accident

[Jules]

now .. I AM really lost .. .

ok ok .. simple - when it rains - drive slower ..

yes, best advice here.....

 

[Jules]

weight of car has no bearing on this. if weight of car played a part on hydroplaning, just think F1 cars..

Bro, I agree with all u wrote except the above sentence....see my formula below.

F (Friction) = U ( coefficient of Friction ) x N ( vertical component of load. = weight of car )

The above formula means Weight is a influence of Friction force. When u aquaplane.....U goes almost to zero so F also goes to almost zero but the N is always present. When F goes to zero, then all hell break loose!

For your example of F1 car....yes they are lite but the weight of car is compounded by the Force coming from the Aerodynamic Aids.....wings, spoilers and bodywork.

Of course, as you can see there's a limit to everything so even F1 cars crash in rain......likewise, there's a limit on how much water can be channeled off by your tyre grooves so if you exceed that, the water lifts up the tyres and VIOLA, no more U, no more grip.....

Hope I made some sense cos I think I confuse myself! he he he

 

[1+2=3]

you are right. and thats exactly what i meant.. downforce aids traction, when your tyres actually touch the road. but when you hydroplane, your tyres lose contact with the road. In F1, the car is light, but has exceptional rain performance, because of the best rain tyres in the world.

i'm sure you always hear this from people, "if a car is heavy, it will have better grip when driving in the rain". End of the day, your tyres performance in the rain is what makes the difference. all the weight in the world ain't going to help you, if you tyres are not in contact with the road.

 

[funfer_fahrer]

you are right. and thats exactly what i meant.. downforce aids traction, when your tyres actually touch the road. but when you hydroplane, your tyres lose contact with the road. In F1, the car is light, but has exceptional rain performance, because of the best rain tyres in the world.

i'm sure you always hear this from people, "if a car is heavy, it will have better grip when driving in the rain". End of the day, your tyres performance in the rain is what makes the difference. all the weight in the world ain't going to help you, if you tyres are not in contact with the road.

Spot on. Heavier car does not translate into better aquaplanning performance. If you exceed the speed the car just "sails" on the road.

 

[affan66]

guys.. wah so much interest.

Car was okay. Just serviced the day before. Tires new. ABS working.
Likely planned job. 2 km from Lembah Beringin exit, which is a few km from Tg Malim.

GOt pics.. will post later.
Pity my sis. She's not gonna have her car back for a while. Guys, give her some support la.... kesian wooo... I feel for her.

BTW, while waiting for the tow truck to arrive, saw a bunch of coupes from the opposite side heading to KL. THought Ah Lian was in the group.

 

[naharnms]

Affan, glad ur sis is okay..

Is she driving the purple color 318is with the plate no Bxx 3181, coz i have seen that car before.. not that many around with the iS model..

 

[affan66]

nope... 818.. maroon. got sharkfin

 

[ah lian]

BTW, while waiting for the tow truck to arrive, saw a bunch of coupes from the opposite side heading to KL. THought Ah Lian was in the group.

huh?? maybe some other ah lians...

but hey, i am glad she is alright.

 

[Rainracer]

Bro, I agree with all u wrote except the above sentence....see my formula below.

F (Friction) = U ( coefficient of Friction ) x N ( vertical component of load. = weight of car )

The above formula means Weight is a influence of Friction force. When u aquaplane.....U goes almost to zero so F also goes to almost zero but the N is always present. When F goes to zero, then all hell break loose!

For your example of F1 car....yes they are lite but the weight of car is compounded by the Force coming from the Aerodynamic Aids.....wings, spoilers and bodywork.

Of course, as you can see there's a limit to everything so even F1 cars crash in rain......likewise, there's a limit on how much water can be channeled off by your tyre grooves so if you exceed that, the water lifts up the tyres and VIOLA, no more U, no more grip.....

Hope I made some sense cos I think I confuse myself! he he he

Sorry to hijack this tread and discuss on hydroplanning here, but just hope to get a better picture too. With all the above formula mentioned, doesn't it reflect that heavier cars will have higher friction? (I'm not a science student) Or is everything 100% contingent on the tires only? I always thought its more than just the tires alone affecting the chance of hydroplanning???

 

[1+2=3]

in general, when your car hydroplanes, no contact with the road so it means no friction.

i'm no math genius, if the formula is right, F=UxN if friction coifficient drops to near zero, or even zero in the case of hydroplaning, F=0x1300(weight of car for example in KG), that should mean friction = 0 right? regardless of the weight of the car. btw, didnt do physics in school.

any math genius here?

 

[535i]

guys.. wah so much interest.

Car was okay. Just serviced the day before. Tires new. ABS working.
Likely planned job. 2 km from Lembah Beringin exit, which is a few km from Tg Malim.

GOt pics.. will post later.
Pity my sis. She's not gonna have her car back for a while. Guys, give her some support la.... kesian wooo... I feel for her.

BTW, while waiting for the tow truck to arrive, saw a bunch of coupes from the opposite side heading to KL. THought Ah Lian was in the group.

Abe Affan ..

If she needs a lift - call me laaa ... ..
Call me if u need car body parts ... might hv lubang for it ..

