SPAL brushless fan

[Bitsyncmaster]

I got the SPAL brushless fan for testing.

Part numbers on the fan:
VA109-ABL321
P/N-109A/SH 12V
10 R-05 8155

Very nice build quality. Cables are long and fan power wires look to be 10 AWG. The fan requires using their temperature sender which has electronics inside the sender that drive a control signal to the fan which turns the fan on via a pulse width signal (looks like the driver is open collector) and the fan electronics capacitor couples that signal to its electronics. The fan blades have a ring around the outside that spins with the blades. I think that is a good design for fan blade efficiency.

The temperature sender has four wires, Ground, Switched 12 volts, force full power (12 volts drives fan to full power) and the sensor output wired to the fan signal input. I will be testing that sender output to make a table of PW values at each temperature. So there are no relays and only one control input that forces the fan to full power.

The fan ramps up which takes 16 seconds to reach full speed. I think the ramp up time should be 5 seconds or less which would give engine idle speed control plenty of time to adjust to the added load.

The standby current of the fan is 36 ua. @ 12.5 volts which is very good for standby current.

The fan draws 22 amps in free air at 13.0 volts on the fan power. With the fan sitting on the OEM radiator that full speed current is 27 amps. So I would guess if I had the AC condenser also resisting air flow the full speed current would be around 30 amps.

[Bitsyncmaster]

My thoughts about using this fan for the DeLorean. Definitely to much current (power) for the need to keep our engine at proper temperature and AC working well.

Even if the fans would run lower currents (not run at full speed) you still need to have the fans running about 7 to 10 amps when the AC is on. So you would need to build a PW controller to run the fan when the AC is on and engine cooling is not turning the fan on.

Even running one fan would still be overkill for the DeLorean and not sure if one fan efficiency would even equal a double fan setup.

Mounting the fans on a stock shroud would be pretty easy. I would cut the shroud so the fans could be mounted at the same distance as the OEM fan blades sit.

At 30 amps I'm sure these fans will move more air than OEM fans. I was going to test air flow but could not find my hot wire anemometer. I put it in a safe space and forgot where that was.

Now you may want to use these fans in another car that needs more air flow.

Maybe someday they will sell lower power units.

[FABombjoy]

Having the driver built-in solves a several problems for PWM fan control, at least with something like Megasquirt. The question has always been which "black box" to integrate into the setup that's most applicable to the fans being used. Many of the aftermarket fan controllers don't post specs, so you have to guesstimate current capacity based on the OEM integration then reverse-engineer the control modes & ranges. If it's engineered-in for this specific fan, problem solved! As long as the frequency is within range of the EFI controller, anyway. PWM frequency seems to be the only specification not listed in the "drive control modes" PDF but is probably available somewhere. Looking forward to reading your results!

https://www.spalautomotive.it/documents/20182/35726/DRIVE+CONTROL+MODES.pdf/dacb5d25-7e78-48de-bbc5-b7cfc4486ddb

[Helirich]

What do they give you for instructions? Is the wire that puts them at full speed intended for AC? Would I be right to assume the ground and switched 12V carry all the current running the fan? (The other two wires are small gauge/small current)

I'm completely out of my depth in electronics, so bear with me. I'm totally guessing that the actual temp sender is a verible resistance like most standard temp senders. But on the back of it is additional electronics to convert that signal to the PWM. Is that what you figure? If so, Do you think the sender could be separated from the electronics?

Here's my logic.

I tend to agree with you that this fan won't be suitable for the Delorean. The only way I see it working is mounting two of them as stock. I understand that you can run two fans off one sender. Since the temp controls the fan speed, that setup would probably work fine for the engine cooling. Probably the fans would never run full speed because they throw so much air. So maybe they would draw less power than a stock setup. The problem is when the AC comes on the full speed wire gets triggered and the amp draw goes through the roof. If there was a way to seperate the sender from the electronics and install a resistor in line, you could make the full power wire be a 1/2 power wire. (Or whatever speed you choose) Unless you do this, you would have to install all new wires to handle the load.

If that was possible, the question is there any benifit? If you could deturmin amp draw at a given air flow is less than a stock fan, there could be. But as it stands, it appears that the amp draw will be the same or worse. I guess what I'm saying is the manufacturer is lying.

Do you have amp draw numbers for a stock fan and the newer stock fan replacements?

