fan reversal

[Gundam]

This post is intended to give more insight into my system for reversing the fan....

First, some facts that I have found out... the cooling fan does not turn on when you are riding at medium to high speed, it is quite obvious, the air flowing past the radiator is enough to cool it down... I have confirmed it by looking at the fan several times at such speed, thankfully without getting my head knock off by opposing vehicles!.... I have also experienced the hot right foot issue when I got stuck in a traffic jam, completely no forward movement for about 15 to 20 minutes!...I then observed or feel rather, that the air coming out the right side is hotter than normal, this I attribute it to the hot exhaust from vehicles in front being drawn into my radiator when the cooling fan turns on, adding to the heat from the radiator, and since the Spyder is stationary, the heat just builds up around the right side....things get slightly better (less hot) when the jam starts moving, though at a slow pace but it is still hot nonetheless... after that to the drawing board...and I designed my system with the following 3 modes of operation controlled by the rocker switch mounted on the top panel:

1) Normal operation, fan rotates normally, pulls air to the rear, on and off controlled by coolant temperature. Used for normal highway cruising.

2) Reverse operation, fan rotates reverse direction, pushes air to the front, on and off controlled by coolant temperature. Used when stuck in a jam or at very slow speed. Even if you forget to switch back to normal mode, the fan will not turn on when the traffic clears and higher speed is attained (see above).

3) Override operation, fan rotates normally, pulls air to the rear, fan remains on regardless of coolant temperature. This mode is used when traffic is heavy and moving not fast enough for sufficient air to enter the radiator. Useful for lowering the coolant temperature during stop lights, idling etc...

With the modes as explained above, I don't think I need to consider using the wheel speed sensor to trigger the fan on or off.... it only adds to the complexity and more electronic items to fail...

I will post a schematic wiring diagram when it is ready and also some photos of the installation...

Also, my experience with this set up so far.... I have done some stationary idling test with the reverse fan operation and normal fan operation and I have noted that the fan takes longer time to switch off when it is in reverse mode, meaning the coolant temperature takes a longer time to reduce to the point whereby it triggers the fan off ... this is probably due to the less efficient way of pushing air through the radiator than pulling it.... maybe that's why BRP using two radiators in the 2014s....

Well, so much for now.... will report back when more kilometres (miles) is piled on...

[jcthorne]

I personally HAVE had my fan run while the bike was moving. So a fixed reverse position is not an option in my hot climate and neither is a manual switch that I will eventually forget and overheat the bike. No thank you.

Needs to be an OEM simple, no user input required solution.

[finless]

Actually, a really elegant solution would be to tap into one of the wheel speed sensors.
The speed sensor counts pulses coming from the wheel.
The faster you go, the more pulses.

So no one's eyes start to glaze over all I will say is it is extremely easy to read the pulses and then convert the pulses into an average volt value.
The more pulses in a given time period - the higher the average voltage.

So let's say we find the average voltage from the pulses is 7 Volts at 15 mph.
We could then build a circuit that switched the fan into reverse mode at average voltages lower than 7 Volts.

Didnt I siggest that in the other post last year?

Someone with good programming skills and a PAL dev board could whip this out easily.

I know someone actually that is good at this. But unless we knew how many would buy a product to do this, I don't think I could interest him in the project.

FYI I think we could make a prototype in one day easily. This is not rocket science IMHO.

Bob

[Magdave]

Didnt I siggest that in the other post last year?

Someone with good programming skills and a PAL dev board could whip this out easily.

I know someone actually that is good at this. But unless we knew how many would buy a product to do this, I don't think I could interest him in the project.

FYI I think we could make a prototype in one day easily. This is not rocket science IMHO.

Bob

The biggest hazard is tapping into the can bus for a triggering signal that is problematic they can be very sensative. But the ability to reverse it in stopped traffic, even manually, might be a good thing.

[Jeriatric]

Is it time to conduct an interest poll?

Just a thought

[finless]

The biggest hazard is tapping into the can bus for a triggering signal that is problematic they can be very sensative. But the ability to reverse it in stopped traffic, even manually, might be a good thing.

You tap into the sensor at the connector. That is a standard magnetic pulse sensor and not Can-Buss. I looked at it already.

Bob

[finless]

Is it time to conduct an interest poll?

Just a thought

I am chatting with my buddy now to see if he is interested. Heck I might even want this on my 2011 for just sitting in traffic. I have some add on ideas for the thing too.
1) A switch to disable it all together
2) LEDs to show when the fan is on and one to show when it is working in reverse.

Yes a poll might help....

Bob

[Magdave]

One last comment and I mentioned it before. That tunnel has the temp sensor in it. From previous reading I understand that sensor provides feedback to the ECM for fuel mapping it isn't just so you can see how hot it is outside. Reversing the fan should cause it to heat up and hotter air leans the fuel IIRC. Not sure what effect it will have on the engine. Time for some gurus to comment on this issue

[Bob Denman]

I will post a schematic wiring diagram when it is ready and also some photos of the installation...
Well, so much for now.... will report back when more kilometres (miles) is piled on...

Thanks!

This could be VERY interesting!

[jerpinoy]

What about a relay with the brake light? When your brake pedal is depress the relay will activate your fan in reverse only.

[Bob Denman]

That idea needs a bit of refinement... you can touch your brakes at highway speeds too.

[Gundam]

I personally HAVE had my fan run while the bike was moving. So a fixed reverse position is not an option in my hot climate and neither is a manual switch that I will eventually forget and overheat the bike. No thank you.

