Had a raunchy spinout first time I drove the C4 in the
wet. 1984 Coupe, standard alloy wheels, 8.5" X 16".
What tires in this size give the best wet adhesion and
good aquaplaning performance?

 

My GY Eagle HP Ultra Plus are great dry, wet and in snow but I don't know if they come in 16" size.

If not maybe Michelin Pilots.

 

What were the circumstances leading up to the spin? Have you
had an alignment performed and if so, what rear toe setting was
specified?

On the C4, rear toe changes in the direction of toe-out as the rear
rises (as when weight transfers under braking). If there is insufficient
static toe-IN, then the rear toe can change to toe-OUT as the
rear lifts causing the car to try to rear-steer if travelling in anything
other than a straight line. Since NZ law requires roads to be twisty,
this toe-out rear-steer issue can become a handful.

Incidently, which part of which island do you spend most of your time?
There are some wonderful (and wonderfully unforgiving) stretches of
road in your country. Perhaps the old path up the hill to the ski area
outside of Wanaka being one of the more memorable ones?

.

 

Actually it was on a twisting, hilly blacktop road in
Pennsylvania just after I got the car there. It had
just rained and there were wet leaves all over. But it
happened even quicker than it would have when I had
a 356 Porsche. Don't know the suspension settings,
just having taken ownership. Sticks real well in the
dry.

The car is now on display in an upmarket classic car
museum in Nelson, NZ until April as part of a 'Muscle
Car Exhibit". But I take it for a run once a month.
Mostly drive around the S Island for the past 12 years
here. Glad you know the conditions.

 

Thanks for that. I'll check it out.

 

Eagle F1 GS-D3 tires are amazing in the wet. They have a few sizes in 16 inch. They're a bit pricey, but they have better wet traction than some tires have dry traction. Check out the test results on TireRack. Another (even more expensive) choice is the Bridgestone Potenza RE050A Pole Position.

 

Hmmm, Barry Meguiar (of Meguiar's Car Care Products) did a segment
on one of your senior countrymen and his extensive collection of
unusual classics. I do not recall the location but I wonder whether
your car is displayed at the same exhibit?

If memory serves, there is an impressive cathedral in Nelson - situated
at the top of a long, broad roadway that provides a great view on approach.

Rain and wet leaves suggests it is less likely that much weight
transfer (toe change) could occur before losing traction. But the
description of the quicker-than-Porsche-like snap oversteer seems
characteristic of toe-out at the rear.

For stock (23 yr old) suspension parts and aged tires used on
narrow roads with little shoulder, sharp drops, blind turns in a
changeable climate, a conservative approach might be to dial in
at least the OEM toe-in value.

I had good results with the Goodyear GS-C. The GS-D3 is the
follow-up. However, for track performance and value, I chose
to go with Kumho.

.

 

My 84 was a pos in rain until I bought some cheap Kumohs. Every other tire I used the car would dart all over . The Kumoh was not as good in dry weather as some others but I could run in rain as good as any other car. Just my experince.

 

Thanks, all. Great advice. Will have rear toe in/out
checked/adjusted. Nelson does have the cathedral.
The large car museum is in Paraparaumu in the N.
Island north of Wellington, and well worth a visit for
some amazing cars. The Nelson WOW Museum is also
worthwhile but with far fewer cars but really top of
the line of each model. An honor to have mine there,
especially since they don't know me from a bar of soap.

 

I would definitely check alignment.

I have Pilot Sport A/S and they are great in the wet.

 

Check Tire Rack via the link on the left of the section pages here. It's a font of info on tire specs for many brands, their characteristics, reviews and etc. They've also got some damn good deals. I've bought from them several times.

 

They're way pricey(in my Z's sizes) but IMHO worth the $. Their tread pattern is a close relative to a semi-wet CART tire tread pattern of the 90's if my memory serves me well! Anyway I remember seeing the pattern of racing semi-wet tires from goodyear in CART' road courses.

