FD cooling system/FANS: Stock, Ebay, or other aftermarket?
06-14-09, 07:02 PM
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FD cooling system/FANS: Stock, Ebay, or other aftermarket?
I have been reading a lot of threads on here about the radiators and the fans and temps. I am going to revamp my entire cooling system, but I don't want to waste time/money buying bad/wrong stuff. I have the Koyo radiator and aluminum AST and that is about it for the cooling system.
1. I either want beefed up fans or stock ones that work.
2. Cooler running T-Stat (Recommendations NEEDED...PLEASE
)
3. 1.3 Bar radiator cap (Does this help keep temps cooler???)
4. Also been reading about the idler pulley that goes in place where the air pump used to sit. I have the under drive pulleys for the water pump and alternator ( http://www.rx7store.net/product_p/rx...%20pulleys.htm ), but I am beginning to believe that the contact patch is not that great. I can move my water pump pulley by hand with little effort. I have a single turbo and that looks like that might pose a problem for clearance with the idler pulley.
The driver side fan on my FD is seized up and only the passenger side works, which I KNOW is not a good thing! I definitely need some new fans or get the driver side one fixed. (I know the anti-Ebay mentality, which is why I'm asking here first.) I was almost going to buy these fans from Ebay, but hesitated because I'm not sure I trust they will be sufficient build, quality etc. especially after reading these threads. Here is the Ebay link:
http://cgi.ebay.com/ebaymotors/RX7-R...mZ110353178601
What are your honest opinions about these fans?
I read in his negative feedback some people were angry that they do not come with relays.
Can anyone confirm that the stock fans make about 2,700ish CFM?
Here are some threads I have consulted:
https://www.rx7club.com/showthread.p...=radiator+fans (stock CFM rating)
https://www.rx7club.com/showthread.p...=radiator+fans
https://www.rx7club.com/showthread.p...=radiator+fans
https://www.rx7club.com/showthread.p...=radiator+fans
https://www.rx7club.com/group-buy-center-69/air-pump-deletion-idler-pulley-kit-807734/ (idler pulley thread)
1. I either want beefed up fans or stock ones that work.
2. Cooler running T-Stat (Recommendations NEEDED...PLEASE
)3. 1.3 Bar radiator cap (Does this help keep temps cooler???)
4. Also been reading about the idler pulley that goes in place where the air pump used to sit. I have the under drive pulleys for the water pump and alternator ( http://www.rx7store.net/product_p/rx...%20pulleys.htm ), but I am beginning to believe that the contact patch is not that great. I can move my water pump pulley by hand with little effort. I have a single turbo and that looks like that might pose a problem for clearance with the idler pulley.
The driver side fan on my FD is seized up and only the passenger side works, which I KNOW is not a good thing! I definitely need some new fans or get the driver side one fixed. (I know the anti-Ebay mentality, which is why I'm asking here first.) I was almost going to buy these fans from Ebay, but hesitated because I'm not sure I trust they will be sufficient build, quality etc. especially after reading these threads. Here is the Ebay link:
http://cgi.ebay.com/ebaymotors/RX7-R...mZ110353178601
What are your honest opinions about these fans?
I read in his negative feedback some people were angry that they do not come with relays.
Can anyone confirm that the stock fans make about 2,700ish CFM?
Here are some threads I have consulted:
https://www.rx7club.com/showthread.p...=radiator+fans (stock CFM rating)
https://www.rx7club.com/showthread.p...=radiator+fans
https://www.rx7club.com/showthread.p...=radiator+fans
https://www.rx7club.com/showthread.p...=radiator+fans
https://www.rx7club.com/group-buy-center-69/air-pump-deletion-idler-pulley-kit-807734/ (idler pulley thread)
06-14-09, 11:17 PM
#2
I don't know where that cfm rating comes from. It's certainly not in the service manual.
I don't see how changing the thermostat would help much. The factory thermostat cracks open at 82ish Celcius and fully opens by 95 C. Any temperature within that range is acceptable for the motor IMO. I say this because that is the exact operating range of 2nd generation Rx-7 thermostats and they had zero cooling issues (both turbo and nonturbo) from the factory in addition to a much longer engine life expectancy than the REW has.
The thing to remember about the stock fans is that they run at multiple speeds. There are a number of wiring modifications you can make so that they run at higher speeds under various conditions, including running them at full speed any time you reach a specified trigger temperature in say a Power FC. Pin 3D puts out +12V with the ignition on and then switches that to ground at the trigger temp. The trigger temp is adjustable if you have a Power FC and a datalogit.
The temperature-based switched ground from the stock ECU or PFC triggers two relays (#2 and #4) which puts the fans on at low speed. If you wire that ground to trigger the other relays, you can run at medium or full speed every time the trigger temperature is reached. The downsides to that are more current draw and maybe a bit more cycling of the fans on and off if you are at a stop and it's cooler outside.
