TDI120: My New Engine

TFG

A2OC Donor
Tom - this may sound a little strange given all the work that you've put in to improving upon the the standard parts, but have you considered mocking up an inlet tract that entirely does away with the intercooler and instead focuses on minimising the running length twixt turbo and inlet manifold? The results may be retrograde compared to the intercooler install, but it would then at least validate it and quantify the gains it gives. The intercooler install itself is crying out for some flo-vis to get some insight as to what's really going on with airflow - another area where the original Audi layout looks compromised to me, irrespective of whose intercooler is fitted. How is airflow managed from the exit face of the intercooler?
 

JIGSAW

Banned
Ive finaly had the time to have a proper read through ... Wow and well done that man .. that was a really good read and congratulations on all your hard work , only thing id suggest or recommend you fitting is a pd150 oil cooler as it has a larger capacity and will help keep the oil temps lower for turbo and engine longevity.
on another note the grill on one of my tdi's intercoolers was cracked and damaged and at the time i left it off rather than refitting until id repaired or sourced a new one and found no noticable difference with it removed, did you consider a front mount intercooler at all as these will have significant gains at cooling the charge air especially with the location of our TDIs cooler or was it more for oem fitment
 

timmus

A2OC Donor
Ive finaly had the time to have a proper read through ... Wow and well done that man .. that was a really good read and congratulations on all your hard work
Thanks very much, Gary. I'm glad you enjoyed it.

only thing id suggest or recommend you fitting is a pd150 oil cooler as it has a larger capacity and will help keep the oil temps lower for turbo and engine longevity.
I am definitely considering this. Myself and Bala_de_Plata were discussing this a few months ago. It seems the TDI90 oil cooler is also larger, so this is something I'll probably change in due course. There's no reason not to.

Did you consider a front mount intercooler at all as these will have significant gains at cooling the charge air especially with the location of our TDIs cooler or was it more for oem fitment
You're right; fitting the intercooler right at the very front is certainly the best option if focusing wholly on performance. However, that would most definitely have been in conflict with my OEM philosophy. I definitely did not want to have to cut away any of the bumper or the front panel. Shoehorning things into place with random bracketry and such really isn't my way of doing things.

Cheers,

Tom
 

timmus

A2OC Donor
Tom - this may sound a little strange given all the work that you've put in to improving upon the the standard parts, but have you considered mocking up an inlet tract that entirely does away with the intercooler and instead focuses on minimising the running length twixt turbo and inlet manifold? The results may be retrograde compared to the intercooler install, but it would then at least validate it and quantify the gains it gives. The intercooler install itself is crying out for some flo-vis to get some insight as to what's really going on with airflow - another area where the original Audi layout looks compromised to me, irrespective of whose intercooler is fitted. How is airflow managed from the exit face of the intercooler?
Removing the intercooler and minimising the inlet tract would be an interesting experiment, though I suspect VW have already done the research for us on the T4 van. I'm no expert in that model, but I know there was a version that had no intercooler and took air straight from the turbo into the engine's inlet. Another version, with the same turbo, took the air through an intercooler mounted under the bonnet and then into the engine's inlet. From what I've read, the version with the intercooler is significantly more powerful and fuel efficient, despite the additional tract length and complexity.

If you have a look at Fig. 14.4, you can see that the exit face of the intercooler is entirely open to the engine bay. I suspect that atmospheric air exiting the intercooler simply flows under the engine and out.

Cheers,

Tom
 
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timmus

A2OC Donor
Update. The TDI120's all-alloy intercooler is now officially available to order here: www.a2oc.net/forum/showthread.php?33015

If you have expressed an interest in purchasing the intercooler in this thread, could I ask that you confirm your order in the official order thread linked above?

Many thanks,

Tom
 
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timmus

A2OC Donor
My intercooler is burst at the moment with intent on fixing it next month. With your new version this puts me in a dilemma. I either drive my car like my with awful performance for longer or buy one now knowing i will need one of these later.

Have you any rough idea of time frame for these tom ?

Euan
Hi Euan,

Sorry to hear of your dilemma. If you can hold out, I'd recommend it, as any other replacement will eventually fail in the same way. Equally, unless you're doing the replacement yourself, you don't want to be paying to change your existing intercooler only to have to change it again later.

As mentioned in the official group order thread (linked in post 65 of this thread), I'm hoping to submit the order on August 31st. It'd be nice if all units could be ready within a short priod thereafter, but I'm not in control of manufacturing.

Cheers,

Tom
 
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<tuffty/>

Member
Just stumbled across this... Nice one dude... just in the process of sourcing parts for a rebuild on mine... I have an engine ready to take apart and a turbo to use as a donor for a hybrid... also quite fancy the MYP gearbox too as my A2 spends most of its life on the motorway...

