Wicked build
 

Lots of nice tech in this build!

If I may plant a seed here, our fan controllers work with pretty much any ecm combination, and also integrate with VA systems...while it does require mounting a controller, it's only the size of your palm:

http://www.entropyrad.com/images/cac..._small.220.jpg

Justin,

How is your system adjusted?

Andrew

They're back. I have more connector parts for the Corvette PWM module. $55 shipped.
http://i242.photobucket.com/albums/f...820_153531.jpg

Scot,

I sent you a PM...

Thanks Dirk

Scot,

sent a PM also....

Thx
Tony

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

Andrew,

Question: when driving down the road normally, won't the fan spin due to airflow through the radiator? I'm curious how much more the motors spin the fans at 5% vs. what air passing through it would be?

That would take some math to figure out I assume, but I am curious.

Running down the road - the fan shouldn't be needed at all.

To clarify, with the C6 fan controller, commanding 5% duty cycle means the fans are totally off. See my video for demonstration.

Andrew

Precisely. See my comment above.

Andrew

Justin, do you have a link to the kit you listed?

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....

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.

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.

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

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).

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.

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

Except for GMPP controllers. GM deliberately disabled the PWM fan control logic (along with AC pressure sensor input and reverse lockout, and who knows what else) to reduce warranty issues.

Not true - it's in there. Main change was to make controller incompatable to use (with GMPP software) in a production vehicle - so you can't defeat theft systems.

Dave

I wish you were right!! :)

I spent a month with a GMPP LS9 (E67) controller trying to get the fans to work. HPTuners happily let me make the changes to the fan tables, but the PWM control wire didn't have a signal. I finally opened a support case with GMPP, and tech support told me that fan control (and AC pressure, and reverse logic, etc.) was deliberately disabled in the GMPP E67s.

I switched to a salvage yard E67 from a V6 Malibu and got that working immediately (wrote ZR1 OS, then copied the GMPP tune plus the fans).

I even documented my journey in this very thread a few pages back.

I have the GMPP LS2 controller kit and turned on the PWM fan and reverse lockout functionality using HP TUNER. Assuming the AC pressure for fan works too. Haven't teases that yet

May be an issue of HPT not having correct address of fan type selection, but I can assure you - the software is in there.

BTW - GMPP tech support may be technically correct in that it is 'disabled' - but only by bit selection (not removal of code).

Dave

I hear ya on the "bit selection". Quite likely in the OS, rather than the hardware/firmware. And not only is the fan disabled, but the AC pressure sensor input is disabled too. I verified both with side by side testing. I was told the reverse lockout was also disabled, but didn't verify with testing.

I was also told that over-writing the GMPP E67 with a later model passenger OS would likely "brick" it. That's why I used a salvage yard 2012 MY controller.

I am pretty sure this can be implemented in the Holley Dominator. Every output can be configured to have multiple trigger events. The Dominator also has quite a bit of programmable inputs.

However, doing all that seems like overkill on my old jalopy...LOL

Andrew

Dave,

First of all, thank you for all the information that you have provided. It has been invaluable!

John and I discussed this in detail and we suspect that at some point GMPP altered the E67 ECUs that come with their kits.

Lous69 was able to make it work on his Camaro and so have others I believe. I bought my GMPP kit back in 2008, but I have yet to implement this on my GTO.

As stated earlier, I think at some point GMPP made changes to the ECU, most likely at the OS level. It doesn't seem likely that GM would alter the ECU at the hardware level as that would greatly increase cost. But making simple revisions to the OS probably only required some programming time, which only adds a little bit of cost.

This is all conjecture of course as we don't have the knowledge or the needed software tools to know for sure.

Andrew

GMPP ECM and OS
 

It isn't at the hardware level because that same part number (before it becomes a GMPP ECU) is used in some model year production vehicle applications.

You can also put the GMPP calibration into the production vehicle service part if you get the correct part number ECU. And you can put production software in the GMPP ECU if you make sure it is a compatible OS (careful because if it isn't compatible you can "brick it").

As far as I know only two OS's exist for the GMPP E67 ECU's:
12638778
19211212

Neither of these OS's are used in production vehicle applications.

Anyone know of any other OS's used in the GMPP E67s?

As was already pointed out differences exist in the GMPP calibration compared to the production vehicle calibrations for anti-theft related reasons so that the GMPP ECM can't be used as a way to bypass GM's production anti-theft ECU calibration logic. Plugging a GMPP ECU into a production vehicle can't be used as a way to bypass the anti-theft requirements of the production applications (to meet Federal vehicle anti-theft requirements).

Do those vehicles use PWM fans? My GMPP E67 pn sources back to an 07 Hummer. Anybody know if 07 Hummers have PWM fan control?

