Drag racers are ditching superchargers for scuba-style tanks and compressed air
thedrive.com
thedrive.com
Colder air is more dense and therefore carries more oxygen. More oxygen allows more fuel, which allows more power.
Here's a better explanation in a single paragraph on the company's website:
> The end result of these expansion processes is that the charge air temperature entering an engine is dramatically lower than can be achieved with conventional MAP increasing technologies (supercharging and/or turbocharging with after-cooling). Hence very high charge densities can be attained at relatively low MAP levels.
The goal is to increase the amount of air going into the engine by making it very cold and dense, not by pressurizing it like a supercharger. Low MAP means low manifold absolute pressure. In other words, it's not boost like a turbo or supercharger.
EDIT: It looks like the website is also unclear. There is some mention of a secondary valve shutting off the intake valve to prevent air leaking out from the air filter.
Their website is strangely unclear. This isn't mentioned in the "Theory of Operation" section but does get mentioned later as an "isolation valve"
A very cool aircraft.
The systems has regulators that step the air pressure down from thousands of PSI in the tank to a much smaller, regulated number at the nozzle that gets sprayed into the intake.
From the source company that sells the system:
> The very low temperature medium pressure air stream is then throttle one more time in the Electronic Pressure Regulator before being discharged into the engine air intake tract. The throttling effect that occurs here is small compared to that which occurs at the Mechanical Pressure regulator but, similar in nature.
The tuner can adjust the pressure that is being discharged into the intake tract, but that's not equivalent to the pressure in the manifold.
The system works by having the air expand rapidly in the intake, causing a rapid cooling effect.
The company describes it better on their own site: https://casupercharging.com/tech/#system-overview
EDIT: There is some mention of an "isolation valve" but not within the "Theory of Operation" section of the company's own description: https://casupercharging.com/tech/#system-overview
So there might be some scenario where the system shuts off the intake valve, too, but it's weirdly unclear from their own system description.
But to your point, I agree. Once the boost is achieved, the effects of the boost occur, because they aren’t really related to the source of the boost or how it is implemented. However, systems that use the engine for power like turbos may lose efficiency compared to compressed gas at the same boost level, depending on how much the gas system weighs compared to your turbo. It’s an interesting idea, especially for drag racing.
Yes, they put in the energy to compress the air 'offline' and then have that free to propel the vehicle. The cooling of the charge also improves the efficiency, the useful energy output is proportional to the temperature difference before and after the combustion.
A high capacity intercooler would be an interesting experiment also in utility vehicles.
We tried something similar to good effect, but we unfortunately had no good knowledge on how to refine it. It's hard to just shoot compressed air into the manifold and not have it blow back out of the intake. Either way we figured out a way to increase the volumetric efficiency as well as gains from running cool dense air. We were very close to pre-spinning the existing turbo/super setups and experimented with that as well. We gave up because Nitrous oxide at the time was much easier to work with and popular, and the tanks we had to experiment with was tiny compared to the large scuba tanks.
We also tried using compressed CO2 bottles to spray towards the intercooler to cool that down considerably, that worked decently as well, but no good data to support.
https://www.carmagazine.co.uk/car-news/tech/volvos-turbo-lag...
Take, for instance, Ford’s car from the 2003 FIA World Rally Championship. Through a knowledgeable automotive tuner and journalist named Stav from the UK (Facebook page), we learned that the 2003 Ford Focus RS WRC used an ingenious, mostly-hidden system to store excess pressurized air from the turbocharger in a titanium tank until it could be advantageously crammed into the engine on straight portions of the course, elevating power beyond what would otherwise have been possible.
Also how they use aluminum for the connecting rods instead of stronger and stiffer metals like titanium, as they can then act as shock absorbers protecting the crankshaft bearings.
Lots of interesting tech to eek out performance and lifetime.
I've been enjoying watching Steve Morris's YouTube channel[2], he shares a lot of such information. He's mainly making drag and drive engines, which has the additional constraint of having to survive thousands of miles of regular roads between races.
I've also enjoyed Brian Lohnes channel[3] for interesting historical accounts from the early days.
[1]: https://en.wikipedia.org/wiki/Top_Fuel#Performance
"This calculation assumes an average racing engine speed of roughly 3,800 revolutions per minute over a period of 3.8 seconds."
I don't know the details of Top Fuel and such, but Steve with his SMX[1] wagon[2] keeps his car at 2000 RPM at the lights, so seems reasonable to assume Top Fuel is around there too.
On the top end the Top Fuel cars are limited to just over 8000 RPM[3], with the red line at 8500 RPM.
So an average of 3800 RPM seems reasonable.
As a cross check, given that Top Fuel cars are single-speed[4], I guess one could calculate the same using the diameter of the wheels, keeping in mind that the tire expands a lot compared to its size at rest.
[1]: https://www.enginebuildermag.com/2024/12/4000-hp-twin-turbo-...
[2]: https://www.youtube.com/watch?v=LnrZdrp77Cs
[3]: https://www.enginebuildermag.com/2023/03/top-fuel-and-funny-...
The 7000 aluminium alloys are similar to titanium in strenght/weight
Again no expert but from what I can see, high-end aluminum rods can use 7075 aluminum[2], which has a Young's modulus of about 72 GPa, while titanium has a modulus of about 105 and up[3][4], depending on grade.
