Interfreezer = Air to CO2 Intercooler

[rs182]

I have been researching intercoolers for my 2001 BMW 540i w/ a Vortech V-2 @ 8 psi. Due to space limitations I am not able to run a FMIC. I have come across a product called the Interfreezer by CryoFuzion. It seems to work just the same as a cylindrical air-to-water intercooler, but instead of water it uses the conversion of liquid CO2 to gaseous CO2 (-109 F) in the intercooler to cool the air charge. Does anyone have any input or additional information about the Interfreezer? Please no comments about CryoFuzion's other products (Cheetah Jets, Flowducer, etc...), I realize they are pretty terrible.

[Evil Result]

there's a jacket of compressed CO2 around your intercooller when the hot intake charge heats the liquid CO2 it boils removing the heat from the intake air and through convection moves the hot gas CO2 to the cooler jacket of the intercooler to dissapate the heat the CO2 then retuns to a liquid to repeat the process.

A liquid can transport and hold heat more effectively than air, the liquid CO2 can hold ALOT of heat and move it fast but if you have to much heatgoing through the intercooler to vaporize all the CO2 or your not cooling it good enough then the jacket of CO2 will be like a blanket.. holding the heat in... it all depends on the design.

A good concept, but i'm not shure how much it will weigh, if the design is good enough it could be a more effective way to creat a colder intake charge efficiencies up to 90-95%(big guess).

[rs182]

The CO2 is not compressed inside the Interfreezer, the solenoid comes before the Interfreezer unit and is holding the pressurized liquid CO2 behind it. When the solenoid opens the extreme pressure is relieved from the liquid CO2 and it converts to gas. The conversion of liquid CO2 to gaseous CO2 is what creates -109 degree temperatures. The gas inside the Interfreezer must be purged out somewhere or it may liquify again and insulate the air charge as you said (although I'm sure the Interfreezer would explode due to the tremendous pressure first). DEI offers a similar product, although it appears CryoFuzion's would prove more effective at transferring heat. Does anyone have any knowledge of intercooler design that might help prove or disprove the efficiency of the Interfreezer? Go to www.CryoFuzion.com and read about the Interfreezer. (Mods please edit if no site posting is allowed).

[Neutrino]

Well i've tried to find on the website a proper description of how it works but I guess i've missed it or something. that is a horibly designed website they have over there.


I can see only two ways it could work. Either it sprays CO2 over the intercooler from a pressurised bottle that you have to refill, or it is self enclosed and it works like a regulaar fridge and in that case it will need another big heatsink and a compressor.

[rs182]

The system is set up very similar to nitrous. You have a tank filled with CO2 under pressure so that it is a liquid (Vapor pressure of CO2 is about 860 psi @ 70 F). The liquid CO2 is pressurized all the way to the solenoid right before the Interfreezer. When you open the solenoid the CO2 rushes into the Interfreezer and loses pressure, therefore becoming a gas. You must find somewhere to vent the gaseous CO2, whether it be through one of their more "ingenious" products or through a vent tube. They do have a terrible website, hopefully they are in the process of updating. I plan on calling them and getting the specifics of their system, I'll post my findings to try to shed some light on the mysterious Interfreezer.

[Neutrino]

Originally Posted by rs182

The system is set up very similar to nitrous. You have a tank filled with CO2 under pressure so that it is a liquid (Vapor pressure of CO2 is about 860 psi @ 70 F). The liquid CO2 is pressurized all the way to the solenoid right before the Interfreezer. When you open the solenoid the CO2 rushes into the Interfreezer and loses pressure, therefore becoming a gas. You must find somewhere to vent the gaseous CO2, whether it be through one of their more "ingenious" products or through a vent tube. They do have a terrible website, hopefully they are in the process of updating. I plan on calling them and getting the specifics of their system, I'll post my findings to try to shed some light on the mysterious Interfreezer.

Yes i'm quite familiar with those types of systems. the idea is simple and good. However you seem to want to use this system instead of an air to water intercooler. And while it might be more efficient it can work only for short times while an air to water works continuously. Those types of coolers are normally meant only to boost a regular intercooler.


BTW instead of CO2 why not use regular air, even if its boiling point is higher its endotermic effect during expansion should be more than enough to supercool the intercooler. And air is much cheaper that CO2 to fill.

[rs182]

The reason I am looking into the Interfreezer unit instead of an air-to-water IC is because of the limited underhood space I have the work with. I do understand that the CO2 cannot flow constantly - it wouldn't last very long at all. I plan on purchasing a 20 lb. bottle so refills won't have to be so frequent. My plan is to engage the system during the burnout at the drag strip, or maybe before prestaging depending on how fast the air charge is cooled. I'll leave it on for the duration of the run and disengage it after I've passed the quarter mile marker. What do you think of the Interfreezer vs. a usual Air-to-Water IC in terms of size (therefore ability to transfer heat). Most Air-to-Water IC's I've seen are fairly small and comparable in size to the Interfreezer. Probably due to H2O's greater capacity for heat abosorption?

