Temp range on SC gauge
 

Someone help me out and tell me if I am working this correctly:

I went and pulled my stock temp gauge today to be able to peek into the side and read the tiny numbers indicating temperature.

I have the stock 81 gauge (I assume) which has a white "boxed in" region in the lower third of the range and a red region in the upper third.

To my surprise I find 90C as the end of the white and 150C as the start of the red zone. That translates to 194 and 302 degrees F! That means if I hit the half mark, I am at almost 250F!

I checked the temp at the oil cooler in the front of the car when I came off the track and it was 260, I checked it in the back next to the oil temp sender and it was 240. All consistent with the reading of the gauge!

Searching for oil temp on this board, everyone seems to agree that 240 is getting there, and 250 definitely is too hot.

Why did the engineers at Porsche design 250 to be the center of the temp region, which I'd consider "safe" or even ideal?

Needless to say, I will have to duct some air throught the carrera cooler which I have installed for the hot track days. I sure am glad I wasn't settling on "I am in the normal range"!

George

Word has it that Porsche just dropped the numbered gauges of the earlier cars because of reactions just like yours to the oil temp. Does your oil cooler have a fan? How about an air scoop?

I have that same gauge in my car. I have never understood that gague either. I don't know what they were thinking when the put that one together. My car barley creaps above the white box on a hot day though. I have the RoW brass cooler and it seems to work very well.

Doug:

Getting it to cool better isn't an issue (I hope). This post was rather about why 250F is the center (perfectly normal) range in the P car!??

We are talking 5000rpm runs for 30 minutes on a track that probably has 120F air temperature over the asphalt. So, it's clear why it gets toasty and it does fairly well for that. I have read what people do to improve cooling and will likely cut a hole in the valance to duct air in before going to the "desert" again.

Thanks for your replies!

George

Is there no answer to this? A guy I know who has raced an SC for 20+ years says if it doesn't get to the red, he doesn't worry. and he does all work himself, such as engine rebuilds (for other cars, don't know the rebuild history on the SC)

The answer for me was to get the (backdated) numbered gague for <$100. It should be here in a day or so, then I won't have to worry about it anymore.

i dont think the engineers expected us to notice the numbers squeezed down the side. in my mind, only the red section means "DANGER!" but you're right, conventional wisdom on this bbs, thinks 250 is too hot. mine just gets to the end of the white box. i think that is 195?

the last time at the track I was above 9'oclock...that's why I cut the runs short. I've got a carrerra coller up front, but I guess I need to do some ducting too. Although it was 105? out, so I was asking alot of the system.

Car seems fine though...and in fact seems to pull harder and smoother after the track day. And my mpg has gone up by one or 2.

I picked these numbers up from another post a while back.

bottom white block ...60 degC....140 degF
- next up white line, 8 0'clock ...90 degC...194 degF
- next up white line, 10 0'clock...120 degC...248 degF
- bottom of red block ...150 degC...302 degF

I have a numbered gauge too, I am just wondering why red is at 300 or so on the non-numbered. If I remember correctly my numbered gauge doesn't have a red mark. The factory is usually pretty conservative about this sort of thing.

we drive tanks! sporty tanks!

These white lines don't apply to the SC gague people are speaking of here. The gague in my SC has a white box on the bottom that goes to about 7 o'clock, then a white line and a red box that starts at about 10 o'clock, and that is ALL. Here is a pic, poor quality, but you get the idea.

http://forums.pelicanparts.com/uploa...1091659022.jpg

CDierks:

Go back to my first post. This is the gauge that I have. The start of the top red is 150 C which is 302 F! The end of the white box is 90 C which is 194F.

Look in the side of your gauge and you will find the factory calibration / test marks.

Here a pic to illustrate this.

Cheers, George

http://forums.pelicanparts.com/uploa...1091663229.jpg

Thanks for the posts guys. My SC runs at the top of the white box most of the time. About 200 F.
The pic from Aigel explains this the best for that style guage.
Must be lucky I guess.
wayne

The gauge interpretation numbers came from my post a while back...ikt applies to the mid 80's Carrera's with the individual white hash marks.

As stated, the SC guges with the "boxes" are slightly different. In any case..the red zone starts at a different number for both gauges...and the mid mark in any event is either closer to 210 or to 230-235, or so.

--Wil

so 302F is ok by porsche AG I guess.

That would be apoor guess...Porsche purposely chose to delete numbers to quell anxiety....like being done here.
Bruce Andersdon's general warning that continued running at 250 degF is when you're much too hot. Occasional running at 250 is OK, as long as it comes down later. Chuck Mooreland gives good advice that the temp reading is only at one spot...our air cooled engines have a wider range of actual temps within the engine than water-cooled cars have ( at "X" temp)...and the 250 linit should be heeded.
--Wil

Wayne:

Come out to the California central valley this time of the year. On an average afternoon at 105 in the shade, drive your car for an hour on track. That's at average speeds of 80mph, 90% of the time at wide open throttle and rpms between 4000 and 6500. Then we will see where your gauge points and how lucky you really are. :D

Just joking. In traffic mine rarely leaves the white box. Road course tracking in the heat is different from daily driving...

Cheers, George

George, I would love to be able to track with you "Cali" boys!
I really have not been caught in a traffic jam in the 911 except once. On the way to Chicago. Dead stopped traffic. Of course, it WAS raining to beat the band.LOL We are getting lucky here in MI this year. temps are staying pretty comfortable. 70 and little humidity. Sure, we'll pay for it in the winter but that's still a ways away.
Wayne

I was being provacative. ;)

I just don't understand why any manufacturer would put a red zone on a gauge WAY past where it is OK to run the engine.

If they didn't, then maybe the bruce anderson 250F gospel isn't quite true.

If they did, The engineers must have kicked and screamed as they were told "people are worried about their oil temps, so we are going to put the red line on the gauge way the hell up past the meltdown zone, please do that for us"

I mean, if you're a non-technical 911 driver running the air conditioner in stopped traffic in houston during the warantee period, and the oil temp gets to 250-260-275-285+ on this gauge, what do you do?

Nothing! you think everything is completely fine since the gauge hasn't gotten to the red. Does porsche want to replace the engine? Would they have to?