detrimental effect on the engine?
Should I have the original rear muffler reinstalled into the system to quieten it down?
Any suggestions would be appreciated.

Thanks
Mick

[scottsride]

Put a brick wall at the tail pipe end to shut the thing up..

Did he weld it or is it unboltable.. I wouldnt mind swaping my exhuast set up for your 3 inch.

I keeped mine 2.5 inch just put a hi flow center muffla on. Made it go better and no drorring sounds.

[noogie]

so do you think a high flow muffler will quieten it down

[scottsride]

Yep and keep the rear brick wall you got on there now.

[D3mike]

Gday Noogie - glad you got the Dfer back on the road again after Dargo.

D3Mike in Jan Juc

[flagg]

what is a brick wall?

[isuzurover]

Hi all

I had my 3 " exhaust put in today on my td5.
There was a bit of a communication problem as the exhaust place has put a straight thru exhaust system in.
I did mention to him that I just wanted the centre muffler removed, but he has put a straight thru system in with a small resonator where the small front resonator was.

It sounds good and you can hear the turbo whistle, but it is a little too noisy when you put the foot down and when excellerating/cruising on freeway. It goes better with less turbo lag noticed but I need to quieten it down.
Does a straight thru system have any detrimental effect on the engine?
Should I have the original rear muffler reinstalled into the system to quieten it down?
Any suggestions would be appreciated.

Thanks
Mick

Won't do any harm - in fact it is a good thing.

Sellers of 2.5" exhaust kits will spread rumours of "turbo overspeed", however such a beast is yet to be observed in captivity.

[aptfab]

For optimum performance straight through is the way to go but I do understand the noise issue.
A good option would be a straight through turbo muffler in front of the rear diff and the resonator at the back, this will prevent a lot of the noise and remove the drone under load.

[Tombie]

Won't do any harm - in fact it is a good thing.

Sellers of 2.5" exhaust kits will spread rumours of "turbo overspeed", however such a beast is yet to be observed in captivity.

Interesting you still claim this to be 'unseen' yet was proven in Lara - Which can overspeed off the line using its 3" system... Producing a massive boost spike.

Here is some more info: http://www.assuredperformance.ie/assets/files/Turbo%20Failure%20%20OVERSPEED.pdf

once a turbo is spinning beyond its designed limit, it can reach a point where the impeller fins are moving too quickly to allow air to move in behind the displaced air from the fins. without resistance from the air, the turbo speed skyrockets... this is the one of the reasons for wastegates.

Also, if the turbo reaches a point past the line on the left of a compressor map (I forget what it's called, surge line?) basically the turbo can/will destroy itself. It does NOT have to be overspeeding for this to happen. Very rare on diesels, shouldn't happen if the turbo is selected properly.

http://www.turbobygarrett.com/turbobygarrett/sites/default/files/PDF/Turbo%20Tech%20103.pdf
^^^
By the turbo boys themselves! (See 3rd page "Speed Lines")

The bigger pipes can allow this to occur....


Remember - bigger sells.... Bigger lifts, bigger diameters etc..

If they could sell a 2.5" for $xxx and a 3" for $xxx+ 50% dont you think they would ;)

[Tombie]

For optimum performance straight through is the way to go but I do understand the noise issue.
A good option would be a straight through turbo muffler in front of the rear diff and the resonator at the back, this will prevent a lot of the noise and remove the drone under load.

this was disproved by a test some years ago in Adelaide.

The boys from Zoom did testing on a flow bench of straight pipe, curved pipe, with muffler, without muffler, different muffler styles etc...

What they found was certain mufflers actually improved flow and performance, whilst straight pipe run worse - in some situations...

The simplest answer isnt always the right one ;)

[harro]

I see no mention of remapping or any other mods for that matter so I would be very surprised if over boosting could be achieved with simply a 3 inch straight through exhaust on a td5.

I am sure if enough mods are done to turbo, inlet/exhaust and fulling it could result in over boosting in any turbocharged engine.

Paul.

[Tombie]

I see no mention of remapping or any other mods for that matter so I would be very surprised if over boosting could be achieved with simply a 3 inch straight through exhaust on a td5.

