Rice Burner

I have had a couple debates concerning hydroplaning...Help me out and tell me what you think.

Ok first case, say you have 225s for all four tires. Second case, same car, now you have 315s for all four tires. I would think that the car with the 225s would be less likely to hydroplane due to a more concentrated amount of pressure (less surface area on the road). Compared to the 315s, which have dispersed the weight of the car over a greater area, thus less pressure per square inch on the contact patch. And once those 315s start hydroplaning, I would think they would hydroplane longer than the 225s, due to the same idea mentioned above.

I found this car on supercars.net one night.... According to the website, the creator of the car says having 6 tires/wheels will lessen the chance of hydroplaning. Now you have even more weight of the car dispersed over a greater area, and even less pressure per square inch.

http://www.supercars.net/cars/2004@$Covini@$C6Wg.html

It seems counterintuative for the additional tires to help, unless of course they are good rain tires, then you run into the problem of the first set of tires soaking the 2nd set.

What do you guys think?

StoleIt

iTrader: (3)

well more surface area = less weight over every square unit (say inches).
so then less surface area (smaller tires) = more weight over every square inch.

now hydroplaning is that the water isn't channeled out of the tire as quick as the tire is moving, so instead of the tire clearing the water out of the way and getting to pavement, the tire drives on a layer of water.

so in my twisted reality, i think weight doesn't have too much to bear, since weight wont get water out of the way any quicker.

airgo : the car with wider tires (more surface area) would hydroplane easier.

concordidly: i believe

fin (yes i threw in some matrix talk)

Cal

iTrader: (1)

This is correct. If you look at sand cars, ATV's and other vehicles used on sand, the opposite philosophy applies. On sand you want maximum floatation, so you use the widest tires you can get, then rely on paddle tires to propel you instead of tread. You have to plane all the time at the sand dunes because there is no hard pack under the sand to bite through to.

Here in Utah, the 295's come off my car every winter and the pizza-cutter like 225's go on, allowing me to drive my car through snow.

Rice Burner

Cool thanks. How is ground clearance with the QTP's? Is your car lowered?

trackbird

iTrader: (4)

But, 6 narrow tires my have the potential to displace the water under them more easily than 4 wide ones. Food for thought.

Rice Burner

Agreed...

trackbird - How'd I know you would have something interesting to say on this subject. Thanks for the input.

trackbird

iTrader: (4)

I guess it is because I can never stay quiet.

Another option, 4 front wheels (like the old Tyrell open wheel race cars) allows the first tire to clear a path for the second tire by pushing water out of the way. Yes, as mentioned, it will get that tire "all wet", but the rotation of that tire will probably spin most of the water off of it anyway. So, you are concerned with the 1/16th inch thick film of water under the tires, not the water falling/spraying on them. And, again, those 4 front tires can be "less wide" than "2 big ones" up front. I'm not saying it is a perfect design (the steering geometry can be quite interesting/ugly), but it has some potential to do a few things well.

Cal

iTrader: (1)

Yes it's lowered 2 inches, and the ground clearance is still very good with the QTP's. I think they tuck up closer than any other brand. The trade off is you can have Y-pipe banging on the driver's side, but I prevented that from happening by reshaping my floorpan with a Cut off wheel and a MIG welder!

Cal

iTrader: (1)

Another tidbit on the hydroplaning issue: Hydroplaning is a very real hazard for aircraft also, and pilots use a mathematical formula for calculating the speed that it will happen. If I can dig that out of my flying books, I'll post it here.

jRaskell

iTrader: (1)

One of the biggest elements of hydroplaning is the surface tension of the water. Surface tension is what makes water feel like concrete when you hit it at high speeds. Anyone that water skis knows what I'm talking about.

With a trailing dual front wheel setup like the Covini has, the leading wheels will help to significantly break the surface tension of the water, allowing the trailing wheels to maintain contact with the pavement much easier.

Rice Burner

With the front set of tires breaking the water, that makes sense for the last 2 pairs of wheels to not have the surface tension to deal with. Thus inproved handling in hydroplaning...However, once the car began to hydroplane, wouldnt it be worse that other cars, although it would be harder to get it to hydroplane in the first place?

trackbird

iTrader: (4)

I don't really grade hydroplaning. You are either "stuck" or "unstuck" and there is very little grey area. Once it is "floating", I'm not sure it matters what size tires are there. Until you get the water out from under them, you are still "unstuck" and that is what matters. So, I'd think you'd see similar performance. That comes back to it possibly being easier to get water out from under the narrow tires (4 of 'em) and it may hydroplane at a higher speed and therefore un-hydroplane at a higher speed as well.

My thoughts.