BYPASS THERMOSTAT UPGRADE (PREVIOUSLY $28 upgrade)
- Thread starter TRS
- Start date
Seems like my 2013 already addressed the problem (comparing to my '11) if you're talking about it cooling off so quickly after a short shut down and start up. Mine stays above 100 degrees after restarting. I might be thinking about a totally different subject here tho if not 
Have not had the 160-170F heat soak when shut off and then the cold shot when restarted. Hits low 130's when shut down and after an hour it is in the 60's. Start up temp is very consistent. It runs at 109-111F out in the snow. This may be an upgrade needed for the turbo boys. I thought I would experiment with it. It will stay on this 2012 Pro sled. I am impressed with the stability of the water temps.
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TRS...clean install... I like those Gates shrink-clamps too.
Diamond Dave and I looked into this in detail back in 2010/11....
Have you run this in marginal snow conditions?
I take it you removed the stock thermostat?
Also... the bypass end of the thermo... Does that remain open when the main circuit is open?
One of the nice things I like about this separate thermo is that it still bypasses some of the coolant through the cooler to help buffer "tip-in" temps.
Dave said to me in an email that he talked to the BRP engineers back in '07 when they were demoing the new XP's.. that the external thermo was giving them more consistent temps than the typical in-head thermostats. He used it to help with some cooling issues on the 1000 doos.
Some dwgs from 2011.
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Diamond Dave and I looked into this in detail back in 2010/11....
Have you run this in marginal snow conditions?
I take it you removed the stock thermostat?
Also... the bypass end of the thermo... Does that remain open when the main circuit is open?
One of the nice things I like about this separate thermo is that it still bypasses some of the coolant through the cooler to help buffer "tip-in" temps.
Dave said to me in an email that he talked to the BRP engineers back in '07 when they were demoing the new XP's.. that the external thermo was giving them more consistent temps than the typical in-head thermostats. He used it to help with some cooling issues on the 1000 doos.
Some dwgs from 2011.
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Flippy Flop
Running the Evans NPG+??
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TRS... how were you reading the engine temps when the engine was shut off??
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Nope, it has a poppet like 600 rush or 900 poo and shuts off the bypass when the stat opens a few mm.
MH,
Thanks, it's an easy install.
Eliminated the stock thermostat.
Good catch. I tried the Evans coolant in the stock configuration with/without a thermostat. It doesn't work in the Pro. In winter temps the Evans gets to thick in our tunnel coolers and will not pump. I had many discussions with John Light at Evans about this. Their engineers are looking for a fix. It may work with the e-tec housing.
As far as temps go, I tried to replicate real world situations. I rode the sled hard and did start ups after 15-20-30 min and 1 hour shut down times. With both stock and e-tec systems.
Marginal snow conditions, yes, Cooke City to Pilot Creek(8.6mi) many times. From -10F to 23F. Scratchers down on basic ice trail and a max of 136F. It is a consistent 114-117 on the trail.
Thanks, it's an easy install.
Eliminated the stock thermostat.
Good catch. I tried the Evans coolant in the stock configuration with/without a thermostat. It doesn't work in the Pro. In winter temps the Evans gets to thick in our tunnel coolers and will not pump. I had many discussions with John Light at Evans about this. Their engineers are looking for a fix. It may work with the e-tec housing.
As far as temps go, I tried to replicate real world situations. I rode the sled hard and did start ups after 15-20-30 min and 1 hour shut down times. With both stock and e-tec systems.
Marginal snow conditions, yes, Cooke City to Pilot Creek(8.6mi) many times. From -10F to 23F. Scratchers down on basic ice trail and a max of 136F. It is a consistent 114-117 on the trail.
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MH,
I was going to use the old heavy thermo housing from my 93 Storm for the test. But this unit is light weight, cheap at $28 retail and has a 99 degree thermostat.
With this setup there are no issues with bleeding the system, basically fill and go.
I was going to use the old heavy thermo housing from my 93 Storm for the test. But this unit is light weight, cheap at $28 retail and has a 99 degree thermostat.
With this setup there are no issues with bleeding the system, basically fill and go.
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Geo,
It's the 99F vrs 120F that Polaris uses. With this type of bypass system it should eliminate the hot spots in the motor. The small bypass hole in the stock thermostat, IMO, causes a lot of problems. One is stagnant coolant. With the e-tec housing it is continualy moving coolant at the max pump output.
