The 24 Hours of Lemons Forums → Lemons Tech → DIY Cool Shirt
Long time listener, first time caller - glad to be on the show! Thought I'd add some tech. We hope to run Can't Git Bayou in late April. Link to my half-assed build blog will be posted shortly in my sig.
Just built this, so far it works great! As far as cost, it came to a touch under $300 for the magic box and 5 complete shirts. Could be built for less if you were supercrafty.
Enjoy!
http://specthismiata.com/2008/08/03/hom … irt-system
That's awesome, I built that exact setup with the same cooler and everything. It really worked great at the Sept CMP (Lemons south fall) race.
You, sir, are my hero.
This is awesome! The only thing I would change ( I'm an engineer, it's required ) would be to have the water outlet above the normal water level so that it would be less likely to leak.
I do think I will be building 2 of these.
How about pics of the shirt?
I made a cooler set up for No Problem last June.
I used a Jabsco pump like yours and it would cavitate once the shirt was hooked up.
I used longer lines than I needed in case someone tried to get out of the car before disconnection, they wouldn't get hung up or damage anything. The longer lines many have increased the probability of cavitation.
I could suck on the return line or mess with the pump to get the thing to flow and it was okay. Unfortunately, it did not just work by simply turning on the switch.
I bought a small Rule pump like Cool Suit uses but have not tried it out.
Another consideration is the size of the cooler. My friend has the small round Cool Suit cooler in his Miata. It's only good for about a sprint race.
Block ice last longer than cubes. Floating blocks of ice are heavy and may destroy the pump.
I used a larger cooler to increase the life of our ice since we try to run 1 1/2+ hour stints.
In my case, 1 gallon antifreeze jugs fit nicely in the cooler I used. We could easily put 3 in the cooler. I stood them up inside and ran a string through the handles and tied them to the far side of the cooler from the pump.
Having blocks of ice in a container allows you to simply swap jugs without have to drain melted water to add more ice.
We did use some cubed ice with the jugs cause it I think we were low on frozen gallons.
Other than the pump cavitation, it worked well.
Something that we added to control the sloshing of all that water and ice was baffling inside the cooler. A cut-up old laundry basket works wonders.
One more tip, to drain out the heated water when you switch drivers is to build add a T with a lever. One side of the T for water out of the cooler, one side directed to the driver and one side with a line going outside the car. That way, when you switch drivers, you can turn on the pump, flip the lever and drain your cooler without having to scoop it out.
One more tip, to drain out the heated water when you switch drivers is to build add a T with a lever. One side of the T for water out of the cooler, one side directed to the driver and one side with a line going outside the car. That way, when you switch drivers, you can turn on the pump, flip the lever and drain your cooler without having to scoop it out.
We added an overflow tube (routed through the floor) to prevent too much water from being in the cooler. After the ice melted, the water would sloush into the overflow and maintain a constant level. Each stop the level was the same so all we had to do was add the ice.
The overflow is a great idea. Not need to scoop out water or drain it in the pits and waist time. Just dump the ice and roll. Nice!
The overflow is a great idea. Not need to scoop out water or drain it in the pits and waist time. Just dump the ice and roll. Nice!
Thanks!
FYI, for those who may be concerned we are pissing water all over the track with the overflow, actually we aren't. As it turned out, the overflow dumps directly on the exhaust and it turns to steam instantly. The first time we used it I kept noticing white smoke everytime we exited T14 at CMP. I thought it was the headgasket, but luckily it turned out to be the cooler leveling itself out.
Hmm, maybe route the overflow to the transmission or some other item that could use a little extra cooling.
FYI, for those who may be concerned we are pissing water all over the track with the overflow, actually we aren't. As it turned out, the overflow dumps directly on the exhaust and it turns to steam instantly. The first time we used it I kept noticing white smoke everytime we exited T14 at CMP. I thought it was the headgasket, but luckily it turned out to be the cooler leveling itself out.
I predict some cracks in your exhaust piping from that! (if it happens very often)
But it is a pretty neat solution to leaving water everywhere.
We've seen some pretty good homemade cool shirts, including at least one whomped together from stuff scrounged up at the track (windshield-washer pumps, $1.99 stryo ice chest, windshield-washer hose duct-taped to T-shirt, etc).
We're building the same setup with the rule-360 pump and UC-13 cooler. Probably going to use some blue ice packs or frozen water bottles for the cold solution
Newbie question here, backed by no experience, just reading all the posts i can possibly consume prior to racing at eagles canyon.
