Radiator Fan Control

Tuning discussion for all second generation Mazda RX-8 (2009-2011)
Post Reply
User avatar
slipshod
Posts: 8
Joined: June 13th, 2022, 7:02 am

Radiator Fan Control

Post by slipshod »

I am wondering if someone could help me understand the radiator fan control settings. I see a primary and secondary trigger in the ECU definitions, but there are five on/off relay coolant temp points as well. What would control the fan speed?

Thanks
User avatar
Ugnius @ VersaTune
Lead developer
Posts: 580
Joined: March 19th, 2010, 11:57 am

Re: Radiator Fan Control

Post by Ugnius @ VersaTune »

You need to adjust the relay temperature triggers. You can look up the ECT sensor volts vs coolant temperature in ECT Sensor calibration table.
See this picture for details on what each relay controls:
tmp-5193-1C4DFt7W3qEW-.png
tmp-5193-1C4DFt7W3qEW-.png (343.38 KiB) Viewed 3071 times
User avatar
slipshod
Posts: 8
Joined: June 13th, 2022, 7:02 am

Re: Radiator Fan Control

Post by slipshod »

Thank you!
User avatar
slipshod
Posts: 8
Joined: June 13th, 2022, 7:02 am

Re: Radiator Fan Control

Post by slipshod »

I was able to set the fan temp triggers to primary 186F (85C), and secondary to 193F (193F or roughly 90C). Basically, I just added 0.17 volts to the on/off fan relay triggers 1-4. I did not change fan relay trigger 5. Plan to reevaluate this during the colder season, if there is one in Texas.
Tedley
Posts: 6
Joined: November 20th, 2021, 8:26 am

Re: Radiator Fan Control

Post by Tedley »

Thanks for posting your steps. I modified the fan triggers last night with the identical 0.17 volt adjustment. Today in 33° C rush hour traffic with the air conditioning on the hugest temperature I saw was 203° F on the gauge.
User avatar
slipshod
Posts: 8
Joined: June 13th, 2022, 7:02 am

Re: Radiator Fan Control

Post by slipshod »

I'm glad this was useful to you. In my climate radiator coolant temps were always a concern and I think this will keep the engine temp under control safer in the long run.
Martin Polite
Posts: 1
Joined: May 26th, 2023, 2:44 am

Re: Radiator Fan Control

Post by Martin Polite »

Tedley wrote: July 28th, 2022, 1:17 pm Thanks for posting your steps. I modified the fan triggers last night with the identical 0.17 volt adjustment. Today in 33° C rush hour traffic with the air conditioning on the hugest temperature I saw was 203° F on the gauge.
That's very good to know that your problem is resolved!
Post Reply