6V92 PWM fan upgrade

[Randy Dupree]

wow,25% more flow?
Maybe i need to change my RPM limit,The PWM will not let it go that high unless called for,right?

[1984Lodge]

Originally Posted by badandy

I got the "right" fan ordered - ACS 216205-32. There are a few options here, but I think this is the highest flowing and efficient one. There's 25% more flow between 2000 and 2500 rpm, and I believe this fan flows more than the stock metal fan, but I have no way of knowing that. I think I might have to start looking for some injectors to test the theory. It won't be warm again here for many months. 3 tonight. Will someone adopt me down south? I love grits and Cheerwine!

I was going to do some readings with a anemometer with my buddies stock metal fan and compare to the new plastic fan I put in. Not exactly scientific, but at least will tell me whether the plastic fan is pulling any more air. I would make sure its the same RPMs and the fan is locked on. Check the air movement from the outside of the radiator at several locations.

We are taking applications for the south... you are getting there with the grits and cheerwine, if you want to be a Florida cracker you have to have fried mullet and grits...
We just did get a cold front here and I had to put on a jacket this morning because it was in the 50's....

[badandy]

Originally Posted by Randy Dupree

wow,25% more flow?
Maybe i need to change my RPM limit,The PWM will not let it go that high unless called for,right?

25% more flow, ACS has all the data in great detail on their website, it's pretty nice. That's why I ended up getting theirs instead of a Borg or Horton, they just don't have published data. Maybe they are all the same, who knows.

You're incorrect about the PWM though. Consider how a wax valve works - the PWM is exactly the same from the DDEC, it's dumb. The only feedback to the wax valve to control speed is coolant temp. The DDEC is exactly the same. If you crank the max pressure up at motor (trim) then something like 80% duty cycle is what used to be 100%. The DDEC will run the fan at the same speed as before for the same cooling needs. If you've never hit 100% fan duty cycle then cranking up the motor pressure won't get you anything because it will never even try to spin the fan harder. This is why I will have a gauge on the dash that shows cooling fan duty cycle. I'm certain you can get this from the DDEC, too.

[badandy]

Originally Posted by 1984Lodge

I was going to do some readings with a anemometer with my buddies stock metal fan and compare to the new plastic fan I put in. Not exactly scientific, but at least will tell me whether the plastic fan is pulling any more air. I would make sure its the same RPMs and the fan is locked on. Check the air movement from the outside of the radiator at several locations.

It would be very interesting! It's hard to compare to ACS, but they tell you exactly what they did on their testing, so I think we could learn from it.

Originally Posted by 1984Lodge

We are taking applications for the south... you are getting there with the grits and cheerwine, if you want to be a Florida cracker you have to have fried mullet and grits...
We just did get a cold front here and I had to put on a jacket this morning because it was in the 50's....

Yeah I don't know about FL, seems tooooooo far south!

[Randy Dupree]

39 here this morning,shorts and t's were the dress of the day.
By 10am it was beautiful and warm.

[ChrisRasman]

80 today. Started out in the 60s. Andy, I might be able to stuff you in on my new driveway. I have 18 feet outside the fence to the street and 15 feet to the (soon to be) front door of my garage. I leave the door up and back my coach up to the back wall you probably fit. Nice family neighborhood. Could give you fresh water and 30 amps. If you have a macerator, could even give you a sewer hookup. Won't need much AC :-) Just can't camp out more than a week or two or the county might come snooping.

[Randy Dupree]

Originally Posted by badandy

25% more flow, ACS has all the data in great detail on their website, it's pretty nice. That's why I ended up getting theirs instead of a Borg or Horton, they just don't have published data. Maybe they are all the same, who knows.

You're incorrect about the PWM though. Consider how a wax valve works - the PWM is exactly the same from the DDEC, it's dumb. The only feedback to the wax valve to control speed is coolant temp. The DDEC is exactly the same. If you crank the max pressure up at motor (trim) then something like 80% duty cycle is what used to be 100%. The DDEC will run the fan at the same speed as before for the same cooling needs. If you've never hit 100% fan duty cycle then cranking up the motor pressure won't get you anything because it will never even try to spin the fan harder. This is why I will have a gauge on the dash that shows cooling fan duty cycle. I'm certain you can get this from the DDEC, too.

I'm back!
So the fan speed is going to be controlled in my case by the engine temp,the ddec will tell the PWM to spin the fan motor harder or to back the rpms off,depending on coolant temp.
But if the "trim" was set to higher RPMs and the cooalnt got hotter and hotter,would the PWM speed the rpms up?

[badandy]

Originally Posted by Randy Dupree

So the fan speed is going to be controlled in my case by the engine temp,the ddec will tell the PWM to spin the fan motor harder or to back the rpms off,depending on coolant temp.

Correct.

But if the "trim" was set to higher RPMs and the cooalnt got hotter and hotter,would the PWM speed the rpms up?

Yes, exactly. Also, keep in mind, if your PWM control dies and the fan has to default to full speed it will also go straight up to the trim speed.

[Randy Dupree]

So having a few extra dilithium crystals in the trim may not be a bad idea.

[badandy]

Originally Posted by Randy Dupree

So having a few extra dilithium crystals in the trim may not be a bad idea.

Yup. I'm still working on the transparent aluminum, probably won't get that one figured out.