[Bitsyncmaster]

A resistor would not work for many reasons. One it would have to be over 100 watts. Two, it would drop the voltage to the fan and it's electronics and the spec is 13 volts to 15 volts I think.

The fan has 3 wires. Power, ground and signal input. Yes the sensor runs on a switched power and it draws 1.6 ma. when powered.

I ran the sensor in hot water. Sensor power at 14.00 volts and a 2.7 Kohm pull up resistor to 14 volts on it's output wire. I then heated the water unit the PWM maxed out at 92% duty cycle. The frequency remains at 121 Hz. I let it cool down and recorded the duty as follows.

Above 185 deg/F = max 92%
180 deg/F = 74%
175 deg/F = 57%
170 deg/F = 42%
165 deg/F = 23%
it switched off (0%) at 161 deg/F

When I get a chance I will read the fan currents with those PWM values applied. It would be simple to use a micro to make a controller but I will just use a signal generator driving a MOSFET to test the fan.

Stock fans I have seen as high as 15 amps each but normally I see around 13 amps each. Vendors lower power fans run 6 to 9 amps each but there was a vendor in UK selling 3 amp fans.

[Helirich]

A resistor would not work for many reasons. One it would have to be over 100 watts. Two, it would drop the voltage to the fan and it's electronics and the spec is 13 volts to 15 volts I think.

Stock fans I have seen as high as 15 amps each but normally I see around 13 amps each. Vendors lower power fans run 6 to 9 amps each but there was a vendor in UK selling 3 amp fans.

I didn't explain myself good. I was not suggesting a resistor between power and the fan. I was suggesting a resistor between the actual temp sensor and the electronics that convert the signal to PWM. (If that's possible) I still believe the actual sender is nothing more than a veri-resistor. I don't know why they didn't put the PWM electronics on the fan motor rather than the sender. I assume so they could run two (or more) fans off one sender. That would be cost effective to big manufacturers like GM/Ford.

Is the sender completely potted? I suppose it will be hard to dissect without destroying it.

This is all interesting, but I still think it would be real hard to justify these fans compared to the venders offerings. The 3 amp fan sounds amazing. I wonder if it only works in a cold country. Lol.

[Bitsyncmaster]

I didn't explain myself good. I was not suggesting a resistor between power and the fan. I was suggesting a resistor between the actual temp sensor and the electronics that convert the signal to PWM. (If that's possible) I still believe the actual sender is nothing more than a veri-resistor. I don't know why they didn't put the PWM electronics on the fan motor rather than the sender. I assume so they could run two (or more) fans off one sender. That would be cost effective to big manufacturers like GM/Ford.

Is the sender completely potted? I suppose it will be hard to dissect without destroying it.

This is all interesting, but I still think it would be real hard to justify these fans compared to the venders offerings. The 3 amp fan sounds amazing. I wonder if it only works in a cold country. Lol.

The sender is potted so the electronics inside the sender convert the resistance of the sensor to a digital signal pulse width modulated. I'm assuming the electronics inside the sender has a microprocessor since the frequency of the PWM seems very stable and is based off the micro clock.

The fan then has electronics inside it to decode that sensor PWM into fan speed. It also probably has a micro to do that decoding and do the ramp up time. They probably could have done all the electronics in the fan but then long cables might cause noise of the sender resistance.

I talked with one owner of the 3 amp fans (this caused problems with my electronic fused fan fail) and he said his car stayed cool. But I would not want to test that here in Maryland.

By the way this sender has 3/8" pipe tap (tapered threads).

[Bitsyncmaster]

Well I decided to make a controller to test the fan. Pretty simple since my fuel gauge circuit board is already set up to do PWM. Well what do you know, if I set the micro clock to 125 Khz the lowest PWM frequency is 121 Hz. So for sure they are using a micro inside the temp sensor.

[Bitsyncmaster]

Designing my micro was really easy and even the software took only 20 minuets. Very basic read the POT value and drive that to my PWM output. So here are the results with the fan sitting on the OEM radiator.

90 % or above is the max fan speed at 27 amps.
88 % = 26 amps
86 % = 24 amps
74 % = 17.0 amps where the sensor is at 180 deg/F
57 % = 8.5 amps where the sensor is at 175 deg/F
42 % = 4.5 amps where the sensor is at 170 deg/F
23 % = 1.5 amps where the sensor is at 165 deg/F

[Helirich]

Interesting.

