Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

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C-ya
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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby C-ya » Thu Sep 22, 2022 6:20 am

Wow, looks great. Quick turn-around, too. I'm guessing you have a local shop doing this? I have done some surface mount work, and one or two of those would be doable, but I wouldn't want to do much more than that.


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VStar650CL
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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Thu Sep 22, 2022 8:06 am

Yah, hand soldering is fine for protos if you're good with solder (which I am), but more than a couple is a job for the easy bake and not an iron. These will need special treatment if they go to any sort of production, though. You might notice the solenoid driver is a SOT23, so it needs a crapload of heat-sinking copper underneath it on the board for a 1A load. That means even high preheat and thermal-reliefs on the pads probably won't assure good joints in the oven. Only retouching with a very hot iron will serve.

I use Sunstone Circuits in Oregon for all my stuff, they're great. Gerbers in, boards out, untouched by human hands until they're packed for shipping. Zip zip.

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Thu Sep 22, 2022 7:07 pm

Good news and bad. Turns out the optimal PWM profile for the solenoid is about 10KHz at 35%, with a 7% safety margin for dropout. That's outstanding, it means a measly 5W will keep the thing lifted at an easy-peasy frequency. Bad news is here:
SOT23 Solenoid Drive.jpg
To translate the pic, the solenoid is switching "on" with the falling edge of the signal. Notice the slope in the edge, that's the SOT23 MOSFET struggling momentarily to pull a hard ground. That's because the FET is momentarily acting like a variable resistor, and just like any resistor, that makes it heat up. The proto confirms it, the FET steadies out at almost 60C even with all that copper underneath it. That wouldn't be a problem if the situation in the car was the same as the workbench, but it won't be. The unit will be potted and living in a relatively toasty engine box. So to be safe, the next spin will use a much bigger package with more dissipation and a lower RDSon, probably an IRLR8726. RDSon is "resistance drain to source" when switched on, and it's the primary determiner of how much waste heat a FET will generate at a given current level. The DMN3042 has an RDSon of about 22 milliohms at the solenoid's amperage, which might not sound like much, but Ohm says it will cause a minimum 330 milliwatts of waste heat and much more during that "slope". That's a lot for a SOT23 peashooter with a maximum dissipation of 720 milliwatts. The IRLR8726 is more like 8 milliohms and can dissipate 38 watts worst-case, so it will be coasting.

One other safety issue occurred to me, which is the possibility of an open sensor. Because of the fixed pullup, an open wire will make the sensor read cold and not hot. There's no easy architectural way around that with a standard automotive NTC sensor, so the next spin will do the next best thing, have the ground for the sensor controlled by the micro so it can detect an open circuit and shut down the solenoid. There are spare test pads on the proto boards, so for now I'll cut the sensor ground pads loose and run a jumper wire.

On to the next thing!

C-ya
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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby C-ya » Fri Sep 23, 2022 9:38 am

Good luck with the changes. Sounds like they should work. How thick are you thinking of for the potting? Bare board with potting or potted inside a small case?

That is the thing with designing and testing. You always find something you didn't anticipate!

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VStar650CL
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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Fri Sep 23, 2022 10:08 am

Small case, with metal inserts potted in and drilled for attachment to the valve mounting screws. Except for the sensor (which needs to be remote), I'd like the whole valve-board-bracket to be an assembly.

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Sun Sep 25, 2022 7:44 am

C-ya wrote:
Fri Sep 23, 2022 9:38 am
That is the thing with designing and testing. You always find something you didn't anticipate!
Yah, it's axoimatic in engineering that's it's never the big, man-eating alligators that bite you in the a$$. You can see those coming. It's always the little, foot-long ones that sneak up and bloody your butt. Here's another one: Because of the way the ground bus on the proto boards was routed, I had to do quite a bit of fancy cutting and jumpering to disconnect the sensor-minus tab from ground and re-route it to the micro:

Proto PCB Mods.jpg
Looks nasty but works fine, and the open-circuit detection works perfectly on the bench. So does the whole rig:

