Audi TT225 Compound Turbo Build

[Dowski12]

So just a couple of ideas...

What kind of spool and hp numbers could I be looking at with a PTE 5858 CEA w/.82 TS hotside and a QSV? Same for a 6262. I know the QSV's are supposed to drop spool by as much as 500rpm, and increase down low torque, and mid range power.

Now that I'm going single setup, your quick spool valve suggestion looks alot more appealing Darkside. Just want to get an idea of some spool characteristic if I was to add the billet wheel, TS housing, 2.0 stroker and QSV into the mix. I assume going DBB wouldn't help much if I was going to run a QSV, or am mistaken?

[Dowski12]

I've also been looking into running a GTX3076R on a twin scroll setup. I've seen some cars making over 500whp on this turbo with outstanding spool. What kind of boost would I have to run to make my hp goals with this kind of setup?

[Dowski12]

Before

After


Huge thanks to Integrated Engineering for hooking my motor up with the 2.0 Stroker.

[20th#726]

what are the old pistons? stock replacement or lower compression? what did you do with them after the rebuild?

[Dowski12]

They were just stockers. As far as what I did with them, Integrated Engineering still has them

[stkshftgti]

They were just stockers. As far as what I did with them, Integrated Engineering still has them

Actually, Rob has them.

[Dowski12]

^ ^ ^ ^
What he said

[Dowski12]

Ok finally some progress. Took some time to get the funds together but now theres nothing holding my build back (until the next thing goes wrong!!!)

Custom Exhaust Mani under way...


Turbo came in, went with a DBB Precision 5858 CEA on a .64 V-band housing...


I still have to order a BBM oil cooler kit, and my AWIC setup.

[DarkSideGTI]

AWIC? Is this going to be a street car?

[Dowski12]

Street and Track

[DarkSideGTI]

Street and Track

Road race or drag race?

[Dowski12]

Mostly drag but definitley miller track days as well.

[DarkSideGTI]

Mostly drag but definitley miller track days as well.

I would consider an AAIC over the AWIC. Ask Pete over at IE how much the Passats AWIC liked being run at high load for an extended period of time.

[Dowski12]

As long as its setup correctly it should be ok. Not saying that the passat's was setup wrong, but as long as the water in the system has enough time in the heat exchanger to cool before being pumped to the IC there isn't much reason for an AWIC setup to not be affective during long durations under load.

I've been in close contact with a fellow TT owner, goes by the screen name Marcus_Aurelius, who has alot of good information on efficiently setting up AWIC setups. He runs one on his Auto-X TT which efficiently maintains IAT's below or close to ambiant.

[pete@integrated]

I would consider an AAIC over the AWIC. Ask Pete over at IE how much the Passats AWIC liked being run at high load for an extended period of time.

Ya, that had no heat exchanger though, and the ice tank was about 1/5th the size it should have been.

I would still do air/air though, it's a million times less hassle and generally lighter.

[DarkSideGTI]

Ya, that had no heat exchanger though, and the ice tank was about 1/5th the size it should have been.

I would still do air/air though, it's a million times less hassle and generally lighter.

O he didn't have a heat exchanger? Still comparing 60 second Auto-X runs to 15 minute+ track sessions isn't going to even be close. A decent heat exchanger is going to be nearly as big an air/air cooler.

[Dowski12]

It might be more of a hassel to go air to water, but I think the benefits definitley out wiegh the drawbacks. AWIC's can be far more efficent if done correctly, and with the components I've chosen for my setup, it should work out pretty good. Spool is a big factor also. Going with an air to water core will shorten up my IC piping by about 4 feet, helping spool and respool quite a bit.

The heat exchanger I'm using is quite large (14X24X1), roughly 3/4 the size of the radiator, but my treadstone core (10.5X30X3.5} isn't any smaller. Unlike the treadstone core, the exchanger is only an inch thick, and will fit under my bumper with out having to modify it at all. Like I said the benefits of better spool, and more effecient cooling out wiegh the complexity of the setup. My opinion anyway

[Levi20AE]

if you want to be able to street drive the car and do a track day now and again I would stick with what works. How many A2W setups do you see on competitive FWD cars? A2W is overly complicated and can not maintain the continuous cooling due to heat soak and you need to run a core of a radiator. You are kinda determined to make this the most complicated build yet. You can fit a 24"x12"x3" intercooler core in front of the radiator. As long as you don't run over sized intercooler plumbing and don't buy an intake manifold with an enormous plenum transient response times wont be a problem.

