[newbvetteguy]

Countless studies and significant OEM adoption has shown that higher engine coolant temps help increase highway cruise fuel economy, but introduce increased risk of detonation under high loads when combined with high cylinder pressures; for this reason the major auto manufacturers have adopted electronic thermostats that can increase engine temps at lower speeds and engine loads and decrease them when more performance is required.


Electronic / MAP-controlled thermostats have been adopted by Audi, BMW, Ford, GM, Volvo, and Volkswagen and they can be controlled by modern aftermarket fuel injection ECU like Holley, Motec, etc... (Most OEMs just use a 3D map consisting of Load %, Vehicle Speed, and Coolant Temp and then send a PWM control signal appropriate for the particular thermostat.

See Mahle Paper: ww.mahle-aftermarket.com/media/local-media-north-america/pdfs-&-thumbnails/catalogs-and-literature/thermostats/mo-2-1013.pdf

-I don't have enough posts on here so I can't post this as an actual link; sorry.


I'm interested in leveraging my GEN1 SBC's Holley HP EFI system's ability to have a custom MAP table generate a PWM output and potentially control an existing electronically controlled thermostat that's been installed inline in the engine "coolant out" radiator hose.

I'm having a difficult time getting details on inlet and outlet sizes for these things and how the bypasses work, and the ideal signal that's required to control them.


I have a LOT of eco modding improvements in my 1979 Corvette, but I'm not looking to make this a "build thread", I'm just looking to explore this idea with other potentially like-minded eco modders.



I am aware that Davie's Craig in Australia has used their electronic water pumps and controllers in a similar PWM control strategy that alters the speeds that the water pump spins at to accomplish the same goal, but I prefer a traditional mechanical water pump for a LOT of reasons, not the least of which includes reliability and increased engine coolant system pressure (most OEMs seem to agree with me, too).



Adam