It would really be nice to know how much air it flows at say 42%. When I get the fan, I can put a air speed indicator pitot tube in front, but I don't know that's a fair comparison. It would measure speed, not volume. Also I would need a controller. What would you charge for one?

If the fan would flow more than a stock fan at 42%, then it might be a benifit. An expensive benifit, but a benifit. Still, to make it work I would need a way to make the top speed be the 42%-57%. (Whether engine or AC) At least to keep stock wiring in the car.

I guess you haven't put a reflector on a blade and measured rpms? Would the 42% be 42% of the rpms? What I mean is, the fan is supposed to spin from 1000 to 4000 rpms. So would 50% be 2500?

[Bitsyncmaster]

Interesting.

It would really be nice to know how much air it flows at say 42%. When I get the fan, I can put a air speed indicator pitot tube in front, but I don't know that's a fair comparison. It would measure speed, not volume. Also I would need a controller. What would you charge for one?

If the fan would flow more than a stock fan at 42%, then it might be a benifit. An expensive benifit, but a benifit. Still, to make it work I would need a way to make the top speed be the 42%-57%. (Whether engine or AC) At least to keep stock wiring in the car.

I guess you haven't put a reflector on a blade and measured rpms? Would the 42% be 42% of the rpms? What I mean is, the fan is supposed to spin from 1000 to 4000 rpms. So would 50% be 2500?

I have an optical tach. Little busy today but will find some time to check RPM later. I can send you my controller but it has an adjustment to set fan speed so you would need a way to measure duty cycle at the signal output. Or I could make that adjustment just do a few preset speeds with a software change.

[Bitsyncmaster]

I found my hot wire anemometer. I think I just have to measure the air flow speed and then I enter the diameter of the fans (both OEM and SPAL are close to 10 inch. and that computes CFM. It's still a crude way to compare since you will get different speeds depending on the measurement at mid point of the blades and distance from the blades.

[CFI]

Interesting.

It would really be nice to know how much air it flows at say 42%. When I get the fan, I can put a air speed indicator pitot tube in front, but I don't know that's a fair comparison. It would measure speed, not volume.

Pitot tubes are useless without a static port. An anemometer would be a better choice. But as you mentioned this still wouldn’t provide any meaningful data.

[Bitsyncmaster]

Pitot tubes are useless without a static port. An anemometer would be a better choice. But as you mentioned this still wouldn’t provide any meaningful data.

All these fan tests by us are only meaningful when we compare the same test at the same time to a standard (OEM fan). The only CFM test I would trust is a very large plastic bag, timed how long it takes to fill.

Basically the power the motor uses is the measure of how much air it moves. But as stated earlier our D does not need the power of OEM fans.

The real test is how it performs in the car.

[JBaker4981]

Out of curiosity, DPI's Fans/Fan Shroud system incorporates SPAL fans - are these the same units or comparable? Probably not, but was simply curious.

When I was trying to figure out what was going on with my Fan Circuit last year, I measured the Amperage draw of each SPAL fan and found they were a moderate ~8.7A at full power.

Driver Fan: 8.74a @ 12.90V
Passenger Fan: 8.68a @ 12.87V


Also not to digress, did you ever test the DPI Fans as you did with the Harvey, Toby, and DMCH fans in your tests a few years ago? I was reviewing that thread recently and noticed you passed on it when Josh offered up.

[Bitsyncmaster]

Out of curiosity, DPI's Fans/Fan Shroud system incorporates SPAL fans - are these the same units or comparable? Probably not, but was simply curious.

When I was trying to figure out what was going on with my Fan Circuit last year, I measured the Amperage draw of each SPAL fan and found they were a moderate ~8.7A at full power.

Driver Fan: 8.74a @ 12.90V
Passenger Fan: 8.68a @ 12.87V


Also not to digress, did you ever test the DPI Fans as you did with the Harvey, Toby, and DMCH fans in your tests a few years ago? I was reviewing that thread recently and noticed you passed on it when Josh offered up.

That testing I did was a long time ago. I think only Hervey and Toby were selling fans back then. I had bought Hervey fans about 15 years ago when I first bought my car. They worked fine but later went with Toby fans just because I liked they used the OEM shroud. Toby fans also have been work fine. These SPAL fans could not be used with stock wiring in the D. You would need to run 8 AWG or 6 AWG wire to power two of them. They don't use relays or fan fail circuits. They use a special temperature sender to turn them on and off. But you could wire them to use the otterstat and AC on but then they would only run at full speed (27 amps or more each).