[Dowski12]

Complicated? Maybe, but I'm more inclined to make it more effecient. Lots of people run AWIC's on the street. Its already been proven that they are more effecient than going air to air. Air to water shouldn't be any less streetable than air to air. It seems like alot of people in Utah shy away from doing new things, but if no one did them you basically wouldn't have anything that we use now! Everyone would stay with "What Works" and no one would be interested in "How Can I Make This Better". Its got to start somewhere. Granted AWIC setups have been done before, but it would be nice to have someone actually leave a comment commending at least one thing done to my car. I dont mind criticism, or suggestions, but its interesting how the utah and nevada forum is the only place where thats all I find. Just an observation

[Marcus_Aurelius]

Hi peeps, beeing lurking on this build and the one in the TT forum for a while but never posted here. I was very curious and even somehow anticipated the outcome of the compound setup, as I saw failure written all over it from the get go. However AWIC is very doable and can net some amazing results when done properly... I don't see why you guys think it wouldn't be superior to a conventional AAIC.

I have first hand experience with AWIC and to be honest the conventional route of air charge cooling can't even come close in terms of performance and potential. Air to Air, in a best case scenario, will lower the charge temp towards the temperature of the air going over the core - but there will always be a substantial delta. With AWIC, this delta can be reduced to zero and even allow the the air charge to go sub-ambient. The reason being that airflow only has to maintain the water temp from getting too hot (even decently warm water does a better cooling job than air could ever achieve). The other performance attribute is the much improved transient response. Someone would have to drive a car before and after to put this in perspective, having close to zero pressure drop and eliminating feets of piping is a game changer (especially with the lazy big turbos discussed in here).

Are there drawbacks? Obviously, the answer is yes, however from my experience they aren't what people say they are. The biggest issue with AWIC is packaging and fabrication. This can prove challenging for some, and the many take shortcuts that ultimately reduces the overall potential. Weight is a non issue, unless you plan to run a huge fluid tank with high capacity for extended high load use (think endurance racing), you won't be adding much weight, if any. A common misconception being thrown around is that a gigantic heat exchanger is required. It's the total opposite, you actually benefit from a smaller heat exchanger core with lots of air and fluid flow available to it. I run 35 psi through a K04 (lots of heat) and more timing than most on a 1.8T, but I use a small 12x12" exchanger with great success. As far a longevity, the pump is a wear item and will have a lifespan. Although I run mine constantly at full duty, a switched setup based on fluid temperature would go a long way at extending the pump life in a true daily setup (changing/rebuilding a pump every 3-4 years is not a bad compromise considering the gains). Heat soak is for setups that are inadequate for the task, much like conventional setups, as long as there is airflow this should be nonexistent unless the hardware is suboptimal. I can run my setup all day, and it will maintain equilibrium at cruise speed and become more efficient and plateau at full load.

In conclusion, a well built AWIC setup that matches the charge temp generated will put the best air-to-air IC to shame. Having low air charge temperature even sitting still with Zero airflow is awesome and still amazes me till this day.

Much more info on my AWIC setup can be found in this thread:
http://forums.vwvortex.com/showthrea...-approach-quot

[Levi20AE]

I'm not gonna turn this into a debate over air to air vs air to water because its up to this kids intended use. I will say definitively that properly sized air to water setup on a track car is by definition less efficient than a properly sized traditional intercooler, thats just basic thermo and heat transfer. You can add a 3-5 gallon resivoir to help prevent heatsoak but that's a lot of weight. This just sounds like another overly complicated solution to a problem with a conventional solution, sorta like a compound turbo...

[Dowski12]

To each his own I guess...

[Marcus_Aurelius]

I'm not gonna turn this into a debate over air to air vs air to water because its up to this kids intended use. I will say definitively that properly sized air to water setup on a track car is by definition less efficient than a properly sized traditional intercooler, thats just basic thermo and heat transfer. You can add a 3-5 gallon resivoir to help prevent heatsoak but that's a lot of weight. This just sounds like another overly complicated solution to a problem with a conventional solution, sorta like a compound turbo...

