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Discussion Starter · #1 ·



Just wanted to inform you guys of a product that we just rolled out. Should be pretty cool for the people that need better cooling.

We have been working with another company to build us a high flow Subaru specific water pump.

These pumps are coated with a heat dispersing thermal coating and are then assembled using a cast steel impeller with closer back spacing tolerances then the factory water pumps. In road course testing we have seen the factory pumps cavitate at high rpms or even fail. Leading to over heating conditions, or worse a blown motor.

With our closer back spacing on the impeller and high flow cast impeller design we have all but cured the cavitation issues, improved water flow, and reduced the power required to move the coolant through the engine. I typical 20-30 minute track session we have seen a reduction in coolant temps up to 20F over the standard stamped steel subaru water pumps.

This is a great upgrade for anyone taking their car on the track or autox, or the enthusiust that lives in the southern states and wants some extra cooling.

**Includes brand new gasket

**Heat Dispersing Coating optional

**Fits all TURBO Subaru models Including but not limited to the following

-Subaru Impreza WRX ALL YEARS

-Subaru Impreza STI ALL YEARS

-All Turbo Forester







 

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I'd like someone to explain the relationship between speed of water movement through the cooling system (say liters/minute through the water pump) and the resulting water temperature.

It sort of seems like faster circulation means the residence time in the radiator is shorter, meaning less cooling, but also that the water spends less time in the engine, meaning less heating.

So the net effect seems like circulation speed doesn't matter much. You need to keep the water moving, but within pretty broad limits moving the water faster doesn't make much if any difference.

I'm not saying it works this way, just saying this is one way of looking at it. Hopefully a heat-transfer guru will clear this up for me. :notsure:
 

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What is the price on these? Any idea how it compares to the pump offered by Crawford?

Its been like 10 yrs since I took heat transfer but I recall that flow speed improves cooling up until the flow reaches Mach 2 or 3? Someone with a better memory could probably answer the question a lot better. On the other hand I've noticed a good temp reduction from running a restrictor in the outlet of the radiator in asphalt late model race cars.
 

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The stock stamped piece has a tendency for the impeller to cavitate during extended high rpm track conditions. When this happens the water pumps looses its ability to flow coolant through the block efficiently and the flow drops. With the TSM water pump this cavitation doesn't happen so the coolant has a constant flow through the engine.
 

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The stock stamped piece has a tendency for the impeller to cavitate during extended high rpm track conditions. When this happens the water pumps looses its ability to flow coolant through the block efficiently and the flow drops. With the TSM water pump this cavitation doesn't happen so the coolant has a constant flow through the engine.
How do you know the OE pump is cavitating?
 

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How do you know the OE pump is cavitating?
With our closer back spacing on the impeller and high flow cast impeller design we have all but cured the cavitation issues, improved water flow, and reduced the power required to move the coolant through the engine.
I'd say that just about any design will experience some cavitation at high RPM's and temperatures. However, TMS's impeller seems to be designed with the vanes of the impeller enclosed and, more importantly, run from the suction to the discharge of the impeller, which would allow for more-uniform flow, reduction in turbulence (and the resultant cavitation.)

Is the pulley that runs the TMS water pump smaller than the stock pump's pulley? If not, then I guess the additional flow comes from the more efficient design.
 

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I'd say that just about any design will experience some cavitation at high RPM's and temperatures. However, TMS's impeller seems to be designed with the vanes of the impeller enclosed and, more importantly, run from the suction to the discharge of the impeller, which would allow for more-uniform flow, reduction in turbulence (and the resultant cavitation.)
I'm just curious how they know cavitation was a problem and that the new pump doesn't have this issue. Obviously either of these pumps will cavitate at some point but when is that? What kind of flow rate change are we talking about with the impeller redesign? If someone sells a new turbo on here everyone wants to see the compressor maps; why would this be any different?

I'm not doubting their new pump is great. Just wanted to learn something...
 

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Discussion Starter · #11 ·
Some good questions in here guys.

The stamped steal design is know to be more of a cost efficient design then performance based. The pulley is the same size, and we have not flow bench tested these pumps side by side. Cast designed wheels are old hot rod tech that just works.

Our testing very simply consisted of taking a car with track with overheating issues and testing it back to back with one of our pumps. We ran this pump in our race car, we run one in our 2011 that goes to the track once a month. Coolant temps go down, which means flow and efficiency goes up.

