Does dry ice really help?

[black mamba1]

Its June and its hot as hell down here in NC. Gonna do some test and tune. I hear alot about guys using dry ice to cool their intakes before doing a 1/4 mile run. I have some questions maybe u guys can help me with:

1. Does dry ice really help 1/4 mile times?
2. Where and how do you put it on an SRT for maximum cooling effect?
3. Is there any danger to the intake from dry ice, like possible hairline fractures?
4. Should the ice be placed in special packaging while sitting on the intake?

Any advice would be appreciated!

 

[rcl4668]

Its June and its hot as hell down here in NC. Gonna do some test and tune. I hear alot about guys using dry ice to cool their intakes before doing a 1/4 mile run. I have some questions maybe u guys can help me with:

1. Does dry ice really help 1/4 mile times?
2. Where and how do you put it on an SRT for maximum cooling effect?
3. Is there any danger to the intake from dry ice, like possible hairline fractures?
4. Should the ice be placed in special packaging while sitting on the intake?

Any advice would be appreciated!

I remember in one of the glossy car mags (C&D, R&T) Hennessey had one of his cars in a supercar comparison and the article noted his prep procedure; this included placing dry ice on the intake plenum. From a basic science perspective cooling the engine and the intake temps would increase the density of the air-gas mixture which would be good. Like throwing cold water on really hot brakes before a cooldown, however, I would be concerned about cracking.

 

[Neil - UK]

cant say ive seen dry ice here, but normal ice bagged up and removed just before start up, also a few blasts on intercoolers etc from a CO2 fire extinguisher

 

[black mamba1]

cant say ive seen dry ice here, but normal ice bagged up and removed just before start up, also a few blasts on intercoolers etc from a CO2 fire extinguisher

What kind of bags? Plastic bag would melt from heat, paper would leak...

 

[black mamba1]

I remember in one of the glossy car mags (C&D, R&T) Hennessey had one of his cars in a supercar comparison and the article noted his prep procedure; this included placing dry ice on the intake plenum. From a basic science perspective cooling the engine and the intake temps would increase the density of the air-gas mixture which would be good. Like throwing cold water on really hot brakes before a cooldown, however, I would be concerned about cracking.

I am also concerned about cracking.

 

[JonB]

Your intake manifold is not hot enuf to melt a plastic bag, carfully placed. Howevere, some drag venues discourage or police or prohibit normal H2O ice melting, because even if bagged or double-bagged it can drip water which then runs out on the track when / after you launch.

Dry-Ice evaporates to a CO2 gas and does not leave liquid, and is much colder. It should be covered for safe handling, and NOT laid bare onto the intake. Heat Rises, Cold Sinks. So the sinking cold is very useful in minimizing post-run and then pre-run heat soak, an enemy of low ETs after multiple runs. Especially while sitting in slow-moving staging lanes.

Once the engine is started, the first cold "GULP" of air is gone....but the cold housings still postpone more heat-soak. In the car-mag tests, there are no prolonged heat-soak wait times, but the Dry-Ice still ensures a cold top end, and is cool-looking as well as spooky-cool as the ice evaporates like a mad-scientist's brew.....

 

[1BADGTS]

Been involved in MANY a Mag test with my Vipers over the years as Evan Smith and his test drivers ALWAYS use bags of ice to cool the cars down between runs (placed on top of intake along with large fans ).But Evan is also one of the best drivers in the country on stock tires -able to get every once of performance out of a car at the drag strip.Unless you have that ability the bit of extra power from running a car cold may be worthless.

 

[black mamba1]

This is great info! Thanks guys! Hey 1badgts, does Evan Smith use regular ice from a convenience store? Or does he use dry ice also?

 

[1BADGTS]

This is great info! Thanks guys! Hey 1badgts, does Evan Smith use regular ice from a convenience store? Or does he use dry ice also?

They supply it(reg ice) at Englishtown for him .When they test they have the luxury of letting those cars sit for an hour should they choose between runs .

 

[1BADGTS]

Ps on a real hot day if the motor is thoroughly cooled down between runs i would ventute to say you will pick up a good 20 to the tire running at around 140 degrees or so.

