15 replies to this topic

[Christiaan]

I remember in 1998 noticing two things that a lot of teams did during a pitstops. The first was emptying a ´small bucket of dry ice on the engine hood. Martin Brundle said this was so the engine could cool down and it was worth about 5Hp. In 1999 I didn't see anybody doing it.

The second was the occurence of a cload of brake dust when the tyres were removed. What was that dust? Was it blown off using a fan? Why don't I see it anymore?

[f1speed]

Cooling the intake does increse power(hot engine) it also helps prevent vopor lock which can stall the engine. I still see the brake dust when changing tires.

[Christiaan]

agreed, but I didn't see any teams chucking dry ice on their hoods this year!

[mtl'78]

The dust is highly toxic burnt carbon, that heat and centrifugal forces make stick to the wheels and suspension. You wouldn't want to breathe that crap!

Dry ice is still put INTO the sidepods before the race, but I always thoughht it was questionable to put it in during a pitstop: the benefits are not that clear, and it is something more to mess up/take more time...

[f1speed]

Just opponion here but I belive it may be at least one of two things; (1)Keeping the rpm's up while the car is stoped might be better (easier) to prevent vapor lock and(2) with 7.5 second pit stops, the dry ice man would have to work fast ! Any HP lost due to heat build up while the car is stopped might be less important because of cold tires. Just a thought I don't have any facts.

[davo]

The dust is indeed carbon worn from the pads and the disc which both wear to death in the length of a GP. Choosing brake duct size is a compromise of small duct & low drag giving high temp/wear vrs big duct & high drag giving low temp/wear. When it is got wrong the results can be spectacular - Williams in Australia a few years back.

The wheel change guns are pneumatic tools and it is their exhaust which blows the dust around.

Highly toxic? I would be a little suprised - althought virtually all dust is not a particularly good thing for you in large quantities.

For toxic concerns the fuels have been/are a worry. Even at club level motorsports (in Australia at least) some people run fuels that make your eyes and nose run but give you a dry throat - magical stuff

Perhaps Joe Jackson is right "everything gives you cancer"

[Ray Bell]

Davo - you're right about the fuels, it's a by-product of the world's changeover to lead-free fuels that has unleashed a whole bunch of new bulk carcinogens on the populace.
And as for the carbon fibre brakes, they indeed do destroy the whole assembly during a practice session or a race. Wear the whole lot away - well wear away to the point that it's impractical to think about going out again with them. Likewise, I don't think that they would be terribly toxic, but you never know what things will do to your lungs.

[Ursus]

Re the dry ice in the sidepods. IIRC before the '98 season i read that some teams were running cooling systems with high pressures. This increases the boiling temperatures of the cooling water and it is possible to make smaller radiators(or smaller air intakes). For the '99 season I belive the allowed pressure was limited requiering larger radiators(or larger air intakes). My theory is that the smaller and hotter radiators(or the smaller air intakes) were less efficiant when no air was forced through them.

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Ursus
Trust me, send money.

[desmo]

Seems like I saw some impressive clouds of brake dust during changes this year, too.

[Christiaan]

you acn't have Desmo...
Its the millenium baby

[desmo]

Last year IS this year 'til Melbourne, I say. To hell with the calander!

[Nathan]

My question is if dry ice cools the incoming air to the radiator, why dont teams put in the air boxes to makes a cooler, denser, therfore more powerful intake charge? Im sure if they do that for their rads, they do for the intake. I know as a Honda engine tuner we add very small amount of water into induction of a forced induced engine to cool the charge more. Also I believe the brake dust cloud were caused by the air from the air guns they use to remove the lugnut from the wheel.

[Christiaan]

Nathan, hmmm looks like we both have the same qustions. I read about that water injection a couple of years ago in a Cosworth tuning magazine. After that I was thinking more on the lines of liquid nitrogen as a coolant

[Nathan]

When will a engine maker hire me?????

I think Nitrogen would be very good. But that mixture is what Nitrous Oxide bascially is. So I think they would have to use water.

[davo]

Nathan & Christian like your creativity, and there must be ways of overcoming the difficulties below. The creative designers like Murray and Chapman certainly did:

"Dry ice" is usually solidified CO2 which sublimates (can't resist the word) from solid to gas soaking up HEAPS of heat from the atmosphere leaving the surroundings cooler but also soaked in gaseous CO2. This means that there would be less O2 for the engine to breath and less HP. Any of the liquified or solidified gases would I think cause this displacement effect. If you sidestepped it with some O2 rich substance I think it would get banned Still works for radiator cooling though.

Nitrous oxide (or chemical supercharging) carries extra O into the cylinder (either as a liquid or as an O rich gas) allowing additional fuel and combustion. It can also have a charge cooling effect, allowing greater O2 density and more HP

Water injection operates on a slightly different principal. The O in H2O is not used in the combustion (its already combusted with the H) but rather acts as a heat sink reducing peak in cylinder temps. This is a power loss (!) that occurs but then allows the engine to be further tuned, spark, compression, or boost which more than makes up for the loss.

It may be (I am a not totally convinced on this one yet) that you can also more than make up for the inlet air flow loss, the displacement of air in cylinder, and the heat loss of the water out the exhaust by the increase in air density gained by the cooling effect of water sprays. It would seem that better intercooling is a better solution. Subaru/STi/Prodrive have used external intercooler sprays for getting but heat rejection.

Ferrari were using water injection with some success in the turbo era and there was at least one attempt to have it banned as a "power adding addative" but Ferrari successfully argued that the H2O is not power adding as it actual takes heat out of the cycle in exiting the cylinder as heated gas. Good for them!

And on board fire extinguishers could be used similarly (to Subarus water sprays) for super efficient intercooler performance - in qualifying perhaps. Not my idea but it worked - then it was banned.

[Ursus]

In F1, cooling of the intakecharge is very prohibited. I think the reg says somthing to the effect that any device, process, measure or whatever that results in cooling the intake charge intentional or unintentional is prohibited. As for water injection or any injection other than the approved fuel is also forbidden.
Damn, you just can't have any fun these days

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Ursus
Trust me, send money.