Why do race cars sometime have their wiper vertical?
Discussion
I was wondering why you often/sometimes see the front windscreen wiper on race cars positioned vertically when 'at rest' whereas normal cars are horizontal?
My initial assumption is that it's more aerodynamic, but most bonnets are designed to shield the windscreen wipers when horizontal. I appreciate that the speeds concerned are much higher but would a normal windscreen wiper not handle 'autobahn' speeds of 150mph+?
Just a random thought
My initial assumption is that it's more aerodynamic, but most bonnets are designed to shield the windscreen wipers when horizontal. I appreciate that the speeds concerned are much higher but would a normal windscreen wiper not handle 'autobahn' speeds of 150mph+?
Just a random thought
MagicalTrevor said:
My initial assumption is that it's more aerodynamic, but most bonnets are designed to shield the windscreen wipers when horizontal. I appreciate that the speeds concerned are much higher but would a normal windscreen wiper not handle 'autobahn' speeds of 150mph+?
you are correct on both counts...in the past, there may have been a justification for it on Aero, these days it seems to be just done cause that's what we all do.
I think you're right - it's for lower drag when not in use.
Your point 'normal wipers surviving autobahn' isn't really relevant. Because the test isn't so much "can it handle it" (i.e. not break) but rather "what's the lowest drag". Parking it in the middle may well be optimal, but daily drivers wouldn't accept it.
PS - You've bigger balls than me if you're doing 150+ on the autobahn and using your wipers!
Your point 'normal wipers surviving autobahn' isn't really relevant. Because the test isn't so much "can it handle it" (i.e. not break) but rather "what's the lowest drag". Parking it in the middle may well be optimal, but daily drivers wouldn't accept it.
PS - You've bigger balls than me if you're doing 150+ on the autobahn and using your wipers!
Well sometimes one is in a hurry! 
MagicalTrevor said:
My initial assumption is that it's more aerodynamic, but most bonnets are designed to shield the windscreen wipers when horizontal. I appreciate that the speeds concerned are much higher but would a normal windscreen wiper not handle 'autobahn' speeds of 150mph+?
I can confirm from experience in testing that normal wipers are OK at that sort of speed.
Cyder said:
MagicalTrevor said:
My initial assumption is that it's more aerodynamic, but most bonnets are designed to shield the windscreen wipers when horizontal. I appreciate that the speeds concerned are much higher but would a normal windscreen wiper not handle 'autobahn' speeds of 150mph+?
I can confirm from experience in testing that normal wipers are OK at that sort of speed.https://vimeo.com/33092652
Scuffers said:
Cyder said:
MagicalTrevor said:
My initial assumption is that it's more aerodynamic, but most bonnets are designed to shield the windscreen wipers when horizontal. I appreciate that the speeds concerned are much higher but would a normal windscreen wiper not handle 'autobahn' speeds of 150mph+?
I can confirm from experience in testing that normal wipers are OK at that sort of speed.https://vimeo.com/33092652
My experience is OEM based on a test track, it's an odd experience sitting at Vmax thundering round a track only being interested in the performance of the wiper blade.
Scuffers said:
Cyder said:
That's a badly designed system then!
My experience is OEM based on a test track, it's an odd experience sitting at Vmax thundering round a track only being interested in the performance of the wiper blade.
you might want to watch the vid first!My experience is OEM based on a test track, it's an odd experience sitting at Vmax thundering round a track only being interested in the performance of the wiper blade.
Ah, spray is a whole different game!
The two cars that I have done over 150mph in the wet both suffered issues.
One suffered from lift - the wipers simply lifted and inch from the screen and were therefore useless.
The other was more amusing - the wipers shot up the screen but the motors weren't powerful enough to beat the drag on the way back down. I couldn't stop laughing!
At those speeds though, water doesn't sit on your screen for long...
One suffered from lift - the wipers simply lifted and inch from the screen and were therefore useless.
The other was more amusing - the wipers shot up the screen but the motors weren't powerful enough to beat the drag on the way back down. I couldn't stop laughing!
At those speeds though, water doesn't sit on your screen for long...
coppice said:
The reason is- or so I have always assumed-that vertical position means wiper is closer to driver's field of vision so if needed quickly it covers that area quicker than if parked in normal position.
This is the best reason I've heard of. It's not aero, as there is no real airflow at the base of the windscreen (thick boundary layer if you will), so it would be an aero benefit at the base rather than IN the moving airflow. Unless being vertical acts as a flow conditioner, but that's not very likely. Lower also has a lower CoG too.coppice said:
REALIST123 said:
???
It takes no longer to come up than go down.
No of course it doesn't - but the location of a vertical wiper is closer to the driver's eyeline I think.It takes no longer to come up than go down.
The eyeline will be mid screen or lower. A wiper coming up from horizontal would clear the eyeline area sooner. Not only that, it would shift the water away from that area permanently, not just push it down to be blown back up again.
Frankly, I doubt there is any practical benefit either way.
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