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Ok, So It's Stupid-Now Tell Me WHY It Won't Work! Supercharged Question

Discussion in 'The Hokey Ass Message Board' started by 38FLATTIE, Feb 3, 2012.

  1. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,363

    38FLATTIE
    Member
    from Colorado

    Rich, this is one of those 'out of the box' ideas', that get me into trouble!

    In my quest to find out how much more HP a centrifugal supercharger is capable of making, over a roots style huffer, I got side tracked!
    I started thinking about how I could get the benefits of a supercharger, without losing the HP it takes to run one.

    Since all a supercharger does is compress air, why not just carry compressed air on the car, and use it for boost? Obviously, it's not that simple, because of controlling and monitoring the boost, compressing the air, etc. but that's another story!

    If 14lbs boost could be achieved from compressed air, the HP gain would be staggering. I approached Woody (Design Dreams, LLC) with the idea, and he sent me the attached pic

    The car was designed and raced by Art Malone, even though the caption under the car reads: The "Air car" at Don Garlits' Drag Racing Museum. Concerned that he was losing too much power driving the blower, Garlits came up with this ingenious car, which featured a large tank of compressed air which was progressively fed into the engine during a run, instead of a blower.

    This started a google search, where I found this:


    Initial testing of various forms of the system was done on three different dragsters and one of Mickey Thompson's Ford Funny Cars, but in all instances, no full quarter-mile runs were attempted. Recently, however, Keane got together with Mickey Thompson and, utilizing Thompson's exotic dyno facility in Long Beach, accomplished an exhaustive testing program. The results were phenomenal. Where a 6-71 blown Boss 429 Ford engine on 20% nitro had produced 1360 horsepower, the same type of engine equipped with the bottled air system in place of the Rootes blower, burning only straight alcohol, produced 2400 horsepower at 6000 rpm! On gasoline, the system made about 1550 horsepower. This success was not easily achieved, as in one week of testing, Thompson reportedly ran 150 gallons of alcohol through the dyno engine.​


    So, long story short, is this a possibility? Can enough air be stored on board, with either bottles, or utilizing the frame, etc., to to run a 366 CID engine, at 14lbs boost, for 3 miles at WOT?

    If not, why?
     

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    Last edited: Feb 3, 2012
  2. badshifter
    Joined: Apr 28, 2006
    Posts: 2,689

    badshifter
    Member

    Figure how much air goes through your engine at WOT. Then do the math and I think you'll see you would need a huge air tank, or a trailer for the air!

    Oh and I think sanctioning bodies made it illegal as well.

    The theory works, just not too practical. That's what nitrous is for.
     
  3. R Pope
    Joined: Jan 23, 2006
    Posts: 2,975

    R Pope
    Member

    Way back when (70's? 80's?) HRM ran a story about someone (Smoky Yunick?) putting a venturi setup on top of a carburetor and shooting high pressure air through a jet, thus entraining a huge volume of air at medium pressure into the engine. A small belt-run compressor replenished the tank, and the system was activated by a full-throttle switch. Since you don't drive around at full throttle all the time-well, hopefully not!- the tank has time to refill between blasts, and more than enough duration for the "street Nationals"!
    I think they got a hundred HP boost with little parasitic drag. Only about 6# boost on their initial model, I think, but worth considering.
     
  4. sakelley22
    Joined: Aug 1, 2010
    Posts: 102

    sakelley22
    Member
    from Easley SC

    look into an older style Mack truck air compressor and check with semi truck dealers about various size air tanks I actually used a mack compressor on a race car tow rig for air to run tools and air tires ect. a few years ago
     
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  5. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,363

    38FLATTIE
    Member
    from Colorado

    I'm looking for the equations I need to figure this.

    As for sanctioning bodies making illigal, this is for SCTA-Bonneville. I've scoured the rules, and I believe it's legal, as long as I run in the supercharged class.


    Actually, I will drive around all the time at WOt. This is for a Cadillac flathead powered Bonneville car, so I only need to power it for 3 miles at a time.
     
  6. squirrel
    Joined: Sep 23, 2004
    Posts: 26,408

    squirrel
    Member

    The reason it takes a lot of HP to turn a blower is because it's pumping a LOT of air. My blower has two 650 cfm carbs on it...my shop compressor (a good old 5 hp unit) pumps about 20 cfm....

    The cfm rating varies with pressure, so this is not really a fair comparison, but still, you get the idea.
     
  7. badshifter
    Joined: Apr 28, 2006
    Posts: 2,689

    badshifter
    Member

    The cylinder volume calc is pi (3.141) x r2 x stroke. Then multiply that for number of cylinders. That is the volume for 1 rpm. Then times that volume by the wot rpms. That is the volume you would need per minute. Multiply that times how long a run lasts. Add a bunch for stable pressure throughout the run.
     
  8. squirrel
    Joined: Sep 23, 2004
    Posts: 26,408

    squirrel
    Member

    And if you are running 14 psi boost, you need roughly twice as much air as he said.
     
