1HDT/WTA intercooler

[TheBigBoy]

No panties bunching here . It's being made out as if we are trying everything as hard as we can to get the thing to work. Adam nor myself have done anything more than bolt a frozen boost WTA set up on it. Cheap Chinese components that aren't very efficient at all. And measured what we have. There is tonnes of room for improvement. Which is why this thread was started to show what you get with an off the shelf system. And what you can achieve with a well thought out set up and components. And that is the route we are currently taking.

 

[gerg]

I agree there is plenty of room for improvement. The original rad from those kits is extremely small. Im interested to see how that extra rad works out for Adam. I think will make a noticable difference.

 

[TheBigBoy]

Absolutely. I have 3 radiators to play with. In the future it will be a custom rad.

 

[FirstToy]

Yes ATA has less parts and is generally more simple in its design. Im sad to day, but instead of blocking your radiator with an ATA intercooler, you will be doing it with a second radiator for your WTA cooler. I guess you could do a top mount radiator. There was enough room up there for my ATA intercooler, so why not a radiator?

I have my W2A radiator as pictured below the radiator so it's not blocking it, and working well. The radiator is a german KTM unit.

W2A are not short duty cycle. I'm not sure where that comes from-maybe the icebox dragster setups.
If the system does not have enough fluid, too small a radiator, or otherwise ineffecient than yes, it will heat up the coolant and not be able to cope. This is the same as a engine coolant system - too little fluid and it won't recover fast enough.
Many OEM systems have W2A IC's when performance counts,not dollars.

I think that's part of the fun/challenge to set it up right. Here are some parameters
http://www.enginebasics.com/Advanced Engine Tuning/Air to Water Intercooler Design.html

*I think you have to note that a too small A2A IC and /or improper piping will also make for a poor system.

It's been important for me to keep my pre and post IC temps monitored and compare the delta to see how well the system works.
That is really the only way you can tell how well any of these systems is working, I suppose.

Yes it's been a fun project and I have re worked my system a few times to improve it.
I think it's great and I'm constantly picking up new tidbits, such as this thread with other IC users

 

[Adam B]

Show me the theoretical math behind a 90% WTA system and what would be needed for an exchanger and radiator to do that. I think that is a large goal. WTA has a short duty cycle. That is the inherent weakness of this system. You will not overcome it with positive thinking alone.

Your math is as good as anyone else's. To hit 90% efficiency from 2 combined exchanges in series, each has to be 95%. Or, the radiator has to be >100% (for the sake of argument we'll pretend it's possible - one can say they're cooling below ambient air temperature with ice or R-134a - since the efficiency we're speaking of is relative to ambient air temp).

The short duty cycle is the double edged sword of WTA systems. They work very well for short runs and low speeds. In the city I'm sure it works better than an ATA system. Once the water heats up they perform kind of like a ATA system. Worse, most of the time.

The idea of using your AC system to get one of your exchanges above 100% is of course interesting. Whether it is actually beneficial in terms of a net gain in torque is yet to be displayed.

I just enjoy playing around with stuff. I chose WTA a few years ago and went with the off-the-shelf Denco kit. I tested it, thought it was decent, then started collecting some actual data and wasn't pleased with the results. I've made some changes and my results have improved. I have more changes planned. My goal is to get above 70% efficiency without spending any more money on it.

I'd be very impressed to see anyone with a WTA system reach 80% sustained in my testing environment. gerg knows exactly what I mean.

I'm still waiting for someone with a nice big front mount air-air to put up some temperature readings so I can ditch this project!

 

[gerg]

The short duty cycle is the double edged sword of WTA systems. They work very well for short runs and low speeds. In the city I'm sure it works better than an ATA system. Once the water heats up they perform kind of like a ATA system. Worse, most of the time.

I agree that WTA systems can be very effecient for short periods of times and that is precisely what I have seen them mainly used for. Short intense duration with long recovery time inbetween. The problem is when it is adapted to trucks that desire longer periods of work. To me the off the shelf systems perform as they were intended to. The difficulties come when they deviate from that.

 

[gerg]

I have my W2A radiator as pictured below the radiator so it's not blocking it, and working well. The radiator is a german KTM unit.

What are your pre and post cooler temps for short runs, and what are they for longer ones, say a minute of sustained boost? If your system works well, maybe these guys just need to do what you do.

 

[gerg]

Here is a good write up on a FMIC. 93% all day long is amazing.
http://www.6speedonline.com/forums/audi/137331-why-our-b7-fmic-so-big.html

Just goes to show you what is possible. All this with 1psi pressure drop. Performance in town would be great if you ran a mechanical fan pulling lots of air. I like top mounts myself, but cant seem to find and good write ups quite like this one. Top mounts do suffer at low speed if you dont have a really good fan, but I really only need the cooling when im pulling stuff on the freeway.

