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I hope you get this figured out down the road! The E55 clutch could be a good option, it's likely got more torque capacity than you need. Putting it on the blower instead of the crank further reduce the torque going through it as well, which helps even more. The packaging of it is of course the big problem, but if you can find a way, that part will probably do the job reliably.
^Thanks Ted!
^ Pat -Agreed, the E55 clutch supports a much higher HP setup, so if it could be made to fit, it would probably be golden.
Apparently, in my most recent testing, it was not actually the clutch that failed. The clutch mounting shaft walked, making the clutch not
align properly (only a small section showed any wear). Probably didn't help the NHV either. I still stand by my earlier comments on clutch issues though.
About a year? ago, I purchased a coated rotor pack for my supercharger off someone on EBAY. It worked great for awhile, but it was starting to sound gnarly, so I opened it up and discovered the front rotor bearings had come loose. (one much worse than the other. This allowed the rotor to move forward, grinding into the front housing.
Fortunately I don't see any damage to the turbo, from the resulting debris and my engine loves eating crap like this. I swapped one of my original rotor packs back in.
I have been off for the past couple of weeks, so have had the time to fix a lot of small issues with the car. Still have quite a few items to work on. I probably will have the time.
Got some new Continental tires. Here is a comparison of 205 RE71R's on 8" rims to Continental ECS on 7" rims. I like the ride on the Continentals, and they stick pretty good in this cool weather. They are a bit skinny though.
Finally put a decent cup holder into the car. I have hated the stick-shift interfering holders that I have had forever.
Got pretty much everything in, to do a cool shirt project. Rather than use a cooler and ice, I plan on using a bunch of donated peltier devices and assorted heatsinking. I purchased a temperature controller, pump and water intercooler blocks which are normally used in computer builds. Still need a water reservoir. Not sure how many peltier devices I need to use, or how large the fan cooled heatsink needs to be, but hopefully the unit will be fairly small, and can be mounted somewhere in the trunk.
Last edited by oreo; 04-13-2020 at 11:26 PM.
Reason: forgot something
FYI: You really need to sink the heat out of the back side of those peltier junctions or they lose their effectiveness quickly.
Related unrelated... the first medical device I invented some 20+ years ago was based on a water cooled Peltier at the end of a dual-walled catheter. You could place the Peltier on the SA node of a frogs heart and it would essentially stop beating. Remove the device or stop the electrical current and the heart would automatically restart. I think I saw one of my prototypes in the attic just the other day.
You could place the Peltier on the SA node of a frogs heart and it would essentially stop beating. Remove the device or stop the electrical current and the heart would automatically restart.
Cool. That is also the purpose of this car
Ok, by doing some testing and surfing, I have determined that the peltier devices I have a CUI devices CP85438's which cost about $20 a pop. So pretty inexpensive compared to some of the devices.
Checking the cool shirt website, they sell an electronic cooler, which provides 300w of cooling, for $3700. They do not provide a lot of details on this.
Anyway, based on this rough requirement of 300w, I ran the following calculations;
Even using the most efficient combination of devices, this will require a crap load of power(600w=45Amps@13.4v), and cooling(900w). It also requires that the Peltiers be run at 8volts,
which means I need to regulate the voltage down from 13.4v. I am hoping that 300w represents the peak requirement, and that steady state requirements will be much lower.
I have found a heatsink and fan that should work, so I am getting those on order. This is going to be bigger than I hoped. I am probably going to need to upgrade the alternator, or maybe
install a nuclear power generator.
^ I looked through your entire "slow torture" thread and found some neat stuff, but nothing on your cooler.
I know this is a bit of YMMV item, but how much ice do you use per hour on a hot day?
Are you regulating the temperature of the water or just using a speed control on the pump or maybe neither?
I think I remember a separate thread for the coolshirt project. I'll look for pictures. I was going through the ice inside every hour or so running full time. It was on or off and let me tell you I always wanted it ON. Never once did I think I was getting too cool because it is so unbearable in Florida in the summer. I would come back from a session and set up the lawn chair and sit next to the car and have the coolshirt running.
I had a big cooler of ice to keep feeding the working cooler. The drink style coolers allow you to drain off the excess water without removing it. Mine is located to drain right through one of the trunk drain holes.
^ good information, thanks.
FWIW, 300w equates to 7lbs of ice per hour, so ice works pretty well. It is bulky and has a short shelf life though.
I had not thought about using the system when the car is not running. I like it. One of the reasons why I was considering electric, is so that
I could use this while in transit to events. Obviously It's not as hot here as say Florida, but it does get very uncomfortable here, and is very humid.
Thanks for the link six. Some good stuff there. I'm probably going to go with ice initially, but may still move forward with the peltier devices at some point just because it interests me.
Says it has a compressor, shows 180 bucks for the 16 quart, 200 bucks for the 21 quart. I don't know if the bigger one has a bigger compressor system.
Anyways cheap, 12V, has a compressor so guaranteed a lot more efficient than a peltier system.
Last though, if you do run peltiers, my miata typically runs at 14.9 to 15.0V when running, 15/2 = 7.5 v. Might be close enough to run 20 units in pairs, and wire them in series for 7.5v instead of 8.0v. Save you from dealing with electronics and losses from stepping down voltage.
I actually just bought one of the 21 quart versions. Cheap enough I can either use it as intended, or making something cool with it.