I could fill you guys full of data all day long, but that doesn't mean its going to WORK! Well this works. Real world vs. paper testing.....i'll take real world any day.

Hope this helps guys.

~Cicio
 

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;) ^^^ I assume this is tongue-in-cheek, and although I'm an engineer type, I do accept that if it works, it works, even though I can't necessarily derive it from theory.
 

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I'm not saying it works this way, just saying this is one way of looking at it. Hopefully a heat-transfer guru will clear this up for me. :notsure:
Q=m*Cp* (Tin-Tout) Cp is a constant, m is mass flow rate, q is heat transfer rate Tin and Tout are the inlet and outlet temps of the radiator (Tout<Tin for any working radiator or other heat sink in a closed system).
Another one applies for the radiator Q=UA(Taverage-Tambient) Q-rate of heat transfer U-constant A-radiator surface area- Taverage=(Tout + Tin)/2 Tambient-Temperature of air flowing through radiator
Most radiators are only rated to get a certain heat transfer rate. So if you are maxing out your radiator, Q would remain constant. So if you were to double your flow, you would half the (Tin-Tout) term. Your Taverage term would remain unaffected. Raising flow also reduces The U constant by effecting the film coefficient (faster flowing water has a thinner film to block heat transfer, therefore U goes down) This should result in increased radiator performance. what I just did is assuming you have an undersized radiator (you should never get over the radiator's heat rating, at least not stay there for too long, as you would overheat eventually). This is also assuming no additional restrictions in the system.
However, your radiator does not really do anything unless the thermostat is open sending hot water to it. This means that your thermostat has more overall effect on temperature and cooling than the water pump does (thermostats control for a setpoint).
 

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Q=m*Cp* (Tin-Tout) Cp is a constant, m is mass flow rate, q is heat transfer rate Tin and Tout are the inlet and outlet temps of the radiator (Tout<Tin for any working radiator or other heat sink in a closed system).
Another one applies for the radiator Q=UA(Taverage-Tambient) Q-rate of heat transfer U-constant A-radiator surface area- Taverage=(Tout + Tin)/2 Tambient-Temperature of air flowing through radiator
Most radiators are only rated to get a certain heat transfer rate. So if you are maxing out your radiator, Q would remain constant. So if you were to double your flow, you would half the (Tin-Tout) term. Your Taverage term would remain unaffected. Raising flow also reduces The U constant by effecting the film coefficient (faster flowing water has a thinner film to block heat transfer, therefore U goes down) This should result in increased radiator performance. what I just did is assuming you have an undersized radiator (you should never get over the radiator's heat rating, at least not stay there for too long, as you would overheat eventually). This is also assuming no additional restrictions in the system.
However, your radiator does not really do anything unless the thermostat is open sending hot water to it. This means that your thermostat has more overall effect on temperature and cooling than the water pump does (thermostats control for a setpoint).
Awesome, thanks.

And if I were to say a pump was cavitating, I'd need to look for pitting on the pump vanes. At least, that's a dead giveaway when working on fire trucks.
 

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Some good questions in here guys.

The stamped steal design is know to be more of a cost efficient design then performance based. The pulley is the same size, and we have not flow bench tested these pumps side by side. Cast designed wheels are old hot rod tech that just works.

Our testing very simply consisted of taking a car with track with overheating issues and testing it back to back with one of our pumps. We ran this pump in our race car, we run one in our 2011 that goes to the track once a month. Coolant temps go down, which means flow and efficiency goes up.

I could fill you guys full of data all day long, but that doesn't mean its going to WORK! Well this works. Real world vs. paper testing.....i'll take real world any day.

Hope this helps guys.

~Cicio
Maybe, but some of us want data instead of some guy saying "Hey, it worked for me." Doesn't carry much weight in the engineering world.
 

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I just want in on the conversation, not in any way saying anything neg. or pos. about this pump. I'm not about to get into that, just want to help along the conversation with some real world experience is all.




It sort of seems like faster circulation means the residence time in the radiator is shorter, meaning less cooling, but also that the water spends less time in the engine, meaning less heating.

So the net effect seems like circulation speed doesn't matter much. You need to keep the water moving, but within pretty broad limits moving the water faster doesn't make much if any difference.

I'm not saying it works this way, just saying this is one way of looking at it. Hopefully a heat-transfer guru will clear this up for me. :notsure:
The coolant/antifreeze is spending less time in the engine also has less time to absorb heat and transfer it to to the cooling apparatus (radiator)
This is why when we run out drag engine with no thermostat, we install a certain size 'disc" to take its place and slow flow to the proper amount.


