By captainOCD - Wed Aug 04, 2021 7:14 pm
- Wed Aug 04, 2021 7:14 pm
#95975
In 100 degree and humid south cakalaky the mechanical fan (even with a new clutch) was starting to struggle to keep water temps where I'm comfortable with if you get stuck in traffic for extended periods of time, with the ac on too of course. Not overheating hot, but still getting to the neighborhood of 215 degrees on the water bridge, which in my mind at least is far too hot for a 170 or 180 degree thermostat.
Some scouring around showed that ford contour fans are about the same size as the 928's radiator. Fortunately for me the local pull a part had some of those in the yard.
Some initial data before taking things apart; with the fan clutch fully engaged it was pulling air at a speed of ~1.5 m\s through the radiator and ac condenser (measured in several spots).
Modifications to the fan were just stripping the extra air temp sensor and other wires not for the fans. The side mounting ears got trimmed off too. The top part of a spare (and already damaged) fan shroud was cut off so that it would nestle over top of the electric fans.
Fits nice and snugly in there. I wound up having to leave it shifted about half an inch towards the driver's side due to some ac lines on the passenger side.
Some simple bent metal tabs are riveted to the bottom of the fan where the stock shroud hangs. Same up top to catch the bolts for the remaining part of the original upper shroud. Wiring just consists of two 60a weather sealed relays (one for high speed, one for low speed) each with it's own auto resetting circuit breaker (40a in this case).
(ignore the dried coolant from the radiator hose incident, it was cleaned off)
Power and ground are got from the jump post and a ground point near it. Currently using the stock aux fan wiring to trigger the high speed of this fan. A cooler radiator temp switch was installed that triggers on at 87c and off at 75c. May still get a colder one.
I don't have the low speed hooked up yet. I'm planning to use a temp probe near the inlet to the radiator to trigger this vs the output of the radiator where the current temp switch is.
Everything tucks pretty nicely under the stock shroud. From the front you can't really tell anything is different.
With the fan just running at battery voltage (engine hadn't run in a week) the fan was pulling air at more than twice the speed through the radiator and condenser. That'll definitely help temps when caught in traffic.
Haven't had a lot of run time yet with this new setup. So far the driving I have done has kept the temps nice and consistently hovering right above the first white mark on the temp gauge. Of course now it's going from being 100 degrees every day to 70s and 80s due to some storms rolling through, but it'll surely be hot again before long to get some more data on how this setup holds up.
Some scouring around showed that ford contour fans are about the same size as the 928's radiator. Fortunately for me the local pull a part had some of those in the yard.
Some initial data before taking things apart; with the fan clutch fully engaged it was pulling air at a speed of ~1.5 m\s through the radiator and ac condenser (measured in several spots).
Modifications to the fan were just stripping the extra air temp sensor and other wires not for the fans. The side mounting ears got trimmed off too. The top part of a spare (and already damaged) fan shroud was cut off so that it would nestle over top of the electric fans.
Fits nice and snugly in there. I wound up having to leave it shifted about half an inch towards the driver's side due to some ac lines on the passenger side.
Some simple bent metal tabs are riveted to the bottom of the fan where the stock shroud hangs. Same up top to catch the bolts for the remaining part of the original upper shroud. Wiring just consists of two 60a weather sealed relays (one for high speed, one for low speed) each with it's own auto resetting circuit breaker (40a in this case).
(ignore the dried coolant from the radiator hose incident, it was cleaned off)
Power and ground are got from the jump post and a ground point near it. Currently using the stock aux fan wiring to trigger the high speed of this fan. A cooler radiator temp switch was installed that triggers on at 87c and off at 75c. May still get a colder one.
I don't have the low speed hooked up yet. I'm planning to use a temp probe near the inlet to the radiator to trigger this vs the output of the radiator where the current temp switch is.
Everything tucks pretty nicely under the stock shroud. From the front you can't really tell anything is different.
With the fan just running at battery voltage (engine hadn't run in a week) the fan was pulling air at more than twice the speed through the radiator and condenser. That'll definitely help temps when caught in traffic.
Haven't had a lot of run time yet with this new setup. So far the driving I have done has kept the temps nice and consistently hovering right above the first white mark on the temp gauge. Of course now it's going from being 100 degrees every day to 70s and 80s due to some storms rolling through, but it'll surely be hot again before long to get some more data on how this setup holds up.
-Matt
-86.5 928S 5 speed lsd swap - prussian blue - runs and drives
-86.5 928S auto - goes and stops... if only it wouldn't idle at 2k
-84 928S auto - parts car
-14 Charger R/T AWD - daily driver
-99 Durango SLT 5.2 (NV242) - been in the family since new, most reliable vehicle I own
-73 Dodge Polara 318 - bought from my cousins because I didn't want to see it derbied
-69 Plymouth Satellite 318 - my grandpap's old car, need a bigger motor
-27 Chrysler 50 coupe - bought new by my great grandpap, still drives
-86.5 928S 5 speed lsd swap - prussian blue - runs and drives
-86.5 928S auto - goes and stops... if only it wouldn't idle at 2k
-84 928S auto - parts car
-14 Charger R/T AWD - daily driver
-99 Durango SLT 5.2 (NV242) - been in the family since new, most reliable vehicle I own
-73 Dodge Polara 318 - bought from my cousins because I didn't want to see it derbied
-69 Plymouth Satellite 318 - my grandpap's old car, need a bigger motor
-27 Chrysler 50 coupe - bought new by my great grandpap, still drives