Whoosh overdriven water pump pulley

[Frontline17]

Any body install one of these? Did you notice any difference in hp or engine cooling? How was the install? Thanks

 

[daloonie]

I did install a PumaSpeed version. No difference in butt-feel. Cooling took no hit(I live in a mild climate though). The install was easy. 4 bolts and a serpentine belt.

 

[Frontline17]

I did install a PumaSpeed version. No difference in butt-feel. Cooling took no hit(I live in a mild climate though). The install was easy. 4 bolts and a serpentine belt.

Cool thanks. This one spins the water pump faster so it should help cooling with the upgraded radiator. Still less weight. Do you know what the torque specs for the pulley was?

 

[atlantaM3]

this is interesting to me because on other/older platforms, ideally you want a bigger radiator and slightly slower movement of the coolant through it, to allow more effective cooling. on other platforms, actually underdrive it to achieve that goal. From that POV, seem spinning the pump faster would be superfluous with a radiator upgrade.

For context, recently did this with an RS - bigger radiator with a lower temp thermostat - car is utterly rock solid on temps. no changes to pulley.

 

[Frontline17]

this is interesting to me because on other/older platforms, ideally you want a bigger radiator and slightly slower movement of the coolant through it, to allow more effective cooling. on other platforms, actually underdrive it to achieve that goal. From that POV, seem spinning the pump faster would be superfluous with a radiator upgrade.

For context, recently did this with an RS - bigger radiator with a lower temp thermostat - car is utterly rock solid on temps. no changes to pulley.

Nice. Yea it is an interesting topic I was looking into it aswell. Svt design and fab makes a underdriven pulley for the fiesta. I watched a video a video that sold me on the over driven pulley. He was stating especially with a bigger then factory radiator slower moving coolant will cause dead spots in the radiator thus reducing the cooling capacity and may cause warm spots in the motor. Faster moving coolant flow would prevent this.

 

[Dialcaliper]

The only real risk I see with overdriving is that especially with an upgraded turbo (which shifts the powerband to high RPM), you could start to get cavitation in certain situations which will f*** a pump pretty good over time.

The rotating inertia of a small component like the water pump pulley is usually negligible. Underdrive pullies are mainly useful when it comes to heavily cammed engines operating well above the factory redline, where the previously mentioned problem of cavitation can occur. You may get a small amount of reduced pumping loss, but it’s not going to make a large difference, at least not on a modern engine

You don’t really get increased pumping by just spinning the water pump faster. Because of the large range of speeds, the water pump (like the oil pump) reaches max flow at less than max RPM (ideally you want max cooling before peak torque when the engine is actually stressed the hardest) and a relief valve limits the water pressure.

The only way to actually increase flow through the engine is to increase the water pressure (relief valve) forcing flow through the block, but that can do funky things to the flow path.

 

[Sam4]

I would think with our over-all high mileage, messing with the waterpump is a big risk. Unless starting with new pump.

 

[Frontline17]

I could definitely see cavitation and reduced water pump life being a thing. I have a hybrid turbo so I won’t be hitting high rpm’s.
“You don’t really get increased pumping by just spinning the water pump faster. Because of the large range of speeds, the water pump (like the oil pump) reaches max flow at less than max RPM (ideally you want max cooling before peak torque when the engine is actually stressed the hardest) and a relief valve limits the water pressure.”
Wouldn’t increasing the pump speed make the system hit the theoretical max pressure and flow sooner then?

 

[atlantaM3]

Doubtful that would make a material difference. What percentage overdriven is the pump, 7%? then you have to math out the differentials in the flow rate between the old and new peak, etc. and what is the delta between those two 'peak' flows for the rpm range that is isnt at peak, etc. - and the target rpm ranges are probably not that different, since the pulley is only a few percent overdriven. Say for example the pump hits peak flow at 2500 Engine RPM. a 7% increase in rotation - using a base calc since I dont know the actual pump rpm - would move the peak flow rate down to ~2325 engine RPM. Is 175 rpm engine speed delta of max cooling flow going to make a big difference compared to a 3x better heatsink in overall cooling? especially since more engine heat is generally produced at higher rpm due to load and additional friction, etc. Very dynamic system. Short version of a long conversation is that a bigger heat sink is going to make a much bigger difference than this part. Just something to noodle on.

I think the intent of this sort of part is an easy change to make a small improvement on an otherwise stock system and is much less install effort that other items such as a lower temp thermostat of fully alloy radiator. Def good in that context.