80mm exhaust on my T4 2.5 TDI

[pjbplumbing@bigpond.com]

Hi there,
Had the bulk of my original exhaust removed last week and a straight through 80mm exhaust fitted from the cat back. With 2x straight through mufflers, no baffles.
Results, after sorting out a rattle; it seems to accelerate easier up hills, not much change internally from exhaust noise.
My long term plan is to eventually get LPG fitted also, which will benifit from the larger exhaust.
Oh, and a DP chip to be fitted next week also.
Will do some photos when posssible.
Peter

[GoLfMan]

sounds great mate, pics would be awesome i wanna do the exhaust on my TDI soon aswell, good to know there's results :)

[pjbplumbing@bigpond.com]

As usual, the thread has gone totally off track...
I was talking about a larger exhaust, as it is common knowledge that a turbo diesel works better with an open exhaust.
But silly me mentioned a chip and woah...off we went on a side track about who has epromed a better chip and so on...?
oh well... we could talk all night about mapping and 3 demensional programing but hey..
As the gals would say...bigger is better.:)
Peter

[GoLfMan]

have you got any photos of it mate? i want to do an exhaust for my TDI polo and i tossing up between 2 3/4" or 3"

[Greg Roles]

Great to hear that the old wives tale of a turbo diesel not really needing a lot of muffling is true. Also good to hear it's assisting boosting!

[mollins]

good stuff with the free flowing exhaust. Good to hear you took the risk of noisyness going straight through and it has paid off.
The turbo evens out much of the pulsing and pressure waves which make a heap of the usual noise. great work.

[pjbplumbing@bigpond.com]

Golfman,
Yeah photo's would be good;
I will try and do a few 2morrow, but my partner is away and she has taken the good camera - all I have at the mo is a toy camera that comes with my phone... I 'll try it and see...get it ..see ??? oh dear!

Yeah I had heard the turbo on a diesel cuts the noise down, and it would seem that it is true. I had asked that the 80mm go all the way to the turbo but was told to leave the cat in position and go from there; so there is about 600mm of original german pipe between cat and turbo.
The DP wizz-banger is worth $1300 big ones, but what appeals to me is:
A/ easy to fit
B/ Motor can be easly returned to original condition
C/ DP has some adustment - fine tuning
D/ I think it may be made in Australia?


From what I know of the ECU board fitted by the Krauts, the factory chip is soldered to the board.
I had thought about removing the original chip and fitting a chip socket to the circuit board - then it would be easy to just plug & play with different chips.
But I havent.
Peter

[Logzy]

Golfman,
Yeah photo's would be good;
I will try and do a few 2morrow, but my partner is away and she has taken the good camera - all I have at the mo is a toy camera that comes with my phone... I 'll try it and see...get it ..see ??? oh dear!

Yeah I had heard the turbo on a diesel cuts the noise down, and it would seem that it is true. I had asked that the 80mm go all the way to the turbo but was told to leave the cat in position and go from there; so there is about 600mm of original german pipe between cat and turbo.
The DP wizz-banger is worth $1300 big ones, but what appeals to me is:
A/ easy to fit
B/ Motor can be easly returned to original condition
C/ DP has some adustment - fine tuning
D/ I think it may be made in Australia?


From what I know of the ECU board fitted by the Krauts, the factory chip is soldered to the board.
I had thought about removing the original chip and fitting a chip socket to the circuit board - then it would be easy to just plug & play with different chips.
But I havent.
Peter

DP is not made in Australia.
Actually changing the chip on the ECU motherboard is old skool and in 99.9% of cases is no longer done or required.
These days the chip is "flashed" with new data.
Can i suggest you do some googling and reading.
At the price you've been quoted for the DP box I'd seriously shop around, if this is the way youre going to go then id be very surprised if you couldnt get it cheaper.
Only trying to help, its your choice.
Cheers.

[gldgti]

i thought this thread was about exhaust, not chips. i dont care much for chips, they make you fat.

its not fair to wreck someone elses thread by chiming in about chips. feel free to clean up your own posts out of respect for the original thread starter unless you feel they are truly significant.

Great stuff with the exhaust mate, if nothing else it'll keep the EGT's lower which is happy days.

I just installed EGT gauge in the mk3 and am happy to report i havnt managed to get it over 550deg, even though i'm running more fuel and 18psi now.

so you have put yourself in a good position for more power later!

[Greg Roles]

So how about the price of oil today, geez!

[Seano]

Peter....I'd like to hear more about the exhaust system you've had fitted. Was it a custom bend or off the shelf? Was the OEM system toasted/rusted or did you just want to do it for kicks? How much did it set you back?

