Dry Ice in airbox

[cntp]

Originally Posted by DoGood

Fill 2 liter bottle half way with water. Drop piece of dry ice in bottle. Replace lid on bottle. RUN -dry ice bomb-

I always preferred the "works bomb" Take 2 liter bottle, fill with a product called "the works," I think it is basically a draino type substance you can get at walmart. Take small bits of aluminum foil and put in the bottle, replace lid.

now back on subject... there are better things to do with dry and better things to do to your rig.

Yes, I've done both of those. Dry Ice can blow up 2-liter bottles, yes, no problem. A dog house, I doubt it.

[mrcarcrazy]

Guys, superchargers do heat up the air. by multiple means. and ice in the intercooler (air to water) does work wonders for lowering temps. Spraying N20 or CO2 over the external fins can help as well. but I see it as a waste.

Actually why would one use an intercooler (extra weight) if it didn't yield more HP.?????

When the Blower is creating boost it is creating heat.

[dcorn]

Originally Posted by mylt1

you need to get that money back for that degree then. 20PSI is NOT going to make a dramatic increase in air temp. thanks for playing though. operating temp is operating temp no matter if your making passes at the track or driving down the street. what do you think the cooling system is for? it MAINTAINS a constant temp. also, a cold engine runs WORSE than a warm one because the ECM is trying to get the motor up to op temp so it runs the car rich, kinda like what a choke does on carbed motors. again, when you learn more about motors and how cars work please feel free to come back and try again.

Dude, please get this through your head. Coolant temp is far different than intake air temp. Do you know how a supercharger works? It compresses air and forces it into the cylinders. Compressing air increases the temperature, so super hot air is going into the cylinders. If you cool the air before it goes into the engine, you can fit more air in each cylinder. More air equals more power. This has nothing to do with the coolant temp that you are seeing on your dash gauge.

Most cars have an IAT sensor (intake air temperature) or sometimes it's integrated into the MAF. This tells the car how hot the air is going into the motor. That air gets too hot and it can cause detonation, so the PCM pulls timing which decreases power. Putting a bag of ice on the supercharger or the intake manifold will cool the material for the next run and give you slightly cooler IAT's. Cobra guys put ice into their intercooler tanks because it makes the coolant going through the intercooler colder, making the IAT's much lower. This results in more power and faster times.

Full on drag cars don't use intercoolers. They don't make consecutive runs without tearing apart the engine and checking/replacing parts. They don't have to worry about heat soak in their superchargers because they are one run and done. Comparing pro drag cars to weekend racers is a bit ridiculous. I guess I should be using nitromethane or 100% methanol instead of 93 octane too.

[Unlimited04]

Originally Posted by mylt1

20PSI is NOT going to make a dramatic increase in air temp. thanks for playing though.

you need a lesson in physics. Read up on the Ideal Gas Law.

You can even do the math yourself:
Racer Math and Engine Performance Calculations
Supercharger Calculators Explained

20 PSI = ~2.4 times temperature increase. Compressing air at 50*F to 20PSI will heat it to ~120*F.

In fact, if compressed air did NOT heat up dramatically, diesel engines would not exist.

[mylt1]

your contradicting yourself. first you say coolant temp has nothing to do with it but then your talking about a coolant based intercooler. so which is it? you cant keep your story strait. detonation happens with your running TO MUCH BOOST and the system is running hot which is why you need a retarder to adjust your timing. also, i know of NO pro drag teams that tear down after every run. motors are usually ran 2-3 runs before tear down. clutches may get replaced but not full motor take downs. get this through your head, IF THE INTAKE ARE TEMPS ARE LOW THEN THEN ECM WILL ENRICH THE FUEL/AIR MIX TO GET THE CAR UP TO OPPERATING TEMP. how hard is that for you to understand? the can also be accomplished buy the ECM bumping the RPM's up to help with warming the motor. a WARM(opperating temp) motor runs better than a cold motor.