 

[Chuck 98 RT/10]

Heat Rises, Cold Sinks. So the sinking cold is very useful in minimizing post-run and then pre-run heat soak, an enemy of low ETs after multiple runs.

That's liberal use of the term heat soak Jon. If street legal drag racers are experiencing heat soak at a dragstrip they've got some serious cooling issues. Other than that I agree with your reply.

 

[1BADGTS]

That's liberal use of the term heat soak Jon. If street legal drag racers are experiencing heat soak at a dragstrip they've got some serious cooling issues. Other than that I agree with your reply.

Believe it or not even at the drag strip it helps as on a hot day with a Pro BEHIND THE WHEEL i seen ET drop 2-3 tenths by cooling the car between runs.On these blower cars even more.

 

[JonB]

That's liberal use of the term heat soak Jon. If street legal drag racers are experiencing heat soak at a dragstrip they've got some serious cooling issues. Other than that I agree with your reply.

Ps on a real hot day if the motor is thoroughly cooled down between runs i would ventute to say you will pick up a good 20 to the tire running at around 140 degrees or so.

.... as 1Bad states, RIDDING yourself of as much heat soak as possible (as in a 1-hourcool-down+ice!) makes a big diff..... if you have back-to-back runs from staging lanes, anything icy is a help, but you gotta contain water drips, overkill the bagging.

 

[Chuck 98 RT/10]

Believe it or not even at the drag strip it helps as on a hot day with a Pro BEHIND THE WHEEL i seen ET drop 2-3 tenths by cooling the car between runs.On these blower cars even more.

I know it helps cool the intake and produce faster times, but heat soak is not simply a hot engine. Heat soak is when the entire engine is soaked with heat evenly throughout. Again, if a street legal drag car is experiencing heat soak after a 30 second idle in staging and 10 second run then he has some serious problems.

If you dipped the corner of a dishrag into water you wouldn't say the rag is soaked. It's wet, or in the case of an engine it's hot, but it isn't soaked.

 

[1BADGTS]

I know it helps cool the intake and produce faster times, but heat soak is not simply a hot engine. Heat soak is when the entire engine is soaked with heat evenly throughout. Again, if a street legal drag car is experiencing heat soak after a 30 second idle in staging and 10 second run then he has some serious problems.

If you dipped the corner of a dishrag into water you wouldn't say the rag is soaked. It's wet, or in the case of an engine it's hot, but it isn't soaked.

It doesnot work like your thinking.The ice is used to drop the overall engine temp to aroung 145 as fast as poissible. On a mag test these cars sit for an hour or more with ice bags and fans all over the motor to get the temp around 145 for a single run .Then its done again over the coarse of a day. .If you have ever ran a Viper on a chasis dyno at say 145 degrees vereses the same car same day at 220 degrees the car is probably going to make 20 plus more at the tire running at 145 .

 

[1BADGTS]

It doesnot work like your thinking.The ice is used to drop the overall engine temp to aroung 145 as fast as poissible. On a mag test these cars sit for an hour or more with ice bags and fans all over the motor to get the temp around 145 for a single run .Then its done again over the coarse of a day. .If you have ever ran a Viper on a chasis dyno at say 145 degrees vereses the same car same day at 220 degrees the car is probably going to make 20 plus more at the tire running at 145 .

Ps the thing i cant reiterate enough is the driver has to have the ability to take advantage of the extra horsepower (run cold for that pass )or it meens nothing .An average driver will never notice BUT a Furman or a Smith will get that extra tenth or two easily by doing this.

 

[Chuck 98 RT/10]

It doesnot work like your thinking.The ice is used to drop the overall engine temp to aroung 145 as fast as poissible. On a mag test these cars sit for an hour or more with ice bags and fans all over the motor to get the temp around 145 for a single run .Then its done again over the coarse of a day. .If you have ever ran a Viper on a chasis dyno at say 145 degrees vereses the same car same day at 220 degrees the car is probably going to make 20 plus more at the tire running at 145 .

Gawd, this is beginning to get painful.

I'm talking about the definition of heat soak.

You're explaining why ice on the intake helps ET.

