I just need some opinions on the Co2 spray that mounts in front of your intecooler. I heard it's a good idea for traffic or drag race driving to lower the temp. Just want to know if this is a good idea for an upgrade or not, thanks

 

What else do you have done to the car? It isnt very pricey but sometimes there are ting that are higher up on the list of importance.

 

Here's the engine:

Engine, it's a jap motor (‘95 JDM)
w/ jacob electronic ignition box, msd wires, ngk racing plugs 9 and
11.5 heat range.
Walbro fuel pump 255 lph
rotary extreme fuel rail for it w/ bosch 1000cc secondaries
The fly wheel is act street light, also new w/ act 6 puck clutch
Oil cooler, there only one, but it's a Morosso 11"x9"x1.5" huge w/ all
-10 stainless lines and A.N. fittings.
The V-mount set up is: the radiator is a Koyo, the inter cooler is an
Evo 8 w/ Precision turbo elbows and tubing.
turbo kit is a Greddy 20g w/ 50 mm racing gate,
power FC ems

 

One thing to think about is where your intake is drawing it's air from. You don't want them sucking CO2 instead of fresh air.

 

I can't tell you whether it is a good idea or not because mine is still under construction. I am doing the full CRYO2 system, air, fuel and dual IC sprayers.
Opinions from previous threads indicate a strong inclination toward water/methanol injection rather than the CO2. Big concern expressed was drawing CO2 into the intake. Don't know whether this is valid or not. Basic N-tercooler or CRYO2 system will cost ~$300, a full system, more like $800.

 

I would bet that an electric fan would be more effective, and best yet it won't need to be refilled. Here's how you can test this:

1. Measure how quickly your coolant temps decrease when the fans turn on. At idle, write down the temp when the fans activate, then measure the time it takes to cool the car down to 180F (82C).
2. Try spraying water on the radiator (when the fans are off), and compare which setup decreases temps more quickly.

-s-

 

Water is not CO2. I don't remember the exact # but the CO2 is at something like
-80 degrees F. You can't even hold the hose the CO2 goes through. When I was speaking of water/methanol injection I was speaking of an Aquamist or similar system.

 

you'll lose power with the co2 sprayer. it'll dilute your intake charge.

water/meth injection would work about 100x better.

 

This has been debated on other threads at length with no definitive conclusion.
Depends on where you spray, where the escaping air is routed, where your intake is, etc., etc. It's not simple and I certainly don't profess to know the answers it's just something that makes good intuitive sence on a turbo/supercharged car and I thought I'd try it. To me it makes better sence than injecting atomized water into my engine, but again, that's just me.

 

I've been reading Corky Bell's book "Maximum Boost." His opinion on water injection is that it's a bandaid and shouldn't be used, although he probably never owned one of these cars.
I have a very basic WI injection because it's my understanding that it keeps rotaries from getting carboned up and it helps prevent detonation. If you are using it for performance and tuning the car for it, then it better have built in fail safes like being able to detect clogged nozzles, etc. If you can be sure your intakes aren't sucking CO2 then by all means install the system. Although short lived, the temp drop CO2 can provide is greater than what WI will provide. Personally I want to build an air to water IC. Just for the hell of it.

 

The "Just for the Hell of it" is why I did the CO2 system. We all want our cars to
be a bit unique and it is an interesting system to install. I'm almost embarrased to say I routed plume sprayers in the fender vents with a seperate switch; just to "rice it out" a bit. I am quite curious to run it.

 

There was a show on the discovery channel about the bermuda triangle and one myth for the disappearnce of aircraft was Co2 pockets underwater releasing into the air. So they took a aircraft engine and set it up and with the engine running they ran Co2 by the intake and with a very small amount it shut the engine down, So it can affect your engine. Also the same company DEI used to sell a system called the CHEETA system they dont sell it anymore but some of you might remeber it and what it was designed to do was it was like a purge that you mounted towards the front and to the side of your car and the idea was to inject into the airpath of the car you are racing, And i never understood what it did until i saw that discovery channel show. So be careful

 

heyy guys, bringing this thread back up bc I'm def interested in the N-Tercooler system. If you use the Intake Heat Shield I see people using on here, wouldn't you be able to effeciently seperate the air coming from through the intercooler(if using the N-Tercooler setup, this would be C02) from the intake? It just appears to me that if you can fabricate intake piping from the front of the vehicle and seperate the intercooler's exhaust air from the intake, this system would not be a bad idea... anybody have any other reasoning why it would be?

See pics...
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/my-custom-heat-sheild-pictures-galore-164836/

 

This may be a stupid question, but isnt the spray from a purge kit of no2 extremeley cold, and if sucked into the intakes would also produce hp gains. I know no2 is not the smartest thing to do to a rotary but it seems like MUCH less would go into the intake... or would this cause issues with heat and the gas actually detonating... also what about oxygen pure oxygen spray?

 

The C02 doesnt go anywhere near the intake of the engine. its sprayed onto the outside of the intercooler. so unless you have holes in your intercooler it cant dilute the intake charge.

I have used it before, but unfortunately didnt notice much difference on intake temps. but i had a pretty big FMIC so lots of mass to try to cool down with a small amount of spray. Its a good idea in principle, I just didnt notice much benefits in practice

 

Actually it's just 12 inches from the I/C to the air intake. If you're running a hot air intake (which I see so many people doing), the risk does exist.

Not sure if the quantity of no2 is sufficient to get you in trouble.

The beauty of using clean water is that 1) the engine doesn't care about water vapor much 2) it's cheap 3) it won't damage stuff. I have to admit CO2 is pretty scary - if it's enough to drown out someone else's engine, it can't be good for you. Plus if the tank leaked in your garage you could pass out and die pretty easily.

Dave

 

No more scary than a fire extinguisher. You can spray NO2 rather than CO2 it is just a lot more expensive. Both cool very well but NO2 is obviously combustable.

 

Except that fire extinguishers have a manual safety. Any kind of sprayer could leak, not the kidn of thing I'd want to discover in my garage one morning.

I guess a NO2 leak would be similarly hard to notice, but less likely to asphyxiate you.

I'm not trying to say these systems are dangerous, but if it has a positive shutoff valve, I for one would use it. These systems do add some safety concerns.

Dave

 

Well what I was suggesting was using this spray option with a SMIC and a heat shield. It appears to me that most, if not 100%, of the C02 would be blocked by the heat shield from entering the hot air intake. Something like a FMIC I could see where gains would be minimal, as the temps of the FM are normally much lower already than the SM. But the stock SMIC is a known heat sink, and I believe temperatures that cold would make a drastic difference on the intake charge. But my original question was, does anybody have an opinion on the effectiveness of the intake shield blocking the C02 from entering the intake?

 

nothing?

 

I'm very likely to try it if I can get some people with some prior experience to share some information on this topic. I'm sure I'm not the first to think of this, but this has been out for awhile and its not a common mod you see to the RX-7. My question is... why?

 

Looking at it from a different point of view: it's been shown that any well-seald CAI setup does substantially reduce intake temps. So therefore the heat shields do work at keeping the hot post-intercooler air in the engine bay and out of the intake, which to me says it will substantially reduce the spent CO2 getting in the intake too. Just how much is hard to say.

Dave

 

Well I may just have to be the test dummy then, because in theory, it works. My only problem with N02 is the flammability factor... last thing I need is my engine to overheat somewhere and catch fire, and have N02 spraying all over the bay...