  9. NONAME
    Joined: Feb 5, 2006
    Posts: 4,284

    NONAME
    Member

    Sounds like NOS power in a bottle
     
  10. zibo
    Joined: Mar 17, 2002
    Posts: 2,344

    zibo
    Member
    from dago ca

    Yeah that's 14 psi more than the air the engine's already sucking in!
    You'd need a compressor with a volume 20% larger than your gas burner engine,
    or is it twice the volume I don't know.

    Either a small fast running compressor or a large slow running compressor,
    along with the tank.
    They should do that on new cars!

    TP
     
  11. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,363

    38FLATTIE
    Member
    from Colorado

    Even if it is illegal, I'd run time only, to see what gains I could acheive, if it were doable!


    Ok, so bore is 3.55", and stroke is 4.625"

    Doing the math. 3.146x1.775x1.775x4.625=45.8424

    45.8424x8 cylinders x 5500 rpm=2,017,065 CI of air

    x2 as Squirrel said=4,034,131 CI

    This translates into 17463.77 cubic gallons of air,per minute!

    Seriously??!!! :eek:

    Surely I made a huge math error here? How did Art Malone manage to get his drag car down the track?
     
    Last edited: Feb 3, 2012
  12. James D
    Joined: Feb 8, 2007
    Posts: 4,053

    James D
    Member

    Electrically driven supercharger, linked to motor speed? No direct drag that way.
     
  13. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,363

    38FLATTIE
    Member
    from Colorado

    James, I think the power required to run the supercharger would be prohibitive, much like the air scenario, but I'll do the math on it.
     
  14. zibo
    Joined: Mar 17, 2002
    Posts: 2,344

    zibo
    Member
    from dago ca

    Alot of big boats, like cruise liners,
    use electric motors,
    but the generators used to power them are almost as big as the motors they replace!
    The batteries or generator needed would rob all the supercharged power!
    TP
     
  15. squirrel
    Joined: Sep 23, 2004
    Posts: 26,408

    squirrel
    Member

    uhhhh...yeah....as I said, my 5 hp compressor makes about 20 cfm, but my engine makes some power if it gets 1300 cfm. Think about how much electric power you need to run an electric supercharger to feed that much air. And how big the motor would be. And the thing about "conservation of energy" and the other thing about "entropy increases" (these are the laws of thermodynamics, which you kind of need to understand if you're going to try wild ideas like this)
     
  16. belair
    Joined: Jul 10, 2006
    Posts: 4,810

    belair
    Member
    1. H.A.M.B. Chapel

    Read the Moon is a Harsh Mistress-TANSTNAAFL - There Aint No Such Thing As A Free Lunch - Physics never gives more than it takes. (although squirrel will know the extropic(?) exception). I remember the French were trying to make a car run on compressed air a few years ago. there might be something there for you. Good luck. Your idea makes sense in way, I hope you find that way.
     
  17. James D
    Joined: Feb 8, 2007
    Posts: 4,053

    James D
    Member


    Yeah, I guess it comes down to the same thing - you can´t get something for nothing.
    Dumb idea actually. :D
     
  18. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,363

    38FLATTIE
    Member
    from Colorado


    You're right about the First Law of Thermodynamics, but I'm really not trying to get a 'free lunch'. The energy, and work of the supercharger is being replaced by compressed air. Obviosly, it took energy to compress the air, when the air was compressed.

    I'm just trying to 'replace' the HP it takes to turn a supercharger, with HP not from the engine-i.e. the HP it took to compress the air.
     
  19. colorado51
    Joined: Feb 24, 2003
    Posts: 1,578

    colorado51
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  20. rschilp
    Joined: Sep 17, 2009
    Posts: 676

    rschilp
    Member
    from Wylie, TX

    How about this idea.

    I see you using some large size Oxy/Acy tanks to store the air at a huge pressure (2,200psi I think is normal) you can store a lot of power and air that way, when in the pits your compressors there charge them (have to figure out how to get a compressor that powerful on the salt)

    Or maybe even better;

    Get some large Oxygen tanks (from your OxyAcetelyne setup) and mount those in the car, they come with ~2,200 psi I think of Oxy.

    Instead of air with about 20% Oxygen you now have ~99% Oxygen at a huge pressure.

    You feed this into the car at a 10psi to 14psi pressure with the additional fuel required to get the ratio correct, you now have several times more oxygen to burn fuel with than you would have had with air.

    Maybe the implementation isn't perfect, but the idea is sound. If you don't believe me put an oxygen tank in place of a NOS tank and see the performance increase in your car.
     
  21. James D
    Joined: Feb 8, 2007
    Posts: 4,053

    James D
    Member

    No offence, I meant the electric blower idea of mine was probably dumb.
     
  22. Mike51Merc
    Joined: Dec 5, 2008
    Posts: 2,598

    Mike51Merc
    Member

    Volume. volume, volume. It's not about pressure. You might be able to install and control an air pressure tank, but it would only provide you with a few seconds of boost and take several minutes to replenish.
     
  23. 42hotrod
    Joined: Nov 3, 2005
    Posts: 811

    42hotrod
    Member
    from S.E. Idaho

    I love really inquisitive threads, it brings out all the smart guys . I'm not one of them but I'll throw in my .02 cents.

