Water pump impeller design question

[Frenchy]

I'm hoping there may be a few on here that understand water pump impeller design a bit. The reason for that is for my personal vehicle and the hope that I may be able to replace the water pump for a design that moves a bit more coolant throughout the RPM Range(even if it's a 5-10% increase, it will help).

For reference this is again for my 2012 Frontier and that is why it's in the General Automotive Section. Also my truck is pretty heavy and has some power adders on it.

Here is the stock water pump. Looking at the impeller it spins clockwise and has a decent curve on each blade/paddle. For a stock application I will agree it's fine.

Here is a different design used on other VQ Engines from the later VQ38, the VQ35, VQ37 and the VR38. Size wise is should fit. That said you will notice the blades/paddles are more cup shaped and will most likely change the flow/volume of the coolant.

What I'm curious about is if design 2 is a little bit more efficient/high flowing compared to design 1? I suspect there is a reason for the two different designs and I want to know. I will also add that the engines running design 2 have E Fans from the Factory vs design 1 primarily having Thermal Fan Clutch.

EDIT: so far I was able to determine that Design 1 has 31 teeth on the sprocket and design 2 has 29 teeth on the sprocket. Going off of the crank sprocket that has 26 teeth, that allows the water pump to spin about 6% faster. That said I am still curious about the impeller design on whether or not it makes a difference. Also I found out that on the VQ40DE with Flex Fuel and the VQ38DD use the same timing chain while the VQ38DD has design 2 while the VQ40DE with and without Flex Fuel use design 1. Fitment wise it seems like I should be ok to run the pump.

Any and all that can help with this will be appreciated! Maybe @airline tech and @P. A. Schilke will have the best input?!

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[RangerBill]

I'm hoping there may be a few on here that understand water pump impeller design a bit. The reason for that is for my personal vehicle and the hope that I may be able to replace the water pump for a design that moves a bit more coolant throughout the RPM Range(even if it's a 5-10% increase, it will help).

For reference this is again for my 2012 Frontier and that is why it's in the General Automotive Section. Also my truck is pretty heavy and has some power adders on it.

Here is the stock water pump. Looking at the impeller it spins clockwise and has a decent curve on each blade/paddle. For a stock application I will agree it's fine.

Here is a different design used on other VQ Engines from the later VQ38, the VQ35, VQ37 and the VR38. Size wise is should fit. That said you will notice the blades/paddles are more cup shaped and will most likely change the flow/volume of the coolant.

What I'm curious about is if design 2 is a little bit more efficient/high flowing compared to design 1? I suspect there is a reason for the two different designs and I want to know. I will also add that the engines running design 2 have E Fans from the Factory vs design 1 primarily having Thermal Fan Clutch.

Any and all that can help with this will be appreciated! Maybe @airline tech and @P. A. Schilke will have the best input?!

Use a smaller water pump pulley to increase impeller speed.

 

[Frenchy]

Use a smaller water pump pulley to increase impeller speed.

As nice as that sounds, my water pump is driven by the timing chain.......

 

[RangerBill]

As nice as that sounds, my water pump is driven by the timing chain.......

Well then, that won't work. It would work on a Ranger 2.3L engine that the 5G Rangers have installed.

 

[Frenchy]

Well then, that won't work. It would work on a Ranger 2.3L engine that the 5G Rangers have installed.

Yeah certainly not a Ranger and why it's in this section. That said I did find out that design 1 has 31 teeth and design 2 has 29 teeth on the pulley and design 2 is slightly smaller therefore making the speed of the pump go up. The only question is if the impeller design makes enough of a difference as well?

 

[Dr. Zaius]

Since it's driven by the timing chain, does that mean you have to disassemble the front of the engine to get to it?

If it was easily accessible I'd try design 2 simply because it looks like it has a metal impeller instead of plastic.

Looking at the differences, version 2 also seems to have significantly shorter fins than design 1. Wouldn't that increase cavitation at the wrong RPMs?

If you're just looking to improve cooling efficiency, maybe try some of the Redline Water Wetter to see if that helps.

When I had my RX7 turbo, this stuff was almost mandatory.

 

[Frenchy]

Since it's driven by the timing chain, does that mean you have to disassemble the front of the engine to get to it?

If it was easily accessible I'd try design 2 simply because it looks like it has a metal impeller instead of plastic.

Looking at the differences, version 2 also seems to have significantly shorter fins than design 1. Wouldn't that increase cavitation at the wrong RPMs?

If you're just looking to improve cooling efficiency, maybe try some of the Redline Water Wetter to see if that helps.

When I had my RX7 turbo, this stuff was almost mandatory.

Technically yes I have to do some disassembly to the front of the engine, but Nissan was kind to have two access plates to remove for changing the water pump vs having to remove the entire cover. Not easy, but doable.

For the impeller both are metal and as mentioned above design 2 is already used in the performance vehicles like the 350Z, 370Z, GTR and the newer VQ38DD that is in the 2020 and up Frontier.

As for water wetter, I remember trying to use it a while ago and I didn't notice mush difference at all. Then again I also have a 50/50 mix of coolant as well and it's the same now(can't find the Nissan Blue outside of 50/50)

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