[Helirich]

Out of curiosity, DPI's Fans/Fan Shroud system incorporates SPAL fans - are these the same units or comparable? Probably not, but was simply curious.

When I was trying to figure out what was going on with my Fan Circuit last year, I measured the Amperage draw of each SPAL fan and found they were a moderate ~8.7A at full power.

Driver Fan: 8.74a @ 12.90V
Passenger Fan: 8.68a @ 12.87V


Also not to digress, did you ever test the DPI Fans as you did with the Harvey, Toby, and DMCH fans in your tests a few years ago? I was reviewing that thread recently and noticed you passed on it when Josh offered up.

I didn't realize DI used Spal fans. They are not brushless, but still I consider them to make the best brushed fans also. On their site, they claim 5.4 amps each. Not sure why these numbers seem to be pulled out of a hat, but your numbers are pretty good. After I give up on the brushless fan, I will probably get a set from DI. Two fans and a shroud cost slightly more than half of what I spent on one fan and sensor. I guess I can't take it with me. Lol.

[Bitsyncmaster]

I didn't realize DI used Spal fans. They are not brushless, but still I consider them to make the best brushed fans also. On their site, they claim 5.4 amps each. Not sure why these numbers seem to be pulled out of a hat, but your numbers are pretty good. After I give up on the brushless fan, I will probably get a set from DI. Two fans and a shroud cost slightly more than half of what I spent on one fan and sensor. I guess I can't take it with me. Lol.

+1
SPAL has a pretty extensive tech ref information and seem to be only producing fan products. Their current consumption is measure with open air so mounted to a radiator and condenser is going to draw more current. I would guess the fan blade design is optimized for the full speed of the motor so running a brushless motor at lower speeds may not be more efficient than a brushed motor.

[Helirich]

Pitot tubes are useless without a static port.

This statement is true, but all air speed indicators I know of have static ports. So I'm not sure what your point is. If your saying the placement of the static is important, that's true for a moving vehicle, but for a mounted fan, just place it out of the wind.

I think we can make a fairly accurate cfm calculation pretty easy. I was worried that there would be differnt air speeds at differnt locations on the fan. (Tip vs center) But after bit of thought, all we have to do is run the fan at the end of a duct and the air speed indicator at the other end. (Wind tunnel) I think 3 feet would be enough to average all the flow out.

[DMC-Ron]

+1
SPAL has a pretty extensive tech ref information and seem to be only producing fan products. Their current consumption is measure with open air so mounted to a radiator and condenser is going to draw more current. I would guess the fan blade design is optimized for the full speed of the motor so running a brushless motor at lower speeds may not be more efficient than a brushed motor.

Open air is worst case. Once you add restrictions, the fan ends up moving less air and does less work. It's a little counterintuitive, like putting your hand over the vacuum hose. All things equal, the brushless will be more efficient than a brushed motor but the difference would diminish as speed decreases. ECM motors are becoming increasingly popular for fans and pumps because of their efficiency. I think Toby's fans are brushless.

Ron

[Bitsyncmaster]

I changed my software to give 5 settings as you adjust the pot.

1) 22.97 %
2) 42.01 %
3) 56.96 %
4) 74.04 %
5) 92.01 %

FYI:
My micro has a 10 bit resolution on setting PWM. So the PWM is divided up into 1024 steps from 0 to 100 %. Not that you need that accuracy in this application. Those values remain at very accurate values since it's all based of the micro clock.

[Bitsyncmaster]

I had to use free air testing RPM of the SPAL fan because the side on intake has a flat surface to put a reflective tape on.

Here are the five speed checks with PWM as last listed.

1317 RPM
2088 RPM
2678 RPM
3385 RPM
4013 RPM

RPM check is only to reference what the fan is doing at those selected PWM control. It means nothing in measuring fan performance comparisons.

By the way, the fan has quite a bit of thrust at high speed. I would guess thrust could be a way to measure performance.

This test was done at 13.0 volts but I don't think voltage affects this fans speed. I will test that.

Tested at 15.0 volts and as expected RPM is pretty much the same. Current drops some at higher voltage, also expected with electronic switching regulator in the fan motor.

