protecting the ECU?

[lognomore]

cooling for the VR

Just got my 07 dragon back together last week and rode on Sunday, ran great!! After replacing the VR, ECU, and stator. I did install a fan in the cover over the VR. The fan is a Panaflo high speed 92mm 12 volt. A resister of 5 ohms, 2 watts was installed in line so that the voltage to the fan would stay at 12 volts versus the 14 volts coming the power plug up front. Use the power plug that has the red/white and brown wires going to it. If you install a fan be sure to use at least 1/4 inch spacers between the fan and cover so that the fan will not hit the cover and cut out the louvers further forward so that the fan will be directly over the VR. Hopefully the fan will take the punishment, we'll see. If you can come up with a plug that will plug into the power plug it will make it that much easier to hook up, I couldn't find one.

 

[R44guy]

VR & ECU Failures w/PCV?

Has any one heard of any PCV failures after losing the VR & ECU? I just wanted to see if any one who has a PCV installed and burned down due to the VR & ECU had any issues with the PCV? I dont think it can happen but I was just looking for confirmation to see if the PCV was ok after the VR & ECU were replaced. Thanks for any help and sorry to jack the thread a bit.

 

[growl62]

Air drawn out, or blown in?

Just got my 07 dragon back together last week and rode on Sunday, ran great!! After replacing the VR, ECU, and stator. I did install a fan in the cover over the VR. The fan is a Panaflo high speed 92mm 12 volt. A resister of 5 ohms, 2 watts was installed in line so that the voltage to the fan would stay at 12 volts versus the 14 volts coming the power plug up front. Use the power plug that has the red/white and brown wires going to it. If you install a fan be sure to use at least 1/4 inch spacers between the fan and cover so that the fan will not hit the cover and cut out the louvers further forward so that the fan will be directly over the VR. Hopefully the fan will take the punishment, we'll see. If you can come up with a plug that will plug into the power plug it will make it that much easier to hook up, I couldn't find one.

lognomore,

Which way do you have the fan air flow going? Is it blowing cold air inward onto the VR, or blowing outward taking the heat out of the electronics area?

I'm considering adding a fan also and was thinking drawing the air outward would be best. This would keep snow from being blown directly onto the electronics panel. Since air can be drawn in around the edges of plastic cover, cold air would still be able to flow past the electronic components, to the fan and then out through the louvers.

Thanks either way for your R&D to this point.

 

[git r done]

Great question-why can a short or voltage spike ruin the ECU? Is this something that the mfct'r should build into the system? You don't see this with auto's why on sleds?

Buy a Cat

 

[LeftField]

VR Thermal testing => HOT!

Got a little more shop time in on the regulator issue. Ruffy - didn't get scope pix of the stator output, but agree it has to be your typical 3ph sine wave. The guys thinking 'too high of VR temperature seem to have hit the nail on the head. It's likely that Polaris is running 'Industrial' rated electronic components which are generally rated -40C (-40F) to +85C (185F). In a typical application the goal would be to run much cooler than this, maybe 50C (122F), to ensure a reasonable life expectancy. A common rule of thumb for electronic design is that every 10C temperature increase cuts the life in half.

I ran a couple of VR temperature test conditions - first a 'stock' configuration, then with a 50mm fan mounted directly on the VR. The tests were done with a thermocouple mounted to the underside of the VR.

In each condition the sled was run (in the driveway, the neighbors love me) for 16 minutes and VR temperature recorded every 30 seconds. No electric start/battery. The idea was to get enough of a curve that a steady state operating temperature could be estimated. The underhood temperatures probably get significantly higher when out doing a few climbs or in some pow, so the real-world VR temperatures may be even higher than I observed.

In the 'stock' test the VR reached 184 degrees at 16 minutes and was still climbing almost 5 degrees a minute. I estimated that it is headed well into the 200's. This was at sea level; at altitude the cooling would be even less. To cut to the chase, this is death to electronics. Polaris needs a giant wedgie in my humble opinion.

In the second test (run the next day), a 50mm fan was mounted directly on the VR (raising the cap ~3/4"). After 16 minutes the VR reached 139F adjusted for the outside temperature). Extending the curve gave an estimated steady state temperature in the 160-170 range. This is a big improvement but is still life limiting for electronics.

Yesterday I ordered a 70MM dual ball bearing high performance fan and will repeat the test. This fan should have approximately 4x the air flow of the 50mm fan I was using. After seeing these temperatures I'm not going riding in the backcountry without a fan on the VR.

Ruffy - I like the idea of some beverage facilitated investigation (-:

Lognomore - nice pix & info - looks like we are headed in a similar direction. I'm planning to move the cap outside the electronics cover (just above / in front of the pto cylinder to allow direct airflow on the VR. Another source of 14V is in the harness near the steering post - there is a 2 wire 'accessory' connector taped up under there. It is a similar style to the 4 pin trailer connectors. I'm using a resistor to drop the voltage also.

Picture of the 50mm fan installation and temperature curves attached.