Ive seen other posts which warn about the elastic in your bvd's melting in the event of a fire, so does it stand to reason that the windshiled washer hose might also melt all over you?
I'm not sayin, im just sayin...
Newbie question here, backed by no experience, just reading all the posts i can possibly consume prior to racing at eagles canyon.
Ive seen other posts which warn about the elastic in your bvd's melting in the event of a fire, so does it stand to reason that the windshiled washer hose might also melt all over you?
I'm not sayin, im just sayin...
At least you would stay cool while burning 
I am going to attempt to replicate one of these contraptions, just a couple questions.
1) As previous Lemons experience has taught me well, BIGGER is not always better, can the same be said for the cooler size? say 48 qt??
2) Likewise, is 750 GPH better than the 600 example? (turbos did not increase speed or power, only a decorative fire)
Our first pump is a larger Jabsco (maybe) pump than the Rule pump Cool Shirt uses.
It works great until a shirt is plugged in. If you suck on the return line ot mess with the pump it will go.
I believe the problem is pump cavitation caused by the restriction of the shirt. The shirt necks down to 4 3/16" lines. So I think that increases the "head" pressure resulting in cavitation. I think the problem is exaggerated when you try to force more water through the system. So I am concluding that a larger pump may not be better.
I have since bought a Rule pump but have no tried it.
Seems to me that a big pump will circulate the water too quickly thru the shirt to work right. Then there's the right tubing diameter in the shirt that is the most efficient. Lots of trial and error to build your own. That's why I had Mr. Chase Visa buy me a Cool Shirt system. 
I purchased 150 feet of latex tubing, 1/4 ID and the rule pump. I will be setting up the systems with adjustable flow.
I will probably drill a small bleed hole in the outlet and or use a bypass driven draft inducer in the return line to get the flow moving.
And if you catch fire the water flowing into your suit might put out the fire but it would also increase conduction from steam so unless the flow rate is quite high it might not be a good idea to race wet.
I am going to attempt to replicate one of these contraptions, just a couple questions.
1) As previous Lemons experience has taught me well, BIGGER is not always better, can the same be said for the cooler size? say 48 qt??
2) Likewise, is 750 GPH better than the 600 example? (turbos did not increase speed or power, only a decorative fire)
Since I have built two of these contraptions let me tell you what I have learned.
1) Bigger is better - More ice means it lasts longer. Bigger ice (blocks) last longer. We just switched to a 48 quart cooler and it lasted all day Saturday.
2) A $25 12V bilge pump from Wal-Mart does just fine.
3) Cycling the pump (interval timer) on and off makes the ice last longer.
4) Get the official "Cool Shirt". You can can build a DIY one, but it's not likely to perform nearly as well. Trust me, you will never put it on, have that cool water hit you, and say "Damn, I paid too much ($120) for this thing.
My homemade shirt works as well as my store bought shirt, and it cost about $25 to make, most of that for the fittings. I used 1/4" vinyl fish tank tubing and an old t-shirt.
We used a 120 quart cooler with 96 pounds of ice this last time. It lasted all weekend, including icing all (around 100) of our beers on Saturday night, and I used it while driving home. It's so huge that the water does slosh to one side though, and sometimes it would get an air bubble that wouldn't clear until I made a left turn, but I'll get that fixed before next time. I need to make some baffles and re-do the outlet pipe so it can't trap an air bubble, but overall it's a great thing to have. 120 quarts is a bit of overkill though. If I was doing it again, then I might go smaller.
My homemade shirt works as well as my store bought shirt, and it cost about $25 to make, most of that for the fittings. I used 1/4" vinyl fish tank tubing and an old t-shirt.
I had the same idea. How did you fasten the tubing to the shirt?
I had the same idea. How did you fasten the tubing to the shirt?
I took a couple of t-shirts that I got at trade shows, then cut big squares out of the front and back of one of them. My wife sewed the squares onto the front and back of the un-cut shirt using 13 vertical rows of stitches. That left 12 vertical channels that I ran the tubing up and down, then around to the back and up and down there, then brought both ends out at the side of the shirt and put fittings on them. I'll take a picture when I get home from Florida.
Edit - Just checked out stu3's link, I did it pretty much like that.
Has anyone made a cool seat? Have pics? Looking to avoid making 4 to 6 shirts and having to deal with connections at driver changes. I still have the factory honda seat, and I'm thinking about just running tubing inbetween the seat foam and the cover. Probably not as effective as a cool shirt, but would be less hassel. Probably going to be unconfortable. Bad idea?
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