..... Very Nice ! ... The Davies Craig controller would be well worth having on a street driven vehicle ... it appears to be very user-friendly and adaptable to any application ... mine is hard wired through a relay with an on/off switch ... I am very confident that it will perform as expected and that it will truly help when going deep in rounds especially here in Florida where the daytime temps are fast approaching the 90's .....

 

..... The electric water pump is a success ... after the first pass , I got back to my trailer @ 180 degrees , shut the car off but left the water pump on with the engine fan on high speed and then set about my post-race tasks ... like putting the tire covers on , topping off the fuel , and grabbing the laptop to download the datalog ... when l got into the car to get the data , the water temp gauge was pegged at the bottom ... it cooled completely down to around 100 degrees in about 3 minutes ...
..... My race day wasn't quite as successful ... I wound up at Gainesville and went out in the 3rd round ... I fought traction issues and my non-engine driven water pump freed up a few horsepower making it difficult to dial in ... I dialed a 6.61 to his 6.92 and ran a 6.592 to his 6.912 ... a double breakout but l was under more than him ... l took the stripe by .0207 and the margin of victory was .0107 ... so I did have room ... my brain was screaming LIFT ! ... LIFT !! but my foot said NO !!!

 

Too much water passing thru radiator too quickly defeats the purpose? Maybe why DC advised only 2, eighth inch holes? More isn't always better.

 

4 1/8 holes are still smaller than a wide open thermostat. The less holes are an attempt to still have some coolant flow to not dead head the pump while still being able to keep some temperature in the engine... at 50 GPM or whatever it's flowing it isn't flowing too fast to work right.... it could but it isn't.

 

More IS better. OP didn't have any issue with cooling, in case you missed that.

 

..... 2 holes might be the best plan for a street driven car ... my '87 is a dedicated drag car now ... but I'm convinced that the 4 holes aided in reducing the engine/block heat in the pits with the engine off and the thermostat closed ... and that , my friend , is the reason for installing this pump in the first place ! .....

 

I use a PWM putput from my ECU and also control the cooling fan. I have also added a power hold relay so the ECU can decide when to cut power. That way I can have a rule in the ECU that control how long to do after cooling based on coolant temp or even 'under hood' temp to reduce heat from the turbo.

One thing I notice, and this is not new, is that the stock alternator does not really keep up with demand, especially at idle. Running four fuel pumps, electrical fan, electrical water pump, AC converter for the laptop, It all adds up.
There are more powerful alternators that fit but from what I have read they seem to fail from overheating, There are modern water cooled alternators that might be an option, but a new bracket would have to be manufactured.

 

..... The new water pump earned its stripes yesterday by keeping the engine temps well under control enough to finish in 3rd place @ Bradenton FL points race ... I would have gone further if only I'd dumped it at the end ... I broke out by .016 taking the stripe by .028 ... my opponent ran 6.051 on a 6.05 dial-in ... coolant temps in the later rounds were dropped quickly to under 140 degrees while topping off the fuel and making adjustments as we were on a fuel-it and cool-it rotation making passes .....

 

I think I missed it, but how are you controlling the water pump speed right now?

I know with Holley HP and Dominator you can use a PWM output to control the pump speed and avoid the cost of the Davie's Craig controller, but the Holley PWM outputs only support 2 amps so you have to send the Holley signal to an SSR with a decent sized heat sink and a fan and then have the SSR wired to the battery to control the load. Control signal can be anywhere from 100hz - 1,000hz, but I've heard that 250hz is a good trade-off that allows the pump to work as low as 1.5% duty cycle and allows the SSR to last a long time.



Just go 1.5x - 2x the amp rating of your actual pump at full speed on the SSR sizing so that it lasts a long time and personally, I'd want to wire the thing up with a 2 way switch so that it could be operated @ 100% if desired OR if the SSR dies. (I have a good bit of experience with SSRs dying...). For a drag only app, I get just keeping it simple and running it 100% or off, but for Street / Strip being able to control it is REALLY interesting. (I know some Ethanol / Methanol guys have theirs run at a very low duty cycle until the engine warms up to deal with cold start in ethanol /methanol apps, but if you drive to the track being able to crank up the temp to 195F - 200F would help with fuel economy to the track, and then go COLD at the track.

Adam

 

With my MaxxECU I also use PWM and a SSR to have speed control of the water pump. I am going to remove the thermostat, but I have not done it yet. During warmup the pump is running at 20% duty for a few seconds and then waiting for a while. This way no thermostat is needed. After initial warmup the pump is running all the time with increased duty as temperaure gets closer to target.

 

..... Mine is wired by a dash switch through a relay ... On/Off only ... my car is a dedicated drag car and never sees street duty , so the water pump runs full time as long as the ignition is on ... I would use/recommend a controller for any street use .....

 

Thermostat seems pointless with this control strategy; totally agree.

I really wanted to use something like your control strategy but with a more traditional Meziere electric water pump but I couldn’t get any information from Meziere on whether their pump could be safely controlled via PWM and if so what frequency switching speed to use…

I’d honestly like to use a strategy like BMW does with their electric thermostats -higher temps at highway cruise for mpg improvement and lower temps when you want performance but I can’t figure out what to use as the X and Y inputs for the custom Holley pwm table… temp and throttle position?


How do you protect your SSR from water? Any pictures? I’ve used a water proof plastic electrical box with the SSR and electrical connections inside the box and then a hole cut through the box with the heat sink attached to the outside in a brewery application before and I’m thinking the same solution would be pretty perfect for automotive apps, too. (I’ve never used 12v SSRs; only 120v and 240v.)

adam

 

How many amps is the stock alternator on your car?

I’ve got a C3 so the stock alternator was only 60 amps, I swapped to a CS144 alt because the lower rpm performance is so much better; I planned to switch to a 140amp model but 170amps was all I could find. I’m vain so I got a polished aluminum Tuff Stuff alt, but maybe the alum case means a tiny bit more natural cooling?

My experience is running electrical stuff close to its capacity is when heat is an issue- when I oversize everything heat doesn’t seem to be a problem.

Adam

 

Don't really know. I bought replacement many years ago. Don't remember the brand.

Edit: I actually found the box for the alternator. It seems to be a 17SI 108A alternator.
A CS144 conversion might be the simple solution as that alternator seems to have improved low rpm charging.

 

It is well protected with a good heat sink.

You can barely se the edge of it in the circle.

 

There are a few threads on the Holley forum about controlling a fan with PWM. You could probably do something similar for a pump. They are using speed and temperature as the X and Y axis. You'd need to have a speed input running as one of your additional IOs if you're running a setup that doesn't have transmission control though. I added a 32 tooth driveshaft speed sensor to my 85 for that.