 

[akrevrider]

Protecting the ECU!

LeftField,

Appreciate the regulator over-heating research & posting your findings.. Those temps are a lot higher than I would expect from a sled's regulator.
The ECU needs more protection that what I initially thought.. Where did you order the 70mm fan from?

What are your thoughts on removing the regulator/ECU cover and moving the capacitor to allow free air flow around the regulator?

Most of us have vents installed to facilitate air flow under the hood and the regulator should run much cooler with this configuration.

The components under the covershould be able to withstand a little exposure to the elements since the cover allows moisture in as it is now.

Your research & recommendations are appreciated.. helping to extend our riding time is appreciated too

akrevrider

 

[sam776]

Follow Up

Mine is a 08 D8, with extra venting in the cowl, and shock tower's. It is rope start. The sled had been being ridden by my buddy who is a rookie, we were in some tight trails, and had been riding in some 12-18" deep powder fields just before we headed into the tight trails, he wasn't running it very hard, so there probably wasn't much air flow under the hood, so I suspect the temps were probably pretty hot.

Thanks to all that are working on this problem, please keep us posted

 

[LeftField]

AK,

I ordered the 70mm fan from xsfans.com. I've built an improved mount for it that lifts it about 3/8" off the VR to allow the air to hit a wider area of the fins. The cover still fits over it but the cap is mounted outside.

I don't see any issue with removing the regulator / ECU cover regarding the environment. All the components are already exposed to water, steam, etc and appear to be designed for it. The biggest advantage of the cover (other than as a belt holder) might be physical protection of the harness and connectors. A few wire ties would probably do the job.

Based on the test with the 50mm fan and my experience with forced vs passive cooling, I don't think that removing the cover and adding under-hood venting will get the VR temperatures low enough to ensure reliability. But it absolutely would be an improvement.

I amused myself by envisioning cutting a small hole in the hood and mounting the VR underneath with fins sticking out - a 'free air' VR

My VR is the 'old' version P/N 4011731

If anyone in the Western WA / Eastside area has a new VR (P/N 4012476) I'd love to see if it runs any cooler.

 

[deepdiver]

Did the VR fail on this particular sled also? I'd sure like to see that thing. What dealer?

yes..it was at Smokey Point Cycle Barn last week...not sure if they have sent it back or not.

 

[deepdiver]

AK,

I ordered the 70mm fan from xsfans.com. I've built an improved mount for it that lifts it about 3/8" off the VR to allow the air to hit a wider area of the fins. The cover still fits over it but the cap is mounted outside.

I don't see any issue with removing the regulator / ECU cover regarding the environment. All the components are already exposed to water, steam, etc and appear to be designed for it. The biggest advantage of the cover (other than as a belt holder) might be physical protection of the harness and connectors. A few wire ties would probably do the job.

Based on the test with the 50mm fan and my experience with forced vs passive cooling, I don't think that removing the cover and adding under-hood venting will get the VR temperatures low enough to ensure reliability. But it absolutely would be an improvement.

I amused myself by envisioning cutting a small hole in the hood and mounting the VR underneath with fins sticking out - a 'free air' VR

My VR is the 'old' version P/N 4011731

If anyone in the Western WA / Eastside area has a new VR (P/N 4012476) I'd love to see if it runs any cooler.

when you did the fan test at home you dont have the benifit of forced air under the hood of 31 deg or less.

A thermometer with a min/max storage would be helpful...use it while riding. The temps may be somewhat different.

None the less last week in about 33deg weather I had stopped for a break after a few good climbs. The heat from the clutch of course goes up right into the electronics box that is covered. The heat coming out of the top of the plastic vented cover was very hot. I would guess around 100deg or so...(could hold my hand on it) If the vented air is 100plus I can only image the ambient temps of the internal componentes embeded in rubber that doesnt let the heat out.

Arctic cat has their Vregs in the front right behind a vent. There isnt much room in the Poo chassis to relocate for the most part...Ahhh what about the under the nose pan cover...there is a vent right in front of it..be interesting to see the air flow and temp in that area. A small bracket attached to the A-arm bolts might hold it well. one would have to vent the flat cover to help out when not moving.

Any additional air will be helpful.. The fan idea is great. I wasnt sure what direction you had your fan. I would be intereasted seeing your temp readings with the fan mounted in the discharge direction vs the other way. You might get better cooling by pulling the heat out which in turn would pull cooler air in.

 

[thefullmonte]

AK,

I ordered the 70mm fan from xsfans.com. I've built an improved mount for it that lifts it about 3/8" off the VR to allow the air to hit a wider area of the fins. The cover still fits over it but the cap is mounted outside.

I don't see any issue with removing the regulator / ECU cover regarding the environment. All the components are already exposed to water, steam, etc and appear to be designed for it. The biggest advantage of the cover (other than as a belt holder) might be physical protection of the harness and connectors. A few wire ties would probably do the job.

