Compressed air supercharging
 

Fairly new to PY forum. I enjoy reading the threads over here on the boost forum. Hoping to get a turbo project going soon, built a couple 20 years ago. Looks like boost has came along ways since my last endeavor.

Being a drag racer, an engineer, and having built a couple turbo systems. Thought this was an interesting concept, not a new idea, I read it dates back to the 70s, but it certainly appears they have taken this to the next level. Compressed air supercharging, took their 400+hp sbc to 900hp. Maybe not feasible yet, interest watch engineering wise. Jay
CA supercharging
http://casupercharging.com
https://m.youtube.com/watch?v=qObzWnWlCfM

I thought this was not allowed in drag racing?
(at least NHRA)


:confused:

I noticed in the video they were testing at an NHRA track. For testing anyway. Jay

What I found interesting is the lack of a need for an intercooler since expanding air actually gets colder.

A couple of comments:

In the July Issue of Hot Rod Magazine on page 42, there is an article "Supercharger by Jet" that describes work by GM Engineering who were "Boosting" a Chevrolet 6 cylinder engine.
Basically the same 6 cylinder Chevy engine that would have been installed in Pontiac Tempest vehicles in the 1964-1966 timeframe.

The system used a 1500 psi belt driven Air Compressor to fill a "Air Reservoir" (Air Tank) with compressed air.

From the Compressed Air Tank the air traveled to a High Pressure Solenoid Valve and from there to a Pressure Regulator that lowered the air pressure to 150 psi system pressure.

From the Pressure Regulator it traveled thru a high pressure line to a "Air Jet" that functioned much like a Car Wash Wand except instead of having a high pressure water coming out of the tip you would have a high pressure/ high volume air source blowing into a carb air horn bonnet (much like a Centrifugal Supercharged or Turbocharged Blow-thru carb set-up would be today. The carb would have to be specially calibrated for the Air/Fuel mixture to be correct for the system when the system was turned on.

That being said, GM never went into production with the system for a couple of reasons:

1) The system was designed for a specific small displacement 6 cylinder engine and specially calibrated carburetor.

2) The system (when operating) made a LOT OF NOISE which was a distraction to the driver. Today with Sound Limits on production vehicles, the OEMs could be hard pressed to get the vehicle to pass NOISE Standards.

Enough of the History Lesson.

The CA Supercharging system looking at the website appears to be a Drag Racing "alternative" to a NOS system. You would go to a Drag Strip (that happened to have a Compressor Bottle refilling CA Supercharging business. They would fill your Race Car Bottles with Compressed Air vs NOS. Same basic idea as NOS but the Air at the Track is basically free. So with 3 Bottles (Which you buy as part of their system MAYBE you get a couple of passes before you are back at the Air Filling Station waiting to get your Bottles refilled.) People have, today, a lot of experience with NOS systems so the Compressed Air set-up at the track would just be a cheaper alternative for the running the "Air Filling Station" at the drag strip. Most Garage Air Compressors are capable of 75 to 100 psi and you need much higher (900 psi?) pressures so filling a bottle with a high pressure system at home might not work so well either.

The idea, just like the GM Engineering idea sounds possible but not very cost efficient for the customer vs say a Roots Supercharger with a much higher HP capability.

Tom V.

Another Ford Research Engineer and I looked at the system and did a cost analysis on the idea and it never went anywhere.

I don't know what a bottle of compressed dry air cost from a gas supply house but the bottles come with about 2300 psi. I also don't know how much cubic feet of air is in a 2300 psi bottle of compressed air. (I guess I could used the Google) I was just intrigued by the cool air aspect and not needing an inter cooler.

I remember this from a few years ago, it is by Jeff Smith, the gentleman in the video.

https://www.hotrod.com/articles/comp...supercharging/

Still can't get over why a POS chebby engine needs 42 degrees of timing to make any kind of horsepower with the engine.

The article is a very good article and does mention the difference in power with a belt driven supercharger vs a Bottle Baby but NOS is a Bottle Baby too.

So comparing two Bottle Babys, NOS vs the Chilled Compressed Air system:

No inter-cooler needed with either system
No belt loads in the comparison as no belt driven boost device.
In both cases you have to buy a filled bottle. Be it NOS or Compressed Air.
In both cases, when the "bottle is empty" you are back to Max NA Horsepower.

So help me out, where is the bang for the buck here?

Tom V.

Why use air? Just use nitrous. More oxygen in nitrous than air, so you could use a smaller tank (I've seen the compressed-air dragster at Garlits' museum, that is a BIG tank!).

No carb or throttle body. Just PWM controlled nitrous & gasoline injected into a sealed intake manifold

Have to agree with you Lee. With the air system you are having to supply the fuel side anyway. What does the Air System buy you vs using known technology and calibrations for a NOS based system.

Tom V.

I would rather have a Mechanical means to shut the thing down though (Throttle of some sort) vs assume that the electrical side is always perfect. Lil Jack might have some opinions about that Perfect Electrical System option.

I second the mechanical shut off as a secondary means to shut that system down. I remember having a motor mount break and the engine yanked the cable out of the holder and sucked the peddle to the floor. Pretty helpless feeling, can’t imagine what that feeling would have been like with 800+hp.

It will be interesting to see these systems go up against the other power adder classes. Should they get to that point. That 800+hp on a pump gas 355 cid engine isn’t bad, almost a category in itself. The dual system or bigger on a proper engine could be entertaining to watch. Anything seems to go in some of these outlaw type cars. Plus just by the nature of this system an 1/8 mile track probably has more possibilies than a 1/4 track.

As far a bang for the buck and why, just use nos. Both are good points. Hard to beat a good turbo or Mech charger system. NOS certainly has it’s own following too. The extreme cold air charge this system has is interesting. Comparing with NOS I do like the idea of having a refuel station in the trailer versus paying to have nos refilled. Especially if it would support several cars. Plus there would be the added bonus that I could take up scuba diving...🙂
Jay

Memory is not great anymore, but the way I remember it was that the extra weight offset the HP gain from not driving the supercharger.

From that article

Also a couple of other reads

World's Fastest Air Car
https://www.popularmechanics.com/car...eville-record/

Landracing Forum
http://www.landracing.com/forum/index.php?topic=10866.0

Stan

I have always looked at a turbo as a nitrous bottle that never runs out!:D