Everybody looks at the pump flow ratings, but nobody seems to ask how much the entire cooling system can flow. I would be willing to bet that the engine block and radiator create a significant restriction to flow. No matter how much the pumps can flow theoretically, it all comes down to how much water you can put through the system. At high RPM, the stock pump is probably trying to cram so much water through the engine block that it's just building up pressure and not actually flowing any additional. That's where the dyno proven gains come from on an electric pump.

Besides, if the water is flowing too fast, it doesn't have time to absorb heat in the engine or to disspiate it in the radiator.

 

Mine barely goes above the 1/4 mark.... usually doesn't even get that hot.

 

^That's what i was trying to get at when i put
You said it exactly right "llafro". I am thinking you start to spin over 5grand and you just are building pressure causing some drops in hp....now this pressure is great if you are running really hot, because pressurizing the water causes it to have a higher boiling point therefore can withstand more heat before it boils....which we all know if left at the factory settings of the fans at 225....your coolant would be boiling probably if you didn't have good pressure. But since we have manual fan switches, low themostats, etc. I think that the Electric water-pump is the only way to go. All the bolt-on LT1's i see hitting around 12.5's are running the Electric water-pumps......i just don't think you can hit a flat 12.5 with the stock pump.

 

What is that 1/4 mark anyway.........i tried to figure it out one day and i think i did, but i forgot it--what temp the 1/4 mark on the temp gauge is......is it 180??

 

The 1/4 mark on mine is 185*...I never see mine go above that, even in stop and go traffic. I have a CSI pump and haven't had too many problems with it...my advice would be to replace the crappy fuse holder they give you with a good one ASAP and carry a spare relay in your glovebox in case yours burns out. I've never had any problems with the pump itself.

 

Yea i hear it's a good idea to have a spare relay in your pocket.....thanks for the heads up^

 

Not true. While the pump might flow less coolant at higher rpms, the car doesnt heat up that coolant any faster, and even autoXing the car, I havent noticed a difference at high rpms with the elec pump. Reason being, the radiator can only cool the coolant so much. Pumping it 10 times faster doesnt increase your cooling any.

 

Ditto on that! much easier to swap out the electric than a stocker.

 

I thought I heard awhile back that you have to say bye-bye to the AC condensor....and move the radiator closer to the nose. Not sure.

As far as a switch, I think that would be pretty easy. You would just have to extend the 12v wire that comes out of the WP and run it to a switch in the passenger compartment(possibly using a relay depending on amperage draw).

 

Definitely use a relay... I used this guide

http://ken.lowrance.com/projects/CSI.../CISHeader.htm

 

I have noticed no difference in cooling between a stock water pump and the electric (highway or stop and go). Only trouble I 've ever had was with a bearing issue causing the pump rotar to bind and blow fuses. Bought a new Mez and they repaired the old one, so I carry a spare. I would keep an extra relay on hand, but if that failes, its simple to bypass it to get going. For most applications, I think a HD unit is overkill.

 

i have had a csi on the ss for 2 years now. works great. temps have never been over 180. most of the time my gauge is just a needle above the 160 mark.

 

Alrighty then, looks like we have put to rest the whole electric pumps don't cool as much as the mechanical. I never really believed the mechanical pumps cooled anymore efficiently than the electric ones....like Spinner said it doesn't matter how fast you pump it, the radiator is what cools it.

 

your aint cam driven your is chain driven