Based on the test with the 50mm fan and my experience with forced vs passive cooling, I don't think that removing the cover and adding under-hood venting will get the VR temperatures low enough to ensure reliability. But it absolutely would be an improvement.

I amused myself by envisioning cutting a small hole in the hood and mounting the VR underneath with fins sticking out - a 'free air' VR

My VR is the 'old' version P/N 4011731

If anyone in the Western WA / Eastside area has a new VR (P/N 4012476) I'd love to see if it runs any cooler.

Great info on VR temps. I'm really liking the fan idea. The fins sticking out of the hood would look trick. Now someone like myself who is running an Airframe hood. Do you you think the fan would be necessary? I plan on running without the plastic electronics cover and relocating the capacitor. I would think this should give pretty good temp control on it's own. Although, I can see how the fan could draw more air across the fins. Just like the old air cooled motors. Sometimes I miss the old days.
Another question I have is why do you think this is mostly an 800 issue? Do we think it is just due to parts that cannot perform as required? If it wasn't an 800 component problem I would think it would show up more often on the 600/700's too.

 

[deepdiver]

Good points Fullmonte

 

[LeftField]

I'm stumped on why the 800s seem to have the most problems - unless there are mostly 800's out there?

I've aimed the fan down for a couple reasons: 1) I think it gives the best airflow directly to the fins (rather than suck air in from the sides); 2) The fan blade is designed to act as an umbrella for the motor and its control circuit - tipping it over would allow the motor area to fill with water. Maybe could drill a drain hole?

The idea of using a fan to draw hot air out from the hood/clutch area is interesting. These fans are light and low power so looking for a good location to install. Have seen some on M8's.

 

[thefullmonte]

I'm stumped on why the 800s seem to have the most problems - unless there are mostly 800's out there?

I've aimed the fan down for a couple reasons: 1) I think it gives the best airflow directly to the fins (rather than suck air in from the sides); 2) The fan blade is designed to act as an umbrella for the motor and its control circuit - tipping it over would allow the motor area to fill with water. Maybe could drill a drain hole?

The idea of using a fan to draw hot air out from the hood/clutch area is interesting. These fans are light and low power so looking for a good location to install. Have seen some on M8's.

Talked with our IT guys about this. They felt that pointing the air flow towards the VR was the best idea too. It would be harder to pull hot air from around the fins than it would be to force cool air over them. The fans just don't have enough oomph.
So, it looks like there are 12v fans available. Would this ease the install? We had a 120mm here that looked like the size of the VR, but I couldn't tell for sure.

 

[deepdiver]

One really has to wonder about Polaris design boys and their CAD programs. They have a clutch system that gets extremely hot...they dont add vents in the hood/shock towers etc to properly discharge the hot air. Then they mount critical electronics directly over the belt cooker(clutch)..then they bury the components in rubber stuff...then put a cover over them to keep the heat in...throw a couple of vents in and call it good. Aggghhh!

 

[diamonddave]

Left Field, very cool stuff. I didn't even realize we're neighbors. Are you testing an 08 or..?? How many miles are on this sled? Any runnability problems with it? Did you turn on the hot grips, high beams, to try and increase the electrical load? Some of the oversee's electrical components are very suspect, probably what we're dealing with here.

I'd sure like to be able to get my sled in my garage for some testing. I've got way too many sleds I'm currently working on and back ordered parts, etc. My sleds only got 60 miles (wife has put most of those on) so I should be able to get a pretty idea on a fresh sled.

I've got a PCV waiting to install also, so I'd figure I'd dive into that at the same time. I will also be fusing my hot grips, so that short to ground doesn't cause a chassis ground issue.

 

[Clarke673]

When i get my sled back i will be doing my own version of a fan , but thanks for the ideas!

Anyone think that water may actually be an issue? After talking to alot of people, it seems the STOCK rentle sleds whit 3000 miles on them have had no problems but all the MOD sleds do.

Its just an interesting opinion/hypothesis.

 

[lognomore]

Thanks leftfield for your research. I found the plug up by the steering post you mentioned so I think I will use it instead as I can get find that type of plug. The fan is a 92mm that fits right in the cover perfect. It does blow onto the VR from above the cover. I believe if you pull the air from the inside that you would pull air from the engine area through the VR. At least there is a vent above in the hood that should provide cool air to the fan area. The dealers that I have talked to all said that my 700 was unusual to have a stator failure taking out the ECU. This site has been a wealth of information. Thanks to all!

 

[Texasron]

Heat removal fan- Lognomore

ALL helmets off and a handsalute of admiration and respect to Lognomore. Job very well done! Thanks, Polaris needs a infrared thermometer and a reward to you.

 

[LeftField]

DiamondDave,

I'm working on an 09 D8 with around 600 miles. It has run spot-on since day one, I love the thing. But I spend a lot of time miles from the roads and the 800 problems give a person plenty to worry about. The electrics were set the way I usually run - grips off and headlight low. I'm hesitant to do too many runs to avoid PO'ing the neighbors (more than usual). I'll probably be doing another run this weekend or Monday with the 70mm fan.