SPAL brushless fan

[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.