And like the G-man......I too would love to see some photos.

I'm not particularily interested in chips........never struck me as good bang for buck. Except for the seller/trader.

[pjbplumbing@bigpond.com]

Here are a few shots of the new exhaust system.
You have no idea what pain and suffering I had to endure getting these from my Telstra ZTE phone? What a piece of garbage.
The whole thing fitted cost $650.00. It was a total custom job, made-up from various bends and mufflers. Mufflers are straight through jobs. The original system was fine. I wanted to free up the Turbo and gain some kW's, and maybe some ltr/100?
As I said earlier, the original cause was to prepare for LPG addition which I hope one day to afford..after I have sold my wife and cut-off my left arm.
I believe the original exhaust is a legacy from petrol motors - in other words, factory fits same to either motor? I see no other reason why such an elaborate system is fitted to a TDI? Not needed.



http://www.vwwatercooled.com.au/forums/images/imported/2008/09/Pic_0923_034-1.jpg



http://www.vwwatercooled.com.au/forums/images/imported/2008/09/Pic_0923_035-1.jpg


http://www.vwwatercooled.com.au/forums/images/imported/2008/09/Pic_0923_036-1.jpg


http://www.vwwatercooled.com.au/forums/images/imported/2008/09/Pic_0923_039-1.jpg

[GoLfMan]

nice one mate :) i wanna do that to my Polo TDI, its only got a 2" factory exhaust :(

[Seano]

Nick work, Peter.

Biggest bummer with my exhaust is the whacking great loop that is required so the pipe clears the T4 syncro driveline out the back....makes a mockery of free flow!!

[pjbplumbing@bigpond.com]

Seano,
Has your van got side windows that open? If not you could exit the exhuast out the side in front of the rear wheel - cool man.
2 door golfs could do ditto.

[gldgti]

as above post says, sorry mate!

i bow down to you all in this public domain and submit my self to any mocking laughter that you may wish to bestow upon me.

on topic - nice xorst!

[GoLfMan]

Derrrr Aydan j:

[Seano]

Seano,
Has your van got side windows that open? If not you could exit the exhuast out the side in front of the rear wheel - cool man..

Mine's not a van. It's a dual cab chassis. Hmmm.....side exit exhaust. Before anyone suggests it I am not going to try a vertical stack exhaust setup like in the average prime mover....because that would look lame.

[pjbplumbing@bigpond.com]

Fitted the DP Chip yesterday, too easy, hardest part was dropping the belly pan. 20 mins max.
Differance; amazing, and I havent messed with any of the adjustments, the unit is running on basic setting (0), there are 9 adjustments available?
As the van is a work van and a daily work horse I find I have forgotten about the chip and then find my self leaving say a certain intersection which faces up a hill, moving off from first and turning as well - when the turbo and chip kick in and - Oh yeah...smile....that was cool... the van just powers on - all 2 tonne of it!
Next thing will be LPG.

[Greg Roles]

You'll need "hell bus" plates mate! :biggrin:

[benough]

Great to hear that the old wives tale of a turbo diesel not really needing a lot of muffling is true. Also good to hear it's assisting boosting!

So then would that mean that if you did a muffler delete on a TDI GT Sport it wouldn't be any louder?

Can anyone confirm the diameter of the TDI exhaust? 2.5 inches from memory...

[Greg Roles]

A nicely mandrel bent 2.5" the entire way.

Restriction is in the DPF, but yeah that huge rear pancake muff could easily be lost for next to no sound diff, and a few less kgs!

The resonator near the rear axle would be best left there to prevent the booming resonance that makes in cabin noise unpleasant.

[benough]

So what benefit would there be?

It would have to out weigh the potential warranty problems if something ever happens with my exhaust/DPF

[Greg Roles]

The minute you mess with anything, theoretically you also mess with your warranty. The risk is always, totally, yours I'm afraid. I accept that risk.

[chisler]

Fitted the DP Chip yesterday, too easy, hardest part was dropping the belly pan. 20 mins max.
Differance; amazing, and I havent messed with any of the adjustments, the unit is running on basic setting (0), there are 9 adjustments available?
As the van is a work van and a daily work horse I find I have forgotten about the chip and then find my self leaving say a certain intersection which faces up a hill, moving off from first and turning as well - when the turbo and chip kick in and - Oh yeah...smile....that was cool... the van just powers on - all 2 tonne of it!
Next thing will be LPG.
Hi, have you managed to get around to fitting LPG yet? I'm really curious about diesel/LPG
also, if chips give about a 20% increase, and LPG gives about 20% increase, are you expecting a increase of 40%?

