Water to air cooler. Thoughts?

[Cyrus051]

Hello,
New here, new to diesels, but not new to cars. I bought a 2014 Q5 with a 3.0 TDI. So far I've done basic modifications like a custom made downpipe, custom Borla full exhaust, and a Malone stage II. I love the power and response thatthe car has, but I know I can squeek out a few more ponies. They do sell aftermarket coolers, but I'm not thoroughly impressed. They up horspower at the expense of turbo lag, which happens to be something I refuse to tolerate. I put some thought into doing a water to air setup. Is this something anyone has done or considered? Any results? I believe I can cut off the end of the intake and 3D print a piece that I can use to rout the pipes a much shorter distance. I believe you'd have far less bends, way shorter piping, way less pressure loss, and way better cooling. But maybe I'm reinventing the wheel here?

http://imgur.com/a/Hxm2hXZ

 

[TurboABA]

What is it that you are trying to achieve?
W2A has its place, but it is not the answer for everything.
Have you logged your IATs under your specific conditions to determine that your intercooling is inappropriate?
Are you attempting to improve low end response or offroading charge cooling ability?
There are many questions to asks here.....

 

[TurboABA]

I've had this "discussion" with people before, so here's a random 10min log I did just to show that on my stock '14, I can't see the need for an upgrade.
Log #437546

 

[Cyrus051]

@TurboABA
Quickest throttle response, most dense air charge, lowest EGTs, and steepest torque/power curve. I'm trying to squeeze as much power out of my stock turbo as possible basically.
Your results are intriguing. You're barely 15* higher at full throttle! What are you logging with exactly?
I'd love to do the same as I'm really curious how my results would compare.

 

[TurboABA]

Standard VCDS diagnostic cable was used for logging.
As previously stated, there are good "arguments" for going down that road, but the grass isn't always greener.....
There's much to consider......
Sure, shortening up the charge piping track\volume will increase response, but realistically, the small snail already responds quickly.
Since you've already started modding, you may already be inducing more heat into the charge, but you need to log data to see what's really happening...... you might have more gains from a properly sized FMIC setup if trying to drop temps at speed, etc....... if you're talking about improving the cooling while rock crawling or being buried in mud, then you'll have more gains from W2A with fan assistance, etc.

Just remember that going W2A still uses airflow to cool down your water.... so you need fans drawing\pushing the air, plumbing, storage tanks, etc.
You're talking about adding a lot of stuff and weight and you may not gain anything in terms of cooling once you're travelling at any significant speed (basically once your velocity creates more airflow over the IC than your fan would).

Lots to consider...

 

[Cyrus051]

@TurboABA Ok, so it turns out whatever scanner I had was not compatible. I ordered another, but haven't figgured a way to upload its logs yet, so you'll have to take my word for it. Durring regular cruising around the temps were around 22* while it was about 6* out. Under hard acceleration and agressive driving I was between 35-47* EGTs weren't crazy until full throttle pulls, but I got up to 815* which I think is close to the turbos limit? I also can't simulate pulling a load without having a load, I imagine it would only accentuate these figures.
Evidently, it looks as though the tune I have is causing the turbo to run pretty hot. I'm actually surprised that the stock cooler gets hot so easily it looks pretty beefy.

I'm unsure of what this will add in terms of weight, but you're right about a lot of added complexity. Considering the numbers I've seen I'm willing to bet my car would really benefit from this however. And if I get really bored it'll be a goog setup for keeping a compound turbo cool. I'm going to do a lot of research and measuring. When I have something to show I'll post up here again.

 

[TurboABA]

Ok, so it turns out whatever scanner I had was not compatible.

Not sure I follow..... with what? Do you mean that you couldn't upload it to the viewer here?

TuneZilla Log Viewer

Visualize and share your datalogs with ease using this log viewer for VCDS, COBB, Edge EAS, ScanXL, ME7Logger, BlueDriver, and OBDeleven tools.

log.tunezilla.com

Durring regular cruising around the temps were around 22* while it was about 6* out.

This seems very hot (in terms of difference) for just cruising.... was this after a log idling period? I have to look up the Q5 IC setup as I don't know if you have a FMIC or SMICs like my Touareg, but whatever you have should work a lot better than this at low loads.

Under hard acceleration and agressive driving I was between 35-47*

That is way too much..... so your IC can't keep up, or your tune is far too aggressive and you're inducing way too much heat into your charge. I would suspect that your pushing your OEM turbo way out of its efficiency, and it's just making HOT air based on the boost you're asking it to produce.

