Process Needed: Adding an electric fan and deleting the air pump?
#1
Three Wheelin'
Thread Starter
Process Needed: Adding an electric fan and deleting the air pump?
Another of my "lack of mechanic skills" questions!
I looked through the Search posts and didn't find anything on the process.
I'm replacing fan with this: http://www.jegs.com/i/JEGS+Performan...52110/10002/-1
What else is needed besides a 4-pin 30 amp 12 volt relay?
Thanks.
I looked through the Search posts and didn't find anything on the process.
I'm replacing fan with this: http://www.jegs.com/i/JEGS+Performan...52110/10002/-1
What else is needed besides a 4-pin 30 amp 12 volt relay?
Thanks.
#2
Rennlist Member
Brian, How are you going to trigger it, with a switch or the temp sensor on the radiator? Why do you want to change from the factory set up?
#3
Three Wheelin'
Thread Starter
That's why I was asking. Mark R. is going to send me some info but I was just wondering if someone had a step by step on it. My air pump is now making a lot of noise and and Mark suggested that I just add a better fan and not even use the pump/belt at all. What are your thoughts?
#5
Rennlist Member
That's why I was asking. Mark R. is going to send me some info but I was just wondering if someone had a step by step on it. My air pump is now making a lot of noise and and Mark suggested that I just add a better fan and not even use the pump/belt at all. What are your thoughts?
Think I have read somewhere to just use a shorter belt and not run / delete the airpump. Should not have to swap out the belt driven fan for electric to delete the airpump unless I miss read the threads.
#6
Three Wheelin'
Thread Starter
That's an option too. I'm sure the fan is better than the 26 year old factory fan. Plus one less belt.
#7
Burning Brakes
Brian, cross reference to see if an '87 airpump will fit. I *THINK* I still have mine somewhere. (eek, maybe) its yours free if I can find it. Worked great when I pulled it a few years ago.
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#8
Addict
Rennlist Member
Rennlist Member
https://rennlist.com/forums/928-foru...intensive.html
See this thread. Maybe it will hellp you too.
https://rennlist.com/forums/928-foru...questions.html
My fan came with a thermostatic switch and inline fuse as part off the package.
I deleted air pump and just went to shorter belt. No problems. Or some have used an idler pulley to keep the belt there. Good luck.
See this thread. Maybe it will hellp you too.
https://rennlist.com/forums/928-foru...questions.html
My fan came with a thermostatic switch and inline fuse as part off the package.
I deleted air pump and just went to shorter belt. No problems. Or some have used an idler pulley to keep the belt there. Good luck.
Last edited by Joe F; 02-26-2011 at 10:09 PM.
#9
Rennlist Member
Brian, not sure that fan will pull enough air in traffic in the hot Texas summer to keep the car cool. If you are going electric, I think you'd be better off with 929Specialists Shark Blade setup The option of just removing the air pump and driving the mechanical fan with a short belt driving the fan directly works. The factory mechanical fan, if the clutch is good, moves a lot of air.
#10
Three Wheelin'
Thread Starter
Thanks, good info and thanks for the links too Joe.
#11
Instructor
Join Date: Jul 2007
Location: Gold Coast, Australia
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If you haven't decided on the fan set up I can thoroughly recommend these guys:
http://www.v12s.com/indxcc.html (just go to 'fan systems' and Porsche 928).
Really nice all alloy shroud - very good build quality and super effective even on the hottest days with air con running, in traffic etc.
http://www.v12s.com/indxcc.html (just go to 'fan systems' and Porsche 928).
Really nice all alloy shroud - very good build quality and super effective even on the hottest days with air con running, in traffic etc.
#12
#13
#14
Nordschleife Master
Brian, not sure that fan will pull enough air in traffic in the hot Texas summer to keep the car cool. If you are going electric, I think you'd be better off with 929Specialists Shark Blade setup The option of just removing the air pump and driving the mechanical fan with a short belt driving the fan directly works. The factory mechanical fan, if the clutch is good, moves a lot of air.
#15
Rennlist Member
I used the twin SPAL 11" unit linked above on Ebay, at around that price. The specs say they move 2780cft/min, and are good for many 1000s of hours. Spal list a 3000cfm single fan, but they note its for Racing use, and carries NO Warranty. These fans cover more than 90% of the core area. I built a frame from L section alloy, epoxied and pop rivetted at the corners. I sized this so that the Spal assembly is a neat fit on the inside, and pop rivetted it in place. You will need to check exactly how far into the frame to mount the fan casings so they are as close as possible to the core to avoid air leaks.
I suspect your shroud set up is NOT S4, so you will need to offset the frame to the (car's) left, to clear the auto trans cooler hoses and ac hoses. With the frame sized as above, the tp and bottom rails will overlap the standard shroud mounting holes, so you can use the std mounts. It is a tight fit but it can be lowered straight down into place, but watch for the AC and tranny cooler hose clearance.
I ran the left fan off the standard radiator bottom sensor, but with a different temp range sensor than std- there are many different ones available in the correct thread - M22x1.5. I tapped a feed off this fan to fire a separate relay for the right fan , with a fused feed off the hot post. I was able to get a damaged top shroud half and with a little cutting was able to get it to fit over the new fan frame, so now from the front it looks completely stock, until you lean over and look down. I tested it on a 100F day with the AC running, and it held under the second white mark, sitting stationary 15mins+. I tapped a feed off the std fan relay to an unused LED on the dash so i could see when it was cycling in/out - this has a down side that at speed the fans drive enough to make the led glow. The led shows that the fan seems to run when the temp gauge indicates it isnt necessary, but i put this down to the bottom location of the sensor. Another 928 driver here who has fitted a top hose sensor reports that it controls the temps better, and the fan cycling more closely tracks the gauge.
jp 83 Euro S AT 53k
I suspect your shroud set up is NOT S4, so you will need to offset the frame to the (car's) left, to clear the auto trans cooler hoses and ac hoses. With the frame sized as above, the tp and bottom rails will overlap the standard shroud mounting holes, so you can use the std mounts. It is a tight fit but it can be lowered straight down into place, but watch for the AC and tranny cooler hose clearance.
I ran the left fan off the standard radiator bottom sensor, but with a different temp range sensor than std- there are many different ones available in the correct thread - M22x1.5. I tapped a feed off this fan to fire a separate relay for the right fan , with a fused feed off the hot post. I was able to get a damaged top shroud half and with a little cutting was able to get it to fit over the new fan frame, so now from the front it looks completely stock, until you lean over and look down. I tested it on a 100F day with the AC running, and it held under the second white mark, sitting stationary 15mins+. I tapped a feed off the std fan relay to an unused LED on the dash so i could see when it was cycling in/out - this has a down side that at speed the fans drive enough to make the led glow. The led shows that the fan seems to run when the temp gauge indicates it isnt necessary, but i put this down to the bottom location of the sensor. Another 928 driver here who has fitted a top hose sensor reports that it controls the temps better, and the fan cycling more closely tracks the gauge.
jp 83 Euro S AT 53k