 

[funfer_fahrer]

Sorry to hijack this tread and discuss on hydroplanning here, but just hope to get a better picture too. With all the above formula mentioned, doesn't it reflect that heavier cars will have higher friction? (I'm not a science student) Or is everything 100% contingent on the tires only? I always thought its more than just the tires alone affecting the chance of hydroplanning???

It's the ability of the tyre to draw away the water around it and it is a function of time. Therefore, narrow tyres are better than wide tyres on wet surfaces regardless of the weight of the car. Those with low profile and wide tyres please pay extra attention when it rains.

 

[affan66]

got halfcut waiting already.. thanks 535i...

 

[nikazwaa]

Just stumbled upon this thread... So sorry to hear about the accident affan.

Hope your sister's recovering. I'm sure Paris (yes... I named her Paris) will be ok too...

 

[K.M.]

Bro.....I think this is a very long stretch. Care to be more specific? ( ie between what exit to what exit?? )

Thanks.

To be more precise..it's from Sg. Buloh R&R until Lembah Beringin exit...be careful.

 

[Schwepps]

i'm no math genius, if the formula is right, F=UxN if friction coifficient drops to near zero, or even zero in the case of hydroplaning, F=0x1300(weight of car for example in KG), that should mean friction = 0 right? regardless of the weight of the car. btw, didnt do physics in school.

Just have to set the record straight here:
Your equation aside, friction is also a function of the force pushing two surfaces together (and the roughness of the surfaces) By your own analogy of F1 cars, they have greater traction because their weight is disproportionate to their mass due to the downforce from their aerodynamics.

So weight plays a big part in hydroplaning. A Kancil will hydroplane more easily than an S80, which will hydroplane more easily than a cement truck, all going at the same speed through the same sheet of water.

Having said that, I've hydroplaned an S80 many times The last thing I would do in a skidding situation like that is to touch the brakes at all, much less to hit them so hard that the ABS kicks in! If you're in ABS braking mode and some wheels have grip and others are hydroplaning, you're guaranteed to have a very theatrical spin. ABS or lack of ABS has nothing to do with getting into or out of a hydroplane situation.

 

[1+2=3]

Just have to set the record straight here:
Your equation aside, friction is also a function of the force pushing two surfaces together (and the roughness of the surfaces) By your own analogy of F1 cars, they have greater traction because their weight is disproportionate to their mass due to the downforce from their aerodynamics.

So weight plays a big part in hydroplaning. A Kancil will hydroplane more easily than an S80, which will hydroplane more easily than a cement truck, all going at the same speed through the same sheet of water.

Having said that, I've hydroplaned an S80 many times The last thing I would do in a skidding situation like that is to touch the brakes at all, much less to hit them so hard that the ABS kicks in! If you're in ABS braking mode and some wheels have grip and others are hydroplaning, you're guaranteed to have a very theatrical spin. ABS or lack of ABS has nothing to do with getting into or out of a hydroplane situation.

thanks for the explanation bro.

 

[Jules]

I have to agree with Schwepps....

To put more words to my tots :

1) Weight matters in RESISTING hydroplaning ( ie. a heavier vehicle hydroplane less since N is large )
2) Once you hydroplane, N is no longer useful......since U is already zero ( ie. one of you are somewhat rite then )
3) Tyres are most important in RESISTING hydroplane especially the WIDTH and thread depth and design. ( hence u see KaNCIL can zoom faster cos their narrow tyres need to disperse LESS water to not float - and see the WRC car tyres in snow condition, all skinny tyres plus spike too for some stages )
4) Wider tyres will always be worse in wet.....in hydroplane resistance!
5) ABS does nothing to resist the above in first place.....
6) So message is clear - go slow in wet.......

Hope I made sense......

 

[Schwepps]

thanks for the explanation bro.

Most welcome bro. Your thesis was very correct except for the weight part!

Actually I found a straight stretch of road on the Rawang-Batang Berjuntai road long ago which has a mini stream running across it when it rains hard. It's deserted and has wide run-offs, so I would drive up and down it to get the feel (thrill) of hydroplaning, like a kid running through a puddle. Crazy I know, but it was my own cheap advanced driving course.

There's nothing like practical experience to get you out of trouble in a hydroplane, tire burst, or cornering skid. You learn not to panic and to use correct steering and gas pedal corrections to get out of it, never the brakes. You learn to brake before and after, but not during a skid. Very useful in a real-life situation.

 

[Jules]

schwepps,
good idea to practise that in safe places, so at least you recognise the sensation of hyrdoplaning. And yes, no brakes or even sudden throttle lift off.....

fuad4,
and yes, if your wheels turn in wrong way and when u retain the grip....u go in the direction u r pointing! hence best to keep steering straight!

on ur water question - best to avoid water cos the bow wave u create will be broken esp when the opposite traffic comes thru as well and the water will surely go into ur bay! Our road cars are not designed to do this. Even with 4WD we are asked to put a sheet infront of car to create this bow during river crossings and we have snorkles ( high intakes ) too.

water may enter clutch even when no press if your dust boot for clutch lever is worn...so best avoid prolonged deep water immersion.