[Bigbob]

Originally Posted by Unlimited04

20 PSI = ~2.4 times temperature increase. Compressing air at 50*F to 20PSI will heat it to ~120*F.

In fact, if compressed air did NOT heat up dramatically, diesel engines would not exist.

Ditto. This is the reason why water or other liquids like cold coffee is used in enemas instead of compressed air. The compressed air gives you bad hot a$$.

[mylt1]

Originally Posted by Unlimited04

you need a lesson in physics. Read up on the Ideal Gas Law.

You can even do the math yourself:
Racer Math and Engine Performance Calculations
Supercharger Calculators Explained

20 PSI = ~2.4 times temperature increase. Compressing air at 50*F to 20PSI will heat it to ~120*F.

In fact, if compressed air did NOT heat up dramatically, diesel engines would not exist.

i meant to come back and address that. i know of no stock street legal cars that could handle 20lbs of boost. my bad for not correcting that.

[Tony89]

Originally Posted by mylt1

get this through your head, IF THE INTAKE ARE TEMPS ARE LOW THEN THEN ECM WILL ENRICH THE FUEL/AIR MIX TO GET THE CAR UP TO OPPERATING TEMP.

get THIS through your head: the ECM does not monitor IAT for warm-up enrichment. it monitors COOLANT temp. the ECM will add extra fuel causing the cylinder (and exhaust) temps to be higher than normal until the engine is up to operating temp.

the ECM monitors IAT for fuel delivery. most factory ECMs (at full operating temp) will try to obtain a 14.7:1 air-fuel ratio. cooler air is denser, thus requiring more fuel to obtain the correct AFR.

so it would stand to reason: for an engine to make power it must have 3 things: air, fuel, and spark. spark is held constant - you will get the same amount of spark energy regardless of how much air or fuel is in the combustion chamber. if spark is held constant, the only way to make more power is to increase the amount of air and fuel in the combustion chamber, while maintaining the AFR. since an engine is only capable of flowing so much volume of air, the only way to get more air in the engine is to make that volume of air more DENSE. the only way to get air more dense is to make it COLDER.

here's how ice works: the IAT sensor reads a COLDER air (which is calculated into an air density) and adds more fuel to keep the AFR correct. this effect is only amplified in the case of forced induction cars where the compressing of air heats it up.

[Tony89]

Originally Posted by mylt1

i meant to come back and address that. i know of no stock street legal cars that could handle 20lbs of boost. my bad for not correcting that.

c'mon now! you can't talk about top fuel dragsters in one part of your argument and then discount them later.

regardless, physics is physics. physics doesn't not know what class its racing in.

[notmyj]

I'm gonna jump in here as I have a bit knowledge, both classroom and hands on in the pits.

To the reference to top fuel cars:

They do not get iced down as they are torn apart, and rebuilt in 72min. When dissasembled the components have time to cool, if they are reused at all.

Also, keep in mind that most if not all pros, top fuel, pro stock, funny car, alky, even the sportsmans classes are running dry blocks. Which means THERE IS NO COOLANT in the engines. The KB blocks that most guys are using don't have cooling passages. And the guys in the few classes that are running factory'ish blocks have mosly filled them with with "dry block". There are multiple advantages to this in a drag race application.

Also notice that none of these cars are driven to the line. They are pulled through the staging lanes, then pushed to the water box. Then fired for the burnout and staging, then the run.

As for the weekend warrior at the local track, yes it does make sense to ice down the roots type blowers, and superchargers. Ice down a turbo? Not so much. For the average joe at the local track with a blower running under 11's in the 1/4, it absolutely makes a difference, IF it is kept cool till the last minute. Meaning, the car has ice on it as soon as it gets to the pits, and is pushed through the staging lanes, to the water box, then fired.

The regular guy isn't gonna be doing half track burn outs, nor spining the blower into much if any boost to heat the tires. If its done right, that is.

Cooler intake air temps will net you a(ballpark) gain of 1% in power for every 10* at atmopheric pressure at sea level. The amount of power gained from lower air temps increases exponentially as air pressure is increased. Meaning, a 10* temp drop will net a lot more that 1% gain at max boost.