What is the spec of the turbo? I see its a larger 6+6 billet compressor with a turbine clip but what size inducer/exducer on the wheels? is it based on a bigger PD turbo?

Ta

<tuffty/>
 

Pinkythelabrat

A2OC Donor
I think Tom is unavailable until the end of Jan at the earliest so might be a while for a reply.
I’d love to help and I know the meaning of all of those words individually but together... ?


Sent from my iPhone using Tapatalk
 

shezlee

Member
Wow,

This is so informative and a great read for anyone looking to keep the original look but want something a lot better (imho).

I was the unfortunate sole that had the forge intercooler made and this post is so correct that it made no real difference due to its location, the one fitted here is so much more effective and if i was to get another A2 would be on the shopping list (this post is pretty much the whole list).

It is great to see the A2 doing so well and far more modification have been done since we parted (written off).

One day I will get another one and now I know where to go and what to do!

Thank you.
 

Jellybean

Admin Team
Just stumbled across this... Nice one dude... just in the process of sourcing parts for a rebuild on mine... I have an engine ready to take apart and a turbo to use as a donor for a hybrid... also quite fancy the MYP gearbox too as my A2 spends most of its life on the motorway...

What is the spec of the turbo? I see its a larger 6+6 billet compressor with a turbine clip but what size inducer/exducer on the wheels? is it based on a bigger PD turbo?

Ta
Believe the GT1749VA turbo from the 130hp 1.9 engine is suitable, and either 130 or 150 injectors. Remap and should get a useful improvement.

Sent from my SM-N960F using Tapatalk
 

Math1962

New Member
9. Getting in the Way: The Anti-Shudder Valve and EGR Valve

In an ideal world, the boost air would be allowed to flow completely unimpeded from the intercooler, along the silicone and ceramic piping, into the inlet manifold. However, just prior to the inlet manifold, in the path of the boost, sit two additional devices, namely the anti-shudder valve and the EGR valve. Both these devices present an obstruction to flow. The AMF engine combines these two devices into one component, as shown in Fig. 9.1. The blue arrows represent the flow of boost air.

Fig. 9.1
View attachment 29578

The anti-shudder valve is only used to stop the engine. It’s possible to stop a TDI engine from running simply by cutting its supply of diesel. However, this causes the engine to shudder to a stop rather than stopping smoothly. The solution to this problem is to also starve the engine of oxygen as well as fuel. This is achieved by introducing a butterfly valve into the flow of boost air, as shown in Fig. 9.2. When the engine is running, the butterfly valve angles itself so as to present as little obstruction to the flow of boost air as possible, shown on the left. When stopping the engine, a vacuum actuator pulls a lever on the right of the anti-shudder valve upwards, as shown on the right. This causes the butterfly valve to rotate, thus completely blocking the flow of boost air and bringing the engine to a halt.

Fig. 9.2
View attachment 29579

Directly behind the anti-shudder valve is the EGR valve. EGR is an abbreviation of exhaust gas recirculation. EGR involves taking a portion of the exhaust gas, mixing it with the boost air, and sending it through the cylinders for a second time. It is a method of reducing the amount of polluting nitrogen oxides emitted by the engine. Fig. 9.3 shows how the EGR valve works. A small branch of the exhaust system is fed to the EGR input, directly beneath the EGR valve. When vacuum is applied to the EGR actuator, the EGR valve lifts upwards, like the lid being removed from a cauldron, causing exhaust gas to mix with the boost air.

Fig. 9.3
View attachment 29580

Whilst the objective of EGR is unquestionably commendable, it has a number of undesirable consequences. Firstly, it causes the boost air to get hot. Having invested so much in getting the boost air as cold and as dense as possible, it is totally counterproductive to mix it with hot, oxygen-depleted exhaust gas just prior to entering the cylinders. This dilution of the boost air, accompanied by the obstruction to flow presented by the EGR valve, causes decreased performance and increased fuel consumption. EGR also causes a gradual build-up of sticky tar in the inlet manifold, cylinder head valves and the EGR valve itself, as shown in Fig. 9.4. This introduction of abrasive contaminants leads to increased component wear and increased engine oil acidity, both of which reduce the longevity of the engine. EGR also increases soot and particulate matter emission, meaning that its positive environmental consequences are counterbalanced by a negative environmental consequence.

Fig. 9.4
View attachment 29581

I intend to keep my A2 forever. Whilst I believe that EGR has a net positive environmental impact for those with a disposable attitude towards their cars, the same cannot be said when a vehicle is destined to be eternally cherished and maintained. As such, I have decided to completely eliminate the EGR system. It is my choice based on the pros and cons. Others are, of course, welcome to disagree with me, but I’d rather discussion/argument about this topic be conducted elsewhere.