Awesome, thanks.

And if I were to say a pump was cavitation, I'd need to look for pitting on the pump vanes. At least, that's a dead giveaway when working on fire trucks.]/b]


Bingo! This also works for jet pumps of PWC and jet Boats. The pitting is a direct result on cavitation. You can't have one without the other.

Now most probably don't know the real meaning of cavitation, but for those who do, know that this is correct.




Quote:
Originally Posted by [email protected]
Some good questions in here guys.

The stamped steal design is know to be more of a cost efficient design then performance based. The pulley is the same size, and we have not flow bench tested these pumps side by side. Cast designed wheels are old hot rod tech that just works.

Our testing very simply consisted of taking a car with track with overheating issues and testing it back to back with one of our pumps. We ran this pump in our race car, we run one in our 2011 that goes to the track once a month. Coolant temps go down, which means flow and efficiency goes up.

I could fill you guys full of data all day long, but that doesn't mean its going to WORK! Well this works. Real world vs. paper testing.....i'll take real world any day.

Hope this helps guys.

~Cicio



Originally Posted by [email protected]
Some good questions in here guys.

The stamped steal design is know to be more of a cost efficient design then performance based. The pulley is the same size, and we have not flow bench tested these pumps side by side. Cast designed wheels are old hot rod tech that just works.

Our testing very simply consisted of taking a car with track with overheating issues and testing it back to back with one of our pumps. We ran this pump in our race car, we run one in our 2011 that goes to the track once a month. Coolant temps go down, which means flow and efficiency goes up.

I could fill you guys full of data all day long, but that doesn't mean its going to WORK! Well this works. Real world vs. paper testing.....i'll take real world any day.

Hope this helps guys.

~Cicio

**********



Maybe, but some of us want data instead of some guy saying "Hey, it worked for me." Doesn't carry much weight in the engineering world.



As someone else said, some kind of proof besides "I said so" is better than none.

I am not an Engineer, I am a Master Tech and Engine builder. One with over 30 years in the industry and one who also to this day keeps up with the "latest and greatest". I don't see 'eye to eye" with most Engineers. I live in the world of real, they live in the world of Theory. Sometimes they both do not exist as planned by the Engineer.

*If I was looking to improve the pump pictured in this thread, I would do away with all the casting marks and rough surfaces to improve flow and reduce cavitation. Those little "pits" will induce cavitation.

Again, my 50cents and not busting anyone chops or products.

 

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Q=m*Cp* (Tin-Tout) Cp is a constant, m is mass flow rate, q is heat transfer rate Tin and Tout are the inlet and outlet temps of the radiator (Tout<Tin for any working radiator or other heat sink in a closed system). ...Snip ...
Seems like, roughly, as m increases the (Tin-Tout) tends to decrease. So it looks like faster flow doesn't always translate to more cooling, but that the optimum flow rate is some intermediate value. This relates to what NJJer said about using a restrictor disc when running without a thermostat.

So I guess faster flow rate isn't necessarily "better", but it might be, depending... :notsure:
 

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[/I]


As someone else said, some kind of proof besides "I said so" is better than none.

I am not an Engineer, I am a Master Tech and Engine builder. One with over 30 years in the industry and one who also to this day keeps up with the "latest and greatest". I don't see 'eye to eye" with most Engineers. I live in the world of real, they live in the world of Theory. Sometimes they both do not exist as planned by the Engineer.

*If I was looking to improve the pump pictured in this thread, I would do away with all the casting marks and rough surfaces to improve flow and reduce cavitation. Those little "pits" will induce cavitation.

Again, my 50cents and not busting anyone chops or products.

There's plenty of room for both worlds, and since I'm a 34 year old engineering STUDENT, I've seen enough real world to know that sometimes engineers don't have a clue what they're talking about. :lol:
 

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There's plenty of room for both worlds, and since I'm a 34 year old engineering STUDENT, I've seen enough real world to know that sometimes engineers don't have a clue what they're talking about. :lol:
Now see here people, this man right here and I would get along just fine. He lives in the same world as I do, reality. :beer:

Just one more bit OT than back to our regularly scheduled show.
I once had a Physics Professor who would say- "You can use Physics to prove that an object is right there in front of me. Then I can use it to prove that it is not there"

Take it for what it's worth.

Now back to boiling water...I mean cavitation and this new pump.
 
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