FlyYellow

i met today with the owner/operator of a company that specialized in oil coolers for early porsches. we looked at a couple of solutions for putting together an aux. oil cooler kit. And we came up with a couple of solutions that may be viable. I wanted to run some of the ideas by the folks on the board. In short, it is likely that a kit could be assembled for rennlisters that would be substanitally cheaper than cargraphic solution and readily available.

So here are some ideas and i'll start with my personal favorite.

1. Place a new (identical to the unit that is already there) oil cooler in front of the existing oil cooler.

Benefits:
- The factory cooler is a very large cooler and there is ample room in the car to place a second one directly in front of it. some brackets would need to be redone and to potentially slide sideways the existing one.
- Install would be very easy. Simply remove the wheel well and install right there.
- will not interfere with A/C.
- Minimal new oil lines and minimizes expense

Downside:
- By placing two coolers back to back you will vent hot air into back cooler and so it will not be as effecient as having two independent systems.

2. Place the secondary oil cooler in front of the A/C fan.

Discussion:
- Excellent cooling for oil; however will make the A/C far less effecient.
- More expensive due to running extra oil lines
- More difficult to install.
- This is the optimal cooling scenario.

3. Place a car cooler in the cavity behind the front grill.

Discussion: It would be difficult to place a large oil cooler there. Thereby the added cooling may not be sufficient.


Again if you could share your thoughts, this could very well be an excellent alternative once properly developed into a product. so think of this as an oppty to aid in the design phase.

Cheers,
Boris

nman413

Boris, I think it's been mentioned that 993 noses arent really optimal for a center mounted air cooling. I think Jim Morton did get something fabbed up though.

My oil cooler is supposedly showing up tomorrow. You are welcome to stop by to take a look at it. I'll be fumbling around with it.

Flying Finn

Kim already said most.

Piggyback idea (in front of the existing cooler) is tested and it pretty much doesn't work.

I think there's not enough room in front of a/c for normal 993/964 oil cooler (too thick) but I could be wrong.

In center is a good solution but you have to create enough space behind it so that there won't be any flow issues.

I've already "mocked up" cheap cooler solution, pretty much the same way OG showed in his oil cooler scenario.
One Mocal cooler in front of the a/c air opening (right behind the bumper cover), size 235, 16 rows.
Whole set up should be little less than $400.

In next couple of months I'll go ahead and do it, and will post the DIY once it's done...

Mark in Baltimore

Boris,

Go with the location that's going to give you the best cooling. I bought the pricey Cargraphic cooler, as opposed to taking the penny wise-pound foolish route that often seems initially attractive to me, and passed right over a cheaper but less effective route. My engine and I scoff at the heat on 90+ degree track days. Yes, AC performance is reduced, but I call that an acceptable, long-term compromise on a dual-purpose car. Frankly, the only time I ever run it and can actually feel a cooling benefit is when I'm sitting on the grid at a DE with a thin cotton shirt on. At a race with my driving suit, the AC feels like an asthmatic 95 year old woman is trying to, um, cool me with with her breath.

Elephant Chuck

I am the referenced owner of the company; Elephant Racing. I've got a lot of experience providing oil cooling solutions on the pre 964 cars. If there is enough interest, I'd like to come out with a solid kit for the 993.

Having had a good look at Boris' car, we have a several options for fitting added cooling. However, everything is a compromise that balances the following: price, ease of installation, oil cooling capacity, AC capacity.

In this case, I don't like solutions that put the cooler right behind the stock fascia. Cooler size would be severely restricted and the exit air would still vent through the AC or existing cooler.

The remaining options are to sandwich a new cooler alongside the old, or alongside the AC ala Cargraphic. Both can accomodate good size coolers.

A - Sandwich with existing oil cooler

Boris hit the key points, both pro and con. I really like the easy-install aspect of this solution, and it doesn't impact the AC at all.

Yes, the sandwiched coolers are not as effective as 2 truly independent coolers. Still I believe this solution has the potential for significant cooling capacity increase. This solution would let us use a second factory cooler, which is the biggest cooler we could hope to squeeze in. All other solutions would use a smaller cooler.

It's also a less spendy solution. Requiring just 1 hose, the cooler and some custom bracketry this would probably come in around $1000 or less.

Boris, if you're game I'd like to do some testing here. What I'd like to do is measure the temperature of the air exiting the existing oil cooler (no mods) vs. ambient. This will tell us how much pre-heat the second cooler in the sandwich will see. From that we can predict effectiveness of the solution and decide if a prototype is warranted.

B - Sandwich with AC

The problems of degraded AC, more complex installation, and higher cost are downside. It may provide better oil cooling than "A" above, however the need to use a smaller cooler (though still good size) may negate some of the benefit.

