Tinwan

Hi all,
I finally need new rubber on my 1990 C4. The current Bridgestone C-02's have the worst road noise and although handled OK. Anyone suggest a best all-round brand for a everyday drive, no track days and mostly dry conditions hot condition (down under) and compatible to the C4's 4-wheel drive system ?
Thanks for any feedback- Cheers, Mark

964rh

Conti sports seem to be popular. Mine had these on prior to me tracking it.

Heirsh

I've run mich Pilot Sports and bridgestone Re050's (A's and Pole Position). I liked the Michelin's better as I had more wet traction and they complained (noise) more when pushed to their edge of traction. The bridgestones are great though. S'o2's are extremely popular as well, but I keep getting the RE050's for cheap so i haevnt tried them, yet. I can't get the michelins in 16" any more.

madmoog

FWIW, I've Conti's on mine (C2), and they seem quite good (although I have no referance point as I've not tried anything else), ware well dispite numerous track days, although the go off after about 20 mins (more abuse than the ought to see on the road!).

Looking to upgrade to more track orientated rubber this year, so may either need another set of rims or have a set of part worn Conti's up for grabs!

Slantnose!

I like the Michelins for street stuff.

joey bagadonuts

The most important spec for C4 rubber is the OD (outside diameter or tire height). They need to be nearly identical front and rear for the AWD system to function properly.

For 17 inch wheels/tires, that means 205/50 front and 255/40 rear. Those specs translate to OD's of 25.1" front and 25.0" rear. A 225/45 translates into a 25.0" OD, so you would also be fine with that size on the front if you're looking to run a little more rubber. Keep in mind, the extra width may cause slight rubbing at full lock.

kos11-12

hi there sorry to jump in ,so what would be the ideal size for 18" Joey,on 225 fronts and 265 rear
thanks Konstantin 92 C4

joey bagadonuts

225/40/18 = 25.1"
265/35/18 = 25.3"

The middle number, referred to as the aspect ratio, determines the sidewall height and is simply a percentage of the tread width. To determine the OD, you multiply the tread width by this number to determine the sidewall height. From there, you convert it to inches, double the number and then add it to the rim diameter to determine OD.

225mm x 0.40 = 90mm (sidewall height)
90mm / 25.4 = 3.5433" (sidewall height in inches)
3.5433" x 2 = 7.0866" (sidewall height doubled)
7.0866" + 18" = 25.1" (OD)

Indycam

http://www.tirerack.com/tires/tires....&tireModel=ZRi

They are bridgestone tires , made in Japan .
I have them on my C4 .

http://www.tirerack.com/survey/Surve...irePageLocQty=
Do a filter by vehicle = porsche , to see what other have said .

kos11-12

thanks joey,I was doing a search on C4s the other day and found a thread were someone was saying that using the maximum OD in the front (to max tolerence?) was helping C4s to turn in better, apparently Audis use to do that ( is there a choice anyway?) have you guys experience that ??
Konstantin

joey bagadonuts

There's a whole host of adjustments you can make to improve C4 turn in but they usually have tradeoffs. Generally, having correct air pressure is the most important step: 36 psi cold all around with 17-inch tires.

So what are you trying to accomplish, Konstantin? Better turn in for track or just around town? If it's the latter, you may want to experiment--in a safe location--the difference in turn in when you trail brake. Unlike a front-engined car, you can't simply brake hard, lift off and then crank the wheel to toss these cars into a corner. The weight needs to remain on the front wheels to generate any meaningful grip.

To improve turn in, apply your brakes in typical fashion as you approach the corner and then retain light brake pressure as you begin turning the wheel. You should feel a night and day difference--the car will be sucked into the corner.

Remember, when you apply the throttle, you remove weight from the fronts, reduce grip and may actually cause understeer if you mash the pedal while entering or exiting a corner. It's only after you have the nose pointed in the right direction that you can actually accelerate hard without veering off course.

Have fun and be safe.