Flexalite variable speed controller sensor placement? Upper or lower rad hose?
Flexalite variable speed controller sensor placement? Upper or lower rad hose? Had the fitech Ultimate LS EFi controlling my turbo 5.3 using fan outputs in my home made GM 3 relay dual speed relay setup. I melted a few fuse holders and decided to ditch it for better soft start systems. I also believe the low speed is much lower than half speed as it seems to only run 8amps for both fans together. Each fan pulls 17-18amps full speed running so I would think 9 amps each or 18 amps total no? I run a mrgasket 160 Tstat for the LS, flowkooler high flow pump and a Afco racing dual row 31x19 racing aluminum radiator. I have Derale dual fan shrouded setup with dual 13” Spal fans. I try to keep my temps below 190, verified Tstat starts to open around 170. I took a chance and grabbed the Derale PWM controller and the unit works but the AC override sometimes works and sometimes doesn’t which scares me as it’s my “backup switch” using the fitech to trigger it at 200*F in case of a failure. But I’ve had the car out and it does work and can’t tell when the fans are on. However turn the key off and the fans run and run and run and I’ve timed it for up to 4min 30s after shutdown. It could be longer depending on temps. Derale wants the sensor (stick on) on the cold side radiator tank, so I installed on the lower rad hose by the port. With the controller on and lowest setting I’m at 183+ depending on driving situation. I could get another sensor and put it on the hotside but given the reviews and the AC override being glitchy I don’t want to mess with it.
Now I ordered and will return the Derale for the flexalite variable speed controller. It comes with a 1/4npt sensor probe that I have to put in the system. Stock head ports are filled so I’m looking at other locations. I got the flexalite 1 1/2” hose adapter with the ports for the sensor in the radiator hose. Flexalite told me to put it in the upper hose... so it senses the heat from the engine but I figured the lower hose like Derale as they claim it’s better for getting ahead of the engine temps for better heat control.
What is is everyone’s thoughts? I’m going to use the fitech to control manual override as well as AC override on the flexalight and I like that the flexalight has better options and ground sided inputs. So guys, upper or lower rad hose and why?
Now I ordered and will return the Derale for the flexalite variable speed controller. It comes with a 1/4npt sensor probe that I have to put in the system. Stock head ports are filled so I’m looking at other locations. I got the flexalite 1 1/2” hose adapter with the ports for the sensor in the radiator hose. Flexalite told me to put it in the upper hose... so it senses the heat from the engine but I figured the lower hose like Derale as they claim it’s better for getting ahead of the engine temps for better heat control.
What is is everyone’s thoughts? I’m going to use the fitech to control manual override as well as AC override on the flexalight and I like that the flexalight has better options and ground sided inputs. So guys, upper or lower rad hose and why?