The AMF engine combines the anti-shudder valve and EGR valve into one component, which means that removing the EGR without also removing the anti-shudder valve is a challenge. Whilst the BHC and ATL engines split these devices into two separate components, making the removal of just one very easy, the standalone anti-shudder valve is unreliable. Graham – forum stalwart Spike – devised a clever solution to this problem, allowing the EGR valve to be removed from the combined unit, leaving the more reliable anti-shudder valve intact. Fig. 9.5 shows that the EGR input has been capped with a blanking plate. The additional black component attached to the anti-shudder lever is the vacuum actuator, as mentioned in reference to Fig. 9.2.

Fig. 9.5
View attachment 29582

However, there’s more to this blanking plate than first meets the eye. Graham has painstakingly removed all the internal components related to the EGR valve, meaning they no longer present an obstruction to air flow. Fig. 9.6 shows that the blanking plate has been precisely machined to fill the hole left behind by the blanking of the EGR input and the removal of the EGR valve. The result is that the internal wall is completely smooth, aiding air flow, and no evidence of the EGR valve remains.

Fig. 9.6
View attachment 29583

Fig. 9.7 shows a comparison of the old unit compared to the new unit made by Graham. Only the anti-shudder valve remains, presenting much less obstruction to the flow of boost air.

Fig. 9.7
View attachment 29584

Graham, I shall remain eternally grateful to you for making this unit for me. It has allowed me to eliminate the EGR system without compromise. I’m delighted to have a piece of your engineering as part of my project. Fig. 9.8 further demonstrates what a gifted and inimitable gent Graham is and what an asset he and his knowledge are to A2OC.

Fig. 9.8
View attachment 29577
Is there a how-to removal of the EGR, is it best tot take out the inleg manifold?
9. Getting in the Way: The Anti-Shudder Valve and EGR Valve

In an ideal world, the boost air would be allowed to flow completely unimpeded from the intercooler, along the silicone and ceramic piping, into the inlet manifold. However, just prior to the inlet manifold, in the path of the boost, sit two additional devices, namely the anti-shudder valve and the EGR valve. Both these devices present an obstruction to flow. The AMF engine combines these two devices into one component, as shown in Fig. 9.1. The blue arrows represent the flow of boost air.

Fig. 9.1
View attachment 29578

The anti-shudder valve is only used to stop the engine. It’s possible to stop a TDI engine from running simply by cutting its supply of diesel. However, this causes the engine to shudder to a stop rather than stopping smoothly. The solution to this problem is to also starve the engine of oxygen as well as fuel. This is achieved by introducing a butterfly valve into the flow of boost air, as shown in Fig. 9.2. When the engine is running, the butterfly valve angles itself so as to present as little obstruction to the flow of boost air as possible, shown on the left. When stopping the engine, a vacuum actuator pulls a lever on the right of the anti-shudder valve upwards, as shown on the right. This causes the butterfly valve to rotate, thus completely blocking the flow of boost air and bringing the engine to a halt.

Fig. 9.2
View attachment 29579

Directly behind the anti-shudder valve is the EGR valve. EGR is an abbreviation of exhaust gas recirculation. EGR involves taking a portion of the exhaust gas, mixing it with the boost air, and sending it through the cylinders for a second time. It is a method of reducing the amount of polluting nitrogen oxides emitted by the engine. Fig. 9.3 shows how the EGR valve works. A small branch of the exhaust system is fed to the EGR input, directly beneath the EGR valve. When vacuum is applied to the EGR actuator, the EGR valve lifts upwards, like the lid being removed from a cauldron, causing exhaust gas to mix with the boost air.

Fig. 9.3
View attachment 29580

Whilst the objective of EGR is unquestionably commendable, it has a number of undesirable consequences. Firstly, it causes the boost air to get hot. Having invested so much in getting the boost air as cold and as dense as possible, it is totally counterproductive to mix it with hot, oxygen-depleted exhaust gas just prior to entering the cylinders. This dilution of the boost air, accompanied by the obstruction to flow presented by the EGR valve, causes decreased performance and increased fuel consumption. EGR also causes a gradual build-up of sticky tar in the inlet manifold, cylinder head valves and the EGR valve itself, as shown in Fig. 9.4. This introduction of abrasive contaminants leads to increased component wear and increased engine oil acidity, both of which reduce the longevity of the engine. EGR also increases soot and particulate matter emission, meaning that its positive environmental consequences are counterbalanced by a negative environmental consequence.

