Gabriel82

iTrader: (8)

Hey everyone,

I'm in the process of planning and piecing together items to convert my S5 NA FC (streetported, stock ECU). to an electric water pump. I do track the car regularly and I'm not a fond of the temps slowly hitting 220degrees when I'm pushing 110mph+. I usually have to back off and let the car cool a little before pushing it again.

I noticed today that the water pump has a very small leak from the bottom right of the cover. This is the second time this year that this has happened. No white smoke from the exhaust which is always a good sign. I'm heavily considering the Davis Craig EWP and controller. I'll have the controller take car of the Flex-A-Lite Black Magic Fan. I'm opting for Built2Apex's EWP adapter as it allows me to keep the stock alternator location. The following are the questions that I need input for

• Are the studs on the front iron removable?
• I'm going to request that Built2Apex tap x2 1/8 NPT fittings in the adapter. x1 for my Defi Gauge and the other for the EWP Controller. Will I need a third hole for the Water Thermoswitch?
  • Can I just dismiss this switch?
  • Will it trigger a CEL light?
  • 
• There is a long hose that goes from the water pump hosing to BAC valve then another long hose that goes from the BAC to the back of the upper intake manifold. Can I plug that off? I believe it's for cold start? Will it trigger a CEL?
  

I'd appreciate any input. I'm going for a cleaner more reliable set up.

Built2Apex EWP Adapter
Turblown - Davies Craigs EWP

lastphaseofthis

iTrader: (8)

you will need that thermo switch for the ecu, you will also need a better alternator. i like 94 maxima.

Gabriel82

iTrader: (8)

That was actually a question that came to mind after posting these questions. I've seen an adapter for the FC harness to plug into the FD alternator. So an FD alternator is part of the equation.

clokker

iTrader: (2)

[quoteGabriel82]

• There is a long hose that goes from the water pump hosing to BAC valve then another long hose that goes from the BAC to the back of the upper intake manifold. Can I plug that off? I believe it's for cold start? Will it trigger a CEL?[/quote]
• Nope, no CEL.

Pete_89T2

iTrader: (4)

Honestly, I don't think switching to an EWP is worth the effort, especially if you don't want to upgrade the electrical system to deal with the additional mission critical electrical loads that an EWP and E-fan will put on the electrical system. Never had an issue with my OEM mechanical WP, no matter how hard I ran my S5T2, so my suggestion is to fix/replace the OEM WP, and replace the WP housing gaskets to fix any leaks you might have. Maybe while you're in there, replace the T-stat too with the Mazda OEM one just to rule that out as a potential issue. Then look elsewhere for solving the high running temperature problem. Some points below to help guide you:

• What kind of radiator are you running? Stock or something aftermarket, and if it's the latter, what kind/specs? The stock radiator is barely suitable for regular driving; replacing just the radiator alone from stock OEM to an aluminum Koyo N-flow dropped my temps from the 195~200F range during hot summer stop & go driving down to the 180F range.
• Do you still have the plastic under tray and the other stock plastic radiator ducting & fan shroud bits in place? If not, put them back in because it makes a huge difference in making sure you get proper airflow thru the radiator with the mechanical fan.
• Lastly, is the mech. fan clutch working properly? Test it per the FSM, if not working replace that.

KNONFS

iTrader: (14)

Install a FD alternator, if you believe that you will have issues with amperage, IMO, the S5 alternator should be sufficient (depending on the E-fan, apparently the lincoln one is a beast, and pulls up to 40amps, YIKES!). Since you are running stock ECU, I recommend you use the davies craig efan\epump controller, and if you do, then you dont need your current water DEFI temp gauge, since the davis craig controller already has temp gauge on it.

I've been running an efan since 1994 on my S5, never had an issue with the S5 alternator. I am now on a different setup, running a S6 alternator, but that was mainly due to a REW swap.