[Helirich]

Interesting. I'll think about it while I'm driving. (Got a few hundred miles to go today.)

[Bitsyncmaster]

You could use these fans with stock wiring setup with my controller set to a value that limits the current. Just wire up the fan power and my controller power to the stock fan wires and then it would switch on with the otterstat and AC.

But for that high dollar cost it it going to provide more, less or same amount of cooling?

[Bitsyncmaster]

Now I'm thinking that thrust is a good way to compare fans. Any comments on that thought?

What I was thinking is make a fixture that you bolt the fan and the shroud to that has four arms (levers) that pivot on the bottom. Movement only has to be one inch at the top. Longer arms are best to reduce the affects of friction and weight of the fans. Then a string passing over a pulley with a weight on it is used to measure the thrust which counteracts the thrust.

[Ron]

If you are only looking to compare for performance, why not suspend them from a pivot, mounted back to back, and see which pushes which...?

[Bitsyncmaster]

If you are only looking to compare for performance, why not suspend them from a pivot, mounted back to back, and see which pushes which...?

:race: That would really make it more interesting.

I thought about suspending as an option but you have rotating forces.

[CFI]

This statement is true, but all air speed indicators I know of have static ports. So I'm not sure what your point is. If your saying the placement of the static is important, that's true for a moving vehicle, but for a mounted fan, just place it out of the wind. .

The vast majority of GA aircraft have a static port separate of the pitot tube.

[Bitsyncmaster]

I'm still thinking about this thrust test. I could just hang fan from two wires and setup a pulley weight system but not sure if the weight of the fan would affect the accuracy. I would think the lever arrangement would has less affect with fan weight.

[Bitsyncmaster]

The vast majority of GA aircraft have a static port separate of the pitot tube.

Yes that static port was always plugged from mud dobbers when I was flying. Good thing the preflight had you check it.

[Ron]

:race: That would really make it more interesting.

I thought about suspending as an option but you have rotating forces. Hmmm, if they were bound together, wouldn't the rotation mostly cancel out...might not be a straight line push but you could tell at what RPM/amp draw they were the same, and know what you were after...

Maybe bind them back to back and put them on a track, rail, (boat ;-) You could then use a force-tension gauge to get more specific data.

[Helirich]

The vast majority of GA aircraft have a static port separate of the pitot tube.

Am I missing something? First you say a pitot is worthless without a static. When I point out that my airspeed gauge has a static, you say they most statics are seperate of the pitot. So what does these statements have to do with what we're talking about?

[Helirich]

As far as comparing two fans, I think an air speed guage in front of a duct would be very accurate. The duct wouldn't have to be fancy. A roll of cardboard would due.

It would also be interesting to test the fan/duct with and without a rad in front. One fan blade design maybe better in drawing air through.

[CFI]

Am I missing something? First you say a pitot is worthless without a static. When I point out that my airspeed gauge has a static, you say they most statics are seperate of the pitot. So what does these statements have to do with what we're talking about?

You said you’d use a pitot tube. I simply pointed out that alone won’t work. My comment about GA pitot tubes having separate static ports was to differentiate from other, advanced aircraft that have static ports built into their pitot tubes.

[CFI]

Yes that static port was always plugged from mud dobbers when I was flying. Good thing the preflight had you check it.

Yes, bugs seem to love messing with those ports.

[Bitsyncmaster]

I like the idea of floating it in water but I would need a large float to keep it stable and a big pool of water. Anyway, I decided to to try making a board with ball bearings for wheels. That should have little friction if tested on a hard surface. I can calibrate the friction anyway with the fan not powered and add that amount to the thrust force. It's good all the fans are 10" because you could not compare other sizes with a 10" as far as thrust goes. The OEM radiator just fits those 10 inch fans.

I ordered some ball bearings and some measurement weight sets.

[Helirich]

You said you’d use a pitot tube. I simply pointed out that alone won’t work. My comment about GA pitot tubes having separate static ports was to differentiate from other, advanced aircraft that have static ports built into their pitot tubes.

Yes, I'm going to use a pitot tube and yes, it will work alone. I've done it many times. I don't understand why the location of static ports on aircraft has anything to do with us testing a fan mounted in a vise. I'm not going to even hook a tube on the static port of the gauge. It's just going to sit on the bench.