I am sure if enough mods are done to turbo, inlet/exhaust and fulling it could result in over boosting in any turbocharged engine.

Paul.

Fitting a 3" exhaust to a bog standard TD5 is like taking a viagra for a night home alone....

[noogie]

I do have my ecu. Remapped .
The pipe has bends in it similar to the original pipe. Just doesn't have the large rear muffler and the two smaller ones.

[harro]

Fitting a 3" exhaust to a bog standard TD5 is like taking a viagra for a night home alone....


Yes,
Have to agree, it would be somewhere near last on my mods list.

Cheers.

[harro]

I do have my ecu. Remapped .
The pipe has bends in it similar to the original pipe. Just doesn't have the large rear muffler and the two smaller ones.

I think you will find the first 'smaller one' was the CAT.
I removed the CAT and centre muffler but ended up putting a high flow muffler back in it.
The drone at 100km/h was dreadful.


Good luck with your truck.

Cheers,
Paul.

[noogie]

Are you happy with the set up you have now?

[isuzurover]

....

Remember - bigger sells.... Bigger lifts, bigger diameters etc..

If they could sell a 2.5" for $xxx and a 3" for $xxx+ 50% dont you think they would ;)

Do we have to do this all again??? (it usually ends in someone having a tanty and going away for a while???) :wasntme:

Noboody is arguing that turbos cannot overspeed. What is being debated is that fitting a 3" pipe will cause any detrimental effects (and/or overspeed).

You cannot provide any proof of overspeed. Conversely, there are plenty of TD5s driving around quite happily with 3" exhausts and have been doing so for many years...

If fitting a 3" pipe to a 110 / 130 causes overspeed, then a 90 TD5 should overspeed with a 2.5" exhaust...

As for the suppliers. A 2.5" exhaust is cheaper to make, easier to squeeze in, lighter and smaller for shipping, etc... BUT - those on the market are no cheaper than 3" systems


https://www.aulro.com/afvb/images/imported/2012/09/1228.jpg
Looks like these guys got it horribly wrong. Exhaust too short, too large, must produce no power and overspeed like crazy...

[Tombie]

Do we have to do this all again??? (it usually ends in someone having a tanty and going away for a while???) :wasntme:

Noboody is arguing that turbos cannot overspeed. What is being debated is that fitting a 3" pipe will cause any detrimental effects (and/or overspeed).

You cannot provide any proof of overspeed. Conversely, there are plenty of TD5s driving around quite happily with 3" exhausts and have been doing so for many years...

If fitting a 3" pipe to a 110 / 130 causes overspeed, then a 90 TD5 should overspeed with a 2.5" exhaust...

As for the suppliers. A 2.5" exhaust is cheaper to make, easier to squeeze in, lighter and smaller for shipping, etc... BUT - those on the market are no cheaper than 3" systems


https://www.aulro.com/afvb/images/imported/2012/09/1228.jpg
Looks like these guys got it horribly wrong. Exhaust too short, too large, must produce no power and overspeed like crazy...

That old chestnut again.... You're like the JohnF of Exhausts....
Their turbo's may be specced to work in that set-up (again - wastegates play a part)...

Or it may not work really well at all - Or it may be capable of more but they havent got there yet... Your argument is pretty light on...

And yes, here we go again.... Even TURBOTECNICS who friggin make the things say that with the 3" pipe a TD5 can overspeed the turbo...

But again, because YOU didnt see it, it couldnt possibly be ****ing real could it...

I got zapped by electricity once (ok 3 times) too, but I cant prove it...

I cant prove or disprove global warming either, but plenty of people here are accepting of qualified peoples opinion on it.:whistling:

And considering this - I don't, haven't, wont sell exhausts so me arguing a 2.5" vs 3" version is irrelevant. I cant benefit from it...

But what I CAN say is - I fitted a 2.5" and got performance and no overboosting/surging from the turbo.
I fitted a 3" pipe and immediately got that VERY phenomenon in 1st gear on hard take off... The engine was then detuned to prevent this rapid spool up from idle.

