So let's talk tire sizes. Ferrari standard tire sizes for the F355 Stock Magnesium Rims: Front 225 / 40 ZR 18 Rear 265 / 40 ZR 18 Ferrari standard tire sizes for the F355 Challenge rims: Rain Tire Front 225 / 40 ZR 18 Rear 265 40 ZR 18 Racing Slicks Front 245 / 645 x 18 Rear 305 / 645 x 18 What other sizes are people running on their stock rims and challenge rims and at the track? Any Photos showing the differences. It was suggested to go up to 235's on the front for the challenge rims and maybe split the difference on the rear. I always like to see lots of info and suggestions. Thanks. Robb
I agree on the standard rims. I'm running Bridgestone's (or Michelin's) at those sizes. And I don't have spacers. I promise. I am curious about rubber for my new challenge wheels... Robb
Ferrari (not PinninFarina) knew what it was doing. Spacers are for people who do not understand that the justifiable suspension makes the spacers unnecessary.
My mechanic worked as a designer at Ferrari on the F355 suspension components - He does not recommend spacers. Robb
You are correct. On my current car, I have 265 rears. When I had my Barchetta GTB, I ran 285s with the challenge wheels, not 295s. Sorry for the incorrect info. Image Unavailable, Please Login
225/45/18 front 26" tall- size up one aspect ratio 275/40/18 rear 26.7" tall- 10mm wider this combo adds a small amount of diameter front and rear to fill up the wheelwell with the addition of 10mm more tread in the rear, since 265's are too small for a 10 inch wheel which is actually 11 inches overall. I 4 corner scaled and set the new ride height after the new tire combo was put on, rides and handles great. you can see the difference. The sun angle is casting a bigger sidewall shadow on the top pic, but you get the idea by looking at the diameters and even wheelwell fitments. Image Unavailable, Please Login Image Unavailable, Please Login
I'm confused. Why don't you ask him if he recommends tinkering with tire sizes instead of strangers online?
I have 245 front, 275 rear Conti's on my factory rims and 235/295 Hoosiers on my challenge rims. Pics are scattered through the forums, pic in my profile has older Dunlop Z1*'s in 235/275 iirc.
Not really, I just like a little more front end grip so went with the larger front tires in the Contis. On track they gave slight understeer trail braking into the turns and slight throttle on oversteer with 35psi front, 33 rear, just the way I like it. I could attack pretty agressively under braking without worrying about the rear coming around and steer with the throttle a bit on exit. Biggest issue was the brakes overheating and fading after 4 or 5 hard laps so I didn't bother with the Hoosiers as they'd overwhelm the brakes even more quickly. I'm hoping to get some track pads and try again in the spring with the Hoosiers, so we'll see. In autox I've gotten the balance virtually the same with the Hoosiers if/when I get the heat into them using similar tire pressures, so not sure the sizes matter as much as getting the tire pressures correct. I have some autox runs on youtube under the same user name, both in the rain on the contis and in the dry on the Hoosiers and you can see the car behavior is virtually the same, and the results were as well (5th or 6th out of 70 or 80 cars) and first in my class. If I can't get the heat into the Hoosiers, it doesn't go as well as I really need A6's for autox use, but I use that more for testing and getting a feel for the car as opposed to trying to outright win. Feel under braking is better with the Hoosiers, don't think that's related to the size at all but the tires themselves. I felt the same way with the Z1*'s compared to the Contis, so I think the contis just don't have quite the same feel. No biggie, though, they're unbelievable in the wet which is why I got them over z2's or other similar tires. In short, I don't think 10-20mm up or down will effect handling that much, at least not outside the parameters of tuning with tire pressures. Maybe you can gain a few tenths here or there, but unless you're seriously racing or time trialing I'd just go with what you prefer visually, take it to an autox and tune your pressures to get the handling where you want and not sweat it.
Bridgestone RE050A. 225/40/18 // 295/35/18 A couple of different angles of how they fit. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