[gregozedobe]

I've read several negative reports on LPG in diesels (increased combustion and engine temps, not as big a saving in $$$ as expected).

Unless you are a risk taker, it might be a good idea to find out if anyone has done it to the same engine as you have, what results they got and how satisfied the owner is (preferably after they have run it for a few months, ie after the "honeymoon period" any new purchase enjoys).

[benno]

I've read several negative reports on LPG in diesels (increased combustion and engine temps, not as big a saving in $$$ as expected).

Unless you are a risk taker, it might be a good idea to find out if anyone has done it to the same engine as you have, what results they got and how satisfied the owner is (preferably after they have run it for a few months, ie after the "honeymoon period" any new purchase enjoys).

My old man did it in his Mitsu Canter (big atmo diesel).

He's been all over aus with it and reckons it's a substantial increase in economy and power.

I'm yet to read a truly negative report on it... got a link?

[chisler]

Unless you are a risk taker, it might be a good idea to find out if anyone has done it to the same engine as you have, what results they got and how satisfied the owner is (preferably after they have run it for a few months, ie after the "honeymoon period" any new purchase enjoys).
thats why I'm asking, just curious on the results.
my cars brand new, so I won't be doing any mods while its under warranty, unless I'm 100% confident about it, and from what I can gather, this means mods that void my warranty :frown:

[gregozedobe]

I'm yet to read a truly negative report on it... got a link?

The reports I read were in the CMCA magazine and web site (private). One bloke blew up the engine in his motorhome due to excessively high temperatures (twice - he must have been a slow learner), the other was a tech report that IIRC said that he hadn't found any significant performance improvements on vehicles that were in a good state of tune, and you can only run a maximum of 30% gas, so could only save a mazimum of 30% of the cost diffrence between gas and diesel.


... and from what I can gather, this means mods that void my warranty :frown:

That's putting it mildly ! I think the VWA warranty people would run a mile if you had any engine problems at all after a LPG conversion to your engine.

[chisler]

I'm yet to read a truly negative report on it... got a link?

The reports I read were in the CMCA magazine and web site (private). One bloke blew up the engine in his motorhome due to excessively high temperatures (twice - he must have been a slow learner),r a LPG conversion to your engine.
I've been reading both positive and negative things, reading online articles, and forums.

1 problem about getting information on this, is that it only seems to be Australia creating diesel/lpg systems for small vehicles. and by small vehicles I mean 4wd/suv's and not trucks and industrial stuff.
I think the government lpg rebate might have something to do with this, and the fact we have so much lpg here.

being in lpg land, I think this is something to keep an eye on, but I wouldn't do a lpg conversion at this point in time, unless I fully understand the process, which I don't.

[dammfool]

Fitted the DP Chip yesterday, too easy, hardest part was dropping the belly pan. 20 mins max.
Differance; amazing, and I havent messed with any of the adjustments, the unit is running on basic setting (0), there are 9 adjustments available?
As the van is a work van and a daily work horse I find I have forgotten about the chip and then find my self leaving say a certain intersection which faces up a hill, moving off from first and turning as well - when the turbo and chip kick in and - Oh yeah...smile....that was cool... the van just powers on - all 2 tonne of it!
Next thing will be LPG.

Try your dp chip on 9 and it will blow u away and blow lots of smoke.When i got mine it didnt seem to do stuff all set at 1.So i usually keep it at 5 when im doing alot of highway cruising,cause when set on 9 and u set the cruise control i cant seem to handle the power.

[shadowmaker]

Here's my T4 2.5TDI manifolds.

http://img.photobucket.com/albums/v211/Petehri/Portteri/Imusarja/Imusarja20.jpg

http://img.photobucket.com/albums/v211/Petehri/Portteri/Imusarja/Imusarja15.jpg

http://img.photobucket.com/albums/v211/Petehri/Portteri/Pakosarja8.jpg

Turbos (two vnt's, the bigger one is good for 5-600hp and ~3,5bar) are going to be located in the trunk. Target is to get 450 road usable hp and 1/4mile time close to 13 seconds.

[mollins]

wow!! that is awesome!!!
Nice manifolds mate.. some great welding on that inlet.

please start a build thread for your crazy van!!

[gldgti]

man thats incredible!

tell me, why do you want to put the turbo's so far from the engine?

[silvershadow]

man thats incredible!

tell me, why do you want to put the turbo's so far from the engine?


Possibly to reduce the turbo component temperatures as the exhaust gas will cool between the manifold and boot-mounted turbo. The exhaust gas pressure will be almost the same as the pressure at the manifold so the turbo output will not be reduced.