Unfortunately my film crew were on a RDO that day and unable to film the event for posterity. :2up:

Interestingly, there are hundreds of TD5s running around on 2.5" systems making plenty of power and happy too... :p

I'm amazed that 2 of the worlds premier TD5 modifiers (not me) - say its bad, and wont warranty their Turbos and thats not acceptable?!?!

If it wasn't a problem, why say anything? You're arguing its based on price... But they Turbotechnics, IRB and BAS dont sell exhaust... So benefit nothing - yet all say NO larger than 2.75"


**** IT - Lets plumb in a 4" and see how we go.....

https://www.aulro.com/afvb/images/imported/2012/09/1240.jpg

[lambrover]

Ha Tombie is this the case as well for a VNT turbo and hybrid turbo?

I am curious as I am looking at fitting one of these up next year.

[Tombie]

Ha Tombie is this the case as well for a VNT turbo and hybrid turbo?

I am curious as I am looking at fitting one of these up next year.

I have been in contact with BAS (Turbotechnics) and Alive Tuning (Largercharger) and both will not cover their VNT / Hybrids with 3" systems attached.

They both recommend no more than a 2.75" system - which is near impossible to find in Australia :(

I don't make these comments for fun - but for warranty / normal performance I am willing to run with them.

I'm currently playing with a 2.5" > 3" combo - 2.5" from the turbo flaring out to 3" after a tuned length (being worked on) to try and optimise the performance.

[uninformed]

are we talking mandrel bent or crush bent?

[rick130]

Mike, there appears to be plenty of TD5's and Tdi's (and lots of other 4wd diesels) running around with 3" systems and we don't seem to hear of massive turbo failures ?

Maybe the length/pressure drop of a 110/130 system vs the predominance of 90's in the UK makes a difference ?
I'm guessing Lara had the wick turned up pretty well too, probably much more than, say a customers ECU in terms of fuel ?

When I built my 3" system all those years ago (and it feels like another lifetime now) I tried to source 2.75" tube and bends and it was going to cost roughly double in materials over using 3" parts, so it was a no-brainer for me at the time.

Do I suffer from overspeeding the little T250 ?
Dunno, analogue gauges aren't the best for recording something like that, and I'll probably jinx myself saying this, but it's still pumping away and the car is about to clock 300,000km.

:D

[harro]

Are you happy with the set up you have now?


There is always room for improvement and the list of things you can do is virtually endless but at some stage money can be spent on other things.
But to answer your question, yes VERY HAPPY:D:D.

A VNT (after the remap) was a massive improvement in drivability.
No EGR is a given
There are a few airbox mods that all help.
Boostbox is a must for remap and vnt.
Uprated MAF (or 2 channel boost box) as airflow was peaking out cutting fuelling.
And on and on and on..............

Don't know if there is much to be gained with a 3 inch exhaust. it is after all only a 2.5 litre engine but as long as there is something to be gained any avenue is worth trying, it's only money:angel:

As I said earlier, the straight through exhaust created a terrible drone that I was glad to get rid of and no noticeable difference when I put a high flow muffler back in it.

Cheers,
Paul.

[Tombie]

are we talking mandrel bent or crush bent?

I always talk Mandrel bends....

[PAT303]

Do we have to do this all again??? (it usually ends in someone having a tanty and going away for a while???) :wasntme:

Noboody is arguing that turbos cannot overspeed. What is being debated is that fitting a 3" pipe will cause any detrimental effects (and/or overspeed).

You cannot provide any proof of overspeed. Conversely, there are plenty of TD5s driving around quite happily with 3" exhausts and have been doing so for many years...

If fitting a 3" pipe to a 110 / 130 causes overspeed, then a 90 TD5 should overspeed with a 2.5" exhaust...

As for the suppliers. A 2.5" exhaust is cheaper to make, easier to squeeze in, lighter and smaller for shipping, etc... BUT - those on the market are no cheaper than 3" systems


https://www.aulro.com/afvb/images/imported/2012/09/1228.jpg
Looks like these guys got it horribly wrong. Exhaust too short, too large, must produce no power and overspeed like crazy...