I am now thinking it might be possible to modify bracketry to put the AC cooler in front of the new oil cooler, exactly opposite the Cargraphic solution. AC will not be compromised at all. The new oil cooler will see pre-heated air when the AC is running thus reducing its effectiveness. But when you need max oil cooling on the track, you will have the AC off anyway and the second oil cooler will be fed fresh air.

This would be a best-of-both solution, providing some added oil cooling with AC on and max oil cooling for the AC off / track conditions.

Installation would be more complex, requiring removal of the fascia and work in both front wheel wells. The kit would be more expensive requiring 2 long hoses, a union, a cooler, and more complex bracketry. Probably closer to $1500.

Feedback and thoughts are welcome. Until we actually do testing, it's all speculation. At the end of the day, the one important question is "how much will it reduce oil temps?". We don't have answers yet.

FlyYellow

Chuck,

I am certainly up for the testing. I'm glad you chimed in here (as I was hoping you would). We may be able to also take a look at Jauder's setup (he is local). and you might get some ideas from that. The nice thing about Jauder's is that it is a TT so you'll see both front bumpers and the differences. This should allow you to make a kit that will work for both cars.

Jauder - are you up for that?

Cheers,
Boris

kary993

Here is my real experience with these solutions.

1. Piggy back with existing cooler provides some help on the street. When it gets hot, on the street or on the track, there heat builds up and this solution generates more heat than a single cooler. There is no way for that much heat to escape because the air connot pass through efficently. Very poor solution. DO NOT DO THIS!

2. The Cargraphic solution has the oil cooler on the outside. The reason for this is simple. If you put the oil cooler on the inside, the air flow is cut dramatically by the AC and you will get minimal oil cooling. The degraded AC with the cooler on the outside is minimal as already pointed out by Kim and I completely agree. If you keep your AC in there and turn it on (not on the track of course), the AC fan goes on and the oil temps are very low in any conditions.

2A) No AC with an oil cooler works very well, specially with a racing front bumper for the wide bodies that allow the air to enter in the front and escape out the side. WORKS VERY WELL. Though not good for street cars because the bumpers do not fit normal 993's.

3. Trying to put a cooler in the front bumper area requires that you figure out a way to get the air to flow out after it enters the cooler. You would need to cut into the trunk and the hood to get the flow correctly. That is what race car do that have cooler in the front for 993 style cars. Paul had posted a possible solution where he mounted a cooler forward of the AC and in theory would allow air flow and minimize AC degradation. In my opinion, this has the best possibility of working better than a Cargraphic setup if you want strong AC, though it still may affect the AC efficency because the hot air will flow past or near the AC.



On a side note, I had already considered developing a solution for 993's (& TT) because obtaining an oil cooler solution from Cargraphic for a reasonable price is difficult at best......oh, forget the reasonable price just obtaining them is difficult.

nman413

Probably at this point. I am floored by the craziness about getting my CG cooler. UPS apparently now cant find my street and they are shrugging their shoulders and saying that they will try monday. I'm travelling for 2 weeks starting Sunday night. Purchasing this oil cooler has been probably the most unpleasant transaction I have ever had.

adsc4s

I'm sorry Chuck, but your solution one is priced the same as the RUF cooler which piggybacks the AC unit and your solution two is priced less than $200 from the Cargraphic unit which is proven.

Elephant Chuck

All good input. Clearly contributors above have differing objectives / needs from an oil cooling solution. There is no one-size-fits-all answer.

To those that are keying on price, there isn't going to be a $400 solution that works. $400 pays for a couple hoses and a small cooler that won't help much. Forget about proper brackets and ducting. Real solutions are going to be in $800-$1500 range. If that's too much, then we just don't have a fit.

Full race cars that are willing to fab and notch the tub, and dump the AC, I've already got peice parts for these guys. They don't need a kit, each one is custom.

The target I have in mind for this solution is a dual-use car. Drive's on the street and wants to keep the AC, but also pushes it hard or tracks the car and sees occasional high temps that should be controlled. Cargraphic seems to have a decent product but the feedback I get is they drop the ball on availability/service, and the price is a little too dear. On these points I can do a better job.

I hear pushback on the sandwich cooler idea. Yet both solutions are sandwich, with similar interference to airflow issues.

If I told you I had an oil cooler that was identical to the factory one, except it was an inch thicker for greater capacity, and it was a drop-in replacement - I suspect we would all agree it would cool better and it would get a warm reception. I submit 2 coolers sandwich is the same thing. Kary I hear and do not discount your direct experience with this. Without seeing your specific solution, it is difficult to offer meaningfull feedback.