 

[FirstToy]

The B6/7 radiator is probably almost 2 feet square, so the AWE FMIC is roughly that.
for a 2.0L engine running stock, small k04 turbo.

The 80 has a 4.2L Diesel or 4.5L petrol motor. Exactly how large does the FMIC have to be with over double the motor displacement?
How could a top mount be adequate? Is there room for a 600x600mm top mount A/A IC?

*I am not saying I'm right, this is just stuff that steered me into my choice.

gerg, what system are you running? What does your A2A setup look like?

I think a big A2A in front of the radiator would be effective since there is enough surface area. Actually, I know someone that ran a Safari turbo w/ a A2A IC- it was a big FMIC.

 

[TheBigBoy]

What are your pre and post cooler temps for short runs, and what are they for longer ones, say a minute of sustained boost? If your system works well, maybe these guys just need to do what you do.

1 minute, held at 20psi. With the last 10ish seconds held at 25. Pre 118, post 56, 33 ambient.

If I drop the boost to 14 (which is easy with dual stage). Significantly reduces the temps.

 

[gerg]

My core is 300x300x100 and I would like to change it out to a 300x600x75 core. I didnt post that other intercooler to say this is what you should mount, but rather what percentages are possible. I think a 600x600 top mount is not reasonable for fitment, but a 600x300 certainly is.

Now that little motor is pumping near 300cfm at about 6psi boost at 6500rpm. Your 4.2 would be almost double that at 3500rpm at 21psi, so that core shown on the b7 link (75mm) would need to be deeper to get away from too much backpressure (100mm?), but would still return some stellar outlet temps. The only things I dont like about the FMICs are the blocking the rad thing and all the piping which is labor intensive. However, once done it requires little in the way of maintenance.

70% for a WTA set up is great. Congrats. You have the best one I have heard of.

Here is my top mount. Mine is a paltry 67% efficient once soaked, but my core is thicker than needed and I think suffers lack of flow through it. No fan, just an ugly hood scoop. Starts working at around 60kmh. I have a 75mm core I will change it out for. Some day.

 

[ForealBoreal]

gerg,

I am planning a top mount for mine, thinking a 3" core. Are you going to run a fan with your next one?
If so would you run it constantly?

 

[TheBigBoy]

I would. I've heard of results from testing top mounts. And even at speed they draw more air with it on. So I'd just leave it on.

 

[TheBigBoy]

Gerg, with the elements I'm currently testing. My next 1 will crack 80%. It's only going to improve from the crap set up I have now.

 

[gerg]

80% would be amazing. Yes I would run a fan, but not just any. I would put it on a therm switch to read post temps, or a simple toggle switch. You need a serous little thing too and not something that is just for blowing Fabios hair around. I found this spal fan that is designed to draw through rads. Its 12" but takes 40 amps, same as my Taurus fan.
http://www.a1electric.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=AEOS&Product_Code=30103202HO

I admit that this last summer I cheesed out and got one the very affordable ebay cutie fans that are available for cheap and, after thorough testing, found that it couldn't alter my post cooler temps by even by a single degree if you can believe it. So I removed it. You need a serous fan. Like one that will chop your finger off.

 

[TheBigBoy]

Get a spal fan.

 

[TheBigBoy]

Ah, I probably should have checked the link first.

 

[FirstToy]

gerg,
intersting info. Forgive my ignorance on A2A, but the cooling ability dependent on windspeed correct?

So at slow working events, like pulling hard up a rutted trail in 4Lo, it would be far less effective or slogging traffic.

Also, I have never fully understood how the air can flow through properly on a top mount when the entire bottom is basically resting on top of the motor. Seems that airflow is blocked and you are cooling basically thru convection.
Is the pressure difference enough that it "sucks" the hot air out?
(just trying to understand the top mount)

thanks- informative thread

 

[gerg]

You are right about air speed and flow for top mounts as they are vulnerable that way if they dont have a good fan. Front mounts on the other hand dont suffer that effect with a mechaniocal rad fan that works all the time and is linked to engine rpm, not speed.

Cooling charged air with a top mount via convection=bad

At speed the engine bay usually is a partial vacume compared to the hood and naturally sucks air in. I have a big ugly hood scoop that also directs air in to flow over the intercooler. My pics dont show it, but there is about 4 inches of space below my intercooler to alow for air flow. im sure it is not as good as if there were nothing below it, but it works.

 

[ForealBoreal]

check this site out.

https://www.plazmaman.com/