[WRC] FORUM8 Rally Japan 2023

[WRCStan]

What I´m definitely sure of is that local drivers never will beat the teams drivers when going in same cars (Rally2). Not even when it´s eight days in a week.

So what was your point in advocating it?

[br21]

First, overall safety regulations from at least two decades back demand to have relay/cutoff in power circuit of the heating of the screens. Not to cause overheating / fire.

Second, if you have had heated windscreen on your car once, you cannot justify the misted windscreens of most of the WRC1 drivers from last night. Just cannot happen.

Third, remeber some times ago Ott to mention about lack of any demister. Believe it was during Hyundai times.

1. In modern Rally1/Rally2 there are no any extra relays, etc. Only master switch. Everything else is managed by power modules (which have kind of software relays/fuses, etc).
2. Yes, I have heated windscreen in my car. But I don't have 900degC exhaust temp in my car, also not 50+degC inside in my car and I'm not driving throught the water like rally guys. Also no roof vent, no bonnet openings, etc in my car. And that is all what makes the difference.
3. Depending on weather conditions you install or remove internal heat exchangers but blowers and heated windscreens are always mounted in the Rally1/2 cars.

[WRCStan]

2. Yes, I have heated windscreen in my car. But I don't have 900degC exhaust temp in my car, also not 50+degC inside in my car and I'm not driving throught the water like rally guys. Also no roof vent, no bonnet openings, etc in my car. And that is all what makes the difference.

Maybe linni meant you cannot justify the designs of these cars. It's heavy rain in Japan like most of us have and would still drive through in our cars. These summertime racecars aren't fit for purpose - a fit and healthy WRC.

[linni]

1. In modern Rally1/Rally2 there are no any extra relays, etc. Only master switch. Everything else is managed by power modules (which have kind of software relays/fuses, etc).
2. Yes, I have heated windscreen in my car. But I don't have 900degC exhaust temp in my car, also not 50+degC inside in my car and I'm not driving throught the water like rally guys. Also no roof vent, no bonnet openings, etc in my car. And that is all what makes the difference.
3. Depending on weather conditions you install or remove internal heat exchangers but blowers and heated windscreens are always mounted in the Rally1/2 cars.

You kind of controversing, having 900 deg C and 50 deg C in the cabin at the same time.
But definitely it`s an interesting topic. Needs some further investigation.
Will find out and be back.

Still, have seen temp differences in lots of rally cars in Scandinavian climate, nothing familiar with this.

[linni]

Maybe linni meant you cannot justify the designs of these cars. It's heavy rain in Japan like most of us have and would still drive through in our cars. These summertime racecars aren't fit for purpose - a fit and healthy WRC.

Yes, that`s the point. You have to be prepared. Like us in here, where winter tires are mandatory during winter time and you just do not go out on summer tires.

[br21]

When it's dry then temperature difference is not that problematic.
When the conditions are like in Japan now you have many different things happening at the same time - just pouring water on red hot exhaust manifold creates loads of mist and humidity, etc.
And if it happens in all 3 cars then you know it's not so simple - of course it shouldn't happen but it happens and because of other reason than just stupid lack of heated windscreen and blower...

[Mirek]

First, overall safety regulations from at least two decades back demand to have relay/cutoff in power circuit of the heating of the screens. Not to cause overheating / fire.

Second, if you have had heated windscreen on your car once, you cannot justify the misted windscreens of most of the WRC1 drivers from last night. Just cannot happen.

Third, remeber some times ago Ott to mention about lack of any demister. Believe it was during Hyundai times.

Listen to br21, he knows.

Please follow this small example.

It's cold outside and it's raining.

You have a road car with internalvolume 2 m3. There is 22°C inside. You come inside completely wet and the water starts to evaporate. The maximum amount of water the 2 m3 of air at 22°C can take is 38 gramms. The rest stays in the form of liquid in the clothes or on the floor.

Now you have a second car with the same internal volume but the inner temperature is 50°C. Again you bring some water inside on your clothes and shoes. The maximum amount of water which can evaporate in 2 m3 of air is now 164 gramms. So your air in the car now contains 4,3x more water.

Where the air hits the cold glass it cools itself and the water condenses because the colder the air is, the lesser amount of water it can take. If you have the same heated windsreen which is capable to heat the screen to let's say 30°C average you have no misting in the road car but you still have big misting problem in the other one (the air at 30°C can take only 37% of water compared to the air at 50°C) and due to the fact that the inner humidity is already 100% the blowers don't work.

So the resume is that you have to either heat the windscreen to higher temperature than what the ambient temperature inside the car is. Or you need to bring less water inside (may not be possible), or you need to lower the humidity (not possible without A/C). Or you need to somehow cool down the temperature inside the car. If you have very high temperature drop between the inside and the outside, heating the screen enough might not be possible, so you need to let as much air from the outside to get in because the air from the outside even if it's wet, will still help because it's much colder but the amount of air you can let in is very limited by the vents. You can't drive on stage with opened windows because it's forbidden. After all you might end in a situation where nothing helps.

[Mirek]

Still, have seen temp differences in lots of rally cars in Scandinavian climate, nothing familiar with this.

When temperature is bellow zero the air humidity is usually low and you don't bring plenty of water inside the car in your clothes.

[WRCStan]

This forum is insane. 20 pages of demister chat and I'm just spending my Friday afternoon refreshing the page to see if anything got added. Well done lads.

[PLuto]

This forum is insane. 20 pages of demister chat and I'm just spending my Friday afternoon refreshing the page to see if anything got added. Well done lads.

This discussion seems more interesting than rally itself