Underdrive pulley recommendations?

[Jake Raby]

I have evaluated the 4" pulley with both A/C and without.. The gains are real, not to mention reduced coolant temps and dramatically reduced power steering temps while on the track.

[stephen wilson]

Actually, there is at least one aftermarket electric water pump with an electronic controller that varies pump speed to control engine temperature, manufactured by Craig Davies.

I don't think any automotive manufacturer would lack the resources to design such a system. They manage to map fuel injection & ignition timing using dozens of sensors, over all possible operating conditions, while controlling emissions. Controlling a water pumps speed would be a piece of cake.

[Jake Raby]

Originally Posted by stephen wilson

Actually, there is at least one aftermarket electric water pump with an electronic controller that varies pump speed to control engine temperature, manufactured by Craig Davies.

I don't think any automotive manufacturer would lack the resources to design such a system. They manage to map fuel injection & ignition timing using dozens of sensors, over all possible operating conditions, while controlling emissions. Controlling a water pumps speed would be a piece of cake.

We purchased one of these last year.. Problem is there is no way to efficiently route the water to/from the engine due to the OE water pump location.. There also isn't any place worth a damn to mount the electric unit.

The engine's design is the variable...

[JFP in PA]

Originally Posted by stephen wilson

I don't think any automotive manufacturer would lack the resources to design such a system. They manage to map fuel injection & ignition timing using dozens of sensors, over all possible operating conditions, while controlling emissions. Controlling a water pumps speed would be a piece of cake.

The only problem is that a better system would cost the OEM five cents more than the one they gave you....................and there is no "sex appeal" in cooling systems.

[stephen wilson]

Yes, the Boxster's tight packaging is problematic, which of course an OEM could solve, but as JFP mentioned, they have no real incentive to do so.

[davemon]

Looking at adding a UDP, has anyone had any issues with engine temp from spinning the pump more slowly? I live in hot a$$ texas.

I saw Jake's post about cooler temps but either that is counter-intuitive or I'm missing something, and I'm comfortable admitting I may be missing more than just something here . Shouldn't less spinning = less cooling???

[amondc]

I live in hot ass Texas also. No problems here. Where are you at?

[davemon]

Originally Posted by amondc

I live in hot ass Texas also. No problems here. Where are you at?

I guess I'm amongst the folks trying to keep it weird.

[Wingnut2u]

Originally Posted by davemon

Looking at adding a UDP, has anyone had any issues with engine temp from spinning the pump more slowly? I live in hot a$$ texas.

I saw Jake's post about cooler temps but either that is counter-intuitive or I'm missing something, and I'm comfortable admitting I may be missing more than just something here . Shouldn't less spinning = less cooling???

davemon

I also live in Texas and I have installed Chris' (amondc) underdrive pulley and I can tell you first hand that my temps are cooler. It is also a daily driver for me and I have had no ill effects.

One of the best bangs for your buck in my opinion.

[mikefocke]

I presume you are reading the temps off the guages.

Driving the accessories at a slower rate would spin the water pump slower which would evacuate heat slower which would mean that the water getting to the radiators would be hotter wouldn't it?

What am I missing here? Make any other changes?