My interest is how will the turbo oil supply will be set up.

[Greg Roles]

I've got a hard on.

[shadowmaker]

It's not the high temperatures I'm afraid of, it's the space under the hood that's insufficient for both turbos. You have to keep in mind that the bigger vnt (gt37v) weights about 40kg and is the size of a soccer ball...

Now what I'm afraid is too low exhaust temperature to spin those turbos. Actually it's the volume of gasses, not the temperature, but as the temperature reduces so does the volume too. I will do my best to keep the heat in the gasses and will use a lot of ceramic coating and some more conventional insulation to do this.

Oil supply is easy as oil pressure from the engine's oil pump is more than enough. Hard part is obviously getting that oil back to the engine from the non pressurized side (=after turbo) and that's why an electrical pump is needed.

Everything is going to be electrically controlled with additional DTA-box + original ECU is going to be changed for a more modern version of it (from a 111kW T4 with original vnt control in it). Gearbox will also come from 111kW as my current one is over it's limits with previous 370hp, 750Nm. Don't get me wrong: 102hp GB is extremely strong, it's just the syncros between 1st and 2nd that always fail.:frown:

[silvershadow]

Now what I'm afraid is too low exhaust temperature to spin those turbos. Actually it's the volume of gasses, not the temperature, but as the temperature reduces so does the volume too. I will do my best to keep the heat in the gasses and will use a lot of ceramic coating and some more conventional insulation to do this.




The operative equation in a static system is the ideal gas law:

P1xV1/T1 = P2xV2/T2 where P = Pressure, V = Volume and T = temperature in deg Kelvin [deg C + 273].

The Pressure in the exhaust system up to the turbo will be almost uniform and will vary in proportion to the engine revolutions so this factor can be deleted from the equation which now becomes:

V1/T1 = V2/T2 which, in turn, may be manipulated to become V2 = V1xT2/T1.

If we do some sample calculations based on exhaust gas temperatures of T1 = 700 deg C [973 deg K] and T2 = 500 deg C [773 deg K], the volume change becomes V2 = V1x773/973
= 0.79V1 [a 21% reduction]

However this applies to a static system and not to a dynamic situation like the one that exists in a Turbo system where the velocity of the gas and its density on both the exhaust gas and combustion air intake sides of the turbo become important factors in the calculation. The mathematics involved now become far more complex and cannot be explained in layman's terms.

However, if some reduction in exhaust gas temperature say up to 100 deg C can be tolerated, the life of the turbo should be improved without unacceptable reductions in volume and pressure of combustion air delivered to the intake manifold.

[gregozedobe]

Presumably on such a crazy build as this you aren't concerned about the extra lag you will get from having your turbos (!!) further away from the head ?

Are you going to be running FWD dragster tyres ? With the amount of power you are putting out you would fry most "normal" road tyres trying to do a fast standing start on FWD van.

[shadowmaker]

Silvershadow:

Are you sure that the reduction in temperature is only ~200C? I'd think it's at least something like 4-500C without any effort against it. With effort I think I can reduce it to a 200C level propably. Really don't know yet.

On the other hand, reduced temps in ex gasses will also reduce EMP in high rev area, so exhaust side efficiency should be better there. Turbo will spool later, but it will also operate higher.

gregozedobe:

I'am really concerned about the possible lag. Everything will be done to fight against it. Sadly the lenght (and volume) of the ex manifold can't be avoided (volume reduces dramatically the strenght of exhaust pulses). I will use two different size vnts to maximise the width of the power band. I will also use an anti-lag system that we have already used succesfully in our MB OM603 engine (1989 3.0L TD inline six, 12 valve, gt37v, 450hp, 700Nm restricted).

I know the limitations of FWD, which are even worse on a heavy van. With 370hp I could smoke tire on 1st and 2nd, but only occasionally on 3rd with my normal 18" tires on dry tarmac. At the track I used DOT approved semi slicks and got ~2.4s 60feet times. Improvements will include new suspension, custom made diff lock and reduced bodyweight. Also brakes will be upgraded to 330mm with 8 pot calibers.

There's no reasonable point for building up a "performance" van, but that's my hobby and passion. I still think it beats the hell out of collecting stamps...

[gregozedobe]

.....There's no reasonable point for building up a "performance" van, but that's my hobby and passion. I still think it beats the hell out of collecting stamps...

I like to hear about what people get up to with their hobby/passion.

If you are building a drag-strip only special you could hang the heavy turbos out the front of the engine to help you get better traction off the line (that way the weight transfer would go onto the front wheels, not onto the rear wheels).