Wired Hardware.jpg
I'll be testing it open-board on the wife's Altie, just high-temp silicone sprayed on it for short-protection. That will be next weekend, I'm still waiting on stainless mending plates to modify for a bracket and some 5/16x3/8 hose reducers so I can remove the H-valve from the CVT cooling loop. The potting box in the pic is the one I intend to use, it's a Bud PB1581. The plan is to make a sandwich with the M5 mounting holes in the solenoid body, the potted board will fit on one side of the bracket and the solenoid on the other with the bracket in between. The final PCB will fit snugly into the box and have guide holes for steel spacers to be inserted during potting, so after potting and drilling the hole locations will exactly match-up with the solenoid. Should make for a setup that's compact and easy to build and assemble.

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby C-ya » Sun Sep 25, 2022 6:33 pm

LOL on the jumpers. BTDT for engineers that the lab I worked in supported. Proof it then they can redesign the PCB. The lab instruments I work on now still have some production boards come through with jumpers.

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VStar650CL
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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Sun Sep 25, 2022 6:57 pm

C-ya wrote:
Sun Sep 25, 2022 6:33 pm
Proof it then they can redesign the PCB.
We generally call it a "spin" and for complex, expensive boards you definitely want to avoid them. But for a miniscule, 2-sided board like these, a spin is a $45 proposition. In this instance I pretty much counted on it, you notice there are no mounting holes. If you look close, I also left three of the unused pins on the micro with exposed test pads. The new detector circuit is soldered to the rightmost one in the pic. The other two may do temporary duty driving a red/green status LED if I discover any problems in operation on the car that require some "burn and learn" debugging.
:naughty:

Proto PCB Mod Pads.jpg

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Sat Oct 01, 2022 5:58 am

Update, I did some measurement on the wife's Altie yesterday as well as several other vehicles in the shop, a Z52 Murano, R52 Pathy, and T32 Rogue. Except for the Rogue, it turns out all of them have interference issues with the battery tray if the solenoid is mounted in the same spot as the existing thermostat. However, there's plenty of room if the solenoid is moved about 2" down and toward the driver's fender. Since the hoses are molded and I want to mess with the routing as little as possible, that means using a right-angle barb fitting at the lower solenoid outlet and a short splice extension at the upper inlet fitting. So I ordered some 1/2" splices and right-angle NPT-barbs for next weekend, then it should be time to hook it up and see how the proto does in the real world. :)
Last edited by VStar650CL on Sat Oct 01, 2022 6:13 am, edited 1 time in total.

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Sat Oct 01, 2022 6:12 am

PS - The L34 Alties and T33 Rogues will need a completely different kit, the plumbing for the PR25/KR20/KR15 is radically different from the QR/VQ plumbing.

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Fri Oct 07, 2022 10:36 pm

Project update: Got all the hardware and the proto is ready to test out on Lola on Monday (yes, that's my wife's car's name). The only hitch I ran into is the mending plates I chose for a bracket. The seller merely advertised them as stainless, but they aren't ordinary 304 or 8-18. Enlarging one existing hole went fine using ordinary coated bits, but when I tried to make a new hole for the second solenoid screw it laughed at an M35 cobalt. Guess I'll be investing in some M42's, although I hate them because they're so brittle. Nothing else is going to cut this stuff. As a result, the proto is assembled with just one screw on the solenoid and Gray Death gluing down the other side. Here's the result:

Ready Proto 1.jpg
Ready Proto 2.jpg
The potting box for the circuit board is just there for fit, the board is actually sprayed with high-temp silicone and will be taped down for experimentation. On "production" units the standoffs you see under the nuts will be potted into the box along with the boards, then drilled through after potting. Here's the way it will fit on an RE0F09B (6-cyl) or RE0F10D (4-cyl):

CVT 6 Mount Dwg.png
The pic is of an RE0F09B out of a Murano, but the 8mm bolt for the existing CVT thermostat is in an identical location on both types ("A" in the pic). The 'stat will be removed and replaced by the solenoid, and the sensor will go inline at location "B" on the fluid outlet from the beehive. I plan to test it using a torque converter stall to heat the tranny, with the radiator fan kept running using work support from the Consult scanner. That should simulate modest airflow through the radiator and trans cooler, along with constant load like a hot uphill run. I'll report back Monday night or Tuesday. Tomorrow is for football, Geaux Tigers!

