what electric water pump flow rate we need ?
80l/m or 115l/m ?

 

I suspect when autoxing, sustained (top of 2nd gear) high revs causes water pump cavitation dramatically increasing temps all around. My assumption is that revving 7000-9200rpm (an in some cases pinning the limiter for 1/2 to a 1 full second in 2nd gear), is creating lots of cavitation and not allowing the coolant to flow when it is needed most. To lower temps more, I am considering under-driving the water pump pulley (or perhaps the main shaft pulley). Which do you all think would be more effective? It makes most sense to under-drive the water-pump since it is the obvious culprit. but it is likely the power-steering is being over-driven as well.

What pulleys specifically will address my goal.

I've heard of the RE-medy Water Pump upgrade with superior anti-cavitation impeller. The unit seems to be out of stock and also is rumored to fail. So that is off the table.

Also, please refrain from making comments on shift points or gearing.

 

I have the RE-medy pump for just the reasons you stated.

My FD is pretty much autox only. The diff gears are 4.77, so the revs stay consistently high.

On a 96f day the water temps never exceeded 215f, and oil didn't exceed 210f.

As for the RE-medy pumps failing, I have had no issues with mine in 3 seasons of autox.

I do know someone else that has had his RE-medy pump leak, replaced it, and now the third one is leaking.

We both have single turbo cars. The difference - there is an idler pulley on my car for the belt to the water pump, and his does not have one.

We think that over-tightening of the belt is the culprit in this case.

 

55g per min

115l per min is about 30g per min. On a rotary I don't think that is enuff.

 

The RE-Medy ould be a good option if they were in stock and available (I have the idler pulley)...

Also, I suppose an electric pump might be a nice option. Is there a source to order eveything needed to switch to electric? If I went electric I could remove the tweakit idler pulley and save weight. It'll also free up load on the drive pulley and power.

Are the electric pumps heavier than the pulley style water pumps?

 

electric EWP about 900 grams

 

Is that heavier than oem?

 

Great write up , thanks for taking the time to do this , tons of good info

 

Rx7_Nut13B how control speed of Stewart pump ? by PWM or simply 0-14V ?

 

900 grams = 1.9 lbs

Oem Water pump + housing weigh 8-9 lbs.
(just now weighed them on bathroom scales)

 

The Stewarts pump is a brushless motor so it has a controller, it runs at 100% speed (55g/min)

You can proably figure out a way or controller that will change the speed but I didn't do that.

I have no T-stat and use my fan controls on the powerFc to control my engine temp. It takes some time to get up to temp but will hold about 170f-180f normal driving and never has been above 200f under hard driving.

I also run Evans coolant with 6psi rad cap.

 

anybody using one of these?

http://shop.pettitracing.com/pettit_.../i-408905.aspx

 

I have a beck arnley thermostat......I paid I think $2 for it or something from rockauto a long time ago on special. It opens up at 180F.....another option for you. Its worked great for me.

 

I used the Pettit one for years. Worked well. Can still had heat issues on the track though, I suspect from issues unrelated to thermostat.

 

I want to make a comment to educate more people here as well about cooling in general and altitude.

My car ran great at sea level altitudes....but when I brought the car to CO at higher altitude.....you really need to beef up the system and ducting is of the uttermost importance. Here are some charts too look at from a Ford guy who looked at how altitude effects air density....and how air density effects cooling properties.

In some cases....the rate of cooling drops 20-30%...which is huge. and since we have turbo cars....the car just spools up more to a higher PSI....which means WHP is uneffected.....which means you burn the same amt of fuel.....and you need to reject the same amount of heat as at sea level.....but now you have 20-30% less cooling capability with the same cooling system.

anyway...I went with dual oil coolers...and am ducting everything now. charts are below.

 

Got a link for that article?

 

http://www.ford-trucks.com/forums/65...-1-of-2-a.html

its off a forum.

I was searching for altitude and the effects of it on cooling systems. While his information was gathered for Ford trucks who pull heavy loads through the mountains with turbo's....the same information applies to any vehicle.

 

Ground connections to fan motors

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On my 1993, depending on operational mode, 2 of the 4 fan inputs can be connected to ground . One of them only connects when relay # 3 is closed. The other should be permanently grounded via a solid connection to the body, (per the electrical manual). I think the fan ground connection to the body in my car has broken. Can anybody tell me where this connection is located on the body. It is the yellow wire which goes to both fan connectors and disappears into a cable harness at the front passenger side. All the other wires from the fans go into this same cable harness and come out at the 4 fan control relays on the passenger side. However, this yellow ground connection line does not emerge from the harness at all, (so far as I can see), so it must be (inteneded to to be) grounded on the body somewhere between the fan connectors and the 4 relays, but I'm dashed if I can see where! If anyone knows, or has a stripped down car in their garage and can easily take an unobstructed look in that area I would be most grateful.

Thanks

Dave

 

This is great. Just answered lots of questions with a couple of pictures.

 

quick one about water pump gasket to the housing.

I've apparently stripped threads of lower alternator tensioner bracket bolt or either hole thread too due to rusty bolt. Now got a leaky coolant situation here from the WP housing at that point ...

So I'm taking it apart to inspect and I dont know if I can just clean off the surfaces and fasten using high temp silicone gasket maker only as a gasket replacement?

 

My setup for Greece temperatures ,summer up to 38 Celsius, koyo radiator 3 row ,99 spec fans,arc low temp thermostat 75 c, fan controller.
Temperature with any load or in city traffic never rise up to 92 celsius normally is about 86-88 c readings from pfc.
For heat soak I use electric pump, runs after switch off the engine with fans in mid scale for about 8 minutes.

 

...take care of both flanges (they should be free of any seal residue and 100% flat), use a good sealant (like Hylomar) and let it dry through and it should work fine.

You can also use some gasket material and cut the sealing gasket by yourself, which should also work fine.

 

thanks for the advice man! I managed to clean out the block hole and get longer threaded stud and it went in like almost 10mm extra vs. original factory bolt which utilizes bare 5mm of its thread, so now its back to one piece will go start her soon to warm up and see how she behaves with leaking or better say NO LEAKING. if it neds to be tore down to where I need new gasket I will take your advice for sure! I do have some supercharger gasket sheets I can cut gasket from that and have RTV High Temp silicone, used for everything to deal with heat and flexibility.

 

learned allot from this impressive write up. GREAT JOB

 

That's nothing. We hit 43C here in the Summer in Phoenix (110F). Granted I only drive it sparingly during the Summer months, but it does "occasionally" get driven in those conditions and my temps stay about the same as those you've noted above