Too bad you're not FI, it would be very interesting to see if the reverse flow improves knock resistance by reducing cylinder head temps.
And if the total cooling system capacity is enough.

Which pump did you use? Are you running water + EG (ethylene glycol) coolant?

Well I will be running nitrous which skyrockets cylinder head temps. It is one of the reasons I built it this way.

I did have a stock radiator, and found it difficult to maintain a high enough operating temperature under normal driving conditions. I am working on a solution to correct the problem. I would like to be able to adjust the performance of the cooling system for various conditions.

I am running a universal remote pump from CSR. I run EG/water for street use, but run straight water at the track for safety/rule issues.

Are you running a thermostat? I wouldn't imagine so if you are controlling when the pump is on. About how much hp do you think was freed up by doing that?

I am running a thermostat that has been gutted. The reason was to restrict the water flow and speed. Without it, the water flows too violently.

It is hard to say how much power at this point. When I changed to the electric pump, I also changed cylinder head and carb chokes. I picked up 5 tenths in the quarter mile with the combined changes on my normally aspirated set up on the first night of testing. I have since torn it apart for other changes and a rebuild.

It is enough that not a single well funded team in drag racing will run without it if the rules allow.

I seem like a have so many questions. So when you do it you want to flow through the front and back of the head, right? Would you do that with a Y fitting off the outlet on the pump?

No problem. Here to help.

On my set up, I have water coming from the top of the radiator into the cylinder head. I plan to have a Y coming out of the radiator and then going to both the front and back of the head.

There is one other problem I need to make you aware of. It was suggested that if the water level was low, that it would stop flowing. I have not experienced this problem yet, but need to test to see how low I can go before the water stops circulating.

If it seems to create an unsafe situation, then I will probably switch to a cross flow radiator. You could also fill the radiator from the top, and pull water from the bottom. That solution would not look as good.

subscribed for more real world experience. I'm going to run a Pierburg/BMW electric pump on my swap and an Arduino to control it per jasonC's recommendation.

miata2fast if you plan to put a Y and feed water into both front and back of the head, you probably will need a restrictor into the front, else the front will hog the flow which is worse than the rear getting all the flow.

Interesting that the BMW/Pierburg electric pump is about half the price of the aftermarket CSR and Moroso pumps out there.

That's the Pierburg CWA200 for those interested.

https://www.miataturbo.net/general-miata-chat-9/electrical-engineers-needed-dc-motor-control-64636/

Meziere also makes some nice and somewhat affordable electric waterpumps.

Since we're talking about electric pumps. I just picked up an MRS electric PS pump to throw in my car. Built in ECU/pump/res and takes the stock NB VSS speed sensor signal. Looking forward to seeing how it does. Best part of all of this, is I can adjust the intensity by getting a voltage regulator.

Okay, I have another question, actually a few more. Just one for now. Say I replaced my stock water pump with an electric one similar to miata2fasts and plumbed it all with -12 fittings and hose (which has an ID of .750 if I'm not mistaken) with a gutted t-stat, a Y fitting going to the front and back of the head, with a restricted hose to the front... Would the -12 be suffient for a street/track car?

Yes.

I have seen this done on other applications. I would feed the pump with a 12, and come out of the radiator with a 12 to the Y and restrict it to a 10 to each side of the head. If I recall, a 10 was about the size of the heater hose.

I believe feeding both ends with a 12 is overkill, and will add unnecessary weight.

Good, because they make a -12 inlet with -10 outlets... I am intrigued now...

Only if we had a like button on here :hsugh:

Bump. Want to see if there's more feedback or data on this subject.

This would seem to be a no brainer for AutoX Prepared classes. You get more power to the wheels, take weight off the front, and reduce heat soak between runs. I've been copying the top CSP guys in spraying water on my Intake Manifold and radiator between runs. An Electric water pump would allow me to flow water through the system too. Unfortunately we are not allowed to change flow direction in Prepared.

With a 1.8L D-Prepared Miata the weight limit is so easy to hit, you could run a 70-100+ lb battery and eliminate both alternator AND mechanical water pump. For us NA guys, this may actually be cheap HP. I'd LOVE to learn emperical data on WHP gains.

There is a possibility that I will put back the mechanical pump on my next rebuild. I have a few design issues that I need to address with my electric water pump, and am wanting to get my motor up and running as soon as my budget allows. Not having the electric will save me some time and money.

There are no gaurantees, but I will try to get either elapsed times or dyno numbers from before and after electric pump.

I'll post relevant links here:

Stewart Components Elct Water Pump, rated for 10K hrs, 4 lbs, $400, assume 38gpm per model no.

Davies Craig Electric Water Pumps (power claims are suspect)

MiataRoadster is selling the "Golden Eagle", claims 3-7 HP gain: Rated for 7K hrs. Pricy at $450, no weight or flow info

Chevy Article (wish they had done a stock config baseline)

An RX8 forum thread

DP Miata set up as I'd like to do for mine (Full loss)

Interesting. This was Keith Brown's car in 2010 or 2011 in grid at nationals.

Offending verbage: "The direction of water flow through the engine shall not be changed
from that which was original for the engine unless authorized in
Appendix A."


My DP car should debut later this month, so this thread is quite relevant.
:shrug:

Edit:
Reread the thread, I didn't realize that 2fast has completely reversed the direction of flow. THAT I'm sure is illegal, but I think a reroute is considered ok.

tpwalsh, I only know a handfull of guys w/DP cars, and I'm totally open to info sharing. Feel free to pm me, and hopefully I can do the same. Here's my DP build/conversion thread.

FWIW I have a coolant reroute too, this was debated and accepted by SCCA AFAIK (but not first hand knowledge), as long as the flow remains bottom to top, and same direction through the radiator, we are good for DP.