Horatio

My electric rigs have a tendency to be going thermonuclear by 8 minutes!! 🤣 Thank God for fans and heatsinks.

The 4200 watt motor I'm using in this is hand warm after 8 minutes with 6S on stock gearing (13/52). Obviously the solution is gear it to the moon.


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Pit stops to change batteries?

Hmmm - liquid cooled brushless motors?

1 hour brushless mains aren't far away in my opinion.

But.......


Nitro smell......

MonkeyCmonkeyDo

iTrader: (4)

Yes. I am just getting into rc boat building and I've been seeing boat racing. If we can water cool those, why not the cars, trucks, and buggys too?

do they on 1/8-1/5 scale? Do they have 1/4...most of the bigger scale I see in UK.
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nitrous36

RC boats have intakes and pickups to pull in water from the surface while the boat is moving. Cars and planes would require a reservoir and pump to hold and move water. That's just more weight and maintenance, plus space is already crammed.

El_Rando

20+ years ago i remember someone on a forum trying to liquid cool the engine in an 1/8 buggy. i can't remember if they modified the head. but i do remember they found copper tubing that was small enough to fit between the fins on the head and wrapped it around. i can't remember what they used for a radiator, but the issue of not being able to run a big enough radiator with enough water quickly became a problem. so people screwing around have tried it.

nitrous36

^^ Not to mention the weight it probably added.

Alexv2024

iTrader: (2)

There are liquid cooled 1/5th scale and larger RCs. Especially those crazy mini V8s and larger engines CNC hobbiest has made, those have radiators and starters and all that. They make so much power they have to be water cooled. Lots of videos on youtube with custom projects like that. Some guy is making an F1 car thats pretty epic. Johnny90 or something like that.

Boats have to be water cooled because of lack of airflow in the hulls to stay water tight, and they are constantly under much much higher load. And the infinite supply of cold water makes it easy.

An 1/8th buggy dont run any where near the minimum racing weight, and using water cooling doesnt benefit anything. Its neat for sure when people experiment with it, but it doesnt improve laptimes at all. If one were to run longer 20-45min mains with an ebuggy you might have to really limit gearing, have a much better blower fan or maybe run 6s but same rpm peak so amps are lower. I think its plenty possible, but I doubt enough people would do it for more than 1 race.

Mean while I'd love to do an edurance race with my 1/10 scale stuff. At least with a 2wd buggy it'd be easy to get an edurance setup. I can run my mod car constantly with just battery changes as is, and I dont even have a motor fan on it.

jiml

iTrader: (3)

What if it leaks during a race?

Horatio

The main appeal when it comes to Nitro/IC racing is the fact the races can be - basically as long as you like. Pitstops, fuelling strategies, tyres etc make it very interesting to watch because different teams try different things.

Brushless machines are usually limited to 15 minute finals. I guess if your gear stays cool, pitting for a battery change and running for another 15 mins wouldn't be implausible.

There isn't an endless source of liquid for cars to utilise a complete loss system - which means carrying water, pumping, cooling and recycling. At 1/8th scale, that doesn't give us much space to work with and it's extra weight to lug around.

But - if there was a way - it would be nice for brushless races to incorporate pit stops to change batteries. I guess if gear is specced right, there shouldn't be an issue with overheating. It's just that as RC enthusiasts, we constantly push the limits.

As for endurance racing, the club I was in did exactly that some years back. A 500 lap with 5 teams, each with just 1 transponder. The teams consisted of mixtures of both electric and nitro buggies and trucks. Only 1 car per team could be in use at 1 time. Pitstops could be used to refuel, or swap car/team transponder. It was such a laugh!

0010

iTrader: (4)

We have been talking about the mechanics of running longer electric races for indoor 1/10 at our local track. If someone would come up with a battery that connected like a cordless drill battery, where it just slides in and locks, that would make pitstops quick and safe (no one wants to plug in a battery backwards).

As far as the temperature thing, you can always gear for temps. If you know you have to make 20 minutes, then you gear for 20 minutes. In 1:1 racing, they have to deal with cooling issues as well. Size of the radiator openings are changed to keep the car cool at the expense of drag and/or downforce. So, we gear for temps.

Back in the 90's when we were running 1300mah nicads, you geared to make the 4 minute race with just enough juice to finish. Now you would do it but for temps. So, again, it becomes a trade-off speed for heat instead of speed for battery life.

Full scale racing also runs different cooling packages for qualifying and for the race in some series. We could do the same.

MonkeyCmonkeyDo

iTrader: (4)

Ya we run a 10hr Enduro race with pits every 15mins to swap battery's. Your essentially driving for 2 one hour sessions and 2 one hour marshal sessions. You also pit by yourself for 1 hr.

The longer races bring in more variables and factors yes and make the racing more realistic and more 1:1 scale. Yes. Like f1 or indy racing where the pits and when u take your pits matters. Ect ect.

I will say this. The "it'll never work" mentality will always be just that. It'll never work. Without out of the box ideas or great Strouds...nothing will ever be accomplished.
I think the technology and manufacturing capabilities are definitely their. I'd rather gear up and go faster smoother if I could. If my drive skills could handle it lol. Computers are water cooled these days. Have been for prob 10yrs now at least.
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jiml

iTrader: (3)

I've brought up making electric races longer and the response always is "You'll burn the motors up" to which I respond gear down. The look I usually get is one where I used some ancient unspoken language that no one understands. "You mean you want us to slow down?"

Billy Kelly

iTrader: (9)

How long are you proposing? With on road I’ve seen VTA mains go 11 minute and more.

7 minute mains are becoming more common for 1/10 carpet off road. I think I’ve done 8-9 minutes at one track

DirkW

iTrader: (1)

7-8 minutes are pretty much the norm in any stock class here. I've even run modified buggy for 7 minutes without a problem. I could run many of my cars much longer than that.

Billy Kelly

iTrader: (9)

5 minutes for Qualifying. 6-7 minutes for A mains. Lower mains usually stay at 5 minutes.

I see often in practice drivers do 9-10 minute runs.

staiguy

iTrader: (7)

Due to # of races, we are limited to 5 min qualifier, 5 min main, 4 min B's+. Time is usually the enemy. Start earlier, not enough people can either get there for a pit spot or get some practice time in before. Start later and everyone is leaving around midnight. Even 1 extra race minute equals a total of 30-45minutes of a total race day (usually there's 10-15 races). Even now they only give us 5-10 minutes of open practice before mains. Before they gave us 10-20 minutes.

Casual wednsday racing is a bit longer. It's not a series race for points like fridays so less people. Less people means we have time for longer 6 minute races, 20-30 minutes open practice before mains AND we are done usually around 10pm.

Back to the topic, I like carpet for its cleanliness, but love/hate being indoor the entire time, but its open during the rain and winter time. I got to race on astroturf outside once and it was a blast on a nice sunny day.