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Old 2nd April 2007, 10:16   #1
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Default Hatches and high speeds

Yday, i took a decently long drive along the east coast road, from chennai to pondy and back. I have a palio 1.2, and am running all stock, with 5 adults and the AC, was able to hit 115 and maintain it for decent stretches. However, the biggest bone of contention was every time a bus passed me in the opposite direction, my car shook like an old mans tooth.

my question is this, is there anything that can be done to make the car "slice" through turbulence? Also, spoilers make the car more stable at high speeds, would anyone know of good products that work?

mod: if this thread is in the wrong place - please change. thanks!
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Old 2nd April 2007, 10:23   #2
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Palio is one of the stablest hatches - surprising that it got unnerved by a bigger vehicle. Nothing can be done thats an OTC solution to add extra stability except wider tyres. A well -designed spoiler will only make itself felt at higher speeds, not those typically achievable on Indian roads
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Old 2nd April 2007, 10:42   #3
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We (A friend, my wife and I) went for a drive in the Bangalore - Mysore highway on a Palio 1.2 nv, the Palio did 127 or 130 KMPH, A smiliar situation did occur where we were passed by a bus in the opposite side.

Nothing happenned!!

All windows were rolled up!!!
The car does not have a rear spoiler
Stock suspension
Tyres were 185/R60 Michellen tubeless tyres


On ECR, the only difference is tracks (Onward and Opposite direction) are pretty close. It would nt be the blast of air coming towards the front of the Palio as it is aerodynamic but it could be the blast coming towards the side of the car.....
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Old 2nd April 2007, 10:44   #4
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You could always call themag and have him sit in the car. he is always ready to help someone in need.

should be very stable after that. While cornering you can tell him to shift accordingly right or left. that will also give you better cornering stability.
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Old 2nd April 2007, 10:57   #5
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I doubt whether spoilers would help at our kind of speeds. I think you need to check nuts and bolts that hold your car's body and perhaps your suspension. Palio being a stable car, you can't do much. A strut brace may help to some extend around corners.

I had a near similar issue with a old M800 and was rectified by tightening all nuts and bolts. My car had good amount of rust as well.
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Old 2nd April 2007, 11:43   #6
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Quote:
Originally Posted by madan80 View Post
the biggest bone of contention was every time a bus passed me in the opposite direction, my car shook like an old mans tooth.

my question is this, is there anything that can be done to make the car "slice" through turbulence? Also, spoilers make the car more stable at high speeds, would anyone know of good products that work?
This has nothing to do with turbulance. What happens when two vehicles pass opposite to each other is there is a low pressure built up between the two vehicles (an extension to bernaullis theorem ) and both the vehicles tend to move towards each other. For the same reason two ships never cross each other when they are too close. This is the same reason why you shouldnt sand near the edge of the platform when a speedy tain is approaching or passing by.
So putting a spoiler wont help. Having better traction on the road will definitely help but this pressure phenomenon will always be there.
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Old 2nd April 2007, 11:53   #7
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Can't do anything about this on a Single carriageway.
On roads with wide dividers, there is enough space between oncoming vehicles, so no issues but on a single road even a heavy car will shake. Of course a lighter car will shake much much more.
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Old 2nd April 2007, 12:37   #8
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the best thing to do would be to stick under 80 kmph on single carriageways or single lane roads such as the ECR..

I think it is one of the most dangerous roads this side of country with a hopeless toll booth doing justice to everyone but the legitimate toll road user.

We still find cyclists / bullock carts without lights / autos etc on the toll road and it is a nightmare to drive on these roads..Wonder what we pay the toll for..??
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Old 2nd April 2007, 12:38   #9
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And most probably..ALL Cars suffer from this problem when passing too close to another vehicle!!
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Old 2nd April 2007, 12:42   #10
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Now, I would DEFINITELY blame his stock tyres.
I've done the same stretch on 5u3zero's Palio 1.6 with 185 Dunlop FM901s and it was like a tank!
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Old 2nd April 2007, 13:15   #11
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Quote:
Originally Posted by rishibravo View Post
This has nothing to do with turbulance. What happens when two vehicles pass opposite to each other is there is a low pressure built up between the two vehicles (an extension to bernaullis theorem ) and both the vehicles tend to move towards each other. For the same reason two ships never cross each other when they are too close. This is the same reason why you shouldnt sand near the edge of the platform when a speedy tain is approaching or passing by.
So putting a spoiler wont help. Having better traction on the road will definitely help but this pressure phenomenon will always be there.
Yup, i know bout the theorem, however, if that was the case, i would have felt it while it was passing, and not after it had passed. cause the low pressure is formed between the two objects. however, in this case, it is after the vehicles have passed, is the turbulance felt. I think the difference between the vehicles (single lane carriage way) would be the biggest factor. I would however, like to work on something that can be attached to cars, that is practical, and not just cosmetic. Any idea on whom i can approach?
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Old 2nd April 2007, 13:34   #12
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Madan, that "vaccum formation,bermuda triangle,black hole" theorem or not, Turbulence is what U faced and its normal.But, U felt it more because ur car is undertyred(although U're a very good ballast ). Get those 185/60/R14 (a la 5u3zer0) or 175/70/R13 michelins and U'll feel more secure.
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Old 2nd April 2007, 13:45   #13
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Quote:
Originally Posted by nitrous View Post
U felt it more because ur car is undertyred(although U're a very good ballast ). Get those 185/60/R14 (a la 5u3zer0) or 175/70/R13 michelins and U'll feel more secure.
Plan to do that pretty soon. Thanks! but still, would like to design some spoilers for the car.
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Old 2nd April 2007, 17:17   #14
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Quote:
Originally Posted by madan80 View Post
my question is this, is there anything that can be done to make the car "slice" through turbulence? Also, spoilers make the car more stable at high speeds, would anyone know of good products that work?
Quote:
Originally Posted by madan80 View Post
I would however, like to work on something that can be attached to cars, that is practical, and not just cosmetic. Any idea on whom i can approach?
Quote:
Originally Posted by madan80 View Post
but still, would like to design some spoilers for the car.
I can read your mind .. you want spoilers. Then go for it... just don't expect it to help you in the situation described.
And would you really like to design it? How will you test its efficiency? Hope you don't come back and tell me that you have a wind tunnel at home.

Last edited by k36 : 2nd April 2007 at 17:20.
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Old 2nd April 2007, 18:46   #15
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Quote:
Originally Posted by madan80 View Post
Yup, i know bout the theorem, however, if that was the case, i would have felt it while it was passing, and not after it had passed. cause the low pressure is formed between the two objects. however, in this case, it is after the vehicles have passed, is the turbulance felt. I think the difference between the vehicles (single lane carriage way) would be the biggest factor. I would however, like to work on something that can be attached to cars, that is practical, and not just cosmetic. Any idea on whom i can approach?
I disagree with you that you will experience the low pressure between the vehicles only at the time you are crossing. When a large vehicle like a truck moves it dislocates a lot of air and as it moves forward the air around it will tend to fill the gap thus extending the l low pressure area to some distance away from the vehicle as well. The drag currents ( you can call it turbulance ) are maximum just behind the large vehicle. I dont know if there is any mod which you can do to prevent this but you can try to avoid the are just behind the truck for a few meters.
Usually when we are moving fast on a single lane carriage way we tend to come to the middle of the road as soon as the vehicle coming from the opposite direction passes by. one can avoid the effect of pressure by avoiding coming to the area which was earlier occupied by the large vehicle.

just trying to apply a lil college physics
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