...

Go Back   Lateral-g Forums > Technical Discussions > Cooling: Radiators/Fans/Controllers
User Name
Password



Reply
 
Thread Tools Display Modes
  #291  
Old 10-18-2015, 09:13 AM
130fe 130fe is offline
Lateral-g Supporting Member
 
Join Date: Jan 2005
Location: Jacksonville, FL
Posts: 767
Thanks: 204
Thanked 38 Times in 27 Posts
Post

Justin, do you have a link to the kit you listed?
__________________
Chris
1968 Camaro SS
LS3/T56
Full of DSE and Holley parts
Reply With Quote
  #292  
Old 10-18-2015, 10:33 AM
4wheels 4wheels is offline
Junior Member
 
Join Date: Jul 2015
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Default fans off testing, ambient etc

Interesting data. Thanks for sharing it.

As you mentioned the 50 deg ambient you mention is a significant variable. So is load (speed, grade, weight, other drag etc.) along with overall engine efficiency (extreme example - a 8.0:1 compression engine with timing set to way below MBT spark is going to put a lot of extra heat into the cooling system). You likely wouldn't be controlling to those temperatures without a fan at 80 or 90 degrees ambient or if you were going up a hill or stuck is stop and go traffic with other vehicles around (less airflow, more heat).

But if you are trying to control to an engine coolant temperature I am not sure having ambient as part of your fan control strategy would help much. The feedback on the coolant temperature should do that. Most OEM's are controlling the coolant temperature/fan operation to above thermostat temperature. When you try to control the coolant temperature with the fans to a temperature around the same as the thermostat then it can get more complicated as the two can be working in phase and out of phase. The thermostat has a range of temperatures (starts to open vs fully open) and where it reads temperature may not be the same as the fans and the difference between the two varies depending on many other conditions.

Just some more variables for you to worry about....


Quote:
Originally Posted by andrewb70 View Post
So........

I am not ashamed to admit that I might be slightly obsessed with the ability to control my fan speed.

Recently I had to add coolant to my system (I was running straight water in the summer) so that I don't hurt anything during the long WI winter. After adding the coolant (good to about -40 degrees) I noticed that the engine ran about 4-5 degrees hotter under previously noted conditions. This of course caused the fan to run faster per the table that I programmed.

So I decided to "retune" the table and just set it to work the best it can in my car. For me, "the best it can" is running the fan as slowly as possible, while maintaining a target temperature. But what is that target temperature? LOL

I know I have a stock thermostat which by all accounts is 187 degrees. Given that information I can turn off the fan and just watch what the temperature does under varying conditions (granted all of this is dependent on ambient temperature and ideal I would incorporate it into the fan control strategy for optimal results, but even GM doesn't do this...Didn't I say that I might be slightly obsessed?)

Driving normally around town (aka like grandma...top speed 35) the temperature never got above 191-192 (about 50 ambient). I then took it on the highway and cruising at a steady 75 mph the temp was stable between 194-195 degrees (all this with the fan off).

So I configured my table as follows at vehicle speed below 40mph...

Temp:fan %

194:5 (off)
200:10
210:20

Then it ramps in rather quickly (I don't recall the exact numbers). The fan basically never kicks on around town and temps is steady at 191-192.

For vehicle speed above 40mph I just configured the cells to be one value off, like this:

194:5
200:5
210:10

etc....again, ramping in quickly. Temp is steady at 194-195 without the fan.

I don't know if this is optimal in terms of thermal efficiency. Probably not because my engine seems to run cooler than it would in the donor vehicle (2009 Colorado pick-up). But in terms of my target goal (cycling the fan as little as possible) I think I succeeded.

Anyway, I thought I would share for anyone that cares.

Comments, questions, and opinions welcome.

Andrew
Reply With Quote
  #293  
Old 10-18-2015, 10:35 AM
4wheels 4wheels is offline
Junior Member
 
Join Date: Jul 2015
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Default Vehicle speed

With some of the newer high output fans the vehicle speed based fan disable strategy isn't used anymore. If the cooling is enough that the fans aren't needed then they turn off due to temperature anyway.

Quote:
Originally Posted by GregWeld View Post
Running down the road - the fan shouldn't be needed at all.
Reply With Quote
  #294  
Old 10-18-2015, 10:42 AM
4wheels 4wheels is offline
Junior Member
 
Join Date: Jul 2015
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Default Stand alone PWM fan control - temperature output signal?

I am doing some testing of a stand alone PWM fan controller for a manufacturer. Since this is a stand alone system it reads a separate coolant temperature sensor and can be used on any vehicle (doesn't have to have PWM fan control strategy in the ECM).

One question that has come up in my testing is what is this other sensor reading for temperature since it isn't the same as the other temperature sensors in the cooling system (not the same sensor and may or may not be in the same location in comparison to engine, pump, thermostat, radiator etc.).

If you were a potential customer for this type of product, would an output of temperature from a fan controller be of interest? For example I would like to see it output temperature as a 0-5 volt signal that I could read with a data acquisition system or even just a simple volt meter. Might even be able to drive a gauge with this output (depends on the gauge type).

Any feedback/ideas?

Thanks.
Reply With Quote
  #295  
Old 10-18-2015, 05:48 PM
andrewb70's Avatar
andrewb70 andrewb70 is offline
Lateral-g Supporting Vendor
 
Join Date: Jul 2005
Posts: 851
Thanks: 209
Thanked 441 Times in 200 Posts
Default

Quote:
Originally Posted by 4wheels View Post
I am doing some testing of a stand alone PWM fan controller for a manufacturer. Since this is a stand alone system it reads a separate coolant temperature sensor and can be used on any vehicle (doesn't have to have PWM fan control strategy in the ECM).

