Back from 2 days at Watkins Glen...
The car is running fantastic...my best lap time was 2:16. I am still trying a few new attacks to the track, so I may be able to bring it down a bit with some more coaching.
The car is amazingly stable at speed and pulls like a bull through all the uphills. We are running 1 bar of boost, so I know the engine is not being stressed out too much.
But, my oil temps got up to 240 degrees and stayed there as long as I pushed the car.
If I droppped it back a notch the oil temp would go down to 210. But, once I got back on it, the temp would jump right back up to 240.
My water temps were remaining at 210 degrees even when I was pushing the car really hard.
I need to replace the stock oil cooler with something bigger.
Any suggestions?
This may be a stupid question, but is 240 too high? Mine tends to run around 230 (non-turbo) and I've not been worried, should I be?
240 is up there at the edge, but not dangerous - i too am close to that when i am really on it - i too am considering something bigger - i'd like to see a peak of 230
i did find that once i got my water temps down, i shaved a bit off the oil temps - 210 is pretty hot - that's the 10 o'clock line - i never get that hot - have you done anything about lowering that yet?
a splitter helps too, as do making sure you have the lower belly pieces installed
Tim,
I'd like to be below that 240 mark, I'm assuming the oil was getting pretty thin because my pressure was down to about 2.5.
I guess that I don't know what the true critical point is, though. I was always of the opinion that 250 was the point of no return.
It wasn't even the dead heat of summer...only about 75 degrees outside!
Flash,
My water temp is usually around 180...but once I've done a few run sessions on the track, it's pretty common to get it to 200~210.
I have the Heritage larger capacity radiator and it has helped tremendously. I do have a splitter and I do have the belly pan.
Jason
250 is teetering on the edge, and 280 is usually serious damage - i agree with wanting ot get it lower - cooler is better
i've seen 200 (twice), but never 210 on the water, even at over 90 degrees outside - we'll see how it does this summer at the track - i've recently done quite a few new things to cool things down, but haven't tested them yet - i'll let everyone know how they turn out
[quote name='flash' date='Jun 9 2006, 12:16 PM']making sure you have the lower belly pieces installed
[right][post="22589"]<{POST_SNAPBACK}>[/post][/right][/quote]
No doubt about this, I currently have the black plastic piece under the splitter and the engine guard off (waiting on a power steering rebuild on my daily driver), and the car will not stay cool driving down the road. It climbs till the fans kicks on, cools, then climbs again.
For my track car I've just mounted brake cooling ducts (a big help). I'm considering adding an additional duct aimed at my cooler. This hasn't been a big priority since my oil temp is typically at 230 and never over 240. Plus, at wide open throttle, my oil pressure is still quite high (4+ bar).
Jason - what oil are you running? I've switched to Rotella synthetic 5-40 and all seems well.
yeah - it's surprising how many people removes the belly pan (i presume for the sake of simplicity of service) but don't realize just how much it helps in cooling
for good cooling, we actually want to reduce, not increase, the amount of air getting under the hood - i know it seems counter-intuitive, but it's the nature of engine bay aerodymanics - it's a high pressure/low pressure thing - we need to reduce the air pressure under the hood, so as to create a high pressure zone in front of the car, and thereby get more air through the radiator, and then suck it out the back -
the belly pan really helps here - it also helps a lot with reducing drag coefficient, and increasing downforce - when it comes to aerodynamics, i have to give porsche a lot of credit
Tim,
I'm running Mobil 1 15W/50...pretty standard I figure.
I switched my front Big Reds from the '92 C2-turbo steel/iron hat to the 993 style with aluminum hats. They seem to dissipate the heat better; and they are lighter, too!
I bet that cooling duct work was a real bugger. How was it to route it around the oil cooler?
Jason
Eric,
Thanks for the link!
I just printed out pages 14-18.
That was a great source of information.
Jason
When I'm on the track my car normally will run to the 3/4 mark on the stock wate temp gauge. That's when my fans will come on the low setting. I have a switch that turns the fans on the HIGH output setting (Boy, fans were nicely done from Porsche).
I can't read the stock gauges.
What do the lines mean?
Starting from the bottom there appears to be 4 basic levels with a white horizontal
line with no temp numbers by them.
I assume the second line from the bottom means that the engine is warm enough to stand on it.
There is no line in the middle but there is a line 3/4 ths of the way up.
I let my car idle for about 10 minutes and when the car got to the 3/4ths
mark thats when my fans came on, immediately the temp drops to the half way point.
Does any body know what teperature these lines reflect?
There is a red line also...never made it that high but what temperature is that setting also?
i am SO all over that - very cool (pardon the pun)
Charles,
I don't know what the temps are that correspond to the lines...that's partly why I went and installed new gauges; with actual numbers. I have water temp, oil temp, oil pressure, boost, fuel and a tach...don't have a speedo, though...I also have an idiot light that comes on if oil pressure fails. We did this because in the heat of a fight, I might not look closely at the oil pressure gauge and this may save my engine.
Jason
the bottom of the lower bar is 40c (104 f)
the top of the lower bar is 60c (140 f)
the first line (8 o'clock) is 80c (176 f)
the second line (10 o'clock) is 100c (212 f)
the beginning of the crooked line is 115c (239 f)
pg 90-16 of the 944 manual
Thanks Flash:
I have marked my owners manual wih this data.
I bought some fancy oil pressure and oil temp guages but
nobody round here seems to know how to hook it up.
Something about guages do not plug right in to oil pan.
Got to seek a gear head that can get these guages wired.
mine is tapped right into the oil pan through the drain plug - dave greimann made it - he may be selling the drilled plugs -
www.968engineering.com
I spoke with a good friend and certified BMW mech about the temps. He stated that you want the oil to be around 235 and anything below 250 is just fine (temp measured at the bottom of the oil pan). 270 and up is a problem and the car needs to be shut down.
I also tapped my drain plug, works quite well (cudos to this site for the write-up).
I don't have a water temp guage, but my temps run at 9 oclock on a 924S guage.
Jason, running the ducts was not that much of a problem, but remember, I'm doing this on a 924S chassis, not a 968.