JT Valves

Have you considered injecting liquid air which is -312F into the system? Nearly anyone who sells liquid nitrogen or liquid oxygen can supply it. It is used for welding and making fog at rock concerts. Spraying the liquid into the air stream should suffice to evaporate it.

As long as you keep it cold it remains a liquid. You won't need to pump it, a pressure cap on the storage tank will suffice. It might make a weight problem for a long race, however.

bill michaels

Bill Michels: Thank you for your help! I am drag racing a quarter mile at a time, so you may be on to something I can really develope/innovate into a real horsepower gain. In the late 70's I was a mechanical tech at Fermilab in Batavia, Ill., building a liquid helium plant where I was first introduced to the world of cryogenics. Am I correct in your proposing to inject liquid oxygen directly upstream from the turbo outlet....., rather than a series of JT valves?...., and the liquid nozzles would turn gaseous(sp?) upstream in the course on the way to the carb giving me a 45# boost pressure of really cold oxygen? Big inch drag motors absolutely LOVE cold air!!!!! If I can use a liquid oxygen bottle on-board and spray it via a few nozzles directly into the boost stream....., that could be worth an easy 100 horsepower!!! Please tell me I'm on the same page as you.

I didn't mean oxygen. Oxygen in any appreciable quantity will ruin your motor, although maybe you could get by with a little. My idea was to COOL your inlet air by mixing it with air at -312F, making it more dense. Same idea as an intercooler. The liquid air will not make much difference in carburation, but you might be able to go to a size bigger jet in the carburator. I certainly wouldn't try pure oxygen, but maybe you could use liquid air which had slightly more oxygen in it than normal. This can be easily accomplished by letting a bucketfull of liquid air set. The nitrogen will evaporate off first and the percentage of oxygen will increase. Be careful, liquid oxygen presents a tremendous fire hazard, and make things explode which wouldn't otherwise.

You might want to try injecting the liquid air at the turbocharger inlet; this should give more pressure through a "super sea level " effect. Maybe even inject both places.

You will probably disappointed to find how big a tank it will take to help for long.

Good luck

bill michaels

wait. what's a JT valve again? is it a joule thomspon expansion valve

Mr. Guest, Yes, I think that is what I'm looking for. Did you ever take a valve core out of a valve stem on your tire and feel how cold the air is coming out on your fingers? There is some science going on there that when you have air pressure that has to neck down thru a reduced size opening the molecules loose energy and that in turn looses heat !!?? I was a pipe welder at Fermilab and welded a few of these jewels , not funny, joules thomas valves in the high pressure helium 4 and 5 inch pipes on the way to the liquid nitrogen intercoolers. When I asked what they did..., I was told what I just mentioned about the valve core removal. I thought that was really cool technology and thought I could apply it to drag race technology? Thank you for your curiosity, can you help me?

JT valves are most efficient when you have a large pressure drop. Your idea is good, but I don't think there is enough pressure drop in your system to achieve any useful cooling. The idea of bringing pressurized gas (or liquid) on board works thermodynamically, but after you calculate the volume you will need to make a difference, I think you find that you can't afford the weight or the space.

I'm assuming that you want to end up with high pressure, cool air blown into the engine. In that case, each expansion valve, to operate, must show a pressure drop -- i.e., the air must expand -- lose pressure. You could expand it back to its original (pre- turbocharger) pressure and back to its original temperature. At that point you'd have an expensive, complicated, normally-aspirated engine. Instead, you could use an intercooler which will cool the charge without having to expand it. This could be air cooled, ice cooled, water cooled, etc.

Dear Ken, Thank you for your wisdom. You are exactly correct. Every one else in the industry offers intercoolers, air to air, water to air, ice to air. I was mistakenly thinking I was on to something brilliant - using cryogenics technology instead of draining melted ice and refilling an intercooler after every run. On an 85 degree day you go thru 20 pounds of ice. I was hoping to run 45 # of boost thru a few jt's and still have 45# of boost on the way to the carb...., only 50 degrees colder without carrying 20-30 pounds worth of water/ice along for the ride. I guess this falls in the "there is NO free lunch category huh? Thanks for your help!!!!!!!! Jim sabin.

What if you were to use an intercooler that was plumbed to a CO2 bottle. By varying a restrictor leading to the intercooler. You would be able to control the time the bottle lasts versus the temperature drop of the incoming charge.

Bob,
Although I haven't done the math, I suspect that any bottle of CO2 you could fit in a vehicle, won't supply enough cooling power to have a measurable effect on the volume of air that requires cooling for a 1/4 mile run.

Nor have I. But in theory it would work. It's just the damn logistics of it all.