Hi, I would like to talk about my car's TDI engine built for performance. I swapped a TDI ALH into a 2004 Audi A4 Quattro and modified it. But now, I'm making a big refresh of all the mechanic of my car. Removed old engine, changing parts that need to be changed, re-fit custom parts to fit better or make it cleaner under the hood...
My CURRENT build (Now it is not running because I already removed the engine from the car, but I ran this build for 60k miles) :
-TDI ALH with stock internals, stock head, and ARP head studs.
-11mm OEM Bosch fuel pump
-PP764 Stage 2 nozzles, injectors calibrated at Stage 1 (less smoke, optimal fuel economy) by DBW
-BEW in-tank primary electric pump
-GTB1756VK at 30PSI
-PD150 intake
-FMIC setup (really laggy, 20 feet of 2inches piping)
-Custom chip
-4 BAR map sensor
-PYRO + boost gauge
-6 pucks ceramic Bully clutch kit with single mass flywheel.
I'm wondering what to change in this build to make it more powerful. Keep in mind that it's a daily Drive, so I want something that is reliable, less smoke as possible, and having the best fuel economy as I can under light loads (economy are really important since I want to make impressive numbers for a Quattro car, with the best power as I can.
The old build described above was too much laggy and lacks power. It also lacks of fueling past 3500RPM, but even in low RPM, power and torque was low and the response was laggy. I'm sure that the lag was caused by too much 90 degree angles on intercooler piping and too long intercooler piping. The lacks of power occured after 2-3 weeks driving with the new setup. At the beginning, even with a chip that was not adjusted, even if the turbo was only at 26psi, even without the FMIC setup and PD150 intake, and even without the Bosio nozzles (I had chinese 6 holes .205 nozzles at the beginning), the car was REALLY impressive, torquey and powerful. After two weeks, the car seemed to lack power. After removing the cylinder head from the engine, I have seem there is no honing marks at all on the cylinders, the cylinders were glazed, there were visual (but not feel with my fingers) vertical marks on the cylinders and the top of the cylinders. The engine took also a quart of oil every 1000-1500miles, even when trying 10W60oil, the oil consumption dropped only at 1 quart every 2000-2500 miles. This oil consumption was what was registered just before removing the head. At the beginning of the setup I removed the head and there was clearly honed marks on the cylinders. The engine had 120k miles at this points. 60k miles later, no cylinders honing marks at all! 430psi compression on all cylinders, but lacks power.
So I repeat was I unliked on my oil setup :
Lacks power at all RPMS, lacks of fueling a bit, but only past 3500RPM, before that the fueling is okay. Really laggy too. High oil consumption.
Now, I will describe you what I'm expecting from the setup :
1-Keep the fuel mileage as high as possible to make impressive numbers for a Quattro car.
2-Reduce smoke output as best as possible, best possible atomisation.
3-I want to have the best HP and torque as possible, but the TORQUE numbers are really important, and low-end torque is important too. The car is heavy and what I like the most is accelerating fast in city or accelerate fast going uphill too see all the torque of the TDI. Also, I can have a lot of torque because traction is not a problem. The torque below 1900 RPM is not important because the engine vibrates too much at this point (longitudinal mounts), but I want to have the maximum peak torque at 2300RPM or less if possible. I want a really quick throttle response setup, it helps for a better feeling of the TDI engine torque.
Now, the setup that I'M building to achieve my goals :
-Custom built rebuild bottom end with PD150 crank and rods, BHW brand new pistons, all that in a ALH bottom end that was honed to 2.0Liters to accomodate BHW pistons. We machined the cylinders a bit more loose to accomodates for piston dilatation when high EGTS situation occurs, reducing the risk of piston seizing into the cylinders. Also ARP head studs like before.
-ALH cylinder head with a porting job made by frank06.
-Cam... Hesitates between stock cam or high lift cam. I don't want to machine the BHW pistons, so if I need to machine, I prefer to stay with stock cams. Keep in mind that I don't want to lose low end torque too!
