LT1 Electric Water Pump - High Volts Low Temps Redux

Testing Meziere's LT1 Electric Water Pump

Jay Heath Nov 1, 2008 0 Comment(s)
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The pump assembly is lowered into place. Although the electric unit sticks out a little farther than the stocker, there should still be plenty of clearance. (Note, however, that some aftermarket camber braces may not fit.) Once all the ancillary hardware is reinstalled, it's time to move on to wiring.

With the cooling system buttoned up, Briese and company strapped the C4 down onto the shop's Dynojet chassis dynamometer and performed a series of pulls. While we didn't expect the car's mildly modded LT1 to register improvements as large as those observed on the LS7, we were slightly disappointed to find that our new electric water pump had only increased rear-wheel output by 3 hp and 3 lb-ft of torque.

Could it be that the LT1's cam-driven pump saps less power than a conventional system, making improvements harder to come by? Or maybe our C4's relatively modest output (290 rwhp) is to blame. Whatever the reason, we should point out that we have heard of LT1 Vettes making as much 10 extra rear-wheel horsepower when equipped with the same Meziere unit.

Where the electric pump really paid dividends was out on the road, where coolant temperatures in typical use dropped from a scorching 210-220 degrees F down to a comparatively gelid 185-195. Installing Hypertech's Power Programmer tuning, with its lower fan-engagement thresholds, slashed those temps by another 10 degrees in all but the knottiest stop-and-go snarls.

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Briese wires the electric pump to run with the ignition in the "On" position. This will allow us to cycle the pump with the engine off-perfect for cooling things down between passes at the strip.

The effects of such a significant reduction in operating temperature aren't hard to grasp. At the strip, we've found that the car makes its best runs at 180 degrees or below; keeping temps in that range on the street is sure to improve real-world acceleration while also extending engine-component longevity.

While we didn't unlock big power gains with the Meziere LT1 pump, the marked increase in cooling efficiency it offers makes the unit well worth its $240 asking price. Throw in an ECM programmer or fan switch, and keeping your cool in a C4 has never been easier.


Tampa, FL 33619




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