One question that has come up in my testing is what is this other sensor reading for temperature since it isn't the same as the other temperature sensors in the cooling system (not the same sensor and may or may not be in the same location in comparison to engine, pump, thermostat, radiator etc.).

If you were a potential customer for this type of product, would an output of temperature from a fan controller be of interest? For example I would like to see it output temperature as a 0-5 volt signal that I could read with a data acquisition system or even just a simple volt meter. Might even be able to drive a gauge with this output (depends on the gauge type).

Any feedback/ideas?

Thanks.
If you are targeting users that may not have EFI, then I see a benefit to having a "temp out." As you said, this can be used to drive a gauge in the dash. I think most temp gauges use a thermister style sensor so the output would need to be resistance.

Andrew
Reply With Quote
  #296  
Old 10-19-2015, 06:54 AM
mikels mikels is offline
Senior Member
 
Join Date: Apr 2006
Posts: 114
Thanks: 1
Thanked 34 Times in 9 Posts
Default

Quote:
Originally Posted by GregWeld View Post
Running down the road - the fan shouldn't be needed at all.
Not completely true - if running the fan creates more negative pressure on backside of cooling system stack, running fan will increase cooling.

For example - when Mark switched Red Devil to 850W fan from 400W, it resulted in ~10 F reduction in coolant and oil temps (oil-to-water oil cooler in radiator) when running on track - with average speeds well above what you typically run on street.

Keep in mind this is a very thick (~5-6") cooling stack as well (A/C condenser, ICHE, radiator)

So ability to create more negative pressure on backside of cooling stack resulted in more airflow across coolers - and more heat transfer as a result.

Dave
Reply With Quote
  #297  
Old 10-19-2015, 08:19 AM
GregWeld's Avatar
GregWeld GregWeld is offline
Lateral-g Supporting Member
 
Join Date: Jul 2005
Location: Scottsdale, AriDzona
Posts: 20,642
Thanks: 504
Thanked 1,076 Times in 384 Posts
Default

Quote:
Originally Posted by mikels View Post
Not completely true - if running the fan creates more negative pressure on backside of cooling system stack, running fan will increase cooling.

For example - when Mark switched Red Devil to 850W fan from 400W, it resulted in ~10 F reduction in coolant and oil temps (oil-to-water oil cooler in radiator) when running on track - with average speeds well above what you typically run on street.

Keep in mind this is a very thick (~5-6") cooling stack as well (A/C condenser, ICHE, radiator)

So ability to create more negative pressure on backside of cooling stack resulted in more airflow across coolers - and more heat transfer as a result.

Dave


Good info Dave.... and Yes - I can certainly see in a racing situation, and with that much horsepower creating additional heat that needs to be dispersed. I was referring to a normal freeway cruising situation where even my Semi truck rarely engages the fan (air engaged fan of ginormous proportions).
Reply With Quote
  #298  
Old 10-20-2015, 08:41 AM
GregWeld's Avatar
GregWeld GregWeld is offline
Lateral-g Supporting Member
 
Join Date: Jul 2005
Location: Scottsdale, AriDzona
Posts: 20,642
Thanks: 504
Thanked 1,076 Times in 384 Posts
Default

I found this info in an article written about the 2016 Cadillac ATS-V:




The enemy of a performance car - beyond speed cameras and over-zealous highway police - is heat, and Cadillac has left nothing to chance there. Every grille and vent has a purpose, and in fact the engineers had to get creative to accommodate every heat-exchanger they wanted to install.

So, there are eight heat-exchangers in total, along with an 850W cooling fan. Each of the “grillettes” - the lower side grilles - has an intercooler, linked with the main cooler for the engine. The auto transmission alone gets two coolers, one in the traditional place behind the grille, and another mounted flat on the underside, near the front, the only spot Caddy had left.
Reply With Quote
  #299  
Old 10-20-2015, 01:33 PM
parsonsj parsonsj is offline
Lateral-g Supporting Member
 
Join Date: Aug 2004
Location: Winter Springs, FL
Posts: 656
Thanks: 0
Thanked 1 Time in 1 Post
Default

Quote:
Originally Posted by 4wheels
Any feedback/ideas?
Yes, it would be awesome for such a standalone controller to also support an AC pressure sensor. All the fan controllers I've seen just turn on the fans to a set speed (usually 100%) with a 12V input signal when the AC is turned on.
__________________
John Parsons

II Much Fabrication's Blog New products, Fabrication sequences, etc.
Reply With Quote
  #300  
Old 10-20-2015, 01:43 PM
mikels mikels is offline
Senior Member
 
Join Date: Apr 2006
Posts: 114
Thanks: 1
Thanked 34 Times in 9 Posts
Default

Quote:
Originally Posted by parsonsj View Post
Yes, it would be awesome for such a standalone controller to also support an AC pressure sensor. All the fan controllers I've seen just turn on the fans to a set speed (usually 100%) with a 12V input signal when the AC is turned on.
This functionality is built into OEM control logic (E40, E38, E67, etc. with PWM fan control. There are cal's based on following:
  • ECT
  • Oil temp
  • Trans temp
  • IAT
  • AC pressure

Way logic works is a % output based on each of these inputs - and highest request wins. In other words, if ECT is requesting 30%, but AC pressure is requesting 42%, fans are driven @ 42%.

Stand-alone controller would need provisions for a scaled 0-5V input based on AC pressure with a cal relating that pressure to a requested output. And same logic where highest request wins.

Dave
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 07:18 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright Lateral-g.net