I'm having a dispute with my dealer who says that the Z06 hydroplanes due to it's lightweight -I think that it's the SC tire design. SO
If you have hydroplaned driving in the rain (if you drive it in the rain)
how many miles do you have on your car and what type of wear on your tires and at what speed did it happen? Your answers could help me out-
Thanks.
Dee
:cheers: :cheers:

 

seems like anything would hydroplane at high enough speed.

i hydroplaned once going about 70mph on the freeway in a heavy rainstorm.
was cruising along in 6th, tapped the gas and the car suddenly started drifting sideways. active handling intervened.

the f1sc tires are known to have pretty poor wet performance. bet you could hydroplane at lower speeds if there was enough water on the road.

-ag

 

I think your dealer is full of it. The supercar tires hydroplane because of the shallower tread depth. Mine has 1500 miles on it and it does it if I'm not careful.

Keep in mind though that a wider tire will always have more problems with this because it has to displace more water to avoid hydroplanning. Goodyear engineered a performance compromise for 'decent' rain performance in return for great dry performance from the Supercar tires.

Another example ruling out weight: BMW 328i - 3250 lbs, 50/50 weight distribution and Michelin all seasons - hydroplaned from day one and got much worse after 20000 miles of wear.
Lexus IS 300, 3250 lbs, 51/49 weight distribution, equal (within one inch) dimensions and wheel base, Bridgestone Potenza RE4s - never hydroplanes. Plows through deep puddles at 80 mph like they didn't even exist! Best car I have ever driven fast in the rain...

So there goes the 'it's not the tires theory'...
:cheers:

 

It's the s/c tire design. The issue is discussed in the video that comes with the Z. The weight difference- 113 pounds or whatever- is laughable. But the less compliant Z suspension wouldn't help. BTW, the video clearly states the s/c wet performance is inferior to the emt.

Compare the emt and s/c tread. The emt's got the old symmetrical gatorback and original F1 tread for pumping out the water. The s/c's intended more for dry track and autocross.


[Modified by rwd, 6:51 PM 6/27/2002]

 

I hit some nasty rain on my trip to Bowling Green in May. The car was handling very well but I was being pretty careful. I got a little complacent when in Montana and was doing around 80 in a rain storm in a mountainous area. I turned the wheel to negotiate a left hand bend in the road and the car kept going straight, almost went through the gaurdrail and down a cliff :eek: . It was my own fault as I thought the car handled pretty well during the other rain storms I was in, I pushed it to the limit, and I shouldn't of. :nono: They are not a rain tire, plain and simple. You can't have the best of both worlds I guess.

 

Hydroplaning occurs when the tires ride up on top of the surface water on a road, rather than through it... So now you have no grip and can go slip-sliding...

So A lighter car will ride up easier due to its lower weight.

Also bald tires or nearly bald tires won't allow the water to get out of the way of the advacning tire as fast and will ride up on the water.

This can happen at any speed though is less likely at low speeds since the water has more time to move out from under the tires... Though it can happen even at 5 mph with enough water, a light enough car and the wrong tread design...

hey you are both right...

Mike

 

I've been ridiculed for this many times before but I'll do it again.
I've been trained at some pretty "high powered" airplane flying schools and the general rule of thumb taught , regardless of weight, tire width, or tread depth.....the GENERAL rule of thumb is 9 times the square root of the TIRE PRESSURE with a standing water depth of 1/4 inch +/-.

Example:

Tire Pressure: 32psi
Square Root Of 32: 5.65
5.65 x 9 = 50.85
This is the APPROXIMATE hydroplane speed.

I just round it off to 36 psi square root is 6 times 9 = 54mph.
APPROXIMATE hydroplane speed 54 mph.

Works for ME! YOUR mileage may vary.

 

Mike, I agree with point number 1.

Point number 2 is however incorrect. Additional weight creates a larger contact patch on the ground and the PSI of pressure the tire is applying on the ground is the same for a light or heavy car as long as tire air pressure is the same.

Bottom line, vehicle weight does NOT matter. Vehicle weight distribution, track, wheelbase, suspension setup, dynamic handling systems and many other factors can affect the car's reaction to a wheel hitting a big puddle and hydroplanning, but the ability to prevent hydroplaning in the first place is all in the tire design and wear condition (tread pattern, tread depth, tire width, aspect ratio....).
http://www.tirerack.com has some good datapoints if you want to research further.

I do agree with your third point, the amount of water the tire needs to clear per unit of time is directly proportional to the speed of the vehicle. So the faster you drive, and the deaper the water, the more water/unit of time needs to be displaced for the tread blocks to penetrate the water and make contact with dry ground.

 

Cool formula, but that doesn't account for tread block design variations and their impact on that critical speed. Also doesn't factor in water depth or tire width, which does have an impact on hydroplanning. For airplane tires, rolling down a well graded runway, I'm sure it is pretty accurate but it doesn't begin to capture all the variables that cars run into on the open road.