-Injectors : I absolutely want to stay with the PP764 stage 2 nozzles. I want very good atomisation for reduced smoke and best fuel economy as possible. Also, these nozzles are very expensive and I will lose too much if I buy another set. It is possible that I'll send the injectors to DBW to open it at better stages but I wondering what stage I'll need for the purpose and if it will be enough
-Fuel pump : Probably will re-use my 11mm bosch. I have thinked about using a 12mm fuel pump because the atomisation will be better than the 11mm and it will compensate with the lacks of fuel of PP764 Stage 2 without sacrifying atomisation of the 7 holes nozzles. BUT I worry about the max RPM and reliability of the 12mm pump...
I will stay with my BEW in-tank primary pump to helps for fueling.
-Turbo... I hesitates to change the GTB1756VK for bigger or not. I'm worrying about the facts that going bigger turbo will make the setup more laggy and have less low-end torque. But in the same time, it will make better HP's.
-I'm building a new ingenious intercooling system to reduce lag. It will be a water-to-air intercooling system. The FMIC will be removed and the stock Audi 1.8t intercooler will be reused : It will be the water radiator at the front of the car. The water-to-air heat exchanger will be directly integrated to the intake by cutting the uppder of the intake and welding it, so I'll have one feet of piping between turbo and intake runners. An isolant intake gasket will be used to reduce heat transfert between cylinder head and intake-intercooler.
What you are thinking about that? According to all that thread, what you will change on this setup? Change turbo or stay GTB1756VK? Send injectors to DBW for opening at higher stages or replace the fuel pump by a 12mm? Is it reliable for 5k RPM or not? A Colt Stage 2 cam will help or not? Remember that I do not want to deepen the valve pockets of my brand new pistons, so if it's needed, I forget the cam.
What I'm expecting is your help because a TDI setup is complex. It's like a cake recipe, and if we change an ingredient, it is possible that we will have to change several ingredients to match. What is the compromise between torque, hp, lag, fuel economy, atomisation and smoke output, and reliability at this point? Some ideas?
My CURRENT build (Now it is not running because I already removed the engine from the car, but I ran this build for 60k miles) :
-TDI ALH with stock internals, stock head, and ARP head studs.
-11mm OEM Bosch fuel pump
-PP764 Stage 2 nozzles, injectors calibrated at Stage 1 (less smoke, optimal fuel economy) by DBW
-BEW in-tank primary electric pump
-GTB1756VK at 30PSI
-PD150 intake
-FMIC setup (really laggy, 20 feet of 2inches piping)
-Custom chip
-4 BAR map sensor
-PYRO + boost gauge
-6 pucks ceramic Bully clutch kit with single mass flywheel.
I'm wondering what to change in this build to make it more powerful. Keep in mind that it's a daily Drive, so I want something that is reliable, less smoke as possible, and having the best fuel economy as I can under light loads (economy are really important since I want to make impressive numbers for a Quattro car, with the best power as I can.
The old build described above was too much laggy and lacks power. It also lacks of fueling past 3500RPM, but even in low RPM, power and torque was low and the response was laggy. I'm sure that the lag was caused by too much 90 degree angles on intercooler piping and too long intercooler piping. The lacks of power occured after 2-3 weeks driving with the new setup. At the beginning, even with a chip that was not adjusted, even if the turbo was only at 26psi, even without the FMIC setup and PD150 intake, and even without the Bosio nozzles (I had chinese 6 holes .205 nozzles at the beginning), the car was REALLY impressive, torquey and powerful. After two weeks, the car seemed to lack power. After removing the cylinder head from the engine, I have seem there is no honing marks at all on the cylinders, the cylinders were glazed, there were visual (but not feel with my fingers) vertical marks on the cylinders and the top of the cylinders. The engine took also a quart of oil every 1000-1500miles, even when trying 10W60oil, the oil consumption dropped only at 1 quart every 2000-2500 miles. This oil consumption was what was registered just before removing the head. At the beginning of the setup I removed the head and there was clearly honed marks on the cylinders. The engine had 120k miles at this points. 60k miles later, no cylinders honing marks at all! 430psi compression on all cylinders, but lacks power.
