[A26B]

My simple answer is to keep the by-pass as is, redesign the impeller to lower the flow rate......(Yea, right, simple!...ignorance is bliss sometimes).... and use a high end radiator.

Well, if you reduce the flow rate by modifying the impeller, all you've done is reduce the amount of coolant that flows through the radiator at all rpm's under the bypass opening rpm.

By Hib Halverson: Two cars were built and tested during the fall and winter. The Mobil/EDS/Goodyear Corvette chassis were stock except for: no side mirrors, lowered front end, reinforced front air dams fitted with ultrasonic "anti-animal" whistles, no rear antiroll bars, transmission and differential oil coolers, 3.07:1 axle ratio on the ZR-1 and a 2.72:1 for the L98 car and 25.5x12.0-17 Special Radial tires that Goodyear built for this effort. Replacing the passenger seats were EDS telemetry systems operated by GM's Service Technology Group. The cars were heavy carrying a roll cage, other safety equipment and 48 gal. fuel cells. As FIA rules require "non-consumable" spare parts (brake rotor, radiator hose, alternator, etc.) to be carried in the car, 300 lbs. of spares were in two suitcases lashed to the cages' rear tubes. Replacements had to come from this stock and, if a failure was such that a car could not get back to the pits; the driver, working alone, had to fix the car. Ab's ghost to smiled even more.

The LT-5 was picked right off Mercury Marine's Stillwater, Oklahoma assembly line. Less catalytic converters and mufflers, but with revised engine management software, its horsepower was about 405. Tests had shown speed necessary to reset The 24 would come at 5500 rpm in fifth gear so the engine had a stop at 70% throttle.

Note: no mention of the rpm limit having been established due to the coolant bypass system.

LT5 Water pump flow rate: 12 gpm @ idle 85 gpm @ 7,000 rpm

I'm still searching for some "hard" data regarding the thermostat bypass valve operation specs.