Electric WP and Fans Question

[cadman]

Background on car:
1988 Supra Turbo. 165,000 miles. Targa.
Only mods are new Radiator, K&N stock air filter replacement, and wheels. I just installed (2) 12" electric fans onto the radiator. I took the power from the battery, to the switch/therm, then to a relay where I split the power to go to both fans.

Goal, to make about 350HP and 400torque to the rear wheels, most broad powerband possible. Driven everyday, weekends, and possibly a couple of track days and late night drags.

I've had no more cooling problems while driving since I did that install. (yesterday) The only problem I have now is that if I turn my car off, then back on again after about 5 minutes, it still has a bit of a heat-soak problem.

Question; would an electric water pump solve this problem, or reduce it in any way? I had an idea that I would be able to use a temp guage and keep the water pump going after the car was turned off, so that it would cool the motor down a little while after turning it off. And I wouldn't have to rely on RPM for the water to circulate faster.

On other threads, I read that they do make a water pump Part# WP136, but I wasn't sure, if applied, how well this modification worked for the car. I also don't even know if it would be worth it.

Ps. On a side note, so far, I have loved my electric fans. I was having a pretty bad overheating problem before, and now it's almost gone. Just an FYI. (Average heat during the day, 85F +/- 10F. Conditions; driving in stop and go traffic, highway, spirited back roads driving, short runs to lunch... and possibly a fiew burnouts...)

Thanks for reading.

 

[JMDigital]

I am by far no expert but I am wondering why you are overheating? You have replaced the radiator because it was overheating? Or it just broke. Was it overheating when the old radiator was working?. It seems to me you need to track down why it’s overheating, not try and increase the air flow and water flow to compensate for it.

I am about as big an amateur as you can get but I wanted to ask those questions.

Good luck, I am shure someone will respond with better info and not just questions and hopefully correct me if I am wrong.. :1zhelp:

 

[cadman]

I am by far no expert but I am wondering why you are overheating? You have replaced the radiator because it was overheating? Or it just broke. Was it overheating when the old radiator was working?. It seems to me you need to track down why it’s overheating, not try and increase the air flow and water flow to compensate for it.

I am about as big an amateur as you can get but I wanted to ask those questions.

Good luck, I am shure someone will respond with better info and not just questions and hopefully correct me if I am wrong.. :1zhelp:

Actually you bring up a couple of pieces of information that would be really nice to have for someone trying to answer my question, so thank you for posting!

The old radiator just seemed to be plugged, and leaking. My car was overheating a lot with the old radiator. Also, my fan shroud was broken when I got the car. So that was a big cause of the overheating.

Even with my new radiator, if I got stuck in stop-and-go traffic, I would start to overheat because of no fan shroud. Instead of trying to get another shroud, I heard that dual electric fans would be much better for slower driving on a hot day.

Because my RPM is down while stopped in traffic, and just before being stopped, I would have been taking off from a stop, heating the car up, I needed a better cooling method. It seemed the electric fans were the answer, and they seem to be working great.

I just wanted to know if an electric water pump would help me out that much more. Not just to increase the flow, but to help the car cool better at low RPM.

 

[lagged]

no. the car should keep it self cool completely stock. if your car is over heating, there are other problems.

fix those. dont add an electric water pump to fix the problem, youll only be covering up (not fixing) some as of yet undiscovered cooling issue.

 

[JMDigital]

I just got a new fan shroud (116.00 new) you should think about going back to stock fan w/ new shroud, I never over heat even in the 90+ temps here in florida. You should track down this problem.

 

[3p141592654]

Your original fan clutch was potentially another source of your overheating. Once the silicone oil leaks out the clutch will not fully engage the fan and you will overheat.

 

[IJ.]

Missing undertray?

 

[cadman]

Your original fan clutch was potentially another source of your overheating. Once the silicone oil leaks out the clutch will not fully engage the fan and you will overheat.

Thanks Pie, that could have been part of the problem. It isn't overheating right now, so I'm guessing that very well could have been it.

It seems that people here don't have a high outlook on electric fans. :icon_conf Do the electric fans not flow as much air?

The water pump idea was just to prepare for more heat from more HP. It isn't sounding like a great idea now though. Thanks for the help guys.

 

[cadman]

Missing undertray?

no, the undertray is there. I think the reason it was overheating before (only while stuck in traffic on a hot day, or slowing down to near stop after running it hard) was because I didn't have a fan shroud.