You like to post up examples like this to justify your replies but what relation is there between a drag car that drives in a straight line for 400mtrs and a road vehicle that has to do everything from towing a boat to picking the kids up from school?.The post is about exhaust size and fitting a 3'' exhaust means fitting a muffler which adds a restriction so you gain nothing over a 2.5'' system which doesn't,like everything on a road vehicle compromise is the key to get the best overall result between performance and comfort. Pat

[noogie]

There is always room for improvement and the list of things you can do is virtually endless but at some stage money can be spent on other things.
But to answer your question, yes VERY HAPPY:D:D.

A VNT (after the remap) was a massive improvement in drivability.
No EGR is a given
There are a few airbox mods that all help.
Boostbox is a must for remap and vnt.
Uprated MAF (or 2 channel boost box) as airflow was peaking out cutting fuelling.
And on and on and on..............

Don't know if there is much to be gained with a 3 inch exhaust. it is after all only a 2.5 litre engine but as long as there is something to be gained any avenue is worth trying, it's only money:angel:

As I said earlier, the straight through exhaust created a terrible drone that I was glad to get rid of and no noticeable difference when I put a high flow muffler back in it.

Cheers,
Paul.

Thanks Paul

Ill go with the high flow muffler I think.
Where did you have it mounted? At the end of pipe?

[uninformed]

You like to post up examples like this to justify your replies but what relation is there between a drag car that drives in a straight line for 400mtrs and a road vehicle that has to do everything from towing a boat to picking the kids up from school?.The post is about exhaust size and fitting a 3'' exhaust means fitting a muffler which adds a restriction so you gain nothing over a 2.5'' system which doesn't,like everything on a road vehicle compromise is the key to get the best overall result between performance and comfort. Pat

Pat am I reading correctly that you mean a 2.5" system with no muffler what so ever?

If so, who runs this on a road going vehicle?

BTW I have a Taipan Xp Vortex muffler......it changes the laws of physics!

[harro]

Thanks Paul

Ill go with the high flow muffler I think.
Where did you have it mounted? At the end of pipe?


I had it put in roughly where the original one was.
Which is about the middle IIRC.

Cheers,
Paul.

[PAT303]

Pat am I reading correctly that you mean a 2.5" system with no muffler what so ever?

If so, who runs this on a road going vehicle?

BTW I have a Taipan Xp Vortex muffler......it changes the laws of physics!

Just a resignator,my Tdi hasn't had a muffler for 10 years and it never came up once in three Blue slip inspections. Pat

[rick130]

[snip]

and fitting a 3'' exhaust means fitting a muffler which adds a restriction so you gain nothing over a 2.5'' system which doesn't,like everything on a road vehicle compromise is the key to get the best overall result between performance and comfort. Pat

Umm, in terms of flow and pressure drop, I don't think so ;)

[rick130]

Pat am I reading correctly that you mean a 2.5" system with no muffler what so ever?

If so, who runs this on a road going vehicle?

BTW I have a Taipan Xp Vortex muffler......it changes the laws of physics!


Just a resignator,my Tdi hasn't had a muffler for 10 years and it never came up once in three Blue slip inspections. Pat

Pat, unless you've fitted an aftermarket system, the TDi uses a 2.375"/60mm system, not 2.5". (albeit nicely made, mandrel bent, etc. and the centre muffler is just a perforated straight tube)

I picked up 20km/h in third gear from fitting the big pipe over the stock system, it made that big a difference through the gears.

[noogie]

Hi all.

Quick update.
I had a high flow muffler put in.
It reduced the noise by half andi haven't lost any performance.
So pretty happy with end result.

She still sounds nice wheni stick the boot in.
Be interesting if fuel economy improves as its meant to.
So long as I go easy on the right foot that is.

the muffler is positioned approx just passed half way along pipe.

Thanks for the words of wisdom.

Mick

[Benny_IIA]

In regards to 3' pipes being used my uk tuners

IRB fit 3' there stage 3 vnt kits.

and the turbo is from turbo technics.

[noogie]

Would a larger intercooler do the same thing if not better?
I'm considering an allisport unit next year.
I'm thinking she'll be running real sweeeeet after that.

[harro]

Would a larger intercooler do the same thing if not better?
I'm considering an allisport unit next year.
I'm thinking she'll be running real sweeeeet after that.