Fig. 9.4
View attachment 29581

I intend to keep my A2 forever. Whilst I believe that EGR has a net positive environmental impact for those with a disposable attitude towards their cars, the same cannot be said when a vehicle is destined to be eternally cherished and maintained. As such, I have decided to completely eliminate the EGR system. It is my choice based on the pros and cons. Others are, of course, welcome to disagree with me, but I’d rather discussion/argument about this topic be conducted elsewhere.

The AMF engine combines the anti-shudder valve and EGR valve into one component, which means that removing the EGR without also removing the anti-shudder valve is a challenge. Whilst the BHC and ATL engines split these devices into two separate components, making the removal of just one very easy, the standalone anti-shudder valve is unreliable. Graham – forum stalwart Spike – devised a clever solution to this problem, allowing the EGR valve to be removed from the combined unit, leaving the more reliable anti-shudder valve intact. Fig. 9.5 shows that the EGR input has been capped with a blanking plate. The additional black component attached to the anti-shudder lever is the vacuum actuator, as mentioned in reference to Fig. 9.2.

Fig. 9.5
View attachment 29582

However, there’s more to this blanking plate than first meets the eye. Graham has painstakingly removed all the internal components related to the EGR valve, meaning they no longer present an obstruction to air flow. Fig. 9.6 shows that the blanking plate has been precisely machined to fill the hole left behind by the blanking of the EGR input and the removal of the EGR valve. The result is that the internal wall is completely smooth, aiding air flow, and no evidence of the EGR valve remains.

Fig. 9.6
View attachment 29583

Fig. 9.7 shows a comparison of the old unit compared to the new unit made by Graham. Only the anti-shudder valve remains, presenting much less obstruction to the flow of boost air.

Fig. 9.7
View attachment 29584

Graham, I shall remain eternally grateful to you for making this unit for me. It has allowed me to eliminate the EGR system without compromise. I’m delighted to have a piece of your engineering as part of my project. Fig. 9.8 further demonstrates what a gifted and inimitable gent Graham is and what an asset he and his knowledge are to A2OC.

Fig. 9.8
View attachment 29577
I SHUT DOWN THE EGR VALVE BY BLOCKING THE TUBE TO THE EGR FROM THE SOLENOID, IḾ NOT SURE BUT COULD IT BE BECAUSE OF THIS THE TURBO LACKS SOME POWER OR ACTS SLOWER< THIS IS HOW IT FEELS?
 

Dasta

New Member
Hi everyone,
I have an audi a2 1.4 tdi AMF and i have a broken turbo, i am going to replace it so i would like to ask if the solution of a BHC turbo on an AMF engine is a good option and what will i need to make it work. The only thing i have to do is to block the EGR? And furthermore do i have to remmap the car after that?
 

timmus

A2OC Donor
Hi everyone,
I have an audi a2 1.4 tdi AMF and i have a broken turbo, i am going to replace it so i would like to ask if the solution of a BHC turbo on an AMF engine is a good option and what will i need to make it work. The only thing i have to do is to block the EGR? And furthermore do i have to remmap the car after that?
The oil feed and oil drain pipes are different for the BHC turbo, so these will also need to be changed. No software alteration (remap) is necessary.

Cheers,

Tom
 

Dasta

New Member
The oil feed and oil drain pipes are different for the BHC turbo, so these will also need to be changed. No software alteration (remap) is necessary.

Cheers,

Tom
Thank you very much, but can you be more specific about the procedure? what needs to be done? is it something hard to be done?
 

timmus

A2OC Donor
Thank you very much, but can you be more specific about the procedure? what needs to be done? is it something hard to be done?
The turbo needs oil. There is a pipe that carries oil from the oil filter housing at the front of the engine to the turbo at the back of the engine. This pipe is not the same for the AMF and BHC turbo. Your A2 will currently have the AMF version of this pipe, and you will need the BHC version. It's not a difficult job; you just need to change this pipe.
The same is true for the oil drain pipe. This pipe carries oil from the turbo back to the engine. It will also need to be changed to the BHC version.

Cheers,

Tom
 

Dasta

New Member
The turbo needs oil. There is a pipe that carries oil from the oil filter housing at the front of the engine to the turbo at the back of the engine. This pipe is not the same for the AMF and BHC turbo. Your A2 will currently have the AMF version of this pipe, and you will need the BHC version. It's not a difficult job; you just need to change this pipe.
The same is true for the oil drain pipe. This pipe carries oil from the turbo back to the engine. It will also need to be changed to the BHC version.

Cheers,

Tom
Thank you very much again. You are the best!!!
 

mrbroons

Well-Known Member
Amazing write up. I think that I was down at WOM when your car was in pieces. As I recall you were in the garage doing some work on it when I was told there was a toothbrush involved!!! Amazing write up and awesome work. Words don't do it or you justice mate. 👍
 
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