Quote:
Originally Posted by Lous69
My thinking is that GM validated those modules for the current draw of just one C6 Corvette fan. Since I have two fans, it seems safest to use two modules vs. "hoping" one module will be able to handle the current draw of two fans.
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No need for 2 fan control modules unless current demands from dual fans exceed capaicty for single module. I've run dual Spal fans from production Corvette fan module without issue (I will say that I have yet to ever use an aftermarket fan that comes close to performance of the factory designed and developed fans).
PWM output from ECM has to match what fan module is looking for. If you are using fan module from Corvette and match the calibrations in controller to a Corvette, will all work fine. 128 Hz is what Corvette fan controller is looking for.
Quote:
Originally Posted by parsonsj
Just to clarify (for me, anyway  ) : the E67 in the LSA crate motor offering from GM (pn 19259293) can monitor the A/C line pressure and turn on the fans? Does it do that with PWM support (just running the fan enough to keep the high side pressure to certain number)? Or does it do that by running the fans full speed until the high side pressure drops below a threshold?
And all the while, it's keeping track of the coolant temp and running the fans appropriately for that too?
Sweet! |
Yes - AC pressure calibration just drives fan high enough to keep pressure within boundries set in cal. It's a table relating AC pressure in kPa to fan output %.
Fan duty cycle is controlled by 5 inputs: ECT (engine coolant temp), AC pressure, IAT (intake air temp), EOT (engine oil temo), TOT (trans oil temp). Highest request wins (in other words if AC pressure is requesting 50% DC and ECT is only 30%, 50% is what is commanded).
Most installations do not monitor oil temp (decrete input into ECM) and trans oil temp is either from descrete input of trans temp into ECM, or over CAN bus from TCM (transmission control module).
If you use PCS (Powertrain Control Systems) trans controller for automatic trans, trans oil temp (TOT) is broadcast over CAN messages and will work with crate engine controller kit to drive fan output.
Typically, ECT and AC will be primary drivers for fan DC - unless you have an unbalanced system from cooling perspective.
Dave