I am not arguing that cooling the motor helps or not. We all know that a cooler dense charge contains more oxygen and produces more power. We get it. What I am saying is that heat soak as strictly defined is not what a street car will experience at a dragstrip. If you wanna experience heat soak do 30 minutes of lapping at Sebring in August then pit without a cooldown lap. That is heat soak.

 

[1BADGTS]

Gawd, this is beginning to get painful.

I'm talking about the definition of heat soak.

You're explaining why ice on the intake helps ET.

I am not arguing that cooling the motor helps or not. We all know that a cooler dense charge contains more oxygen and produces more power. We get it. What I am saying is that heat soak as strictly defined is not what a street car will experience at a dragstrip. If you wanna experience heat soak do 30 minutes of lapping at Sebring in August then pit without a cooldown lap. That is heat soak.

Maybe your strickly defining it as that but iam telling you that on a 90 degree day two back to back runs down a drag strip o-130 drive back go 0-130 is the defination of heatsoak in mine and alot of other peoples book. No matter the type of racing if the cars engine temp is over 230 at the end of the race what the hell is the difference?

 

[1BADGTS]

Maybe your strickly defining it as that but iam telling you that on a 90 degree day two back to back runs down a drag strip o-130 drive back go 0-130 is the defination of heatsoak in mine and alot of other peoples book. No matter the type of racing if the cars engine temp is over 230 at the end of the race what the hell is the difference?

Ps my buddys Ford Gt gets heatsoaked on the dyno AFTER 3 back to back runs the thing loses 70 to the tire and is like a blast furnace. Because its not done on A road track what hes experiancing is not heatsoak?

 

[Chuck 98 RT/10]

Maybe your strickly defining it as that but iam telling you that on a 90 degree day two back to back runs down a drag strip o-130 drive back go 0-130 is the defination of heatsoak in mine and alot of other peoples book. No matter the type of racing if the cars engine temp is over 230 at the end of the race what the hell is the difference?

Is coolant blasting out of the overflow? If not then your motor is not yet completely soaked with heat.

I'm out. I let you get the last word.

 

[GR8_ASP]

Heat soak is heat soak, no matter the cause. And water type intercooled cars are more prone to heat soak as the intercooler gets heat soaked robbing lots of power for the ensuing run. Most need air velocity to cool the intercooler system down again and in an engine off condition take a long time to cool down.

That said anyone who uses an iced down (well below ambient temperature) intake or intercooler to make an impressive run is cheating in my book. Meet them on the street and let's see them ice it down before whooping their ass. A long cool down is fine, but artificial cooling beyond ambient is not. And I care not what professional race cars do. If you are trying to use the drag strip to show a street cars real capability then icing is cheating. Especially if trying to prove a stock cars capability.

As to the above comments that a supercharged Viper cannot do road racing I suggest that same person (who always states you have not been there and done that) to go to a freaking road track event and witness it himself. I just did an event Friday with my Paxton supercharged Viper. All you have to do is size the intercooler properly (air-water-air in my case) and it should work just fine. And an air-air intercooler is less affected by track conditions. Lest we state that turbocharged cars cannot compete in road track events.

 

[1BADGTS]

Is coolant blasting out of the overflow? If not then your motor is not yet completely soaked with heat.

I'm out. I let you get the last word.

Hell yes when Smith gets done with a car THEN SOME -TOO FUNNY.

 

[1BADGTS]

Heat soak is heat soak, no matter the cause. And water type intercooled cars are more prone to heat soak as the intercooler gets heat soaked robbing lots of power for the ensuing run. Most need air velocity to cool the intercooler system down again and in an engine off condition take a long time to cool down.

That said anyone who uses an iced down (well below ambient temperature) intake or intercooler to make an impressive run is cheating in my book. Meet them on the street and let's see them ice it down before whooping their ass. A long cool down is fine, but artificial cooling beyond ambient is not. And I care not what professional race cars do. If you are trying to use the drag strip to show a street cars real capability then icing is cheating. Especially if trying to prove a stock cars capability.

As to the above comments that a supercharged Viper cannot do road racing I suggest that same person (who always states you have not been there and done that) to go to a freaking road track event and witness it himself. I just did an event Friday with my Paxton supercharged Viper. All you have to do is size the intercooler properly (air-water-air in my case) and it should work just fine. And an air-air intercooler is less affected by track conditions. Lest we state that turbocharged cars cannot compete in road track events.

