Quote:
I just bought a fan yesterday on Ebay 220w bought the biggest i could get , not sure how good they are but just need to get this car running and see how it works
Dave
Well I hope the blades are the right way around to pull air through the rad. I know what nearly (but not quite) all the sellers say about them working both ways, but the fans with blades that are curved in section can't work as well when they're run backwards - that's what the bit about the blades being stalled rather than flying properly means: To pull air through, the part of the blade nearest the rad needs to have the smaller pitch and the part at the back needs to have the larger pitch, so the air accelerates smoothly across the blade as it moves across the airflow. Sorry if that's a bit Janet and John.
There's another argument about blades curved along their length, i.e. whether they should turn with the tips leading or trailing. But I'm not going there.
If because the motor's that big it draws a bit too much current when idling, you might be able turn it down with something like one of these:
https://www.ebay.co.uk/itm/6V-60V-30A-D ... SwxxFfUO~j
If it draws a enough less than 20A at 12-14v, one of these might do:
https://www.ebay.co.uk/itm/DC-9V-60V-20 ... 4035900453. Though I'd worry the margin is a bit small.
For my 120 Watt fan, I'm thinking of one of these:
https://www.ebay.co.uk/itm/12V-24V-DC-M ... 3962329967 But I think I'd also have a switch in parallel with the controller, so if I want I can let the fan run at full voltage - the controller is likely going to drop something like a volt or so, even at 100% mark and no space.
Modifying that to control fan speed off the coolant temperature with a threshold and some hysteresis might be interesting.
Graham