I have been chasing down a leak as well. I thought perhaps it maybe have been just boiling out while overheating. I need a little time to see if it will still loose coolant even when it isn't overheating.

 

[IJ.]

I run an electric pump as a booster on a correctly functioning cooling system it's a great idea.

 

[cadman]

Where do you put the pump in your coolant line IJ?

 

[IJ.]

CM: Here ya go>>

Electric Water Pump

 

[jdub]

Heat soak is a MAJOR problem here in Phoenix (or this time of year...hell). The daytime temps hit 110 deg F on a regular basis. I got around it with a CSF radiator and the FAL fans you have. The CSF rad provides the volume of coolant to minimize the heat spikes you're talking about...it able to "absorb" the heat and dissipate it with the dual core and high capacity. I got it here...you'll probably be able to get a better price somewhere else though:
http://www.coolradiator.com/HPAToyotaSupraTurbo3.htm

I use electric fans for the same reason you do...in stop-and-go traffic they provide better/constant flow (IMO) than the stock fan. However, at higher speed the stock fan does flow better. One difference is I run a FAL Variable Speed Controller. Runs the fans "on demand" based on coolant temp from off to 60-100% speed. Combined with the CSF rad...it works very well, even in the extreme temps we get here. It also runs constant full speed when the A/C is on and for 30 sec after you shut down...that helps with the heat soak problem as well. Here's the controller on the FAL site:
http://www.flex-a-lite.com/auto/html/electric-fan-accessories.html

I'm running Toyota Red coolant at 50/50 and a 180 deg F thermostat. My temp gauge has never went above the 3:30-4:00 O'clock position even with the A/C on and running up extended inclines with it 110 deg outside. Pretty pleased how well it works for me.

 

[lagged]

you said at "high speed" the stock fan flows better....

at highway speeds you dont need any fan. you can have your electric fans shut off even. the air coming through the front of the car is more than enough to keep the car cool.

 

[jdub]

you said at "high speed" the stock fan flows better....

Ok...high RPM or higher engine speed....

at highway speeds you dont need any fan. you can have your electric fans shut off even. the air coming through the front of the car is more than enough to keep the car cool.

Hence the temp dependant variable speed controller...as ambiant (highway MPH speed) airflow provides the flow necessary, the controller reduces the fan speed (RPM) as coolant temp drops. If it drops below the set temp (mine is set at 190 deg F), it cuts off completely.

 

[cadman]

I'll post pictures of my dual fan setup if I can figure out how to post them, I'm sure it's pretty simple.

On my way home today, in stopped traffic, those fans kicked on and that temp guage never moved. It stayed right under half way.

 

[cadman]

Here are the pictures of the installed fans and wiring. (if I can get it to work.)

And thank you very much for the pictures of your inline water pump, I might do that.

 

[jdub]

Have you run this set-up in the cooler weather yet?

What's happening (I think) is when you shut your car off and re-start after a short time, the heat has not had the chance to dissipate due to no airflow. In hot weather, the physics of temp transfer between the hot air and the hot rad is just not going to allow it to happen quickly. The stock rad just doesn't have the volume to absorb the extra heat with no airflow.

Mine does this too...it just doesn't get hot enough to make the temp gauge needle move (our temp gauges are a POS BTW). I can tell because the fan comes on immediately after a short stop like you described. That means (in my case) the coolant is over 190 deg F.

Edit: Is the dual fan shroud sealed around the edges?

 

[cadman]

In this picture you can see the 2 fans a bit better. The shroud does cover almost the entire radiator. It's been working great.

Jdub, you are right about that. That's the nice thing about this fan setup, it keeps running after the car is shut off until the temp goes down. The only thing right now is, the water has stopped flowing, so the engine stays hot.

IJ's idea is great, keep the water going for just a little while after you shut it down just to get rid of some of the heat soak. So if I shut it down just for a little while, then come back, I won't get a temp spike.

The information I have gotten on this board is probably the best information I have ever got off any board. Just wanted to let you all know that.

 

[jdub]

Yep - IJ's da man when it comes to these cars :bowdown:
And your premise on his set-up is correct...the booster pump will move the coolant through the block to move the heat out. Combined with the fans running for a short time = very effective.

Consider what I said about the higher volume, dual core rad though too. It does work