With a remap on the td5 I have always thought the inlet side of the engine requires more work than the exhaust.
Uprated intercooler, full Egr removal, airbox modifications and silicone hoses as a precaution against eventual delamination.

If you can afford it the bigger intercooler is a good addition:ohyes:.

Cheers,
Paul.

[noogie]

I removed the egr already and done the silicon hoses also.
What's involved in modifying the air box and what is the benefit?
May as well do the lot while im at it.

[Benny_IIA]

I removed the egr already and done the silicon hoses also.
What's involved in modifying the air box and what is the benefit?
May as well do the lot while im at it.


The large hump is removed from the airbox.

Some people say it decrease low down power but I can not understand how.

I have done on both my td5s running 3 different turbo, and only had good things from doing it.

also ugrading the intake piping from the airbox to the wing or snorkle is a good idea as well. Replace the all the orignal rubbish with 76mm rubber hose from a truck joint.

https://www.aulro.com/afvb/images/imported/2012/09/1030.jpg
https://www.aulro.com/afvb/images/imported/2012/09/1006.jpg

[Tombie]

In regards to 3' pipes being used my uk tuners

IRB fit 3' there stage 3 vnt kits.

and the turbo is from turbo technics.

Thanks mate...

Yes, correct - but their Stage 3 VNT is custom - not the std offering.

And 3" is within the designed turbos parameters.

[isuzurover]

...fitting a 3'' exhaust means fitting a muffler which adds a restriction so you gain nothing over a 2.5'' system ...

Sorry Pat - back to school. All else being equal, a 3" muffler will have less pressure drop (restriction) than a 2.5" muffler.

Pressure drop ~ V^2/D

If you increase diameter of a pipe (or muffler) you reduce V and increase D.

Anyway - As Rick said - where are all the turbo failures on TD5s with 3" exhausts?

[harro]

The large hump is removed from the airbox.

Some people say it decrease low down power but I can not understand how.

I have done on both my td5s running 3 different turbo, and only had good things from doing it.

also ugrading the intake piping from the airbox to the wing or snorkle is a good idea as well. Replace the all the orignal rubbish with 76mm rubber hose from a truck joint.




This mod to the airbox also worked well for me;).

Also in mine there was a static fan blade at the inlet side of the airbox.
Removal of this also made a big difference when combined with increased boost.
I wouldn't bother doing either without a remap installed.

Cheers,
paul.

[goingbush]

Does anyone know of any aftermarket / performance airbox for the Td5,
I think a more free flowing box with larger filter area would be a great improvement. I always thought the Td5 filter too small for a 4x4

One of these will fit but would need to be removed to change out the element

G082528 Donaldson Single Element Air Cleaner 3.75in Inlet 3.50in Outlet +Bracket | eBay (http://www.ebay.com.au/itm/G082528-Donaldson-Single-Element-Air-Cleaner-3-75in-Inlet-3-50in-Outlet-Bracket-/380464652101?pt=AU_HeavyMachineryParts&hash=item589575df45#ht_853wt_806)

or even one of these for better airflow & still plenty of filter area

NISSAN PATROL HI FLOW ZD30 AIRBOX SUIT TURBO / V8 GQ GU | eBay (http://www.ebay.com.au/itm/NISSAN-PATROL-HI-FLOW-ZD30-AIRBOX-SUIT-TURBO-V8-GQ-GU-/190723235466?pt=AU_Car_Parts_Accessories&hash=item2c67fd9e8a#ht_1180wt_1039)



.

[rick130]

also ugrading the intake piping from the airbox to the wing or snorkle is a good idea as well. Replace the all the orignal rubbish with 76mm rubber hose from a truck joint.


https://www.aulro.com/afvb/images/imported/2012/09/1006.jpg

I did the same thing nine years ago on the Tdi, except I used 80mm ID (or 85mm ??) hose from the snorkel to the air box, cutting the 50mm spigot off the snorkel too.

A 2" hose from the mudguard to air cleaner is crazy.

[Benny_IIA]

Thanks mate...

Yes, correct - but their Stage 3 VNT is custom - not the std offering.

And 3" is within the designed turbos parameters.


I think I have the first one in australia :D