EGTs weren't crazy until full throttle pulls, but I got up to 815* which I think is close to the turbos limit? I also can't simulate pulling a load without having a load, I imagine it would only accentuate these figures.
Evidently, it looks as though the tune I have is causing the turbo to run pretty hot. I'm actually surprised that the stock cooler gets hot so easily it looks pretty beefy.

EGTs don't seem that hot, but you didn't mention what location you're reading.... is that pre-turbo? Post-turbo?
Post a pic of your OEM IC so I have an idea of what you have and where it is.

Lastly, get rid of that CAI.... I bet you're just ingesting HOT AIR to start off with, and causing have your problems with that alone.
Even if you just reinstall the OEM intake and re-log just to prove me wrong.... you may be surprised!

 

[TurboABA]

So I looked up your IC, and it appears that you have a FMIC.

2014-2018 Audi Inter-Cooler 8K0-145-805-AC | Genuine Audi Parts

2014-2018 Audi Inter-Cooler 8K0-145-805-AC

www.genuineaudiparts.com

What kind of condition are its fins in? Is it clean or full of debris? Does it get proper/clean airflow, or do you have lightbars\winches\stuff blocking it?

 

[TurboABA]

The Q5 has tons of room for an FMIC upgrade, and there are already options available if you don't want to do full custom.
A proper air2air setup would be more efficient IMO for what I suspect your typical use is.

If it were me, I'd stuff the largest FMIC in it, and just open up airflow to it. Cut a window into both the plastic bumper and the rebar behind it to allow as much unrestricted air flow to the core. Here's my 30sec paint visual for you.

 

[Cyrus051]

Not sure I follow..... with what? Do you mean that you couldn't upload it to the viewer here?

TuneZilla Log Viewer

Visualize and share your datalogs with ease using this log viewer for VCDS, COBB, Edge EAS, ScanXL, ME7Logger, BlueDriver, and OBDeleven tools.

log.tunezilla.com

Sorry, that was vague. I'd hoped that I could use my tuner for logs, but it doesn't work like that. I bought a bluetooth reader that I currently connect to my phone, but there doesn't appear to be a way to save the logs in a file that I can load to anywhere.

This seems very hot (in terms of difference) for just cruising.... was this after a log idling period? I have to look up the Q5 IC setup as I don't know if you have a FMIC or SMICs like my Touareg, but whatever you have should work a lot better than this at low loads.

Yes, it is abnormally hot, I did sit and idle for a bit, but even after driving around the heat didn't dissipate much at all. If my logs are correct, my turbo is actually loaded constantly(13ish PSI), especially in sport mode. Which would explaint the heat, but I'm not sure how that's really possible.

That is way too much..... so your IC can't keep up, or your tune is far too aggressive and you're inducing way too much heat into your charge. I would suspect that your pushing your OEM turbo way out of its efficiency, and it's just making HOT air based on the boost you're asking it to produce.

I would expect this from such a small turbo, but aternatively I really don't want to add a bigger turbo to fix this. By all means though, the car is NOT struggling to make power, it's actually a constant struggle not to blow past the spead limit haha!

EGTs don't seem that hot, but you didn't mention what location you're reading.... is that pre-turbo? Post-turbo?
Post a pic of your OEM IC so I have an idea of what you have and where it is.

Lastly, get rid of that CAI.... I bet you're just ingesting HOT AIR to start off with, and causing have your problems with that alone.
Even if you just reinstall the OEM intake and re-log just to prove me wrong.... you may be surprised!

Pre-turbo I believe, but the OEM limit is either 800* or 850*. Hopefully my tune removed the fuel cut-out.
There's no cold air, just a quick photo shopto show how a W2A setup would look like.

What kind of condition are its fins in? Is it clean or full of debris? Does it get proper/clean airflow, or do you have lightbars\winches\stuff blocking it?

It's in pretty great shape and clean, maybe a nick or two from road debri, but it's solid. No offroad stuff, this is pretty exlusively a street machine.

The Q5 has tons of room for an FMIC upgrade, and there are already options available if you don't want to do full custom.
A proper air2air setup would be more efficient IMO for what I suspect your typical use is.

If it were me, I'd stuff the largest FMIC in it, and just open up airflow to it. Cut a window into both the plastic bumper and the rebar behind it to allow as much unrestricted air flow to the core. Here's my 30sec paint visual for you.

Those intercoolers are always tempting. I've run a few of similar style on other cars I've owned, but the sad exchange was always boost lag, which is one thing I absolutely despise in any car. Even my 1500rpm loading is obnoxious to me in all honesty. If it were reasonable possible I'd run a Kenne Bell blower on my car, but there's no where near the space for that sadly.

 

[Cyrus051]

http://imgur.com/a/N2VN1Pk

 

[TurboABA]

How much coal are you rolling with this tune that you're running?

