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Good point ... I should have thought of that .
I called BMP and they said they set the fan to come on at 185 F with their stage 3 tune
I cant seem to find on the website what AA has his set at ? I will have to warm it up tonight after work and see where it kicks on
Well I should have considered some of these points before opening my mouth .....maybe it is not the split tank making the 6 or 7 degree reduction in ECT....maybe it is one of these other factors at play
At least I know I am not crazy ...o_O
 

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Aspiring Perfectionist
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You're not crazy lol, and it's still a possibility the spit tanks are contributing really, just have some other variables at play too ( you know...like I do it :ROFLMAO: )

On/off isn't the only factor in the fan performance, you can change the duty cycle of the fan at a given temp as well too... like say BMP & AA both come on at 185... but BMP runs 70% duty cycle until 200, and then moves up to 90 at 210...etc, but maybe AA kicks on at 80% and moves to 90% at 195 (those numbers are all made up, just as an example)...definitely would make a difference in airflow over the radiator
 

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OK ...I get it that makes perfect sense. I never thought of that but should have.
Well I guess the only way to be sure would be to remove the tank and re test with no other changes .... Not happening too much riding to do right now and not enough time.
I understand why no one so far has been able to prove the exact effect on the split tank mod too many variables I guess Frustrating ... I always like to prove the changes when adding something new to the machine .
Oh well ..
@gfourth ... your up bud ! see if you can get some good numbers before and after .... without a lot of variables
 

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Discussion Starter #64 (Edited)
Ah so. Many comments:

Yes, the AA tunes turn on the fan at a lower temp. I seem to recall 185f

Yes, 93 octane will reduce engine temp. The flaggragation rate (rate of flame front expansion) is slower, which both delays ignition (which is why it tolerates more timing) and reduces CH temp. This is also why running excess octane reduces HP and fuel mileage.

I find the AA tunes incredibly rich. I experience twice the fuel burn on my stage 3 for what, a 15% HP increase? That is not a lean tune. Mind you fuel is a lousy coolant per say, but its certainly contributing.

Altering the CAC temp, which is most of our hope and dream, would not account for the reduced engine temp. I to think lower CAC coolant temps will occur, to some degree or another, but the engine BTU didn't simply vanish. That extra heat will have to present in the engine coolant, or similar. yea, the air may be slightly cooler, but the water temp will be slightly hotter.

To be candid, I don't think it really happened. I mean it did of course, Max has too much comittment and experience to mis-report, rather that there are other factors, those similar to what we're now hearing, that pretty much have to account for it.
 

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Discussion Starter #65 (Edited)
So now testing:

Testing engine coolant temp isn't going to tell us much, if anything. I won't redo the whole thermostat discussion from my cooling post, but all we MIGHT see by looking at engine coolant temp is an altered EP. Maybe.

So now, after some thinking on this since we started talking this post, I"ll share what my present thought is for testing:
  1. I intend to bring mine back this fall. When I do I'll install, and plumb, but not connect up, a DIY split tank.
  2. I'm also going to place, on the return line, at the CAC, and maybe on the engine side, something like this:
    1. Trail Tech TTO Temperature Meter Radiator Hose Sensor - RevZilla
      1. Or
    2. Amazon.com: UTV INC 1" ID Inline 1/8 NPT Water Temp Sending Unit Housing: Automotive
      1. I hope to be able to determine radiator coolant temp, not engine temp, for I want to know if I've affected the system efficiency, and I don't want to be misled by the thermostat. The radiator tank will be a fine heat soak buffering that problem.
  3. I'm going to measure temperature offset to ambient.
  4. I'm going to have to find a long run of consistent HP. So long as I test next spring, back up north, I can run for 10 or 15 minutes down a highway at 60mph, turn around, and do it again. With the windshield up and half (the drivers side) of the rads blocked off I should be able to heat soak the system in that kind of time AND have a repeatable test.
I'm hoping to see a stabilized (relatively) temperature at that point. Then I can swap in the new system, bleed it, and re-run the test. (Fair warning. I'll already have changed over to a higher water percentage, but all tests will follow that mix).

This eliminates all the variables I can, and gives me the purest data I can get (short of a dyno run), and allows me to see how I've affected the system.

Mind you I do think looking at charge air temp differential is just fine, for it's not being affected by a thermostat.

Anybody got a better plan? Of a cheaper way of getting those cut in?

Am I right in thinking the water lines returning to the back are 1"?

Thanks guys!

-d
 

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Discussion Starter #66 (Edited)
Yep, 185. Here's an AA cut and paste:

Fan on/off at 185 degrees Fahrenheit (190 is stock). The fan also ramps up in power quicker to keep you running cool.Seatbelt limiter disabled

RW: I'm not sure if the ramp up logic is in the ECU or the radiator. I've been led to believe it's a "smart" fan and it's got it's own logic. I've assumed fan speed decisions. I've literally no idea, so please correct me!!


Gfourth: As the Pats would say: Next man up!
 

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RW: I'm not sure if the ramp up logic is in the ECU or the radiator. I've been led to believe it's a "smart" fan and it's got it's own logic. I've assumed fan speed decisions. I've literally no idea, so please correct me!!
It is controlled in the ECU tune, there’s actually 4 or 5 different parameters in regards to on/off and duty cycle you can change if I recall correctly. Nothin smart about the fan itself, outside of the controllability of a PWM fan at least.
 

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Morris Racing #711
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The fan is definitely controlled by the ecu. I have complete control of the fan with the motec I'm running, which is really nice for me.
 

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Discussion Starter #69
It is controlled in the ECU tune, there’s actually 4 or 5 different parameters in regards to on/off and duty cycle you can change if I recall correctly. Nothin smart about the fan itself, outside of the controllability of a PWM fan at least.
Thanks!
 

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@Max H Do you know what size the threading is on the fill necks on the HCT split tanks? They shipped mine without the overflow barbs... I had one laying around, need another, but no clue what size it is.


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I think it's just 1/8 NPT ...but I'm not positive
 
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Captain/Paramedic
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Be sure to contact HCT and let them know that they didn't include all the parts. I had the same issue when I got my kit but i didn't have to pay for it so I didn't complain much
 

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Be sure to contact HCT and let them know that they didn't include all the parts. I had the same issue when I got my kit but i didn't have to pay for it so I didn't complain much
I did reach out when I realized they were missing, and he said they would send it right out... its been a couple weeks now. Would just like to move on and get them myself but they seem like a funky size.

They're not ⅛ npt, theyre smaller than that. At the hardware store, it fit into the ⅛ compression threads on the thread tester thingy, but there isn't anything that size that would work.

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Captain/Paramedic
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I would call them on Monday and tell them about shorting you parts and then not getting you replacements in a timely manner. HCT is owened by Daystar Products and they have had a change in management and their quality isn't the same as it us to be. Let them know.
 

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Discussion Starter #75
Jsut to complicate things, there is a thread standard used in some compressor fittings call "briish pipe thread". For which there is like no interoperability with anything. so yea. I'd call and ask them not for the part, but for the thread specs.

Congrats on the new toy!

-d
 

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Captain/Paramedic
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I pulled one out of my HCR split tank and measured it.You need a 1/16 x27 pipe thread. You may have a hard time finding it at a hardware store. Might have to order on line. Good luck hope this helps.
Todd
 

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I pulled one out of my HCR split tank and measured it.You need a 1/16 x27 pipe thread. You may have a hard time finding it at a hardware store. Might have to order on line. Good luck hope this helps.
Todd
Thanks for doing that, much appreciated.

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