I believe there are positives to going with an efan and ewp, but in my experience, one of your biggest hurdle is the engine bay space on the FC, and the location of the stock radiator hoses. Mounting he EWP at or below the bottom radiator hose was not easy for me, and I ended up coming with unique approaches in order to install them in a manner that I thought to be "perfect".

Gabriel82

iTrader: (8)

I'm using a Koyo N Flow and Radiator Cap which was installed in June 2018. I do have the under-tray and the clutch-fan shroud on the car. I replaced the thermostat, water pump and gaskets February of this year. The small leak I current have is coming from the front cover of the WP on the bottom right. Normally with regular driving the temps would stay stead at 180F (as per my Defi Gauge). Yesterday before noticing the small leak it would rise to 185F if pushed the car a little and drop back to 181-183F. I did hear some high pitched winding sounds yesterday once I started the car(cold) and again after I left the store.

Gabriel82

iTrader: (8)

I did find that IRP can upgrade the FC altnerator amperage to 140.

https://www.irperformance.com/produc...mp-alternator/

KNONFS

iTrader: (14)

That leak is a warning that your water pump is on is way out

Absolutely not needed for what you are trying to do.

KYPREO

Current draw from an EWP is very low when being controlled via PWM or the Davies Craig controller as most of the time it will be on lower duty cycles and pulsing operation. Even at full duty the current draw is maxed at 7.5A for the EWP150 model.

E-fans are a different story and can have very large current draw, but this is mostly in-rush current on initial startup. This can be mitigated by PWM control or using a soft-start controller. Again, though, if the cooling system is working properly and properly specified (good radiator with good airflow to it), then the e-fan should only ever come on when the vehicle is sitting stationary for a period of time and then switch off against after no more than 30 seconds....maybe up to 60 seconds in very warm climates.

If you want to set an EWP up properly, you need to address the fact you need a proper recirculating bypass thermostat if you plan on driving this on the street, otherwise you will suffer prolonged warm up times and dramatic overcooling in cold weather and freeway driving. None of the aftermarket conversion kits for rotaries properly address this issue. They're fine for race cars, but not street cars.

I have written on this topic extensively in the following links:

Electric water pump ??? - AusRotary
ewp electric controller - Page 2 - AusRotary
https://www.rx7club.com/3rd-generati...-flow-1110563/

KNONFS

iTrader: (14)

Agree with everything you said, and here's my experience with my setup (using PWM on efan and Epump, no thermostat):

- I dont see pronlonged warm up times, than when I was running just an efan (PWM controlled) with the mechanical pump. Perhaps when compared to a mechanical fan and mechanical pump, there is a prolonged warm up times?
- It is tricky when the weather changes from summer to winter. The best I have mastered with the PWM control on efan/epump is around 10f difference between the extreme weather changes. What I mean is that without touching the setup, engine water temps will run about 10F cooler during the winter time (I could chose to do it the other way around, where it runs normal temp in winter, and 10F hotter in summetime) Keep in mind that I dont know what I am doing, and I am learning as I go...

KYPREO

From what you've described that sounds quite bearable. on my setup, coolant temps would not exceed the pre-set temp of the EWP controller (where duty is 100%) unless the vehicle was completely stationary, then after a while the fans would kick in (at 5'C above the set temp). I had the EWP controller set at 80'C (176F). On the freeway at night temps would then drop to 60'C (140'F). That's a big drop.

The other thing I was concerned about is that, without a thermostat or bypass, if there is zero EWP flow during the warmup stage, coolant within the block would continue to heat up, while simultaneously coolant in the radiator would continue to cool down to ambient (as the vehicle is moving and air is passing through it without coolant circulation). Eventually, through convection and conduction, coolant at the temp sensor will eventually register enough of an increase in temperature to active the EWP, but at this point, the temperature of the stationary coolant around the combustion chamber is likely to be considerably hotter than the measured temp at the temp sensor - on a cold day, this temperature differential could be significant. Ambient temperature coolant from the radiator would then rush in to replace the hot coolant within the block. This thermal shock could be disastrous.

