Intercoolers - Air to Air or Water to Air

[littleoldman]

Has anyone done a water to Air intercooler application on a Porsche? I thought I'd ask the 930 crowd for their knowledge on the subject. I'm rebuilding a 3.3 and adding a turbo, plus I wanted to fit the intercooler under the ducktail. Is this possible? Where would one suggest the water to air intercoolers get fit (quarter panels?). If so, how would I get the fresh air there?

Thanks

[quattrorunner]

You'll get lots of negative comments on the subject here.
First of all, air to air works. Second the engine compartment is smaller than you might think. And third, you'd have to make a system which doesn't seem too hard but I've never done it so I don't know.
You want to fit a duck which I think is awesome.
I've seen lots of different air to air inter coolers fit under a standard deck lid or a duck. And I've seen a duck fit an Intercooler too.
Do a search on the subject. As a hint, use google, most likely it will lead you back here but it's quicker/easier.
Good luck.

[timspu]

You may want to have a look on the 993 site. I have fitted a water charge cooler to a supercharged 993. It adds a lot of weight due to additional radiators in the front, double length water hoses front to back, water pump and reservoir plus the inter cooler. PWR make a barrel cooler which is pretty neat and come recommended as they are a better shape with better flow than the traditional square shaped ones.
If you can , space allowing stick with the trusted Air to Air cooler.

[T77911S]

what about something that was cooled with reifridgerant? maybe like a chiller system for a large building. you could have a large diamiter tube that is wraped in refridgeration lines that would cool the air. or finned refridgeration lines in side a tube with the compressed air passing over.
just a tought. of course the HP gains would have to overcome the loss of the AC compressor.

[Raceboy]

The best solution for intercooling on 911's is similar to the approach used on Ruf Yellowbird: air-air, effective and fits under stock engine lid and narrow body.

[tadman]

IS there a need for an air/water intercooler system? Probably not but you will have to determine your needs and performance goals.
Porsche designed the water/air inter-cooler for the early 934's out of necessity. Rules for that year did not allow for a large air to air cooler and or modifications to the deck lid to house a larger inter-cooler. Porsche reasoned a smaller air to water cooler could be used to achieve HP needs and satisfy rules. Air/air has been the main cooling of choice, 934.5-935's. With Porsche and racing it was and still is all about performance, reliability, and the rules.
I built a Laminova core based air to water inter-cooler system for my 934 clone.
My goal, fit a small inter-cooler under the early 930 decklid with the ability to still chase more HP. I have tried to make my system as efficient and reliable as possible and it does work well for me. But with that said I agree with what I have read on the forum that the negatives outweigh the positives. Positives really only being three things, smaller inter-cooler that can match cooling ability of a larger air to air cooler, possibly cooler charge air and ability to run a little higher boost because of it. Negatives are cost, complexity, weight, and increased probability for failure.
Air/air is the simplest, cheapest, most reliable way to go. Especially if you can achieve your HP goals with a small air/air cooler to fit under ducktail. For me it was more about the challenge than anything else. Hope this helps, Cheers Tad

[quattrorunner]

That is a pretty slick setup, actually the whole car is creamy. So nice it makes a great case for water charge cooling. As long as you don't need ac that is.

[willtel]

Who is it here that has one in the back seat area? It doesn't seem terribly practical but it does look the business.

Didn't Eddie Bellow abandon water to air on his car because the intake charge was too cold?

[tadman]

Quattrorunner thx for the compliments. As for radiator placement anywhere you can get good airflow. The original 934 the water cooling radiators were up front. This means long runs of waterlines etc. I have three oil coolers in front on my car I mounted radiators in the rear seat area with airflow from rear quarter window naca ducts.
three front oilcoolers- excellent cooling engine
water cooling radiators mounted rear seat area/ airflow naca ducts quarter windows

[rsrfan]

Who is it here that has one in the back seat area? It doesn't seem terribly practical but it does look the business.

You may be thinking of Stroker. His beast should be putting close to 1000 hp to the rear wheels by now...

[littleoldman]

Great feedback and help. I spoke with Chris at Turbo Kraft and gained a lot of understanding from the posts and him. A direction has been set. No A/W - straight A/A. Cant wait!

[krasuskyp]

<-------------picks up jaw off floor

tadman... doooooooooooooooooooooooooooooooooooooooooood

[Unobtainium]

For what it's worth, my car is air-water. It took a ton of R&D and it wasn't cheap.
I really wanted something one-off and it had to work. I can monitor the intake air temps (IAT) and intercooler outlet air temps (OAT) on an Aims dash unit.
Suffice to say its incredible on and off repeated boosts, both on street and track. There is no heat sink at all, and I would do it again.
Properly engineered this is something that can work flawlessly. If you give it the go ahead, let me know if you need to bounce any ideas around.

[quattrorunner]

Pics please.

[Unobtainium]

[Unobtainium]

[spence88mph]

Eddie Bello, is installing another water to air right now. Check it on his facebook page. https://www.facebook.com/EddieBelloRacing

Originally Posted by Unobtainium

For what it's worth, my car is air-water. It took a ton of R&D and it wasn't cheap.

Looks great dude.

[Speedy Squirrel]

The RUF CTR solution is great for a twin turbo layout, but it is hard to make that layout work for a single turbo. Plus, it requires those inlets in the upper rear fenders, which I think ruin one of the best parts of the vehicle, aesthetically.
Air-to-air intercooling is great for what the 935 was built for, which was endurance racing. The engineering of heat exchangers is a fairly precise engineering discipline, and has been for a long time. One important factor in engineering heat exchangers is the velocity of the cooling flow. During the age of the 935, the average speed around the La Sarthe was well over 120 MPH.
Many boosted high performance cars now use air-to-water, since their average daily driving speed is usually something less than 120 MPH. Air-to-water provides several advantages:

1. Compactness – Water has 10 times more thermal capacity than air. This means that the charge air to water heat exchanger can be made much smaller. This can allow for improved flow paths to the engine (less pressure drop), and smaller manifold volume for the same amount of cooling (better throttle response, better packaging).

2. Performance – Because the cooling fluid is water, the charge air heat exchanger and the cooling fluid radiator can be optimized for their respective task. For instance, the fluid radiator can have round passages, thin fins, high fin density, and preferential mounting. The charge air heat exchanger can have more passages and thinner walls. All of this can be exploited to reduce system size, and lower charge air temperature. I believe a well-engineered air-to-water system can easily outperform the SECAN air-to-air intercooler that was used on the GT2 EVO, and still fit entirely within the whale tail.

3. Efficiency – In the old days, water pumps for air-to-water systems were either engine driven, or single speed electric driven pumps. With modern pump systems, either the speed, the on time, or both can be controlled electronically. Under high demand, coolant flow can be increased/optimized to handle the required cooling, without using up excessive power. Further, at low speeds, cooling can still be achieved, to a greater extent than air-to-air systems.

From what I know, I see no reason why an air-to-water system could not be developed for a 930 that could handle 500 – 600 HP, fit entirely within the whale tail, and out-perform the SECAN intercooler.

[TurboKraft]

Nice MODE setup in the dp935.

Originally Posted by Speedy Squirrel

From what I know, I see no reason why an air-to-water system could not be developed for a 930 that could handle 500 – 600 HP, fit entirely within the whale tail, and out-perform the SECAN intercooler.

Agreed, but where to place a sufficiently large radiator with good airflow on a stock-bodied 930? Put it in the wing like the stock A/C condenser, or mounted over the engine in place of the stock intercooler?

[Fabien]

hello*

here is my project watercooler for my turbo 3L, now I have an intercooler 965 I want to delete. to install the original wing