Sandwiched coolers with proper ducting can improve cooling capacity and I believe a solution like this can work, and offer a significant price and ease of installation advantage over the cargraphic solution. Frankly, it is a fair investment in time and cash to test this out. If the market (you guys) are going to discount it out of hand, then there is no point in proceeding.

Again, comments are welcomed.

TonyN

Based on the posts here, I would prefer the Cargraphic approach for a cheaper price, and it seems that the RUF kit produces that, so there does not seem to be any need for a 3rd kit. Any downside to the RUF solution ? Where can one get the RUF kit and how much is it ?

Now there's a thought. I've substituted better/thicker oil coolers on other cars, and that works well for dual-use cars. Can that work for the 993 and be cost effective ? Also is there enought oil capacity in the stock oil lines or does one have to upsize the lines to get more oil flow to these upsized or dual coolers ?

kary993

Chuck, are you a Rennlist sponsor? I did not see your name on the list though that might not mean anything as you might be in the process of being a sponsor. I only mention it because it has been a sore point for many on this and other boards who try and market their products.

To your point about providing a thicker cooler, I am not sure how much experience you have with a 993 and the available room on each side where the oil cooler and AC condensor sit. It is already a seriously tight fit for the Cargraphic cooler so adding a wider cooler would require some serious attention at the least. It would be possible to add a thicker cooler on the stock location side with some modifications.

In either case, the issue is the heat escaping the tight enclosed area. Adding more or bigger coolers only makes this issue bigger. The area where air can escape is small which is largely the issue and would require a larger hole of some sort. Many, including me have discussed cutting into the wheel liner to allow heat to directly escape but this causes other issue with stability on big tracks with lots of speed. While I am not pleased with Cargraphic availability nor the service, the solution does work for the target audience you are trying to hit. In fact, since I street and track my car it not only works but it works very well. Certainly better than any solution suggested so far with the exception of the RUF solution which is the only one I have not been exposed to either directly or indirectly. So for you to offer something else you will need to reduce the price significantly, or you will need to increase AC performance (maintain it without degradation), and you would need to make it turn key to install as is the Cargraphic solution.

That is a tall order and considering your initial posts about solutions we (rennlist members) are obviously providing you with the critical information to make your offering competitive.

Robert Henriksen

I think this is the area that sounds most interesting to me. I've learned to be dubious, though, of things that SOUND like they'd work just great, without empirical evidence to back it up. I learn more & more each day just how much I don't know! I'd be really interested to see test results comparing the effectiveness of two sandwiched stock oil coolers versus a single replacement cooler that was deeper/larger, and how the performance of the latter compared with stock, and stock plus the cargraphics design.

Flying Finn

Chuck,

Thanks for your input.

However,

I'll bet that 400 bucks that Mocal (or other similar radiator type) oil cooler right behind the bumper cover (where the air goes into the a/c) works better than biggyback in front of the stock oil cooler.

It (biggyback) has been tested by many and it just doesn't work. Looks like it would work in theory but it doesn't, like Kary said, it might be even worse.

Radiator cooler (as Turbo S) but radiator type and little larger installed right behind the bumper cover will have great airflow since it's not next to the a/c, so even though it's not the same sice or capacity as stock cooler, with the good clean airflow and about the half size, you do get quite good cooling.

Mocal cooler is about $130, about 10' braided oil line is about $80, and right fittings are little less than $200, in my opinion, not so bad. Of course, when adding about $250 to that figure, you'll get two radiator cooler on both sides, other will dump warm air in front of the stock cooler but still, that $650 will get you a lot of cooling and I don't see why it wouldn't be viable solution.

In fact one of guys down here has that kind of set-up (two extra radiator coolers) in his 993 TT and he said his cooling improved greatly.

BTW Mark,

You're calling me a "fool" now?!

FlyYellow

Couple of thoughts to share...

1. i don't believe chuck is a rennlist sponsor yet and chuck is not yet trying to sell something to rennlisters (as he has no product for us).

2. the real point of this thread is to discuss a product idea that if it worked would eventually end up as a "kit" that could be offered to rennlisters. I can vouch for Chuck on this front.

DISCLAIMER: I have nothing to gain accept for the satisfaction of potentially helping someone produce a kit that could be provided at what i hope would be a lower cost solution to rennlisters with hopefully a better experience than cargraphic.

So what i was hoping for (which i need for myself) is opinions on the various solutions. At this point please treat this as such.... If you help me get a good solution in place you may help yourself get an alternate solution in the future.

so i'd ask people to keep on focus for product ideas that might help get a good solution designed.

Thanks so much for your help.

Cheers,
Boris