[Helirich]

I like the idea of floating it in water but I would need a large float to keep it stable and a big pool of water. Anyway, I decided to to try making a board with ball bearings for wheels. That should have little friction if tested on a hard surface. I can calibrate the friction anyway with the fan not powered and add that amount to the thrust force. It's good all the fans are 10" because you could not compare other sizes with a 10" as far as thrust goes. The OEM radiator just fits those 10 inch fans.

I ordered some ball bearings and some measurement weight sets.

Dave, could you take some pics of your setup? What will you use for a scale? (Fish scale)

[Bitsyncmaster]

Dave, could you take some pics of your setup? What will you use for a scale? (Fish scale)

I will when I get it setup. Still waiting on the ball bearings. I will use weights attached to a string over a pulley to measure the force.

[Helirich]

I will when I get it setup. Still waiting on the ball bearings. I will use weights attached to a string over a pulley to measure the force.

I really think a fish scale would be easy and accurate for measuring the force. They have digital ones at Walmart for $10. You can tack that on my next order.

BTW, I drove another 500 miles today. While I was driving, I reached back and felt my (stock) RPM relay. It was hot. I can't wait to get yours in there.

[Bitsyncmaster]

I really think a fish scale would be easy and accurate for measuring the force. They have digital ones at Walmart for $10. You can tack that on my next order.

BTW, I drove another 500 miles today. While I was driving, I reached back and felt my (stock) RPM relay. It was hot. I can't wait to get yours in there.

Stock RPM relay was first thing I changed. It fails because it runs so hot and the heating and cooling breaks the solder joints on the relay inside.

[Helirich]

Stock RPM relay was first thing I changed. It fails because it runs so hot and the heating and cooling breaks the solder joints on the relay inside.

I just got home and your rpm and hot start relays are here. Woohoo!

[Bitsyncmaster]

I got my ball bearings so I cut the board 14" x 24" and cut some slots for the axles. Axles are 5/15" round steel rod. I will turn the ends down to 0.250" so the bearing will slide onto the ends. I was going to try to keep this fixture light but the fan weighs 73 oz. so I just used some paper board for the bottom that I had on hand. I plan to de-grease the bearings that serve as the wheels. Then I need to make some supports for the fan to mount it.

No plans drawn up just in my head.

[Bitsyncmaster]

Well I turned the axles and was going to drill and tap the end for a screw and washer but after drilling the first one I thought, just use some tape to keep the bearing from sliding off. So I glued those axles onto the board.

Now I was thinking about supports for the fans. I think I will just buy some hardware store aluminum tubing. That cheap stuff is a very soft aluminum so I can just flatten the ends in a vise and make those quickly.

I think I will test the OEM fan first so I can adjust the SPAL fan to equal the OEM fan current and find out if the SPAL is better, worse or the same. I will cut my OEM fan shroud in half to I can mount the OEM fan the same as the SPAL which has it's own shroud (covers the ends of the blades). I won't be testing with the radiator with this testing.

[Bitsyncmaster]

I cut the OEM fan shroud in half and got it mounted on my test board. Now I need to design a pulley holder for holding the measurement weights. I will plan to also measure the air speed with my hot wire anemometer but I still think the thrust will be more consistent for comparing fan performance.

[Bitsyncmaster]

Here is the working set for testing thrust. There is zero friction to move the setup. Actually it shows me the counter top is not perfectly level since it moves to one side with no weights attached.

The fan is very noisy so I have to wait till the wife is not watching TV in the next room to start testing. I need to read up on using my hot wire anemometer anyway.

[iflights]

Here is the working set for testing thrust. There is zero friction to move the setup. Actually it shows me the counter top is not perfectly level since it moves to one side with no weights attached.

The fan is very noisy so I have to wait till the wife is not watching TV in the next room to start testing. I need to read up on using my hot wire anemometer anyway.

It's a very understanding wife that lets her husband turn the kitchen counter into a test bed.

[Bitsyncmaster]

OEM test complete.

720 grams of thrust. That is the calibrated weights and 20 grams for the bag and clip. Test done at 13.0 volts (12.5 amps) bought voltage up slowly and kept adjusting weights till 13.0 would move that weight. No friction so nothing to modify that test.

Did the air speed test holding the sensor mid point of fan blades and 4.0 inches distance to the rear of the blades. As you can see in the photo:

2425 ft/min speed
1322 CFM

But that is expecting you tested in a round 10.0" duct for computing CFM.