So I repeat was I unliked on my oil setup :
Lacks power at all RPMS, lacks of fueling a bit, but only past 3500RPM, before that the fueling is okay. Really laggy too. High oil consumption.
Now, I will describe you what I'm expecting from the setup :
1-Keep the fuel mileage as high as possible to make impressive numbers for a Quattro car.
2-Reduce smoke output as best as possible, best possible atomisation.
3-I want to have the best HP and torque as possible, but the TORQUE numbers are really important, and low-end torque is important too. The car is heavy and what I like the most is accelerating fast in city or accelerate fast going uphill too see all the torque of the TDI. Also, I can have a lot of torque because traction is not a problem. The torque below 1900 RPM is not important because the engine vibrates too much at this point (longitudinal mounts), but I want to have the maximum peak torque at 2300RPM or less if possible. I want a really quick throttle response setup, it helps for a better feeling of the TDI engine torque.
Now, the setup that I'M building to achieve my goals :
-Custom built rebuild bottom end with PD150 crank and rods, BHW brand new pistons, all that in a ALH bottom end that was honed to 2.0Liters to accomodate BHW pistons. We machined the cylinders a bit more loose to accomodates for piston dilatation when high EGTS situation occurs, reducing the risk of piston seizing into the cylinders. Also ARP head studs like before.
-ALH cylinder head with a porting job made by frank06.
-Cam... Hesitates between stock cam or high lift cam. I don't want to machine the BHW pistons, so if I need to machine, I prefer to stay with stock cams. Keep in mind that I don't want to lose low end torque too!
-Injectors : I absolutely want to stay with the PP764 stage 2 nozzles. I want very good atomisation for reduced smoke and best fuel economy as possible. Also, these nozzles are very expensive and I will lose too much if I buy another set. It is possible that I'll send the injectors to DBW to open it at better stages but I wondering what stage I'll need for the purpose and if it will be enough
-Fuel pump : Probably will re-use my 11mm bosch. I have thinked about using a 12mm fuel pump because the atomisation will be better than the 11mm and it will compensate with the lacks of fuel of PP764 Stage 2 without sacrifying atomisation of the 7 holes nozzles. BUT I worry about the max RPM and reliability of the 12mm pump...
I will stay with my BEW in-tank primary pump to helps for fueling.
-Turbo... I hesitates to change the GTB1756VK for bigger or not. I'm worrying about the facts that going bigger turbo will make the setup more laggy and have less low-end torque. But in the same time, it will make better HP's.
-I'm building a new ingenious intercooling system to reduce lag. It will be a water-to-air intercooling system. The FMIC will be removed and the stock Audi 1.8t intercooler will be reused : It will be the water radiator at the front of the car. The water-to-air heat exchanger will be directly integrated to the intake by cutting the uppder of the intake and welding it, so I'll have one feet of piping between turbo and intake runners. An isolant intake gasket will be used to reduce heat transfert between cylinder head and intake-intercooler.
What you are thinking about that? According to all that thread, what you will change on this setup? Change turbo or stay GTB1756VK? Send injectors to DBW for opening at higher stages or replace the fuel pump by a 12mm? Is it reliable for 5k RPM or not? A Colt Stage 2 cam will help or not? Remember that I do not want to deepen the valve pockets of my brand new pistons, so if it's needed, I forget the cam.
What I'm expecting is your help because a TDI setup is complex. It's like a cake recipe, and if we change an ingredient, it is possible that we will have to change several ingredients to match. What is the compromise between torque, hp, lag, fuel economy, atomisation and smoke output, and reliability at this point? Some ideas?
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