924Board.org

[John H]

I've raced a 931 for 14 years (makes me fairly old) and in that time I've run both dyno and synthetic oils.

When I first started racing I ran Amsol but it was real difficult to get in New Zealand so I changed to Mobil 1 synthetic. I ran this for about a year but the turbo woudl occassinal blow smoke.

for the last 12 years I've raced the car on Dyno oils either Shell Helix or Penzoil.
As I cahnge the oil prior to every race meeting and the oil filter every second meeting and also run the standard oil cooler plus a small 9 row cooler I have no problems with the oil overheating and breaking down.

The waste oil used to go in the truck I
used for work (it was tired an burnt a lot of oil).
The type of oil I beleieve doesn't matter much as long as you choose the highest spec of either Dyno or Synthetic and ensure that it doesn't get cooked. Also you cahnge it regularly to suit the application you're doing. If it's around town driving you should change ar shorter intervals than doing highway driving.

Again choice of oils is personal preference.

[-nick]

John H- obviously you're not going to have any oil problems no matter what you run if you're changing that often! i'm surprised you were having problems with synth though. i've never heard of that before.

cs et al- i couldn't find any viscosity as a function of oil temp data which is what i was looking for to discuss the optimal operating temp. for almost all of us on the street/occasional trackies, i think a cooler for the 924 is a great idea. on the highway with my four speed i can see some pretty high oil temps cruising at speed (~4k rpm) for long periods. a cooler would quickly take care of this ("it's on the list...")

for those interested- racer's parts wholesale has the best deals for adding an oil cooler and are very reputable. i think this is where Vaughan went for his very nice installation.

regards,
-nick

[cs]

i tried looking for some more information on it and i wasn't able to come up with much either. except that the viscosity you run should be made for the temps you operate in. redline doesn't recommend using their 20w50 in engines running less that 212F oil temp. another thing i was looking into is the clearances built into the engine and the wear on older engines, if the lower temps would interfer with them since the gaps close up as the engine heats up, but i don't think running the oil temp down into the low 200 range would affect overall engine temp enough to notice. i think if nothing else, we could maybe use the lower oil temp as a chance to run thinner oil.