If it is to be road registered and look vaguely "stock" then this isn't really such a practical option. Some of the USA FWD dragsters look quite bizarre, with the engine hanging way out the front of the drive wheels, but they are getting surprisingly good results.

Keep up the good work :biggrin:

[Greg Roles]

Propane? From what I've been reading this can throw your exhaust temps up, and in your case you will actually want that, for power AND temps. But then given your serious mods, I'm sure you've already considered this.

Geesus I'd love to know what you can do to make less lag in the VNT apart from a bi-turbo...:biggrin:

[Transporter]

Silvershadow:

Are you sure that the reduction in temperature is only ~200C? I'd think it's at least something like 4-500C without any effort against it. With effort I think I can reduce it to a 200C level propably. Really don't know yet.

On the other hand, reduced temps in ex gasses will also reduce EMP in high rev area, so exhaust side efficiency should be better there. Turbo will spool later, but it will also operate higher.

gregozedobe:

I'am really concerned about the possible lag. Everything will be done to fight against it. Sadly the lenght (and volume) of the ex manifold can't be avoided (volume reduces dramatically the strenght of exhaust pulses). I will use two different size vnts to maximise the width of the power band. I will also use an anti-lag system that we have already used succesfully in our MB OM603 engine (1989 3.0L TD inline six, 12 valve, gt37v, 450hp, 700Nm restricted).

I know the limitations of FWD, which are even worse on a heavy van. With 370hp I could smoke tire on 1st and 2nd, but only occasionally on 3rd with my normal 18" tires on dry tarmac. At the track I used DOT approved semi slicks and got ~2.4s 60feet times. Improvements will include new suspension, custom made diff lock and reduced bodyweight. Also brakes will be upgraded to 330mm with 8 pot calibers.

There's no reasonable point for building up a "performance" van, but that's my hobby and passion. I still think it beats the hell out of collecting stamps...

You can always install the jet engine like this bloke did. :biggrin::biggrin:

3714
3713

[Greg Roles]

You'd have to feel a bit nervous pulling up behind that at the lights...."geez, that looks like.....looks like a JET!" :eek:

[Transporter]

You'd have to feel a bit nervous pulling up behind that at the lights...."geez, that looks like.....looks like a JET!" :eek:

Just don't get any ideas Cogdog! :biggrin:

The pictures were taken at Whyalla last weekend at Monster truck show.
To be honest that van was pathetic and toooo slow. :duh:
The jet was running on diesel.

[silvershadow]

Silvershadow:

Are you sure that the reduction in temperature is only ~200C? I'd think it's at least something like 4-500C without any effort against it. With effort I think I can reduce it to a 200C level propably. Really don't know yet.

...


The rate of gas cooling between the manifold and turbo inlet will be determined by the velocity of the exhaust gas, the difference in temperature between the exhaust pipe and the atmosphere and the rate of heat transfer between the inside and outside of the pipe. My 200 deg example was only a guess as to what cooling might take place in the system - a couple of probes will soon provide the required information for whatever size system you are considering.

As far as the gas velocity is concerned - the larger the pipe, the lower the velocity and the more time the gas has to cool down between the manifold and turbo but has the benefit of a lower pressure drop than with a smaller diameter pipe.

The rate of heat transfer across a stainless steel pipe is much less than that for a mild steel pipe so the use of a stainless steel system will give higher gas temperatures than the same system in mild steel.

Also keep in mind, part of the energy transferred by the turbo to compress the intake air comes from expansion of the exhaust gas as it passes through the turbo and this expansion reduces the gas temperature if the turbo casing stays at a relatively constant temperature. The exit temperature of the exhaust gas leaving the turbo will then be much less than the entry temperature. You can increase turbo efficiency by reducing back pressure in the system after the turbo discharge to take advantage of this expansion.

We are into a complex area of fluid flow and thermodynamics - I have tried to keep the essential elements simple to give an appreciation of the areas that are worthy of experimentation.

[shadowmaker]

Jet in a van can be a fire hazard.:biggrin:
http://www.youtube.com/watch?v=6CM0XpCJJe4

My van will be in everyday use as it has been for the last 100 000km with over 200hp. Last 20 000km it has had over 300hp in it. My wife drives it too to get my company's things done. At least for now it has been quite nice to drive and consumtion is about 8L/100km on highway (100-110kmh). Previous clutch hold ~850Nm when warmed up, but now I have a dual disc setup (good for 1200Nm) with no dampning what so ever. I think that's going to be the worst part for driveability.

I'm not going to use propane or NOS. Too easy.