I have a friend who is running Flex-a-lite Black Magic e-fan (single speed). I helped him wire it up so PFC pin 3D would trigger it with a target temp of 87C. I'm not sure it's any better than stock fans running at maxed speed with similar control logic.
I don't see how changing the thermostat would help much. The factory thermostat cracks open at 82ish Celcius and fully opens by 95 C. Any temperature within that range is acceptable for the motor IMO. I say this because that is the exact operating range of 2nd generation Rx-7 thermostats and they had zero cooling issues (both turbo and nonturbo) from the factory in addition to a much longer engine life expectancy than the REW has.
The thing to remember about the stock fans is that they run at multiple speeds. There are a number of wiring modifications you can make so that they run at higher speeds under various conditions, including running them at full speed any time you reach a specified trigger temperature in say a Power FC. Pin 3D puts out +12V with the ignition on and then switches that to ground at the trigger temp. The trigger temp is adjustable if you have a Power FC and a datalogit.
The temperature-based switched ground from the stock ECU or PFC triggers two relays (#2 and #4) which puts the fans on at low speed. If you wire that ground to trigger the other relays, you can run at medium or full speed every time the trigger temperature is reached. The downsides to that are more current draw and maybe a bit more cycling of the fans on and off if you are at a stop and it's cooler outside.
I have a friend who is running Flex-a-lite Black Magic e-fan (single speed). I helped him wire it up so PFC pin 3D would trigger it with a target temp of 87C. I'm not sure it's any better than stock fans running at maxed speed with similar control logic.
06-17-09, 12:52 AM
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Good info you present here, thanks. So it sounds like you lean towards the stock radiator fans instead of going aftermarket. I forgot about the variable speeds on the stock fans. I have the Power FC (No data logit yet) and I like the idea of controlling the fan speed through it. What is the: Pin 3D puts out +12V? Is that one of the 4 wires on the wiring harness that had to be cut when installing the PFC?
Any opinions about the 1.3 bar radiator cap and why its available? Does it create more pressure to keep the water temps cooler?
Oh also I would like to fab up some ducting to the radiator since I have the FMIC in the way.
Any opinions about the 1.3 bar radiator cap and why its available? Does it create more pressure to keep the water temps cooler?
Oh also I would like to fab up some ducting to the radiator since I have the FMIC in the way.
06-17-09, 10:56 AM
#4
Old Rotary Dog
The 1.3 bar cap won't make you run cooler. The extra pressure will just raise the boiling temp of the coolant/water mix. It is a patch at best and you are better off figuring out what is wrong with your cooling system first.
What is your application (street, race, drag?) and where are you having cooling problems? As has been hashed out in the past, the first and best approach to keeping the car cool is to make sure that you duct as much air as possible into the radiator. Add panels and weather stripping and what not to make sure that air coming in through the nose cannot go around the radiator (esp. the sides).
Do you have an FMIC? If so, figure a way to vent air around it or go back to an SMIC.
Underdrive pulleys on the water pump? Only if you are running at constant high RPM for an extended time (ie. race track). They don't help you on the street as far as I have seen and can in fact hurt you.
The stock fans are pretty good. I would find a good used set and run those.
Good luck,
-b
What is your application (street, race, drag?) and where are you having cooling problems? As has been hashed out in the past, the first and best approach to keeping the car cool is to make sure that you duct as much air as possible into the radiator. Add panels and weather stripping and what not to make sure that air coming in through the nose cannot go around the radiator (esp. the sides).
Do you have an FMIC? If so, figure a way to vent air around it or go back to an SMIC.
Underdrive pulleys on the water pump? Only if you are running at constant high RPM for an extended time (ie. race track). They don't help you on the street as far as I have seen and can in fact hurt you.
The stock fans are pretty good. I would find a good used set and run those.
Good luck,
-b
06-17-09, 11:03 AM
#6
Stock dual 11" fans 2780CFM (combined)
11&3/4" high, 12" wide (1390CFM x2)
3.7" deep
When I replaced my radiator with a Koyo, I kept the stock ones because it's TOUGH to find a fan that's slim enough and still flows like the stock ones. Mine have been going strong for over 150k miles, so reliability isn't an issue with the stockies.
11&3/4" high, 12" wide (1390CFM x2)
3.7" deep
When I replaced my radiator with a Koyo, I kept the stock ones because it's TOUGH to find a fan that's slim enough and still flows like the stock ones. Mine have been going strong for over 150k miles, so reliability isn't an issue with the stockies.