2007 H2 and H3 have a fan clutch, so no electric fan.

Hummer ECM
 

The H3 might be an E67 ECM but the 2007 H2 is an E38 and had a conventional mechanical fan (with a thermostatic clutch).

The H3 might have a PWM controlled clutch fan like the Trailblazer etc but it doesn't have a PWM speed controlled electric fan.

stand alone controller testing
 

Full speed over-ride input for AC, manual fan switch etc but not enough inputs on this controller to accept an AC pressure signal and a temperature sensor. Maybe the next version. 8-)

E40, E38 and E67 have ability to control PWM fan or dual discrete or ECM controlled engine driven fan output. All use AC pressure, oil temp, IAT, trans temp as well as coolant to control fan output. Can not mix and match fan driver type - must pick one.

Difference between discrete and PWM is you only have on or off with discrete - which is set to 50% and 100% output from fan cal. PWM drives the motor at whatever the percentage is based on the inputs.

If using the discrete outputs with dual electric, I prefer to set them as parallel / series control rather than have each fan driven by output. That way on 50%, you are driving both fans @ 50% rather than one @ 100%.

I hate listening to noisy fan(s) masking sound of engine - exception being when in track usage - where you NEED the fan output.

Dave

BTW - reason E40 & E67 were used in TBSS and H3 is vehicle communication was still Class 2 while Powertrain was CAN - E40 & E67 can handle both (E38 is CAN only).

dual electric parallel/series
 

I too prefer to use the three relay parallel/series control on two fans (where both fans are run together low speed or high speed but never individually) but you need to be careful what fans you use for this. Some fan motors don't work well at half voltage (get close to or drop below motor stall speed/torque). Also some fans won't be fuse protected in that configuration (you can stop the blade and fail the motor without blowing the fuse). If you are going to run the series/parallel configuration the easiest is to just use fans that are run that way from the factory (plenty of GM examples to choose from between Camaros, Corvettes, CK trucks etc.).

BTW - if you are running one fan you can also have two speeds with most GM PCM,s/ECMs using a two speed fan relay. Volvo has one that takes two inputs and switches a single fan from low to high speed.

Volvo Cooling Fan 2 Speed Relay, Volvo OE part numbers (used in lots of Volvos so cheap at the junk yard):

• 9442933
• 1398845
• 3523872

Kaehler also manufactures a part that is similiar to the Volvo Cooling Fan Relay. The part number is:

• KAE 3702300

I'm always battling heat in my '07 Z06 (E38), especially when I run at Sebring. Oil temps often go north of 280*. I'm assuming that my fans aren't running above 35 mph. True? Can that be changed with HPTuners? I gotta admit I've never looked at that...

There is no speed dependency for fan control. Strictly based on temps vs. fan output %. ECT, EOT, TOT, IAT each have their own table - and highest request wins. What this means is say each input below with respective fan %:
ECT = 60%
EOT = 40%
TOT = 35%
IAT = 0%

Result will be fans driven at 60%.

You can access fan tables with HPT or EFILive.

Don't make mistake in assuming max fan % is only ~90% - so you should raise to 100%. PWM fan controllers have max output at some level <100% (depending on controller). Raising will NOT increase fan output, but can damage fan controller.

BTW- 280 is well within temp limits of synthetic oil, so will present no problems.

Dave

If you decide to run the Corvette fan module & control the fan from the ECM, I have the module connectors. $55 shipped.


http://i242.photobucket.com/albums/f...820_153531.jpg

Speed based fan enable
 

Dave,

Might not be speed based fan control in the E38 or E67 (I haven't looked at all the code or all the OS's that exist for all of those ECM's to be able to make an across the board statement like that, one way or the other) but plenty of other earlier GM systems did have speed based control criteria. The controllers used with the Gen III GM V8 engines ("Warren PCMs") all had speed based fan control criteria available in the code and most of the vehicles had it enabled.

PSS

PWM too high
 

Yes, most of the PWM fans reserve the low end of the scale and the high end of the scale for error criteria or other operating modes so most of the fan motor controllers built into the fans are expecting somewhere in the 10% to 20% as initial on speed and somewhere between 80%-90% duty cycle for maximum fan speed control. Above what ever the maximum expected duty cycle won't result in higher speed.

Not saying people should raise the PWM duty cycle over what ever setting than fan is expecting to see but how would this damage the controller? It wouldn't cause it to operate at higher current. The PWM duty cycle doesn't directly control fan speed - it is a fan speed request signal to the internal BLDC motor controller inside the fan. Also the PWM signal is just a communications level signal - it isn't driving any current into the system itself.

Just wondering.