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Discussion Starter #21
CEP: Great info. Thanks!

I have to admit for a moment I panicked, for 120f IC coolant seemed hot. Then I realized you'd been in 110 ambient. Hot indeed!

I've personally accepted they intermix, and data clearly shows that. Yours shows it again. (thanks) What intrigues me is that, HCT's thermostat and bypass mod left out of the equation, the engine will now have less cooling capacity, and the IC side more. You'd think this would be apparent in results. I see a few potential scenearios:

1) Stock intermixed - Substantial amount of flow between radiator and expansion tank:
Engine coolant benefits from IC cooler. (engine runs cooler)
IC changes higher than needed (we should be able to test for this easily enough!)

2) Stock intermixed - Relatively low flow between rad and expansion tank:
The expansion tank will show intermixed temps, but the two systems will have very independent results, with minimal implications to both.

3) Split (only matters if case #1 above is true)
If the engine coolant remains the same we can't tell much, for the cooling system is too dynamic.
However, the IC temps should drop relatively significantly.

This question has some. This is poorly grounded, but it appears we could say that for every 40 degree f change in charge temperature we're costing ourselves 10% HP. Are we to conclude there is a 15% HP loss? No, there is no way the expansion tank is fully in the flow of the IC cooler.

As I've suggested before, what we need is before temps, not of the expansion tank, but of the IC reservoirs. I think a laser temp will do nicely. I suppose a machine at idle after brought up to temperature will do nicely, for the IC pump runs full time. Once we start seeing expansion tank temps of 185 it should be check once or twice after (after idling so we're not charge hearing the IC coolant that way)

As an aside, and I've not mentioned it yet on purpose, their is solid testing that shows two things:

1) A water IC, not heat soaked, will present, in general, at 10f degree over ambient. And in turn:
2) IC charge temps should also be 10f over coolant temps. Ergo, IC charge temps, non heat loaded, should generally be 20f over ambient.

(both have been attributed to kinetic heat transfer)

Mind you I still intend to build my DIY version this winter when my machine is home again. For under $100 in parts why not?
 

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This might be a little shift, but seemingly still on topic....Just to seemingly defy physics... this is BEFORE I put my split tanks on.... I don't remember outside air temp this day, but I would assume between 85-95 base on when it was, and normal climate around here, this was a clutch tuning run that I logged, so it's a slow roll to about 10 mph, then WOT until about 65 mph, and a roll out after, about 17bs of boost.

653726


I had a couple conversations about the DJ datalogs in the past, and how it doesn't seem possible for these numbers to be correct, the basic understanding of physics I have doesn't seem for it to possible as well, but I have spoken to 4 different "experts" at 4 different places that have said that the sensors do provide accurate data ( I mean.....you'd expect that, right? ), and that it is possible that the intercooler is this efficient, and 1 "expert" that just doesn't buy it no matter what.... I tend to trust the 4 over the 1 from personal experience with them, and others experiences as well..but it still doesn't add up to me from a physics standpoint

A quote from 1 of the 4:

"The intercooler is extremely efficient, the data is correct! Keep in mind the sensor location though... charge tube is a much smaller piece and heats up easier. The entire intake plenum does not heat soak as easily either. The map sensors do take air readings, but when the tube next to them heats up easier the air will always read hotter. "

From what I've found from looking at numerous logs, both before and after split tanks, the Pre TB temp in relation to Post TB temp, almost never has any consistencies.... I have logs like this, which show almost a 200° drop before split tanks, to logs after split tanks that show a drop from 185° to 100°, and everything in between. I'm almost reaching some conclusions....but for now, here's just some observations from looking at data and things I've changed ( I'm never good at only changing one thing at a time....ask @Max H :ROFLMAO: ....so the scientific method gets thrown out the window a bit usually ), these are "usual" ranges during mostly similar riding conditions

Pre Split Tanks, Pre Oil Cooler
ECT: 195-210 ( Highest I have recorded is 215)
Pre TB Temp: 180-280 ( Highest I have recorded is 294)
Post TB Temp: 70-130 (Highest I have recorded is 141)