A word if I may about what to look for if wet performance is important to you. The water has to be removed from under the tread blocks. The most effective way is to send the water to the side wall so it exits from under the tread out the side of the tire. That method does not throw the water backwards in front of the following tire. If you look at rain racing tires you will notice that as much as possible the tread patterns are all designed with this in mind. Also that direction of removal is like a boat hull's bow parting the sea....pointy end first right?
Look for a tread pattern that has side drainage. You would like to see sweeping grooves from the center to the shoulder, straight lines are less effective. You don't want an inter-locking pattern as that interupts the water flow with direction changes. Most passenger car tires are not designed that way because they become LOUD in the dry due to air movement. The narrower the tread blocks and the bigger the sweeping grooves the better the water pumping action but the louder the tire on dry road. Also the worse it will handle in the dry due to heat & tread squirm. But that part is not really important unless you track or autoX. The D3's are LOUDER on cement & just LOUD on asphalt, oh and they're expensive but I feel they work on my Z, 275's front & 315's rear, and no "vague" feeling in reasonable puddles at speed or on sheet water on a road, also excellant brake "feel" in those conditions. They remind me of the VR/CN36's of the 70's....they were a copy of the rain racing tire used in the WRO.

Sorry to run on about this but most tire sales people don't know squat about wet vs dry tires so ya can't ask them!

Tom

 

Do you know how old the tires are????

Old tires, even with good tread depth, can become disasters with regard to traction, both wet and dry, but especially wet... The rubber on the tires age and harden and even tho they look good they don't perform...

If the tires are more than 4-5 years old, new tires should fix the problem......

I have personally had good experience with BFG KDWS and Goodyear GS-D3..

 

Another vote for the Goodyear F1 GSD3's. It rains quite a bit here in Washington, and I've done some research on what my next tire will be. Wet traction is very important, but so is dry handling, as I autocross occasionally, and hope to get into doing a lap day or two each year. Like 90Z51 said, the D3's get better wet traction than many tires(even in the same class) get dry. They are a little more expensive than most tires, but they're the only thing that keeps you stuck to the road, and arguably the most important part of the car.

 

Nothing gets your blood pumping more than suddenly going down the interstate backwards at 60 mph! Traction control and michelan pilots do a great job for me!
Bernie

 

Another vote for the Goodyear G3 F1's

my first 94 has Sumitomos,,,, the second 94 had the F1's

The Sumi car would break the tires loose hitting 3rd gear
the second would barely scratch second, and hooked in the rain under fairly heavy accel

 

The selection of good grippy tires for either wet or dry conditions in 255/50-16 is gong to be really limited. The chances are that in NZ, you may have difficulty in getting tires from the US shipped to you.

If you go to the Tire Rack website, you can do a search on your 255/50-16 tire size to find suitable tires in the proper size. http://www.tirerack.com/tires/Compar...t=All&x=77&y=8

Unfortunately the suggestions like the Goodyear G3-F1 and GS-D3 are great ones but they are not available in the factory size for your 84. There is a GS-D3 in 245/50-16 but it's pretty narrow for your wheel width width and the tire is a full inch narrower in tread width.

I would look at the Yokohama AVID V4s or the BF Goodrich g-Force Sport tires. Based on the reviews, they appear to have decent grip in wet/dry compared to the Dunlop or Sumitomo tires.

As mentioned, tires over 5 or 6 years old tend to lose the compounds in the tire and the tread gets hard. This results in a loss of performance of the tire.

 

do not buy "summer only" tires.
definately look at "all season" tires, like the kumho ASX

 

In general, summer tires will have better wet performance than all-seasons. All-seasons give up wet and dry performance for cold and snow performance.

Of course, there is overlap. A top of the line all-season will outperform a bottom feeder summer tire in all conditions.

 

make sure you have the right tire presure too
check out this article:
http://www.tirerack.com/tires/tirete...e.jsp?techid=3