A few points you consider a long cool down to be fine all that the ice does is accelerate this .There are not only pro race cars that do this as McMullan Argus does it in hot weather to all there tested street cars .Every tuner EVER does this as well .AT every main track in the country ice is sold to be used by the general publc to cool their own cars during test and tune nights.As I stated earlyier the driver has to have the ability to take advantage of the extra power from icing

 

[1BADGTS]

Hell yes when Smith gets done with a car THEN SOME -TOO FUNNY.

To be specific Water, Antifreeze ,oil,Serpentine belts ,Supercharger parts (cracked housings impellers).Rearend parts (halfshafts ,driveshafts exploded pumpkins )and if hes in a real ambitious mode connecting rods LOL

 

[ShadowLight]

I've used it before and think it's worthwhile to do. However, it's not worth packing so much ice that it will last you a whole day on the track...the gains are marginal and as mentioned before other factors can completely void the gains. However, as any track rat will agree, having another factor that can help is completely worth it!

 

[spotter]

GR_ASP, Are you saying that air to air intercooler is more efficient then water to air?? Because water will get rid of the heat much more efficiently then air to air.

Is your paxton modified? Because the intercooler on a stock paxton is a water to air setup.

 

[GR8_ASP]

GR_ASP, Are you saying that air to air intercooler is more efficient then water to air?? Because water will get rid of the heat much more efficiently then air to air.

Is your paxton modified? Because the intercooler on a stock paxton is a water to air setup.

No I am saying an air - air intercooler is much less sensitive to heating as it lacks the thermal inertia to retain heat. With air - water if the coolant is hot the intercooler radiator has to expel not only the charge heat but also the coolant supply heat. And the delta T across the intercooler will be less, meaning a warmer inlet charge temp.

Yes, I have a second intercooler radiator mounted at the rear behind the differential and 2 coolant pumps in series.

As to 1BAD yes I know tuners use all the tricks in the world to make their numbers look better. That does not make it right. When I chassis dyno I use only a frontal fan to simulate road conditions. My runs back to back to back within a 30 minute session have always been within 10 RWHP. No ice, no dry ice. So when I meet someone on the road my 690 RWHP is real and ready. Not waiting for someone to ice it down first.

 

[1BADGTS]

No I am saying an air - air intercooler is much less sensitive to heating as it lacks the thermal inertia to retain heat. With air - water if the coolant is hot the intercooler radiator has to expel not only the charge heat but also the coolant supply heat. And the delta T across the intercooler will be less, meaning a warmer inlet charge temp.

Yes, I have a second intercooler radiator mounted at the rear behind the differential and 2 coolant pumps in series.

As to 1BAD yes I know tuners use all the tricks in the world to make their numbers look better. That does not make it right. When I chassis dyno I use only a frontal fan to simulate road conditions. My runs back to back to back within a 30 minute session have always been within 10 RWHP. No ice, no dry ice. So when I meet someone on the road my 690 RWHP is real and ready. Not waiting for someone to ice it down first.

Let me ask you this if i were to take your car on my buddys chasis dyno on 95 degree day and make 6 straight redline pulls (one directly after another )just out of curosity would that 690 be real and ready then.

 

[1BADGTS]

I've used it before and think it's worthwhile to do. However, it's not worth packing so much ice that it will last you a whole day on the track...the gains are marginal and as mentioned before other factors can completely void the gains. However, as any track rat will agree, having another factor that can help is completely worth it!

Exactly if a driver is average at best all the ice and cool down isnt going to do anything.

 

[ViperTony]

Gawd, this is beginning to get painful.

I'm talking about the definition of heat soak.

You're explaining why ice on the intake helps ET.

I am not arguing that cooling the motor helps or not. We all know that a cooler dense charge contains more oxygen and produces more power. We get it. What I am saying is that heat soak as strictly defined is not what a street car will experience at a dragstrip. If you wanna experience heat soak do 30 minutes of lapping at Sebring in August then pit without a cooldown lap. That is heat soak.

I'm glad to read a real world experience from a real word driver about this issue. As always Chuck, thanks for putting this into proper perspective.