 

[Cyrus051]

How much coal are you rolling with this tune that you're running?

Surprisingly not a lot, I think they did a pretty good job with the tune. You'll get a little puff on WOT usually, but that's about it.

 

[TurboABA]

I can only suggest that you try to find an IAT log from another Q5 owner to compare against..... I myself find it really hard to believe that the OEM FMIC is that bad, and if you don't already have a CAI, I can't explain why your temps are so elevated.... unless once again, Mark is pushing that OEM turbo WAY TOO hard. (but even then, I can't explain the high temps during normal cruising, etc)

Are you deleted? Do you have other DTCs going on? Is everything else good?
You can also ask Mark if he's raised or removed the EGT limit... I believe the stock one is 850c pre-turbo..... so you're approaching it, but not there yet.

 

[Cyrus051]

I can only suggest that you try to find an IAT log from another Q5 owner to compare against..... I myself find it really hard to believe that the OEM FMIC is that bad, and if you don't already have a CAI, I can't explain why your temps are so elevated.... unless once again, Mark is pushing that OEM turbo WAY TOO hard. (but even then, I can't explain the high temps during normal cruising, etc)

Are you deleted? Do you have other DTCs going on? Is everything else good?
You can also ask Mark if he's raised or removed the EGT limit... I believe the stock one is 850c pre-turbo..... so you're approaching it, but not there yet.

Yes, I'll look around a bit, someone has to have something. I don't know Mark well, are hot temps a more ususal ordeal with his tunes or something?

Yeah, all the sensors,add blue, and cats are gone.Next up are the flaps and EGR. No DTCs. As long as I'm not going to damage the turbo, I'm not as worred about EGTs I guess. But I'd really have to data log things while towing to see how high they get.

 

[TurboABA]

I'm sure that malone will want to see logs if you contact him to say you've got high EGTs and\or IATs... so without data, there's nothing really to look into unless you just want to do random "upgrades" to see what results you get.

 

[Cyrus051]

So I've been bored, and have been researching a bunch about diesels. Sadly it's not a well-developed subject like gasoline engines. There are lots of unusual factors that play into performance. An example would be the temperature of the post cooler air charge. Lots of varying opinions on what is good(my local tuner runs 120*F on all of his diesels from 500-2500hp), but for our diesels with much more advanced methods of controlling fuel, the magic number seems to be around 67*F, which is basically the point at which the air temperature is best for maximum ignition of the fuel. What this means to me specifically is that my states average annual temperature is 47*F, so I want to keep a temperature stable enough to try to maintain somewhere close to the 67* mark. On regular diesels every 10*F temperature above or below standard operation can result in a 1 percent reduction in power.
Basically, it's super easy to overkill with liquid cooling if you're doing it right. The question I'm left with is not how to cool, but rather how to keep the cooling in the specific range I'm looking for. Debating on pulse width modulating the cooling pump based on boost reference, but it might require more inputs than just that?

Of note, I'm running 34 LBs of boost WOT, so reducing the bends in the pipes and running a W2A setup would be able to reduce pressure drop significantly, greatly increase flow, reduce heat, and would greatly increase throttle response. Even if you null out all changes in cooling I feel like the benefits would be very significant. After Christmas I plan to keep you updated on the progress I'm making. Hopefully, it will be something that can benefit this community. The ambition is to keep it simple, lightweight, and significantly more effective than an OEM setup.

 

[TurboABA]

I have no idea what you're talking about!
Your charge pressure sensor is located after the IC and just before the intake ...... it simply reports the pressure that's about to be ingested into the engine ...... it doesn't care how much pressure is in the system pre IC or how much pressure drop there is, etc. The ECU map will "request" X amount of pressure, and the turbo will attempt to produce and sustain said request as best as possible..... if there's capability, it will "meet" those requirements, but if there's limitations (turbo, rpm, fuel, whatever) it will only do what it can....
Reducing bends and restrictions in the system will only reduce pressure drop across it, but it won't change the pressure at the intake.....

 

[Cyrus051]

I have no idea what you're talking about!
Your charge pressure sensor is located after the IC and just before the intake ...... it simply reports the pressure that's about to be ingested into the engine ...... it doesn't care how much pressure is in the system pre IC or how much pressure drop there is, etc. The ECU map will "request" X amount of pressure, and the turbo will attempt to produce and sustain said request as best as possible..... if there's capability, it will "meet" those requirements, but if there's limitations (turbo, rpm, fuel, whatever) it will only do what it can....
Reducing bends and restrictions in the system will only reduce pressure drop across it, but it won't change the pressure at the intake.....

Sorry, I realized that I did word that poorly, I was just trying to get my thoughts out before I got distracted by something else. Fixed to be a little more politically correct