Martin S.

It does, it indeed does. I have a RLC datas logger that monitors oil temperature and oil pressure. When the oil temp gets to my pre-set initial warning temp, the digital oil temp read out numbers turn red...when the #'s go critical (I believe I have set 260 Degrees F as critical), the dash goes red...thankfully I have only seen my stage one pre-set of 220 once.

Today I did four 25 minute sessions at Thunderhill Raceway in Willows, CA. Three out of the four sessions were run at ambient temps of 100 degrees +. The hottest my car got was late morning, I saw 216 degrees F. When the day got warmer, the car actually ran cooler...strange.

I have:
1. Stock oil cooler with manual override switch.
2. Ruf oil cooler in drivers side fender, backed up to the air conditioner radiator. This is a piece of history as it was installed by the one, the only, Viper Bob!!!! Back when he was in the Bay Area.

If I can drive the pants off the car on a 100+ degree day, and keep the oil temps below 220 degrees F, I am a happy chappy.

Kein_Ersatz

Good to know.

IXLR8

I take it you are primarily recommending this set-up for track use because I've never been much above 210F on the street with ambient temps of 95F.

No HTwo O

It's amazing just how cool these car can run. I don't track, and don't sit in city stop-n-go traffic, no mufflers and no engine tray. Been in 100 degree heat, and the needle at cruising speed is nice and cool.

I'd put in a secondary oil cooler, if I were doing DE's, but I can't justify it for doing 300-mile weekend counrty road sprints.

IXLR8

I once measured the oil temperature in the oil pan of my air-cooled BMW motorcycle after a highway run; 217F using a thermocouple probe immersed in the oil. It has a very small OEM oil cooler with no fan. When stuck in traffic, then I would worry.

M. Schneider

Having assisted with installation of a OEM TT-S aux oil cooler in a MY97 993tt,,, it is several hours of DIY work; Front bumper fascia removal, etc. This TT-S aux cooler is a finned loop arrangement positioned on the right side (drivers) in front of the HVAC condenser. Conversely, the aftermarket oil coolers by others RUF / FVD / Cargrafic are substantial in size. Significantly larger in size than the puny TT-S aux oil cooler we installed. Hey,, to-each-his-own.

77'3.6vram

I have put two 16 row MoCal's(FVD GT2 Kit) in the turbo and the RS clone has a factory turbo "S" secondary oil cooler. My 77' that has a 98'Vram in it is cooled by Elephant Racing's dual fender setup with finned oil lines.
In May 2004 Excellence magazine had a question in the Tech Notes section named "993 Valve Guide Problem"(starts on page 18). In their answer they stated "The blockage usually consists of coked oil residue." They go on to state " Most of the cases have occurred in the warmer climates, when the cars also have a lot of city driving.These conditions produce extra heat and can create the right conditions to overheat the engine's oil in this area and then cause the coking." Reading this and living in South Florida I asked my mechanic what can be done to help prevent this problem. He proceeded to tell me that installing a secondary oil cooler was the best option. That is when I had the extra coolers installed.The RS clone now has 60k more miles(88k total milage)on it and no CEL issues. Four months ago I had Dan Jacobs pull the engine for a plethora of work I wanted done.I asked him to do a leak down test at that time to see what condition the internals were in.The results were amazing. Cyl 1- 2% Cyl 2- 1% Cyl 3-1% Cyl 4-2% Cyl 5-1% Cyl 6- 0%. I believe keeping the oil from ever getting over 200deg is the reason I have such a strong running CEL free 993. I am a firm believer in the benefits of a secondary oil cooler.The proof is in the pudding.

Cupcar

One thing for track use, Porsche eliminates the fan which improves flow through the cooler at speed and 964 Cup cars used only one cooler this way. A a problem in traffic though unless you keep the car moving. I used to make sure that I let gaps develop between me and car in front so that I got a bit of flow as I moved in slow traffic.

I installed a factory second cooler kit in my 964 Cup with no fans and it worked fine in traffic and everywhere else.

trophy

Great data points Martin.....

My entire oil system is out of the car at the moment getting cleaned and will be going back in with a second cooler.

One thing I did find was the original cooler had a lot of debris in the fins, if you haven't cleaned out the cooling fins in a while or ever, it's worth a look and will improve the efficiency of your cooler (back to when the car was new)

IXLR8

Steven, one thing I've done to the coolant rad or oil rad in my past daily drivers and motorcycles is tie a section of black fiberglass screening in front of the rad. (fiberglass, so that you don't get abrasion as you would with metal screening)

Coolant and oil temperatures remained the same (5 bars before and after on my GS oil temp gauge), though I'd bet they are up a bit.

Bugs and any other debris simply wipe or wash off the screen. BTW, Bug-B-Gone by Seafoam is a great product for dissolving insects.

trophy

I like the idea of using fiberglass screen in front of the cooler..... Good one Alex

race911

Uh, yeah. First RSA racer we put one on was probably for the '95 season. Before that I had the owner coming in before sessions were over. I remember one Day From Hell at Buttonwillow @ 112 ambient, and the massive cooler I had in the '74-with-3.5 couldn't keep up.

Know what the hot, rather "cool" setup is on our fastest GT2 (PRC race class, NOT 993 GT2 cars)? Mat Lowrance out of Reno is siamesing two 964/993 coolers to stick in the noses of these built-to-the-limit torsion bar chassis cars. Lots of ducting involved, of course. But the coolers are inherently that good to keep the racing 3.8 and 4.0 oil temperatures under control.

Back to the 3.8 in the yellow car. It goes ~230F on a ~100F day when run in the 2:02 range on the full track. It'll go down a bit if you back off a couple seconds/lap.

Been to Thunderhill before?

Paddy

An aux oil cooler is a must for these cars if tracked heavily. Here's that setup Ken is talking about:

https://vimeo.com/32604980

Bill Verburg

For street use you 99% probably won't nee a second cooler, for track use you 95% probably will need one

You can use a second stock one behind or replacing the A/C condenser but the stock ones are a bit harder to plumb because the I/O ports are on the top.

Ruf/Cargraphic/FVD all sell a kit that was developed for the Cup/RSR race cars, there are 2 versions on has a wider mount for use w/ A/C the other is designed to be used w/o A/C, the A/C unit can also be used w/o A/C

Here is the kit


mounted w/ A/C




having the I/O ports in front makes it much easier to plumb




oe unit

Martin S.

Before I went to the Ruf unit, I tried the Turbo S cooler...close to worthless, it is too small to be effective for California summer heat. Once the Ruf went in, all worries disappeared. As Bill mentioned, Cargraphics has a cooler too.