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Sat Oct 08, 2022 5:57 am

Assuming the testing goes well, this is the design that will fit in the box for a "production" version. It will have power, status, and "blown fuse" LED indicators to help with installation and troubleshooting. For the uninitiated, the polyfuses shown in the schematic self-reset once the short or overload is removed, so the device won't need external fusing other than to tap power from a fused circuit. In the tests I'll be tapping the TCM power supply. The "bottom" of the PCB as shown here will be face up in transparent potting, with the LED's and pins exposed and everything else out of sight on the inverted "top" side.

CVTT v01 Schematic.png
CVTT PCB Top.png
CVTT PCB Bottom.png

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Mon Oct 10, 2022 2:43 pm

Well, now... it isn't every day in engineering that you can call the first shot a complete, raving success. This was. With the H-Valve removed and the proto installed, it took about 5 minutes of 1300 RPM converter stall to push Lola's CVT to 175F, then nearly 20 minutes more to push her to 194F. Within 5 minutes of releasing the stall, she was cucumber-cool again at 165F. The latter is what I was really looking for, proof that with the heat injection to the beehive halted, the Hayden and OE exchanger are vastly more efficient. Without the solenoid, the same cooling took almost 20 minutes. That means on the highway with many times more forced air flowing through, they should have no problem keeping the temperature under tight control. The testing took all day, but color me happy as a pig in slop.

The only problems I found were purely mechanical. The solenoid assembly wouldn't fit behind the fill tube and needed to be wormed around it to get into place. That may not be possible on the RE0F09's where there's more crap in the 3-pound bag, so it will definitely be necessary to notch the bracket and allow it to be "turned" in at 90 degrees. Other than that, everything should fit as planned. The lower hose to the existing thermostat will get cut back about 3" and the upper hose extended 3~4" with a coupler. The sensor will just require cutting the hose about 2" from the hive and inserting the tee.

These pics were taken looking through the lefthand wheel well with the cover pulled back. Once the bracket design is straightened out, the installation should be a 2~3 hour job. Ignore the pink and white wires, the pink was my temporary power jumper and the white was for a kluje-wired status LED that won't exist on the final version. I removed the solenoid assembly after the test but left the sensor in place, Lola will definitely get a permanent installation once the design is finalized:

Proto Test 1.jpg
Proto Test 2.jpg
Proto Test 3.jpg
Proto Test 4.jpg
Vis the accuracy, the Ford sensors worked almost exactly to spec, changeover thresholds were within 3F across the board compared to readings from CVTz50. The next step is to order a panel of "production" PCB's and see if I can find someone local to machine or plasma-cut brackets. In the meantime, I only need one of the two protos. If anyone wants to be a guinea pig and figure out their own mounting scheme, I'll part with it for the cost of the components. I'll figure that out if one of you wants it, but it should be under $100.
:woot:

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby itsa300zx » Tue Oct 11, 2022 8:54 am

Wow, great work so far, Vstar!!!
I'd like to be a guinea but the weather here is turning cold for the next 7 months and I'm not sure my data would help.
I'm def interested in a set up for the hotter summer months. I still yet have to install my 4 port bee hive and cooler later next spring.

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Tue Oct 11, 2022 9:33 am

itsa300zx wrote:
Tue Oct 11, 2022 8:54 am
Wow, great work so far, Vstar!!!
I'd like to be a guinea but the weather here is turning cold for the next 7 months and I'm not sure my data would help.
I'm def interested in a set up for the hotter summer months. I still yet have to install my 4 port bee hive and cooler later next spring.
Tyvm. I'll have some "early production" units in hand before spring, so you'll probably be best off waiting and getting one of those. You're right, I doubt you'll be having heat issues in Alberta anytime soon.

BTW, it won't be necessary to have an aftermarket cooler in order to use one of these, although on cars with 2-ports you'll definitely want one. On cars with OE heat exchangers in the radiator, this will still remove the beehive heat load from the exchanger and keep it from needing to undo the beehive's bad work. So on later models, it may work just as well with or without extra cooling.