After Split Tank, Oil Cooler additions
ECT: 185-195 ( Highest - 198, my machine has not broke 200° at all since I did the cooler and tanks, not just on a datalog, but period )
Pre TB Temp: 140-190 ( Highest - 201 )
Post TB Temp: 70-110 ( Highest - 121 )

I would love to see someone gather the data that I skipped past, a direct comparison of air temps before a split tank, and after, with nothing else changed, but I think that data may surprise some in how inconsistent it may be. My thought on my setup is the oil cooler did almost as much to help keep the air temps down as the split tanks did, just from keeping the turbo cooler to begin with, and reducing the Pre TB air temps, so the IC has cooler air into it to begin with.
 

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My thought on my setup is the oil cooler did almost as much to help keep the air temps down as the split tanks did, just from keeping the turbo cooler to begin with, and reducing the Pre TB air temps, so the IC has cooler air into it to begin with.
So does that mean the new big turbo that is water cooled like the XP Pro comes with or the one AA sells , would be better or just as effective as the split tank and oil cooler combo in reducing AIT temps and ECT?
If so for $800.00 more I would definitely go with the water cooled big turbo and say the hell with the split tank and oil cooler ...,.not to mention all the performance benefits

HCT split tanks $500.00
Oil cooler ......... $350 .00
Total ....$ 850
OR
AA Big water cooled turbo
$1650.00

$800.00 difference
 

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So does that mean the new big turbo that is water cooled like the XP Pro comes with or the one AA sells , would be better or just as effective as the split tank and oil cooler combo in reducing AIT temps and ECT?
If so for $800.00 more I would definitely go with the water cooled big turbo and say the hell with the split tank and oil cooler ...,.not to mention all the performance benefits

HCT split tanks $500.00
Oil cooler ......... $350 .00
Total ....$ 850
OR
AA Big water cooled turbo
$1650.00

$800.00 difference
I can't say for sure, but I absolutely would think that to be true at this point, at least to an extent. One think to keep in mind tho, is that both the PXP and AA Turbo still flow engine oil through the turbo to lube the bearings, which will inherently put heat into the oil, just not as much as a turbo that's using oil for the main cooling fluid.

But, that being said....the water cooled turbo without a split system is still working against itself in some manner....it's pulling heat out of the turbo in coolant that's still getting circulated through the intercooler, so it really would all depend on the efficiency of the system, which should be plenty adequate, but it is still cooling a turbocharger that houses a turbine that can operate in excess of 1000°F too...but I do think that starting with cooler air, makes it easier to cool, and maintain a desired temperature of that air through the intercooler and intake manifold, and that turbo system should very well be able to achieve that exact result.

I definitely think you should find out for us! 😁
 

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I am waiting to see what Pol comes out with this year before I dump way more into my 2018 XPT.
If they dont do something truly awesome ,then the AA water cooled turbo might just be my Xmas present to myself .... :unsure: 💸
 

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... if it is the same chassis and stuff.. keep what yah got.. my old 16 leaves the new units in the dust still... and driver mode helps... i wont jump platform until there is a huge change... I toy with going to a turbo S... but then i start over and i dont see the financial point in that as of now
 

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This is just cruising some county roads to let my springs settle out after a tender swap. And it’s been idled in the drove for awhile. It’s def toasty outside. But never saw over 190° and it’s sunny humid and about 85-90° for air temp.

This is just the split tank in mine. When doing the tender swap I can say it made the drovers front bolt tighter to remove.

I have some limit straps on the way. They are PRP ones and I’m hoping it will clear the longer bolt n such. I may need to shift the tank just a bit to clear. Not sure yet. But unbolting the tank you can shift it to get access to the bolt ok. Figured I would share that with everyone.


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Yeah that split tank can make getting too the top drivers side shock bolt a pain but its doable
 
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I am using a split tank on my 16 XPT and after a discussion I had with a few people I removed the block off & reducer and reinstalled my thermostat, and left the split tank in place. The concern was that the reducer and block off would cause cavitation within the system which could possibly lead to motor damage.It is my understanding that the IC and coolant do not intermix due to leaving the split tank in place. I have laser temped the split tank after running the car to warm up enough to have the thermostat open and cycle the coolant, and there is a noticeable difference in temperature. Has anyone else done this, and if so what were the pros/cons?
 

