SteveDoten

I've recently installed the Dewitts/OEM C6Z51 EOC lines setup and the DRM Ron Davis/AN lines DRM system

.....was going over the Pfadt's motor/trans mounts and noticed they have an oil/air setup using the front plate area

I don't personally run a track/HPDE car, so I CANNOT speak from experience on the optimum solution

What are CF A&R thoughts?

96solo

I have the Dewitt Radiator with the inner cooled incorporated oil cooler. I believe this is the way to go for a few reasons. The Dewitt unit interchanges heat from engine coolant and engine oil averaging the two. According to Dewitt, The heat exchange to fluids is more efficient the fluid to air exchange.

The Pfadt unit mounts in the license area, and if you have a small shunt, you're done for the day. With that you have additional length in oil lines (weight of longer lines, and more expose to leakage), not to take in consideration of the price of the unit, I believe this area is best for Cats lights or additional air flow into the radiator.

2000BSME

I like the simplicity of the radiator cooler for water to oil transfer. I have the dewitts unit, or ron davis, I never can remember which one I bought.

CorvetteZ51Racer

Yes, oil to water is a better means of heat transfer, so to get equivalent cooling, you need less surface area of oil cooler to get the same BTU rejection.

A front mounted oil cooler does lend itself to a bit of damage if you have a big off. However, that ends your day. I have seen combination units that failed between the coolant and oil side. That's usually not found until the motor's shot (which doesn't take long). There's a reason professional racing teams run separate coolers for the most part.

Like with everything, there's a pro and con to just about everything.

SteveDoten

C6Z is also seperate

I don't think wt. is the factor

trackboss

I've had the dewitts radiator and still saw 300 oil temp on the road course. The heat exchanger for the oil cooler is pretty small. In thier defense, there is not much room for anything larger and still have a drop in replacement radiator. Here is the exchanger they use:

Recently I completely re-designed and built my cooling system. (I was building a custom skid bar/radiator mount anyway) What I did was get an off the shelf dual pass stock car radiator of similar dimensions to the factory C5 radiator. To that I welded on my own brackets for custom mounting and to allow me to keep my a/c condensor. For oil I chose to use a laminova heat exchanger which I built into the lower radiator hose. That all allowed me to use a 1.5" lower hose as opposed to the 1.25" factory hose that expands at the thermostat. I used a single spal fan simply because the stock fans are not cleanly installed (IMO) and seem a bit clumsy to me. They do work well. I built a custom plug that allowed me to use the factory fan wiring and run the single fan off the #1 relay at full power.
I prefer to open up the core with as little restriction as possible to improve airflow and reduce drag/lift. Anything in front of or behind the core restricts airflow. Not using an air to oil cooler in the air stream and only one fan for the radiator helps with that as well. The laminova is extremely nice and very robust. Looks heavier than it really is.
So far I've only run the car sitting still to bleed the air out and with up to 15 min. with the engine running the temps were really low. The dual pass I'd estimate improves cooling about 10% over a cross flow.

VetteDrmr

..and the "cooler" fluid cools itself with air. Personally I go with an EOC. Generic 44,000 btu cooler, running -8 lines through a 180 degree t'stat on my street car it mounts in front of the AC condensor, and cools my stock LS1 quite well, both on a 1st gear autocross and DEs.

Going to put a similar system on my LS1 Miata, but without the t'stat. I'm going to try an insulated cover to keep the oil warm enough when in street mode. If it runs too cool then I'll go with plan B.

HTH, and have a good one,
Mike

96CollectorSport

Keep them seperate, there is a reason that pro teams do it this way.

The radiator & oil cooler combo was designed for packaging convenience and ease of install. For ultimate cooling keep them seperate like a race car should.

RX-Ben

Pro teams use both methods.
I have beat the crap out of my car on the track and never gotten above ~235, surprised to see that others have gotten up there. I am confident that my gauge works b/c I was at 320F before the cooler.
I don't run the A/C condensor, but if yours is clean, it shouldn't make much difference.

drivinhard

it actually makes a huge difference, even a clean one blocks a lot of air.

geerookie

And creates quite a bit of lift

SteveDoten

anyone using the GM C6Z cooler on a C5?

NemesisC5

I kept mine separate, didn't want to add any extra heat to the water. The C5 is a bottom feeder so the Pfadt O/C didn't restrict airflow in my factory configuration with Dewitts radiator. It seems that many have had success both ways and my choice worked well for me.

I like the single fan setup that trackboss displays below. Spal also makes a twin 11" setup with hinged vents that allow pressurized air to escape but obviously his setup would work better for unrestricted airflow through the radiator.

Bill Dearborn

I had a DRM kit that used a Ron Davis Radiator with EOC and a remote oil filter. Lowered my oil temps significantly in my 97 and 03Z. That radiator had a lot of cooling capacity.

The EOC was in the passenger side tank which didn't get very warm on cold days (40s) which then caused issues with getting the oil warm enough when driving on the street. I could drive 30 miles at 75 mph in 40 degree weather and not get the oil temp above 150. If the car was in 6th gear I couldn't get it above 140 or so. I eventually had to install a thermostatic bypass valve so oil temps would get higher.

On hot track days the coolant temps ran right at 200 with a 195 thermostat and oil temps were at 230. With my C6Z I see 230 coolant temps and 260 degree oil temps and on cold days I see oil temps well below 150.

Bill

dfinke23

I tried just about every setup available and was still having high oil temps. The coolers that provided cooling that was barely adequate were a pain to fit in the car properly, and the ones that fit didn't cool very well.
I decided to develop one that functions properly (outperforms the Setrab by over 20% on my 468 LS7 - 300+ to 235), fits on the stock C6Z mounting points, and works with the stock cooling lines or any aftermarket AN setup. Here's what it looks like:

SteveDoten

468 LS7? nice.

Z06trackman

You asked, "In tank' EOC vs 'stand alone/air', ie: Pfadt, which is more effective.........?"

I did a ton of research on this before purchasing and installing mine. The research came from posts on this forum where actual before and after oil temps while running on the track were published. It also came from conversations with vendors.

Bottom line: expect 20F drop from no cooler when install an integral cooler. Expect 40 - 60F drop when install a large external cooler mounted in front of the condensor.

I mounted a 7 x 13" Mocal plate type cooler and I also insulated the lines where they pass near the exhaust manifold. I got a 55F drop. In 95F weather I don't get above 235 while running very hard.

SouthernSon

I suppose the oil could raise the engine coolant, also. Thereby reducing further the ability to lower oil temps using the internal cooler (water/oil).
I use the air to oil cooler and still get high 280's but that is better than the 310plus that I was getting.