[Helirich]

Very cool!. That's more cfm then I would have guessed for one fan. Can't believe your wife went for that.you were definitely the right man for this job.

[Bitsyncmaster]

SPAL test: At 13.0 volts

Using same 720 gram weight I adjusted the speed via my controller until it pulled that weight and current draw was around 13.2 amps. Note the current seems to run higher at first and drops a little the longer you run it.

2807 Ft/min
1530 CFM

Max speed about 21.8 amps.

1040 gram thrust
1970 Ft/min
1619 CFM

Just some quick thoughts.
1) A switching regulator typically runs at 85 to 95 % efficiency so some power is lost in the electronics.
2) The gain in Thrust running full speed was less than the power added. So it looks like the fan blades are not optimized for full power.

Now you see why I don't trust CFM numbers since that full power only showed a little gain.

[Helirich]

Very interesting. It would appear that there is no benifit to the brushless at the lower power settings. One thing I noted from there website was all the motors look the same no matter which fan diameter you get. So it could be that you are right about it not being optimized.

It certainly doesn't look like candidate for my car. Please send me a bill for the additional expenses you incurred performing this test. Now for the big question I have no right to ask. If I order a set of Spal fans (brushed) from Delorean industrys, could you test it on your rig?

If you think of anymore tests to preform, by all means. I'm in no rush to get this fan. If you decide to test the DI fans, you could ship them together.

Thanks again and to state the obvious, we are so lucky to have you in our community.

[Bitsyncmaster]

Very interesting. It would appear that there is no benifit to the brushless at the lower power settings. One thing I noted from there website was all the motors look the same no matter which fan diameter you get. So it could be that you are right about it not being optimized.

It certainly doesn't look like candidate for my car. Please send me a bill for the additional expenses you incurred performing this test. Now for the big question I have no right to ask. If I order a set of Spal fans (brushed) from Delorean industrys, could you test it on your rig?

If you think of anymore tests to preform, by all means. I'm in no rush to get this fan. If you decide to test the DI fans, you could ship them together.

Thanks again and to state the obvious, we are so lucky to have you in our community.

Yes it would be interesting to test the lower power fans. I expect thrust to be lower but we have found lower power is fine for a normal D.

I wish I could easily pull my Toby fan to test but I don't feel like pulling the shroud.

The box may get to big to ship back all the fans at one time. I will ship your fan back soon. If you like I can send my controller which I modified so you still get the 5 presets but move a jumper and the pot is now adjustable from 0 to 100% PWM.

[Helirich]

Yes it would be interesting to test the lower power fans. I expect thrust to be lower but we have found lower power is fine for a normal D.

I wish I could easily pull my Toby fan to test but I don't feel like pulling the shroud.

The box may get to big to ship back all the fans at one time. I will ship your fan back soon. If you like I can send my controller which I modified so you still get the 5 presets but move a jumper and the pot is now adjustable from 0 to 100% PWM.

Let me know how much the controller costs via PM. I'm not sure what the future of this fan will be. (It maybe an expensive paperweight)

I will talk to Josh at DI tomorrow. If he has it in stock, it will be coming. Thanks.

Ps, I sent you a E-mail about some of your other products.

[Bitsyncmaster]

Testing the DPI fan. I thought of a better way to measure thrust. Record what the fan can hold and record what the fan can pull. Take the difference to use for thrust. That takes out any friction or level error. It's my goal to have other people measure thrust and get the same result with very little error. This should also correct for weight difference of the fans.

1) Can't hold 490 grams.
2) Can hold 480 grams.
3) Can't pull 430 grams.
4) Can pull 420 grams.

So it looks like I do have some friction.

So my result is 450 grams of pull for the DPI fan with free air at 13.0 volts which draws 8.5 amps. Now your current draw goes up when blocked by the radiator and condenser. I would guess the thrust drops with those restrictions but I have not tested that.

I use a paper bubble mailer with a clip to hold the weights which I accounted for that 20 grams in my readings.

These DPI fans are very light and DPI shroud is a thing of beauty with welded seams. Also very thin fans and motors.

[Rhye]

Now your current draw goes up when blocked by the radiator and condenser.

The current will actually go down (and the RPM will increase) when restricted 'cause there's less air to be moved = less work to be done.

