olddragger, I agree that an electric water pump has many advantages. But I just wouldn't get too excited about noticable power gains without actual RX-8 data.

 

you need to figure out waht you have first in order to determine if the effort is worthwhile, for all you know the RX-8 water pump only flows 1/3 the capacity of the Ford pump at twice the rpm ...

how many times do we have to go through the exercise of making grand assumptions of improvement only to discover that Mazda already got most of what there is? I find it a bit amusing when concern is expressed about Evans coolant catching on fire but the idea of having an electric water pump failure instantly frying your rotary engine is inconsequential. If in fact there aren't any gains from using an underdrive pulley system, which is additionally slowing down the alternator for even more potential savings, then just how much do you expect to really accomplish?

 

lots of unknowns here. Yes we dont even know the flow rates for our pump yet. But, when trying to improve on anything, the problem or concerns 1st have to be identified. These are two concerns of mine and some others.
1- cooling--for me mainly on the track --for others driving in slow moving traffic in hot weather.
2- we all want more power.
There are many approaches toward those 2 concerns--better radiators, Evans coolant, more airflow, extra oil coolers, underdrive pulleys etc. We discuss them all here. That is one reason this forum is so good. The concept of the electric water pump is worth exploring. And that is all it is at present --a concept. In speculating what may occur if this system would to be installed on the 8 one can only operate on what knowledge we currently have. That is some limited studies done by certain independant parties on other types of engines and the knowledge we have of reducing rotating mass and the parisitic drain of peripherals. So we theorize.
Team I understand what you are saying, we have many fluids in the 8 that could ignite , but it is to me a little amusing that the raditor fluid could also! That(like the electric water pump) is a "new concept" to come to terms with and like the elect pump has many advantages to our present system..
And in addition ANY pump failure would not instantly fry your engine. Course it would cause some problems like a lot of what we do would.
olddragger

 

umm... sure because its not like the engine is really up to proper operating temperature with proper oil/metal temps. By the time the city water circulates it comes out almost boiling just like a radiator.

 

One other possible way to check the pump draw- hook an electric motor up to the stock water pump and measure the electric eneergy needed to spin it at various RPM's. This would probably give you a more accurate measure of the actual draw of the pump than trying to do a whole dyno with and without.

 

Now thats a good idea dsmdriver--any talent out there that can do this?
olddragger

 

with the current recall/temps/engine failures etc etc etc issues I thought I would revitilize this thread.
olddragger

 

Yesterday I was actually just trying to think of a better way to circulate water around the engine. I just had seen someone whose water pump broke. The part that makes the fins rotate (drive shaft?) came off center and the fins started to dig into the housing. Once that happened the fins got stuck to the housing. That caused the drive shaft to stop spinning which caused the belt to pop off.

An electric pump sounds like a neat idea. There is also no reason why it has to be in the same location as the stock pump. You could route some hoses to the pump and store it where ever.

I think it would be awesome to see this in action on the RX8.

 

So NOBODY has an electric water pump on their RX8 huh, just another great reason for me to put one in my STARX8 project...

 

i believe dan has one--his is track only car --i think.

 

Probably someone out there does or at least tried, but it's complicated, expensive, with little net gain, on a car that's no longer in production, so the chances of people, or better yet, some company developing it, are slim to none.

But if it's your passion, have at it

 

http://www.rx8performance.com/produc...ric-water-pump



http://www.summitracing.com/parts/PRO-66225R/?rtype=10

http://www.summitracing.com/parts/MEZ-WP136S/


I am so trying this out.. If not with those parts then one of these pumps http://www.ebay.com/itm/380419242876...84.m1423.l2649 integrated into a mechanical pump's plate, custom of course.

 

Just use a mazmart water pump. Better design, won't cavitate, less drag at a fraction of the cost of an electric pump setup.
Besides, building an oe pump blocking plate with fittings costs around 25$ in parts, no need to waste money on that plate either. Buying a random electric water pump is stupid, too. You have to know what are the needed requirements for your pump of choice. Specs etc matter.

 

You are kidding yourself if you honestly believe that

As soon as I'm in a competition class that allows it my car will have an electric pump and more. It is one of the most under-utilized midifications on the RX-8.

 

For drag racing, I see the value, and indeed in other forms of competition; but my primary interest is addressing cooling at low speed, where we also have air flow issues, such as getting stuck in stop & go traffic after a prolonged highway journey or even a bit of track driving. I'm still trying to sort out whether coolant flow or air flow is the greater limit; but I'm curious about the collective findings of this thread, if any are ever realized, should coolant flow at low speed prove the greater problem.