As for what that pressure is? I have seen them over 40psi on top fuel and alky cars, turning 14-71 blowers. None of that little 8-71 stuff they sell at Summit Racing.

And yes the alky cars are a bit different s they will ice up the intakes. Nitro and gas will not.

Moroso makes fuel cooler that mounts to the firewall and is filled ice. it runs the fuel through the ice bath in an aluminum heat exchanger, then to the fuel injectors or carbs. The fuel will get a bit more dense, but more importantly, it lowers the over all temp of the incoming air fuel charge.

I could go in to more detail, citing the formulas for heat vs temp (temperature and pressure are directly related) and other stuff but my thumbs are getting sore as I'm on my blackberry.

Bottom line, yes icing down a blower, will net a gain. If measures are taken to keep it as cold as possible as long as possible. Even if that gain is only there for the first 3 seconds of a run. In bracket racing, races are won and lost at the tree, not in the traps. Cooling the incoming air with an intercool/aftercooler, etc will net HUGE gains. Even the liquid to air intercoolers that run "hot" engine coolant will net a big gain even on street cars.

Some street cars are getting close to if not over the 20psi mark from the factory, so yes this is relevant even to factory cars.

[Unlimited04]

Originally Posted by mylt1

i meant to come back and address that. i know of no stock street legal cars that could handle 20lbs of boost. my bad for not correcting that.

FYI: Lots of street legal cars can run 20lbs of boost. WRX STi's, Mitsu's, Cobra Mustang, SRT4, turbodiesels...some of those can even do it on the stock turbo/supercharger...

[dcorn]

Originally Posted by mylt1

your contradicting yourself. first you say coolant temp has nothing to do with it but then your talking about a coolant based intercooler. so which is it? you cant keep your story strait. detonation happens with your running TO MUCH BOOST and the system is running hot which is why you need a retarder to adjust your timing. also, i know of NO pro drag teams that tear down after every run. motors are usually ran 2-3 runs before tear down. clutches may get replaced but not full motor take downs. get this through your head, IF THE INTAKE ARE TEMPS ARE LOW THEN THEN ECM WILL ENRICH THE FUEL/AIR MIX TO GET THE CAR UP TO OPPERATING TEMP. how hard is that for you to understand? the can also be accomplished buy the ECM bumping the RPM's up to help with warming the motor. a WARM(opperating temp) motor runs better than a cold motor.

Originally Posted by mylt1

i meant to come back and address that. i know of no stock street legal cars that could handle 20lbs of boost. my bad for not correcting that.

In addition to the stuff that Unlimited04 and Tony89 said, let me clarify for you.

03 Cobras have liquid to air intercoolers. There is a completely seperate system with coolant running through it to cool the air after the supercharger. The heat exchanger in front of the radiator cools down the coolant, which is then pumped through the intercooler in the lower intake manifold. This is what cools the air after the blower, effectively lowering IATs and allowing more air into the cylinders (more power). Many owners, especially those that drag race, get bigger intercooler tanks that allow them to be filled with ice. This sends very cold liquid through the system and gets the IATs down a lot. Even if the engine coolant is at full operating temperature, the IAT's will still be cold.

Oh, and there are tons of cars out there now that can handle 20psi. 03/04 cobras can run over 20 psi on a whipple or Kenne Bell and make low to mid 600s. I have a friend with a 04 that has a stock motor and a 76mm turbo making over 700whp at around 24psi.

[mightydog78]

i imagine it works just as good as a K&N air filter....doesnt work at all

[DunerDude]

Originally Posted by mightydog78

i imagine it works just as good as a K&N air filter....doesnt work at all

haha ahmen, I went back to OEM paper elements after reading all of the bad threads. I did run a tube from my airbox to my cowl area to help suck cooler air though....

[Mark4883]

Heard about this myth when I took an engine R&D program in college, its total BS.