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06-17-09, 07:32 PM
#8
What is the: Pin 3D puts out +12V? Is that one of the 4 wires on the wiring harness that had to be cut when installing the PFC?
On my 2nd gen turbo car I am using pin 3D to switch a single speed fan from a Pontiac 6000 2.5L . On my friend's FD he is using pin 3D to switch a single speed Flex-a-lite Black Magic fan. With the datalogit set at 87 C trigger temp, cycling is minimal. Whatever you do, utilize the ECU's temperature control trigger. Don't use an external aftermarket fan trigger, those things are unreliable.
I've never personally done this, but on the factory fans you could rig it up so that the fans always run at full speed once the trigger temp is reached. Or you could rig it so that the fans always run at medium speed once the trigger temp is reached, and then run an FC thermoswitch to trigger it to high speed. There are all sorts of different ways to do it depending on your preference. Just doing the minimum adjustments of changing the low speed trigger in the PFC and adding an FC thermoswitch would also go a long way, and you may want to consider that first.
06-21-09, 02:05 AM
#9
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The 1.3 bar cap won't make you run cooler. The extra pressure will just raise the boiling temp of the coolant/water mix. It is a patch at best and you are better off figuring out what is wrong with your cooling system first.
What is your application (street, race, drag?) and where are you having cooling problems? As has been hashed out in the past, the first and best approach to keeping the car cool is to make sure that you duct as much air as possible into the radiator. Add panels and weather stripping and what not to make sure that air coming in through the nose cannot go around the radiator (esp. the sides).
Do you have an FMIC? If so, figure a way to vent air around it or go back to an SMIC.
Underdrive pulleys on the water pump? Only if you are running at constant high RPM for an extended time (ie. race track). They don't help you on the street as far as I have seen and can in fact hurt you.
The stock fans are pretty good. I would find a good used set and run those.
Good luck,
-b
What is your application (street, race, drag?) and where are you having cooling problems? As has been hashed out in the past, the first and best approach to keeping the car cool is to make sure that you duct as much air as possible into the radiator. Add panels and weather stripping and what not to make sure that air coming in through the nose cannot go around the radiator (esp. the sides).
Do you have an FMIC? If so, figure a way to vent air around it or go back to an SMIC.
Underdrive pulleys on the water pump? Only if you are running at constant high RPM for an extended time (ie. race track). They don't help you on the street as far as I have seen and can in fact hurt you.
The stock fans are pretty good. I would find a good used set and run those.
Good luck,
-b
The pins cut during installation are US-spec emissions related wires and are not relevant here.
On my 2nd gen turbo car I am using pin 3D to switch a single speed fan from a Pontiac 6000 2.5L . On my friend's FD he is using pin 3D to switch a single speed Flex-a-lite Black Magic fan. With the datalogit set at 87 C trigger temp, cycling is minimal. Whatever you do, utilize the ECU's temperature control trigger. Don't use an external aftermarket fan trigger, those things are unreliable.
I've never personally done this, but on the factory fans you could rig it up so that the fans always run at full speed once the trigger temp is reached. Or you could rig it so that the fans always run at medium speed once the trigger temp is reached, and then run an FC thermoswitch to trigger it to high speed. There are all sorts of different ways to do it depending on your preference. Just doing the minimum adjustments of changing the low speed trigger in the PFC and adding an FC thermoswitch would also go a long way, and you may want to consider that first.
On my 2nd gen turbo car I am using pin 3D to switch a single speed fan from a Pontiac 6000 2.5L . On my friend's FD he is using pin 3D to switch a single speed Flex-a-lite Black Magic fan. With the datalogit set at 87 C trigger temp, cycling is minimal. Whatever you do, utilize the ECU's temperature control trigger. Don't use an external aftermarket fan trigger, those things are unreliable.
I've never personally done this, but on the factory fans you could rig it up so that the fans always run at full speed once the trigger temp is reached. Or you could rig it so that the fans always run at medium speed once the trigger temp is reached, and then run an FC thermoswitch to trigger it to high speed. There are all sorts of different ways to do it depending on your preference. Just doing the minimum adjustments of changing the low speed trigger in the PFC and adding an FC thermoswitch would also go a long way, and you may want to consider that first.
However I think my cooling issue may not be as bad as I thought. Even with only 1 fan working the 7 was running mostly around 95 degrees today and peaked once at 102. Based on this info I decided to go stock fan route, they should be here this coming week. Having two fans working should really help keep things in check. When the fans show up I will change all the fluid out with new as well as add some Redline water wetter. I think what else helped keep the temps down was removing the main CAT yesterday and replacing it with a mid-pipe. It's a lot louder now
I think I have a vacuum leak now because it is idling around 2500 rpm. I think the place where the air tube from the back of the intake manifold to the main cat was is leaking and needs some attention.
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