Electric fans worth it?

[L31MaxExpress]

My only desire to do this is out of the hope that the PWM control allows for the fan to run say 50% or some (insert variable coupling percentage) rather than 30% to 100% to 30% to 100% and on and on and on that it does now. If it balances out at say 50-60% coupling and gives the necessary cooling; the fan will be quieter, will take less power, be easier on the water pump bearings and belt and the mpg should be better. This will also allow the fan to respond more quickly to cooling demand changes than giving it simple On/Off commands or relying on a thermal clutch. I can always crank the duty cycle up around idle to say 75% so that it couples the clutch for cooling the condenser. As it is the ac works pretty darn well even with the fan in freewheel mode. The Duramax fan pulls more airflow freewheeling than the factory fan did with the clutch fully coupled. When the duramax fan fully couples it moves something like 12,000 cfm and sounds like a semi pulling away from a stop in hot weather. It eats 15 ft/lbs and 10 hp at the tires when it engages.

The Duramax fan completely coupled on this dyno pull on a ~100F day when the van had the 350 still in it. To me the fan was louder than everything else. You can clearly hear it over the engine, drivetrain and dyno. There were several electric fan vehicles that boiled coolant with 3 dyno pulls. This one was running cooler on the last pull than it did on the first pull. It was still heat soaked from driving there and sitting when the 1st pull started.

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Sorry for changing direction. I just feel the EV Clutch control will bring a mechanical fan up to the control of electric fans while giving better cooling.

 

[95burban]

@L31MaxExpress is that at speedtek performance?

 

[L31MaxExpress]

@L31MaxExpress is that at speedtek performance?

It sure was

 

[95burban]

Figured it was, is the drive shaft still stuck in the wall?

 

[L31MaxExpress]

Figured it was, is the drive shaft still stuck in the wall?

Was when I was there. GMT800 driveshaft from memory. Think they said years ago it was from an Avalanche or Suburban or something like that.

You would think they would have learned their lesson not to pull a truck in 3rd gear. They still tried to pull this one in 3rd. I had the speed limiter set at 85 mph. Thought it was funny when they stomped it and it immediately fell on its face. This was after I told them to put the shifter in 2nd and leave it. I had the shift tables programmed for 2nd gear start, no WOT downshift and lockup at 20 mph with the shifter in 2nd and use the feature all the time when the roads are wet and slick. I could not convince them to lay into it from low rpm. They were convinced I had no clue what I was talking about and that it was going to immediately downshift, which it did with the shifter in Drive.

Interesting to note, they also launched the driveshaft out of my friend Randy's red regular cab Dodge Ram too a while later. They made a 3rd gear pull and it managed to find itself spitting out on the floor.

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[95burban]

You from the ftw area?

 

[L31MaxExpress]

You from the ftw area?

I am guilty. HEB area here. Moving out to the Jacksboro/Graham area though.

 

[95burban]

I live northwest of ftw but usually in the ftw area daily or north ftw/heb going out to eat or shopping

 

[Dropped88]

I looked at the OE 2003 5.3 trailblazer fan settings. All the normal fan settings are set like a mechanical fan truck. Looks like the EV fan clutch uses engine temp and perhaps only ac status for control. I do not see any reference to ac pressure for fan control.

I forgot I segment swapped a Camaro part under system so the truck computer would control ac by pressure

 

[Scottm]

Do you guys have a favorite gm part number for a mech clutch?