 

I have no cooling issues in my ride, no restrictions and such allow it to run cooler so I do not have an RX8 sort of say, much of you guys already know this.. My main concern for converting to electric is power, there has to be a reasonable gain in removing the mechanical pump, pulley and belt even if it is minimal it surely will be a gain and like OD says both pumps are prone to fail in their own way so pump failure is imminent and not awaited for, I have aftermarket gauges but like I said my ride has no cooling issues and runs supa cool.



http://www.daviescraig.com.au/Electr...umps-list.aspx

 

Racing is different than daily driving and casual track days. A dry sump works wonders too since every little bit counts power wise.

Your car shouldn't overheat in such conditions unless you're driving in over 40°c temps during traffic jams...
The cooling system doesn't look like the culprit. However, opening the oil cooler's vents inside the wheel well liner helps. Not water cooling related stuff though...

Mazmart's pump offers some minimal gains as well. System choice depends on what trade-offs you'd rather face.

 

Glad to see there is some renewed interest in this. I would like to mention one thing. Electric water pumps have many advantages in our case but there is one area in which I still question and really can't find much info about. That is ---pressure. I dont know if the ewp can provide the pressure needed to run regular type engine coolant. Now with a coolant like Evans--pressure is not a concern at all. So the benefits far outweight the negatives. Running a computer controlled ewp with no thermostat and evans coolant is the best set up I can think off.
Anyone out there with info on the pressure question?
I do like the hard mount type over the in line type. That conversion plate would allow that--or like G says--make your own.

 

You have to conside that nothing is 'free' i.e., what gain you get in HP from removing a mechanical pump, must be made up in electricity (more or less) by the alternator doing the same work, and so using up that HP again, all things being equal. Of course they aren't really, but with equal cooling, the only net HP might be that the pump is over-pumping much of the time (or not - who knows what HP the OEM pump uses) and being able to control it's use thru feedback could extract some savings. That would certainly take some significant experimentation, given all the dynamic conditions an engine's performance and heat generation takes. One exception might be drag racing where you could have a separate wasted battery just for the pump.

When you have it all figured out, sell it to the community. Though I'm pretty sure it will be yet another way too expensive kit with a net .5 HP gain, and a 10 lb weight. But please prove my prediction 500% (at least) wrong

 

Huh? Cooling system pressure is cooling system pressure. Whether 0 psi or 100 psi relative to outside air, the water pump sees essentially the same conditions for both cases.

 

DUHHHHHH---i just reread my post!!!
I meant the pumping action UNDER PRESSURE---me dummy for today--maybe longer.
Will this make a difference? No? Actually, just because there is pressure in the system-there isnt any more restriction--so gocha--- I am back in the class. I am so familar with thinking increased pressure means some type of restriction.

 

it's not just about power consumption, you gain total control over coolant flow regardless of engine rpm and load ... including zero rpm

I love how people blindly regurgitate stuff based on what someone told them without ever verifying it's authenticity, Polly wanna cracker?


.

 

Do we always need total control over the water system? I can see that as being useful in your case where you may have to stop right after a run. For most other people there's always the cool down lap. A well taylored mechanical pump is more than enough in that case.

 

It was over 40C (104F) ambient, my daughter was asleep, and my wife was insisting on the AC being run full blast while the car was stuck at a crawl that was slower than my walking pace. It was the Summer after I converted to Evans waterless coolant and my Scangauge II reported coolant temperatures of 118.33C (245F). It was hot enough that day that after driving for 3+ hours on the highway before getting stuck in traffic, my TPMS went off because the pressure in my tires hit the high pressure warning threshold (which I didn't even know existed until that moment). My wife stopped trusting my car for family road trips after that (I prefer the 8 to her car: it's more comfortable to drive long distances, more fun, and, unlike her car, has run flats.). Frankly, I'd like to address both the coolant and air flow parts of the issue under low and no speed conditions so I get to take the fun car on family trips again.

Control over coolant flow at low RPM and no RPM (engine switched off) is why I am interested.

If we are talking about track conditions, sure, a cool down lap is an option. In a daily driver, my personal experience says that isn't so.

 

Does Evans run hotter in general? 118°c just for daily driving with the A\C seems absurd. If that fluid doesn't play a role i would check for other issues in the car.
Opening the oil cooler vents and an open front grille instead of our fake one should be enough to keep the car cool even during a traffic jam.
The only cars i saw run that hot all had other problems (catalytic converter, poor maintenance\compression etc).