Last though, if you do run peltiers, my miata typically runs at 14.9 to 15.0V when running, 15/2 = 7.5 v. Might be close enough to run 20 units in pairs, and wire them in series for 7.5v instead of 8.0v. Save you from dealing with electronics and losses from stepping down voltage.
Wow, that seems high, but when I measured mine, it was not that much different at 14.6v.
It turns out that running 28 devices at 7.3v generates 308w of cooling at about the same power as with the 20pcs at 8v.
That is a great suggestion!
I did some research, and this refrigerator looks to be too small. The compressor is rated at 45w according to the website.
Math: (as I see it anyway)
300w of cooling is 1030 BTU of cooling.
Looking at 12v refrigerator compressors, I see units from a couple hundred BTU to 1300. Ebay compressor
Comparing the rated power draw to the cooling capacity, it looks like most units are in around 3.75 BTU, per watt of energy used.
The best peltier solution above is 1.7 BTU, per watt of energy used.
(actually neither of these efficiencies will be reached, because they do not include all items, like the fan and pump etc)
So the compressor is much more efficient, but would need to draw about 275w, to provide 300w of cooling.
Still, that is a very good price if you're looking for an efficient portable fridge.
I may end up building a cooling suit at some point with it. I'm going to do a bit of testing, see how it performs. I would guess I'd need it to cool water to about 75°F or so, not 35°F, so the COP may be higher than you are estimating. Anyway it would be easy to take some basic measurements, just need a heating element to put in the cooler with a temp sensor, let it run at 100% duty cycle and see how much heat I can dump in to maintain a given temp with a given ambient temp. I can share if it looks possible. Probably won't dump 300w, but I bet it might do 80-100 which I would like to test and see if that's good-enough for a cooling suit of any value.
lol Six... people here like to build their own units for the challenge.
Guys, don't get all stuck up on btu numbers - I've found that the chinese LOVE to bloat btu capacity numbers. And those guys touting 1800 btu on their unit with a 1.9cc compressor is lsughably optimistic... maybe that with evaporating temps at 80° lol... Truth is in application and all the conditions surrounding it... like what ambient air temps and flow through the condenser, evaporating pressure/temps dictated by txv or cap tube, how efficient everything is (insulating properties), yada yada yada...
I've got my Cubit to maintain about 48/50°f @ max cooling running in 110° ambient temps. Drawing about 15~17amps... but I keep messing with it after finding better parts so I haven't officially rolled it onto the market yet. I'll likely make them "build to order" and carry a small stock supply. Maybe it'll become big enough to stop the scientific refrigeration I've been doing for the past 20yrs and get into manufacturing...
Look on Alibaba for complete chiller systems... hell, you can even find Chillout's system made by CoolingStyle, or their version of it. They offered to make my system lol - notta chance, cause I know I can do it better and I don't want it copied.
Wow, that seems high, but when I measured mine, it was not that much different at 14.6v.
It turns out that running 28 devices at 7.3v generates 308w of cooling at about the same power as with the 20pcs at 8v.
That is a great suggestion!
I did some research, and this refrigerator looks to be too small. The compressor is rated at 45w according to the website.
Math: (as I see it anyway)
300w of cooling is 1030 BTU of cooling.
Looking at 12v refrigerator compressors, I see units from a couple hundred BTU to 1300. Ebay compressor
Comparing the rated power draw to the cooling capacity, it looks like most units are in around 3.75 BTU, per watt of energy used.
The best peltier solution above is 1.7 BTU, per watt of energy used.
(actually neither of these efficiencies will be reached, because they do not include all items, like the fan and pump etc)
So the compressor is much more efficient, but would need to draw about 275w, to provide 300w of cooling.
Still, that is a very good price if you're looking for an efficient portable fridge.
Well, it came in. Cools drinks pretty good.
I did a test of course. Results are, pulling 58W of input power from a 120V ac adapter, the unit was able to pump 40W of heat with a delta T of 37°F.
I'm guessing this big enough to cool a pair of shoes.... So not enough to be much use.
Results are, pulling 58W of input power from a 120V ac adapter, the unit was able to pump 40W of heat with a delta T of 37°F
Actually not bad efficiency for the complete system, considering it is so small. I have read that at rest, the body consumes about 100w, so it may make a measurable difference when going to and from events.
Things moving slowly on the cool shirt project. The plan is to support ice cooling initially, with a longer term goal of either full or partial support using a peltier system.
Got a bunch of things on order, which are taking forever, but have done some things.
Planning on using about 1/2 of this heat sink.
Tests have worked out well for both the water cooled and air cooled end of the system. I do need to use a good thermal grease though.
Have decided on Arctic MX2, because it is reasonably priced and according to their website, will not degrade for 8yrs. I have 60g on order
which should be significantly too much.
Only real surprise is that there is not much of a temperature drop down the fin of the heatsink (test below). With about 900 w going into the
heatsink and the miata blower fan at full speed, I was only measuring a 2 degree C difference from the base of the heatsink to the tip of the fin. I was expecting much more.
Here is the new supercharger clutch plate I am building. It will mate against the entire side of the pulley (about 80% more area than the current clutch) and has 2 sections that will have
friction material. I would have preferred it if the friction material was on the inside and the metal on the outside, but that would mean remaking the pulley.
The plan is to make this part and just strengthen the hub which started to separate. This should be enough to tell me if this could ultimately work.
04-12-2020, 12:27 PM
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