FredR

[QUOTE=dprantl;7858583]You are correct. I am also running the 75degC thermostat and find my car runs cooler with it. A lot of people forget that the thermostat has a range of operation, so a lower temp thermostat will be fully open earlier providing maximum cooling at a lower coolant temperature.

Dan,

The 75C thermostat only allows the car to run cooler if there is "excess cooling capacity" in the system. Once the cooling system is fully loaded the temp will rise until there is sufficent driving force to maintain equilibrium at whatever temperature the system settles at. With a bigger radiator, bigger fans, water wetter, lean coolant mix, my more or less stock 928 still struggles to cool during our summer with temps in the region of 44C. The needle will show over the last redline and climb even higher if I work the engine hard. Stock 928's in stock coolant trim run close to and sometimes over the red line.

I have used the 75C thermostat for years - in summer it makes no difference but in winter time [20C] the car struggles to make temperature. In winter time the car runs cooler with the a/c on than it does with the a/c off which I attribute to the cooling fans being automatically switched on with the a/c working.

I am surprised that with a turbo fitted the owner reckons the car runs cooler despite an intercooler in front of the radiator.

Regards

Fred

ptuomov

Here's another cooling observation. Without an IC in front of the radiator, but with turbos, in about 90 degree NE summer weather the data logged coolant temperature hasn't yet gone over 91C. The gauge is in between the two white lines, occasionally getting really close to the higher line. I think I have the stock 87C thermostat. I have the '87 5-speed stock radiator with the oil cooler in the side tank.

It seems to me that there are a lot of car-to-car variation in how hot these cars run.

Dictys

My S4 here in Dubai which is stock runs at just over the 3rd white mark in our present 110F heat. I thought it was running hot but it seems not. I am going to add water wetter once I can source some.

mark kibort

I have a stock radiator, 6.5 liter engine, and WOT more than not, and its right at the center during a race. now, on the street , on the hyway, its right in the middle as well. (even in 105 degree heat)
do your fans work?
have you bled the system (burped it) when it is hot like that, go out and feel the face of the radiator to see if it is really hot top to bottom. water weter, etc etc, wont do much. those are the fine tuning things.

Lizard928

if the car is running really how make sure that there are no obstructions to the rad.
It may be worth while removing an end cap off the radiator and rodding it out to ensure that it doesnt have any blocked pores.

FredR

My post should have read "last white line".

You can get water wetter from an outfit in Sharjah who are the agents for Redlne products. I think they trade under the name of "MoGroup". Look up: MOCA Mohamed Omar AI Majid Group Tel: 04-2855313 www.mogroup.ae. No idea if the number quoted is correct but they moved to Sharjah a few years ago.

After refilling the system I always bleed the radiator by running it niitally with the header tank cap removed and squeezing the big hoses to help bleed air out of the system.

I find water wetter very effective as well as increasing the water content of the collant mix to 70% [we are hardly likely to freeze up over here].

I use the SPAL twin fan kit.

Marks experiences suggest that cooling is well under control on his car but then maybe he is going a whole lot faster than a street car "normally" does and the air blast wins.

My UK racing friends tell me that the fans make no difference at speed [just as in F1 cars that do not have them].

I also feel that the 928 needs more oil cooling in these extreme temps.

Another point is that on Mark's race car I doubt he has a/c fitted yet alone going ***** out to keep the plot a bit cooler inside the car- correct me if I am wrong Mark.

Best wishes

Fred R

MarkRobinson

Loved that intake/IC setup: so clean. Might replicate it again if I have time before Third Coast. Selling the car this fall with <23k miles on it. Love the car, still have the 928 racer.

Mark.

Randy V

It's the eRams, dude.

eijun

Woah, what type of intake system is that on Louie's car? The piping area looks nice and clean.

Adamant1971

Are there any more pics of this set up. I have been noodling a rear mount turbo for a while and need some more inspiration.

dpower$

Mark's setup is a "mid-mount" with the turbo near the bell housing. His rig could only work on 5 speeds as the autos don't have the space needed. Clearly the coolest turbo system I have seen in person. I waited quite a while for him to create an auto ready system, but finally went with a supercharger

James Bailey

Actually his turbo was at the rear of the torque tube no where near the bell housing...... the big torque convertor of the automatic transaxle also at the rear of the torque tube ate up all the "extra space" .... making it a 5 speed only option

Otto Mechanic

Second that! I've been noodling a turbo 928 for at least 20 years now. Any advice appreciated.

Otto Mechanic

I've been thinking about trying to get it in where the A/C compressor lives.

dr bob

Challenge with that location is how to kompressed intake air to an intercooler and to the MAF and throttle at the rear of the engine. Space is the final frontier!