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HCT advises me to not do that as the plug separated the system from mixing. And the reducer is in place of the thermostat as the pressure with the thermo in with the plug the pressures would get out of line etc.

Never heard of cavitation issues and I have ran a split tank since 2016


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HCT advises me to not do that as the plug separated the system from mixing. And the reducer is in place of the thermostat as the pressure with the thermo in with the plug the pressures would get out of line etc.

Never heard of cavitation issues and I have ran a split tank since 2016


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I removed the reducer and block off plug. The only change was leaving the split tank in place.
 

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I removed the reducer and block off plug. The only change was leaving the split tank in place.
They they should be mixing in the system over time according to what HCT said when I put mine in my RZR.


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HCT was bought out by Daystar a while back. So if you call them now, they are not up to speed on things like before when the main man / founder was there ...cant remember his name at the moment.... I talked with the main man about this in the past and he said ...it is no problem if you want to run the thermostat especially if you are in colder areas of the country. He recommends not running the thermostat for customers in the dunes / very hot high load situations and also those customer that had overheating problems back especially with 2016 XPT models ..his instructions are a little outdated , If you run the thermostat you dont need the alum bypass plug

If you call and ask the guys currently at Daystar / HCT ....they will only quote you what is in the instructions and will say you need to remove the T state and add the plug. I installed my HCT tank several weeks ago and I did not remove the T state or add the plug... and it work great
 

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They they should be mixing in the system over time according to what HCT said when I put mine in my RZR.


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That's incorrect. The only place the two systems ever mix is in the reservoir tank. Once you split the tanks, there is no mixing of the cooling systems.

I run mine the same was as @Max H & @SDCO, thermostat and bypass still in place.
 

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HCT was bought out by Daystar a while back. So if you call them now, they are not up to speed on things like before when the main man / founder was there ...cant remember his name at the moment.... I talked with the main man about this in the past and he said ...it is no problem if you want to run the thermostat especially if you are in colder areas of the country. He recommends not running the thermostat for customers in the dunes / very hot high load situations and also those customer that had overheating problems back especially with 2016 XPT models ..his instructions are a little outdated , If you run the thermostat you dont need the alum bypass plug

If you call and ask the guys currently at Daystar / HCT ....they will only quote you what is in the instructions and will say you need to remove the T state and add the plug. I installed my HCT tank several weeks ago and I did not remove the T state or add the plug... and it work great
In regard to running the T stat with no block off plug, I spoke with BMP, as I run their tunes in my car and they stated the same thing.
 

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Good to know. I’ve had one way prior to the buy out.

I had questioned running the thermostat and such. And was only given what I had shared. The thermostat would be nice for late fall rides. But I havnt an issue yet.

So if I decided to put the t stat back in just be sure to pull the plug out correct?

It’s easy enough I may try it for curiosity sake.


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Good to know. I’ve had one way prior to the buy out.

I had questioned running the thermostat and such. And was only given what I had shared. The thermostat would be nice for late fall rides. But I havnt an issue yet.

So if I decided to put the t stat back in just be sure to pull the plug out correct?

It’s easy enough I may try it for curiosity sake.


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Correct, put T-stat back in, pull the plug, and reconnect the bypass hose.
 

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Discussion Starter #38
I really do need to post my "cooling" write up some day, but yea, I would never run without the thermost. Just too much good happening when it's there..
 

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I run mine without the thermosat and use the bypass block. I have not had any issues with it since I did the installation. In the winter I don't have a problem with it heating up. To me it acts as if the thermostat was still in the system. For where I ride and how I ride I'm very happy with the split tank.
 

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I run mine without the thermosat and use the bypass block. I have not had any issues with it since I did the installation. In the winter I don't have a problem with it heating up. To me it acts as if the thermostat was still in the system. For where I ride and how I ride I'm very happy with the split tank.
I agree. I don’t ride when it’s a blizzard or crazy cold here in Nebraska myself


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