Needs to be an OEM simple, no user input required solution.

If your fan is running while you are moving, then you are not moving fast enough for sufficient air flow into the radiator, that's why the fan has to cut in... the "fixed" reverse position is controlled by the Spyder original coolant temperature sensor, so once you are moving fast enough for the air to cool the radiator, it will cut off the fan..... like I have already mentioned, there is no "off" position for the fan, forgetting to switch to different modes will not overheat the bike.... even if all my additional relays and switches should fail at the same time, the system will revert back to the original unmodified circuitry automatically... I wil be posting the schematic wiring diagram shortly...

[Magdave]

If your fan is running while you are moving, then you are not moving fast enough for sufficient air flow into the radiator, that's why the fan has to cut in... the "fixed" reverse position is controlled by the Spyder original coolant temperature sensor, so once you are moving fast enough for the air to cool the radiator, it will cut off the fan..... like I have already mentioned, there is no "off" position for the fan, forgetting to switch to different modes will not overheat the bike.... even if all my additional relays and switches should fail at the same time, the system will revert back to the original unmodified circuitry automatically... I wil be posting the schematic wiring diagram shortly...

If the fan runs in reverse all the time it will only be a matter of time until the motor gets burned up. 2 opposing forces will cause it to freeze at a certain speed and I am sure it is not very fast. How can it cool if the reverse airflow meets the incoming airflow it will be static.

[Gundam]

DSC_0048.jpg
The above is how I wired up my Spyder for the three modes of operation namely; coolant temperature controlled reverse fan direction, coolant temperature controlled normal fan direction (un modified) and override normal fan direction....the relay used for changing the polarity of the fan motor is break before make type.... this circuitry is easily installed as I have done, I will post some pictures of the actual wiring done when I have a chance to open up the Spyder again...

[Gundam]

If the fan runs in reverse all the time it will only be a matter of time until the motor gets burned up. 2 opposing forces will cause it to freeze at a certain speed and I am sure it is not very fast. How can it cool if the reverse airflow meets the incoming airflow it will be static.

The fan will not run in the reverse direction all the time, when you speed up to a certain point, the air flow into the radiator will overcome that of the fan and the radiator will cool down causing the fan to turn off...

[Bob Denman]

To my simple and well-untrained eye ; it looks like a real game-changer!!

[Magdave]

The fan will not run in the reverse direction all the time, when you speed up to a certain point, the air flow into the radiator will overcome that of the fan and the radiator will cool down causing the fan to turn off...

The period of time between air flow in cools and shuts the fan down WILL end up damaging the fan motor over time. It will over heat.

[Gundam]

The period of time between air flow in cools and shuts the fan down WILL end up damaging the fan motor over time. It will over heat.

I have already installed and run this system on my RT for several days now...and I am always watching the temperature gauge during this trail period, the gauge remains stable with no signs of increasing.... if you are worried that you might burn out the fan, then switch back to normal mode....

[Magdave]

I have already installed and run this system on my RT for several days now...and I am always watching the temperature gauge during this trail period, the gauge remains stable with no signs of increasing.... if you are worried that you might burn out the fan, then switch back to normal mode....

You are not getting it Sure it may work for a while. take a CPU or Power supply fan and jam it and apply power and wait for it to smoke. A fan is not made to be jammed over and over again and that is what keeping it running in reverse will do or it will pop a fuse your are exceeding the design parameters of the fan. I am not saying you have not done good work but leaving it in the reverse mode is not a good thing.

[Bob Denman]

The fact that a system is up, running, and being tested, is a VERY good thing...
Time will tell the story... Good Luck, and please keep us posted!

[jcthorne]

If your fan is running while you are moving, then you are not moving fast enough for sufficient air flow into the radiator, that's why the fan has to cut in... the "fixed" reverse position is controlled by the Spyder original coolant temperature sensor, so once you are moving fast enough for the air to cool the radiator, it will cut off the fan..... like I have already mentioned, there is no "off" position for the fan, forgetting to switch to different modes will not overheat the bike.... even if all my additional relays and switches should fail at the same time, the system will revert back to the original unmodified circuitry automatically... I wil be posting the schematic wiring diagram shortly...

If the fan is running in reverse and you drive away, there will be zero or very near air flow across the radiator as the fan and bike movement work against each other. Will overheat. The system needs to revert to normal direction flow at speeds above a few MPH.

The idea of a relay off the brake light circuit is actually a good one if it were paired with a time delay relay set to about 2 sec. IE if your foot is on the brake for more than 2 seconds, the fan reverse relay switches. Time delay relays are pretty common items. I think I will start looking into this.

Not really worried about the temp sensor. It may not have much effect while stopped and the engine is unloaded. If it does, it can be moved without too much difficulty.

[Magdave]

Personally, if not automatic, I think the best solution is a simple on off BRP switch (for those of us with room) for the DPDT. Turn it on at stop and tap it off when moving. No muss no fuss and no chance of fan damage. We all know this will have little if any effect on the engine bay heat but is a good comfort item.

[Bob Denman]

Working a time-delay, into a circuit fed by the brake light holds a lot of promise...

[Magdave]

Not really worried about the temp sensor. It may not have much effect while stopped and the engine is unloaded. If it does, it can be moved without too much difficulty.

I am still waiting on the real answer to that if it leans the engine and you are stopped long enough it WILL get hot maybe very hot possibly negating the usefulness. There is a reason it is tucked into the wall of the nacelle with a filter on it.

[Bob Denman]

Stopped in traffic; no load on an idling engine...
It won't damage anything....