To combat this, the Davies Craig controller uses a algorithm so that from ignition on the EWP pulses at 6V for 10 seconds on 30 seconds off until 20'C below the target temp. However, if you are using an aftermarket ECU to control the EWP you'll need to ensure your control strategy circulates some coolant during warmup. Under either of these scenarios, warmup times will be increased over factory as comparatively cooler coolant from the radiator is constantly being re-introduced into the engine

But if you use a bypass thermostat setup, then the radiator is shut out of the loop and only comparatively warmer coolant from the engine block is being recirculated. As the thermostat opens, cooler coolant from the radiator is gradually mixed in. I think this has to be better from a longevity perspective. In my experience, the warmup times using EWP + EWP controller + bypass controller were actually significantly reduced compared to factory. This makes sense because whereas in a factory setup coolant flow rate is fixed to engine rpm irrespective of coolant temp, in the EWP + EWP controller setup, the flow is only being pulsed every 30 seconds when the engine is warming up allowing it to warm up more quickly.

For the same reasons as described above, heater performance was horrible without a thermostat, but superior to factory with EWP + EWP controller + bypass controller.

KNONFS

iTrader: (14)

Man it is GREAT to bounce data with you. I was thinking about what I said, and I have to look at my logs. The coolant temp swing might be more than what I described, maybe the static temp change was 10F warmer from spring to summer, and 10F colder from fall to winter. I have to look at the logs, but something tells me that during spring/fall, the temp was always the same, and when the weather changed drastically, the temps would increase/decrease by 10f. So, 185f in fall/spring, 195f in summer, and 175f in winter.

I can share my haltech PWM map for the efan and EWP if you would like to take a look. Also, the EWP runs at all time, but at very low DC when the engine is cold, my idea was to mimic what you described with the davies craig algorithm.

Again, I am not an expert, dont even know what I am talking about, just presenting what I see on my setup. Also, I would run a thermostat if the option was easy and feasible, meaning I agree with what you are saying.

dguy

iTrader: (8)

I see a lot of people wrestling with multiple cooling control strategies when going EWP and eFan so I thought I'd chime in since I've been using EWP setups for quite a while, its very easy to get into analysis paralysis when applying an EWP to an already 'fragile' engine when exposed to high temps which can lead to overly complex systems. My recipe is pretty simple and never includes a Davies Craig controller as they can be a little annoying to adapt to your other cooling strategies such as e-fan switch/speed states.

(This is on an m800 setup I've just delivered, obviously if your ECU isn't capable of easily building these tables there may need to be some hacks.) I run a simple PWM/speed vs RPM table to essentially turn the EWP into a dumb/standard pulley driven pump and rely on my fans for temperature control (soft start on at desired temp with a 5 degree hysteresis usually works well). Then I apply a second PWM/speed vs Temp correction table to combat coolant stagnation during warm up that just pulses similar to the Davies Craig strategy, though I shut it off much sooner depending on where the temp sensor has been placed. I never have had to run more than ~90 pump capacity/speed, I just keep that last 10% for a safety net if say temps run past 220 from a blocked radiator or maybe dead fan (obviously don't sustain this, its just a buffer before shutdown).

Hope that helps, I know I got way wrapped up with getting it perfect on the first few only to have a few of my complex strategies bite me in the *** while doing trackside support.

P.S. Also, and again this depends on what your ECU is capable of, if I can specify my temp correction map as a math channel that is just multiplicative of PWM/speed vs Temp that works even better. Below 40C .2 above 50C .5 above 70C 1. Something like that.

KNONFS

iTrader: (14)

Thanks for sharing your data/info! Doing the PWM vs temp correction table is an awesome idea. I dont know if the PS1000 has the capability of adding a correction table, need to check on that, if so it i will be a matter of adding a "speed sensor" to the ECU (although, I might be tapped out on inputs as we speak...hmmm) Your process/approach makes TOTAL sense, and quite easy too, once you have the capabilities!