    I see the same problems everyone else is seeing, and that is volume and storage. I am a firefighter for my job, and one of the tools we use for auto extrication is a plain air chisel. We run it with a special regulator off of one of our SCBA bottles. (breathing air) Compressed to a MASSIVE 4500 PSI (not a typo, over 4,000 lbs on our backs when we go in a fire).

    We get about 3 minutes of good tool time before we have to change out the bottle running the tool at 90 PSI. The storage bottles we have in our fire station are filled to 5,000 PSI by a special compressor, and they weigh about 250 Lbs each and wouldn't last you a ton longer even if you had the ability to refill them. The compressors run an average of 30-50 K depending on volume and other options.

    So you see, even compressing at very high pressures for storage, the volume still wouldn't be there. With some amazing engineering you might get a 1/4 mile car to work running the system for 4 or 5 seconds, but 3 miles? I just don't see that as a possibility.

    I would just like to finish out by saying I do love the out of the box thinking, thats why records get broken every year out on the salt!


    Scot
     
  24. rschilp
    Joined: Sep 17, 2009
    Posts: 676

    rschilp
    Member
    from Wylie, TX

    OK, so get a few of those 5,000psi 250lbs tanks and regulators.

    There is a huge difference between 90psi and 10psi to run an engine. I agree that volume is the trick, but being heavy is a good thing on the salt, so a dozen or so of the 5,000 psi tanks may do the trick and give a nice balast for getting going.
     
  25. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,363

    38FLATTIE
    Member
    from Colorado

    Haha! You might want to 'google', and see the results of introducing pure O2- it's very unpredictable, and blows stuff up! It's been tried, though!

    James, I was using the quote from belair. No offence taken- I asked, you answered, and I appeciate that!

    I'm not a very smart guy,for sure, or I wouldn't have asked the question.

    After seeing the numbers, I agree that this is not going to work. I believe that SCBA bottles hold about 80 CF of air, correct? I'd have to have a semi load of them onboard!
     
  26. 42hotrod
    Joined: Nov 3, 2005
    Posts: 811

    42hotrod
    Member
    from S.E. Idaho

    I did think of the difference between the PSI, but what would kill you on the big bottles would be the volume. As Squirell pointed out, you have to think in terms of how much air the engine needs at WOT. To make it simple, with a naturally aspirated Big block, typically you will need around 1,000 CFM for a well built engine. Thats 1,000 cubic feet per minute of air. I googled it and one of those 5,000 PSI bottles (the size is like your big oxygen bottles for a torch) has all this info on it:

    DOT cylinder manufactured in accordance to DOT-E-10869-5000 specification. 472 SCF capacity
    CYL-0062 referenced to 70°F and 5000 PSIG. Nominal water volume 1.59 cubic feet. Includes cylinder valve
    with CGA 347 connection. Valve includes a pressure relief device. Weight, 158 pounds empty.

    heres the link, go to page 2.
    http://www.bauercomp.com/sites/default/files/upload/pdf/Product-Flyers/Storage-Systems-Brochure.pdf

    Thats a lot of bottles for a 1 minute run :)


    Scot
     
  27. metlmunchr
    Joined: Jan 16, 2010
    Posts: 287

    metlmunchr
    Member

    A 350 cid engine at 14# boost will use about 0.2 cu ft of air per revolution. At 6000 rpm, it would use 1200 cu ft in one minute. The biggest high pressure air bottles you can get from a welding supply house hold about 300 cu ft of air, so you'd have to have 4 of those on board to supply the boost for one minute.

    That air volume would scale directly as a function of rpm or engine displacement. For example, a 350 turning 9000 would need 1 1/2 times as much air, or a 525 cu in engine running at 6000 would also need 1 1/2 times as much air.

    One of your biggest expenses in a setup like this would be the pressure regulators capable of handling 1200 cfm at the outlet and 2500 psi at the inlet. That ain't your average oxygen regulator, or even a half a dozen of them in parallel.
     
  28. 42hotrod
    Joined: Nov 3, 2005
    Posts: 811

    42hotrod
    Member
    from S.E. Idaho

    The last problem I see is releasing that type of pressure at a volume high enough to feed the engine. The valves on high pressure bottles have a very small outlet on purpose, fill them too rapidly and the bottles get very hot very fast. Now, release that air rapidly and it gets cold. To the point if there is humidity you instantly get frost buildup on all of your valves and any restriction you have in the system. Just another thought to throw in the mix.
     
  29. Mike51Merc
    Joined: Dec 5, 2008
    Posts: 2,598

    Mike51Merc
    Member

    I'm not a chemist, scientist, engineer, or race car mechanic, but I think 99% oxygen at high pressure would probably send your car into a 5 second quarter mile--1/4 mile straight up into the sky!

    Nitrous Oxide (as an oxidizer not a fuel) has been used to do what you propose a bit more safely.
     
  30. 42hotrod
    Joined: Nov 3, 2005
    Posts: 811

    42hotrod
    Member
    from S.E. Idaho

    Yeah, and nitrous has ONE extra oxygen molecule, Imagine 99% :eek:
     

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