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Wed Oct 12, 2022 8:00 am

For anyone interested, cost for the Proto would be $81.84 plus postage.

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Wed Oct 19, 2022 2:07 pm

Quick update, Sunstone is done with the "production" boards and I should get them next Monday (maybe Saturday, UPS is manic with Ground deliveries). I also decided to ditch the stainless mounting and go with 6061 aluminum instead, much easier to work with and just as durable. It can't be formed for a rotation-stop like steel, but a tapped screw will serve instead. Looks like this thing will be ready to go by weekend after next.
:)

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Fri Oct 28, 2022 7:21 pm

Monday should be the final fit and real world checkout on Lola. These are the new boards, stuffed and ready. They passed bench testing with flying colors:

Pre-Production PCB.jpg
Pinout.jpg
And here's an assembled unit with the board potted and drilled, mounted with the solenoid on what I hope is the final bracket. The only difference between this and "production" units should be the exposed reprogramming header on the circuit board, just in case beta testing reveals any glitches. I really don't expect any, but better safe than sorry. I can always clip and coat the header pins later:

Pre-Production Unit.jpg
Pre-Production Potted.jpg

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Tue Nov 01, 2022 8:12 pm

WOOHOO!

Works great. Here's the real life performance. Ambient temp high 70's, car is equipped with a Hayden 512 in addition to the OE heat exchanger. On the way home from the installation, with the car good and warm, I hit the Shell truck stop at Alexander and purposely TC-stalled it up to 192F. Then I hot-footed it back onto the highway and set the cruise at 84 until bailing out at my exit and taking the jughandles toward home. It never gained from the 192 despite the acceleration, but it lost only 7F in the first two miles or so. Then loss of thermal mass took over and it dropped like a rock. By the time I completed the jug it was a sweet 172F, steadied out there and hit 170F pulling into my driveway half a mile later. This thing works gangbusters.

Temp Map.jpg
Installation took about 2 hours with a lift and power tools, figure 3~4 in a driveway depending on your equipment. I already did a preliminary instruction sheet based on the proto testing, here's a link:
https://drive.google.com/file/d/15baVIo ... sp=sharing

The only thing left is costing it out, I should have that done tomorrow and be able to take orders for those who want one in about a week.
:)

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Wed Nov 02, 2022 7:07 pm

Looks like these things will cost $68 to build, plus a couple hours labor per unit. For Nico members I'll let them go for $110 but I'll want performance reports. I'll give one unit away as a beta test to someone with a bad problem who promises to install it promptly and report in detail. Reply here or PM me, first qualified taker gets it.

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby FantomLightning » Fri Nov 04, 2022 9:24 am

This is amazing VStar! Would this fit for an S35 Rogue?

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Re: Mountains, CVT, did the oil cooler install, still can't get uphill, now what?

Postby VStar650CL » Fri Nov 04, 2022 1:44 pm

FantomLightning wrote:
Fri Nov 04, 2022 9:24 am
This is amazing VStar! Would this fit for an S35 Rogue?
Not directly, although I'd like to try to make a kit for the RE0F10A trannies. I just don't have one to play with like I have the 10D on my wife's Altie. Your car would already need to have an add-on cooler and 4-port beehive (the 10A's all came with 2-ports). The sensor location shouldn't be a big issue, it can go anyplace in the outlet hose to the cooler, but the 10A's have the CVT thermostat mounted in a hard pipe instead of flex hose. So you'd need to work out your own plumbing on the coolant side and a place to mount the solenoid assembly without it rotating loose. The diagram below shows your setup, you can see it's radically different from the 10D pictured on the first page of the instruction sheet. It looks like you might be able to amputate the 'stat and keep the pipe, then mount the solenoid assembly on the bolt hole for the 'stat.

Gen1 Rigue CVT Stat.jpg
That said, the way it would work on a 10A is no different from a 10D. So if you want to figure out how to rig it up mechanically, I'm at your service. Having a 10A kit to install along with a cooler would benefit a lot of people here with older Rogues.


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