Like I said in an earlier post, BMW 328i and Lexus IS 300 are basically dynamically identical cars (weight, weight distribution, length, wheelbase, tire/wheel size....). Check their respective stats if you doubt me, but with Michelin MXV4s at 32 psi the BMW was all over the place at 60-65 mph in the same conditions the Lexus takes in stride at over 80 mph with the Bridgestone Potenza RE4s at 32psi as well. Very different tread pattern if you look at both tires and the Bridgestones are summer tires with larger water channels and fewer bigger tread blocks. Made all the difference in the world.
http://www.tirerack.com for more info..... :cheers:

 

My Z06 hydroplaned at 65 mph in heavy rain. Active Handling kicked in and straigtened in out before I could react Toyo Proxes will be my next tires... :rolleyes:

 

I would say that it is 95% because of the F1SC tires, I switched to Toyo Proxes T1-S tires on my Z06, with a water-shedding treadpattern, and haven't hydroplaned since. The treadpattern, low tread depth, and width of the F1SC tires make them fantastic for performance on dry pavement, but with the thunderstorms that we have here in Ontario I found them too dangerous for everyday driving.

Sure, you can slow down to 30mph on the highway to avoid hydroplaning on standing water, but then you run a very big risk of being smushed by a semi that is still flying along above highway speeds. Not good! :sad:

imp.

 

70 seems to be the magic number for me at 30 PSI. Last time I got caught in the rain I was around 5k miles. I am now around 8K, and I'd say the F1's are down to about half tread left. TC/AH is a wonderful thing when you get caught in the rain. Quite honestly, the car feels really squirley to me in the rain.

 

We all know that Active Handling cannot overcome those pesky laws of physics.

Aggressive driving when the streets are wet...even a little wet...is to be avoided.

The combination of LS6 torque and F1SCs optimized for DRY-pavement grip creates an imperative to slow down and drive defensively whenever the streets are wet.

Ranger

 

In racing, everything makes a difference, including weight, tread and the actual tire pressure. The same applies to street use. I will say that one person well-placed with the old Goodyear Formula One effort told me that he thought getting the ratio of contact surface to groove area correct for the conditions was almost as important as the tread itself. That's why they have different tires for different rain conditions. Bottom-line, if you drive a Z in the rain often, other tires are a good investment.

 

I really appreciate the replies. What's pissing me off is that my tires are half worn and yet I had to slow to 35 on the interstate 95 last week which almost did get me smushed by a dumptruck. Also hydroplaned at 40mph on the street. The car just started turning but the active handling didn't seem to be kicking in. SO I called Chevy and they inspected the tires (which I know are ok) and told me that GM is not responsible for what conditions we drive are cars in. I asked for them to recommend a replacement tire (which they wouldn't) that was better suited for the weather conditions. While I know these tires are great on dry pavement -if the Z06 is your daily driver then this becomes a problem. Since it hasn't stopped raining here in South Florida for a couple of weeks this is hurting my business if I can't get out. Wish I'd know this before. :confused:
I know about the laws of hydroplaning and it seems pretty apparent to me that it is the design and depth of the tread. So I've been extremely careful on the throttle but it hasn't helped. It seems that every 1/16 of an inch of tread wear reduces your hydroplaning threshold by 5 mph in these FL rains.
From what I've been reading on this board and others the Toyo's seem like the way to go. Was hoping to hear from more Florida drivers though. Thanks Bertrand -if you see a black Z06 driving sideways in the rain -give a wave. :cheers: :cheers:
Dee

 

Sure thing! :seeya I'll probably be sideways right there with you! :jester

I try my hardest to keep to the IS300s when it rains bad like the past two weeks because it can make for a stressful ride otherwise. In case you're looking for a foul weather beater, the IS300s with the 17" summer tires go through those puddles at 70-80 in stride where my vette and past BMW 328i would have been winning a water skiing competition... And they are very sporty for a four door (specially brakes and handling). Just sharing my observations (I don't own stock in Lexus or sell them for a living....).

:cheers:

 

I posted a few months ago about my experience with SC's in heavy rain with about 5000 miles. I did some 360's when the car kicked out on the rear after hitting a deep puddle. .

All I can tell you is I replaced the SC's (since we get a lot of rain in FL) with Toyos and I have not had any incidents. TI drive the same strech of road five days a week, rain or shine.

I am back to the setup I had with my 95 when I replaced my Eagles with Michelins. The Eagles on my 95 also were squirrely on the same patch of road. The Michelins were great, but they don't come in the correct front size.

If you see a pix of the Toyos they look like LeMans rain tires lots of grooves and they start with 10/32's . No regrets. I have no issue with SC's, great tires.. but for me I like to keep drivin' in any weather.

By the way, to all those who have Halltech Sidewinders, after several deep water excursions and drenching deluges, the side winder system did not injest any water! Although it did get damp.. no biggie.

I should change my handle to scubaZ06 or somthing.

 

How did the Toyos compare to the SCs in the dry? And where did you buy there? Is there a link on line to buy them? Didn't see them on tirerack.com for the Z06...

Thanks for the help.

:cheers:

 

Good excuse to get some new wheels, too!

 

I will buy that speed. The tires are real hydroplaners in standing water. I just go real slow under those conditions. I think they are quite good on wet roads however.