[Bitsyncmaster]

The current will actually go down (and the RPM will increase) when restricted 'cause there's less air to be moved = less work to be done.

That is not what I find testing.

[Helirich]

Am I reading this right? The DPI fan has less thrust then an OEM? I realize they draw less power, but I wanted less power and the same or better proformance. I'm going to test them against a radiator. Possibly the newer fan designs have more ability to pull air through. If not, I spent a lot of money to keep what I have.

About your friction, didn't you say the counter is not level? Is it pulling up hill?

Anyways thanks for all your work.

[Rhye]

That is not what I find testing.

Yes, my mistake - I simplified it too much. It seems it greatly depends on the character of the inlet restriction (just checked it using a much smaller setup).

[Bitsyncmaster]

Am I reading this right? The DPI fan has less thrust then an OEM? I realize they draw less power, but I wanted less power and the same or better proformance. I'm going to test them against a radiator. Possibly the newer fan designs have more ability to pull air through. If not, I spent a lot of money to keep what I have.

About your friction, didn't you say the counter is not level? Is it pulling up hill?

Anyways thanks for all your work.

I think the Thrust and CFM (power of a fan) will pretty much follow the power consumed by the motor. Now that is assuming the fan blades are designed for the RPM that the fan runs at. Now weather more blades or different shape may have a little affect in the efficiency I don't expect any gains would be large. The OEM fans are way overpowered for our car.

My counter top did tend to move my test setup one way not powered but the level error is very small. Anyway my new testing method would account for that.

[Bitsyncmaster]

I set up a duct to do a better CFM test. The duct is 4 foot long and has an ID of 12.4 inches. I put the probe at 3 foot from the fan so it had 1 foot of duct after the probe. The probe was inserted about 4" into the duct. This should be close to what manufactures use to measure CFM.

As always I’m testing with 13.0 volts on the fan. That is my guess around what you will get at the fans because of voltage drop of the harness. Although lower power fans should get a little higher voltage since less current to drop the voltage over the harness.

OEM fan:
1998 ft/min = 1670 CFM

Your DPI fan:
1547 ft/min = 1275 CFM

The spec sheet for the SPAL fans used in the DPI fans states 802 CFM with a static pressure of 0" of water. As you can see my CFM numbers are not even close to the SPAL spec. It only has some value when the same test is done at the same time with the same test setup.

I will do the push pull test again on the OEM just to have a better reference since I did not do that test on my first testing.

[Helirich]

I see that the CFM test on the OEM fan went from 1320 to 1670. (Two differnt testing methods) I do believe the second method is better. Could you test the DPI fan the old way to see if the improvement is the same? If the numbers correspond than I could compute a CFM on the brushless fan.

Sorry Dave, I just saw the PM. Don't worry about the test. Thanks.

[FLUX @88]

Digging up an old thread here but when I had my oem fans the temp gauge would drop quick and you could really hear the fans moving air. Since installing different fans that draw less power the fans do take more time to lower the temp. Is this normal?

[Timeless]

Digging up an old thread here but when I had my oem fans the temp gauge would drop quick and you could really hear the fans moving air. Since installing different fans that draw less power the fans do take more time to lower the temp. Is this normal?
Same experience with OE fans & radiator. I now see a bit more time pass for coolant temp to drop down with new DMC radiator & DPI fans. FWIW this is now during hot S. FL summer - no experience in lower temps until we cool off here at the end of the year.

[FLUX @88]

Same experience with OE fans & radiator. I now see a bit more time pass for coolant temp to drop down with new DMC radiator & DPI fans. FWIW this is now during hot S. FL summer - no experience in lower temps until we cool off here at the end of the year.

Totally understand. I drive mine mostly in the cooler months after summer and temp gauge usually stays at first tick or a hair above and in the summer it?s always under 220 or in the middle of first tick and 220

[mhanch]

I have DPNW fans with the original shroud, and they seem to work the same as the originals with a much lower draw. Really happy with them

[FLUX @88]

I have DPNW fans with the original shroud, and they seem to work the same as the originals with a much lower draw. Really happy with them

I have the same fans.

[mhanch]

Yeah, i just replaced my old ones - talked to Toby a bit since he's local to me. one of the things that we discussed was that the original shroud is good to keep since it allows better air flow than some of the replacements, a fully flat shroud can leave dead spots with poor airflow.