At least that's my understanding.
[1]: https://en.wikipedia.org/wiki/Young%27s_modulus
[2]: https://www.enginebuildermag.com/2017/03/racing-rods-builder...
[3]: https://titanium.com/alloys/titanium-and-titanium-alloys/gra...
[4]: https://titanium.com/alloys/titanium-and-titanium-alloys/ti-...
Aluminium is also significantly cheaper, and easier to machine.
Titanium (or high strength steel, which is the strongest both per area and per weight and also the most expensive and difficult to machine) would be used where the volume of the part would be a concern.
In my quest I stumbled upon this[1] article where they discuss composite connecting rods for Fop Fuel dragsters:
Designed for Top Fuel engines, this connecting rod is half the weight of a conventional aluminum rod, yet is projected by company engineers to last an entire season instead of just 12 to 15 races.
Seems they're still at it, perhaps it'll be the next thing?
[1]: https://www.performanceracing.com/magazine/featured/08-01-20...
The only sweeter sound is a V12 Merlin coughing into life.
I snagged a ride in a P51 once. OMG. That machine just leaped into the air. I was smiling for a week.
But by age 7 I knew that I was a born engineer. Engines, electronics, software, structures, all of it.
When are the kids in California going to grab a tank, point the nozzle down, and ride that thing like a rocket from the beach, parachuting into the ocean?
We could call them "beach jumpers".
is it skirting some kind of rule and being specifically NOT nitrous?
Or maybe it is just cost - scuba compressor to fill tank.
When battery weight gets cut in half next decade and capacity doubles, the only reason why they will race ICE engines is for the noise
Now cut those heavy batteries in half because you're not driving from SF to LA, and I could see that Porsche turning 8s if you could get the power to the ground (IOW, launch control and much better tires than stock).
https://en.wikipedia.org/wiki/Top_Fuel
> Top Fuel is a type of drag racing whose dragsters are the quickest accelerating racing cars in the world and the fastest sanctioned category of drag racing, with the fastest competitors reaching speeds of 338.94 miles per hour (545.5 km/h) and finishing the 1,000 foot (304.8 m) runs in 3.641 seconds.
https://www.youtube.com/watch?v=5JYp9eGC3Cc
Although you can in theory buy one, it uses down force fans so I don't know if it would even be street legal in most places. Personally, I find car like this to be way more interesting than drag racers.
Even with half weight and double capacity- the worlds fastest EV will get walked by a fast gasoline street car
There is an energy cost to supercharging. While you get an overall horsepower boost, it's less than what it would be if the compression cost nothing.
I'm assuming the costs involved in making engines capable of withstanding cryogenic temperatures probably make that impractical (?)
Look up "critical point" and a phase chart to understand why. It's an interesting physics topic that isn't obvious if you've never seen it before.
This was tried in the 1950s and 1960s. IDK why it didn't make the cut then. Probably cumulative weight of tanks. It takes A LOT of air to run an engine.
https://gist.github.com/s0kil/9bd6815ea2ab4e65a786c6382a5bfa...
Had this idea since the 90s, but no racing team listened to me just because I was a kid in school.
Using nitrous or cool compressed air keeps most of the benefits while mitigating the problems of using pure O2.
Held in a lightweight composite thermic bottle.
They’re what firefighters use.
On the other end of the spectrum you have racing types that are more of a competition among drivers with the vehicle not really making or breaking anything as long as it's typical for the class.
The first time I took my 286 intake manifold off, it took 4 hours. The 4th time I took it off, it took 20 minutes. Once you know exactly what to do, it really cuts the time down.
I'm sure every member of the team knows exactly what to do and it's down to a dance.
For fun, look how fast they change the tires on a Formula 1 pit stop.
What is it the kids say? "Tell me you know nothing about drag racing without saying you know nothing about drag racing"? Drag racing has all of that, squeezed into 1/4 of a mile. That's why top fuelers get an engine rebuild after every trip down the track.
It's like saying, "I get ultramarathons, but 400m foot races involved little skill or training." Look, if you don't get it, fine. Probably best to just leave it at that.
But I've never felt any interest in drag racing at all, it's a pointless waste of fuel. Press accelerator, press brake, done, little to no skill required. And in something like the R8, would require a $20,000 dealer visit after a weekend of runs.
Are they? At least in Europe they are usually blue collar guys that pick a neighborhood at random to hold a car meet, terrorizing that neighborhood until deep into the night, including street races. And if they aren't accommodated they'll aggressively clash with the police.
They're easy to spot too, pumped up douches with tribal tattoos and gemstone earrings that behave like they're prone to pick a bar fight with you.
The meets I'm talking about are like this [0][1]. There's a lot of the tattoo gemstone guys in [1]'s timestamp. Is this what you mean? I'd love some examples.
[0] https://www.youtube.com/watch?v=_bAq_qD9i2s
[1] https://youtu.be/q4lvEYLJaOY?t=340
>And if they aren't accommodated they'll aggressively clash with the police.
If you're a car guy you're basically begging to be hunted constantly. In my opinion this is all downstream of the death of folkracing.
You don't have to understand how something amuses someone to understand that it amuses them. You also don't have to belittle people to ask them why they are amused.