It's the 99F vrs 120F that Polaris uses. With this type of bypass system it should eliminate the hot spots in the motor. The small bypass hole in the stock thermostat, IMO, causes a lot of problems. One is stagnant coolant. With the e-tec housing it is continualy moving coolant at the max pump output.
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A
ak
Well-known member
Xp owners were ditching the stock ones for this one a few years back maybe it's better?
http://www.engine-tech.com/shop/product_info.php?products_id=48
http://www.engine-tech.com/shop/product_info.php?products_id=48
ak... looks slick...but then you would have to change the title to the $168 upgrade... ha.
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Hope it works. I went with a aftermarket heat exchanger from HM Turbos. It plumbs in to the stock plug by thermostat and then you drill out the plug in the unused hose port on the coolant bottle. The exchanger is 19" long and 6" wide. It mounts on the flat part of tunnel under fuel tank towards the front of the tunnel. Part of the cooling issues with the stock heat exchangers it that they are lacking coolant volume. It would work better it the rear of the tunnel, but this requires no cutting and welding. Also I turned up oil and rerouted ves vent hose while everything was apart. Cannot ride again until Sunday so I will let you know how it works. It is however a $350 - $400 upgrade. Another $28 might make it a complete package. Sorry if I jacked the thread, but the combo might end all our heat problems.
BRP
1- 509000499 Thermo housing with internal thermostat
1- 509000372 3/4 x 1 barbed tee
Napa
4- power grip 42934
2- power grip 42925
1- 5/8 bypass cap 660-1696 1-8205 hose
1-7378 hose
Polaris
1- CT clamp 7080533
Washer for thermostat replacement 34mm OD, 27mm ID, 1mm thick
1- 509000499 Thermo housing with internal thermostat
1- 509000372 3/4 x 1 barbed tee
Napa
4- power grip 42934
2- power grip 42925
1- 5/8 bypass cap 660-1696 1-8205 hose
1-7378 hose
Polaris
1- CT clamp 7080533
Washer for thermostat replacement 34mm OD, 27mm ID, 1mm thick
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G
geo
Well-known member
Thanx TRS.
Marginal is good as long as it is enough. I find my sled balances out about 133 to 140 (I'm good with that) crawlin`in the trees in this spring type weather. Last year my PC HCR (short front cooler) never did. It would continue to climb in temp and then I had to dig in. Friends following were unhappy lol.
I believe the difference is the greater amount of heat sink (material that carries the heat away from the coolers) available for the Pro coolers. `Bin watching and feeling for that lately (cause I intend to improve on this next year, extra ccs will need extra cooling lol).
Did you know that the rear bumper brackets are part of the cooling system lol. Have a "feel" lol.
I was thinking of removing the thermostat for spring (and replacing with the "correct" washer). Did you try that TRS?
Also does this set-up eliminate the "coolant spike" at full load? My sled will climb to 131-133 (and stay there 'til I back out) quickly at full load in deep snow and it is not a lack of snow on the coolers issue. It's like there is a "short-circuit" during full coolant flow in the head?? The rest of the time she is quite happy at 125.
I definately will be do what you have done here for next early season riding. You just saved me some weight and money lol.
Marginal is good as long as it is enough. I find my sled balances out about 133 to 140 (I'm good with that) crawlin`in the trees in this spring type weather. Last year my PC HCR (short front cooler) never did. It would continue to climb in temp and then I had to dig in. Friends following were unhappy lol.
I believe the difference is the greater amount of heat sink (material that carries the heat away from the coolers) available for the Pro coolers. `Bin watching and feeling for that lately (cause I intend to improve on this next year, extra ccs will need extra cooling lol).
Did you know that the rear bumper brackets are part of the cooling system lol. Have a "feel" lol.
I was thinking of removing the thermostat for spring (and replacing with the "correct" washer). Did you try that TRS?
Also does this set-up eliminate the "coolant spike" at full load? My sled will climb to 131-133 (and stay there 'til I back out) quickly at full load in deep snow and it is not a lack of snow on the coolers issue. It's like there is a "short-circuit" during full coolant flow in the head?? The rest of the time she is quite happy at 125.
I definately will be do what you have done here for next early season riding. You just saved me some weight and money lol.
Nice work TRS. I've been too lazy to do this, still have my t-stat to try. I've been testing some other stuff.
You are correct about the stock bypass hole in the t-stat. I have been adding 2 additional bypass holes to the stock t-stat and notice less temp swings on start-ups since.
You are correct about the stock bypass hole in the t-stat. I have been adding 2 additional bypass holes to the stock t-stat and notice less temp swings on start-ups since.
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