Not looking to derail a build thread myself, but stating that AWIC when properly sized is "by definition less efficient than a properly sized traditional intercooler" and "that's just basic thermo and heat transfer" sparks my curiosity. Can you elaborate on the basis for your statements?

As far as I know, when governed by the known laws of physics:
At a constant base atmospheric pressure of 1.013, air has a specific heat value of 1.00, while that value is about 4.18 for water. Not an even playing field in terms cooling capacity if you ask me.

As far as needing tons of fluid volume to prevent heatsoak, the practice showed me that it is not the case. If the components are well matched (no oversized/undersized components and major neck downs to create unwanted pressure, restriction, and heat in the fluid system) this is not needed at all. If your airflow is capable of keeping the fluid at a temperature plateau that can cool the air charge at full load, there is no reason to ever heat soak the system. As I said, I can track my setup for a long time without any issue ... the faster you go, the more efficient it is (the fluid is being perpetually circulated and cooled again and again).

Regardless, to each their own and I hate when people have preconceived notions about something without ever putting them to the test. I have personally built, autocrossed and road raced both (not HPDE crap but real wheel to wheel sanctioned competition) and I can say that in my book it's not even a fair comparison when both approach are well executed and properly sized. Maybe you've had some personal experience and data with both on a platform and can share your findings with us, until then know that there are countless examples, including mine, to refute your claims. For the OP, ask yourself why the engineers of the Ariel Atom, Bugatti Veyron, or Lotus Esprit choose, as Levi put it, a "less efficient" way to go on cars that were not bound by conventional packaging or budget restrictions.

[DarkSideGTI]

The new M5 uses AWIC's so it can be done on a street car. I haven't seen what they do on the track, but they also don't run as much boost so there is less heat.

[Dowski12]

Like Marcus was saying, he runs 35 psi on his stock K04, which if you think about it, creates quite alot of heat. Using an AWIC, he has been able to keep IAT's as close as possible to ambiant, and even below. When done right, the cooling capacity is pretty amazing. He has been able to run such high boost on a stock frame turbo for the last 2 years, making close to 400hp, because he's not affraid to think outside the box. Alot of people would think that A2W setups, direct port injection or any one of the non-conformised mods Max has done to his car, are a hassel or an "overly complicated solution to a problem with a conventional solution", but judging by his track record, there really is a method to the madness.

[corradoswapT]

I for one am excited to use a awic set up. I found It really simple to set up and run.

[Dowski12]

Are you going to run your A2W setup on the street?

[corradoswapT]

Are you going to run your A2W setup on the street?

yes Its a street car! I just bought an extra set of slim fans to run on the condenser for extra cooling just to make sure it doesnt heat soak

pics for refrence. this motor is actually torn down right now due to interference between the valves and pistons.... it will be back together soon!

[Dowski12]

Looks good

If you don't mind me asking, where did you purchase your IC? Did it come as a kit or did you piece it together yourself?

[corradoswapT]

thanks! I purchased it off of a friend who was done fed up with volkswagens. I rebuild the motor with je 83.5 mm pistons and tuscan rods. also had a mild p&p on the head with a 3 angle valve job

[DarkSideGTI]

Looks good

If you don't mind me asking, where did you purchase your IC? Did it come as a kit or did you piece it together yourself?

Frozen Boost has some pretty decent prices.

http://www.frozenboost.com/index.php...7c2f8e57b7b5b0

[corradoswapT]

I think thats where my friend picked up all of the a2w components. they have some really nice condensors. the one Im using is much larger than the intercooler I was previously using

[stkshftgti]

thanks! I purchased it off of a friend who was done fed up with volkswagens.

I hear he is off messing around with E30's now.

[corradoswapT]

I hear he is off messing around with E30's now.

you got that right

[Dowski12]

Frozen boost is where I'm picking up my components. Pretty much going with their 600hp setup but I'm going to be running 2 pumps, the cobra that comes in the kit, plus some ungodly expensive one that rob suggested. The cheaper ones are known to die pretty quick so he wants to make sure I wont be replacing pumps every year.