[Neutrino]

Originally Posted by rs182

The reason I am looking into the Interfreezer unit instead of an air-to-water IC is because of the limited underhood space I have the work with. I do understand that the CO2 cannot flow constantly - it wouldn't last very long at all. I plan on purchasing a 20 lb. bottle so refills won't have to be so frequent. My plan is to engage the system during the burnout at the drag strip, or maybe before prestaging depending on how fast the air charge is cooled. I'll leave it on for the duration of the run and disengage it after I've passed the quarter mile marker. What do you think of the Interfreezer vs. a usual Air-to-Water IC in terms of size (therefore ability to transfer heat). Most Air-to-Water IC's I've seen are fairly small and comparable in size to the Interfreezer. Probably due to H2O's greater capacity for heat abosorption?

Well I haven't seen any instrumented testing between the two so I cannot say which one would be more capable of tranfering heat given the same size.

However what worries me is that without a constantly functioning intercooler during daily driving the intake temperatures can soar, especially during hot days, and this could lead to detonation. Although with only 8 psi its not extremelly dangerous.

[rs182]

That is my only concern Neutrino. My supercharger system is made by Dinan for my 2001 BMW 540i and installs operating at 6 psi. I have read about a few 540i's running up to 9.5 psi (smaller pulleys) with the exact same system and not experiencing any detrimental effects. The main reason I'm considering an intercooler is get more power out of the supercharger system without voiding my warranty (BMW's love to be serviced!). Nitrous is still an option, definitley a 50 shot couldn't hurt, after the warranty expires that is.

[Neutrino]

Originally Posted by rs182

That is my only concern Neutrino. My supercharger system is made by Dinan for my 2001 BMW 540i and installs operating at 6 psi. I have read about a few 540i's running up to 9.5 psi (smaller pulleys) with the exact same system and not experiencing any detrimental effects. The main reason I'm considering an intercooler is get more power out of the supercharger system without voiding my warranty (BMW's love to be serviced!). Nitrous is still an option, definitley a 50 shot couldn't hurt, after the warranty expires that is.

Are you sure the super won't void the warranty IC or not? Or is Dinan factory aproved?

But anyway I think a nice compact air to water in my opinion would be your best bet. Its nice to have a little bit of insurance against detonation during daily driving by having colder intake air.


BTW i know yoy said you have no space for an FMIC but for only 8psi it can be pretty small. maybe you can make some supports and fit one in there. the SRT4 intercooler might work its a bit long but quite short so it might fit under the radiator. Or even the new mazdaspeed miata IC that thing is tiny.

[rs182]

Dinan covers any part of the warranty that isn't covered by BMW. I'm actually having warranty work done on it on Monday. The supercharger system isn't working very well and my BMW dealership is terrible and didn't install some part of the system right so Steve Dinan is flying out from California to fix it. I'll keep looking around on the car to try to find a spot to fit a small IC. If I do end up getting the Interfreezer I'll post my results. Do the tubes that carry the intake air on Air-to-Water IC's run in straight, parallel paths through the core like Air-to-Air IC's?

[SaabJohan]

A watercooled intercooler can usually be made very small. When used with a turbocharger the system will cool itself when off boost but I'm not sure how that will work with a supercharger. 8 psi is a quite low pressure, and the temperatures we should expected are around 80 degC when it's 20 degC outside.

For a watercooled system a tank, pump and a small cooler is required. It should also be possible to supercool the water (well, actually coolant should be used) by using CO2 or similar or by using the AC system in the car. However, the simplest way is usually by trying to find an air to air intercooler that will fit, you usually can fit them somehow.

The system Evil Result described is in violation of the thermodynamic laws, heat won't transfer from a colder body to a warmer one. The only way to get this to work is to introduce a compressor for the cooling fluid.

[rs182]

I agree an Air-to-Air would be the way to go, but the custom tubing and modifications necessary would prove to be too difficult and expensive to justify. The design of the Interfreezer seems very similar to that of an Air-to-Water IC and has a MUCH colder medium for heat transfer one would think that it would effectively cool the intake air. I never made it to Thermodynamics while I was majoring in Mechanical Engineering (Changed major to Pre-Med), so if anyone has an extensive knowledge of the subject please comment!

[SaabJohan]

The problem with using CO2 is that when once ised it's wasted, water is cooled and recirculated.

To fix a good air-air intercooler shouldn't be that difficult. Buy an intercooler from some truck or car that fits (you doesn't need to buy a new one). Use a saw if you need to reduce the size of it. Fix the end tanks and buy aluminum tubes with a suitable size. Then it's just to try to find someone that can weld it together.

[rs182]

I have since decided that the use of nitrous would be more effective. Nitrous oxide's boiling point is -127 F, compared to CO2 @ -109 F! I emailed a bunch of companies about the intercooling efficiency of nitrous, the general consensus was to double the horsepower output of the shot you are using (25 shot = 50 HP, 25 extra from intercooling).