I just ordered a new set of wheels and tires for my f430 through a local performance shop who assured me that everything will fit. Wheels:ForgeLine ZX3R Front: 19x8.5 (same as stock) Rear: 19x10.5 (same as stock) Tires: Hoosier R6 Front: 235/35, OD=25.6" vs stock 225/35, OD=25.1" Rear: 295/30, OD=26.1" vs stock 285/35, OD= 26.7" Question: With the overall diameter of the new front tires being .5" larger than stock and the OD of the new rear tires being .6" smaller than stock, isn't that going to screw up my ABS, Track Control, and Stability Control? I would think the sensors would sense the rear wheels are slipping since they are rotating faster than the stock wheels due to the smaller diameter size and vice versa with the front wheels. I know this will screw up my odometer mileage. The Pilot Cups (235/35,305/30) are a bit closer to stock OD size (25.5" and 26.3") but my guy told me the performance is not up to par with the Hooziers. Any ideas?
You'd probably get more responses on the racing and tracking thread. http://ferrarichat.com/forum/forumdisplay.php?f=6
I am here. Here's what I would suggest. Go to: http://www.miata.net/garage/tirecalc.html There are two tire size calculators there. Try each, and you'll see what effect the tire size will have on the speedo. If you go too far afield from a comparable OEM size (O.D.) you'll throw your gearing off a bit as well as the speedo. The sizes are not too far out of line, and I do not believe you'd experience any handling difficulties you mentioned. It would be good to know what the offsets are of the rims he's recommending to see if they differ much from the OEM. It's the tire choice I would question. I believe most folks here go with Michelin PS2's (that's what I have in 19"), Pirelli's, Continental's, or Bridgestones. I can't speak to Hoosier's, and I have not heard of anyone using them. Maybe the dealer's margin is better with the Hoosier's, but I would seriously consider one of the brands I mentioned. The rims would not be an issue for me. It would be the choice of tires. Anyone know about the Hoosier brand? BTW, welcome to FChat. Please fill out your profile so we know who you are.
He didn't ask about handling problems, he asked about malfunctions of the ABS, and ASR which are real possibilities. We are not told what the tolerences are for those systems because the system and car manufacturer both say not to modify the car. You will just have to wait and see unless someone has already tried that combination. These are reasons some European countries do not allow modifications of any type.
Thanks for the input. If you look at the Hoozier R6's they are very close to a slick tire with only 2-3 grooves and made out of a race compound so are a superior track tire. Not sure what you mean about the rim offsets though. Front and rear are both 19" wheels, just like stock. Thanks
The offset is the distance +/- from the center of the wheel bearing to the outer rim area of the wheel. It determines where the vehicle load is placed over the wheel bearing and where the wheel will sit with respect to the body as well.
The Pilot Cups in the 305 works fine. The 235 and more agressive tread helps with the understeer in front when compared to the P-Zero Corsas. I have thought about trying the Pirelli slicks from the challenge series on the car. the sizes are right for the car. The hards should have a little more grip than the hoosiers. The reason I haven't rushed to test it (and something you should consider) is that the car is really sprung too softly for this level of grip. I can't imagine getting lucky enough to maintain the balance. However, I bet someone has tried the challenge slicks on a car. If I was going to try something like this, I would try the Pirelli slicks before the Hoosiers considering the size issues. P.S. I assume this is for the track, right?
Do you know what exactly which Pirelli slicks being used in the f430 challenge car? I can't seem to find this info anywhere. I was originally thinking about trying to use those but could not find any info, all I ever read is "super slick tires from pirelli". Yes, these would be used for track events but also need to be DOT compliant b/c will be driving back and forth to track. Thanks
The model name is the "P-Zero Race Slick". They are not DOT. Given your use and the fact you are getting wheels for them, you should just get Pilot Cups. They work well on the car. P.S. I didn't mention this before, but stock fronts are 19 x 7.5. You should use 19 x 8 inch wheels for the 235 tires. 10.5 in the rear for the 305's is fine.
Yes, I misspoke, stock wheel is 19x7.5" for front but my guy ordered 19x8.5". Do you think it will be a problem running 235 tires on 8.5" wheels? The Hoosiers R6 are DOT compliant and are closer to a slick that the cups. He said they would save me a good second on our local track (aprox 1:18 seconds lap) compared to the cups. So you think the car is sprung to soft for the hoosiers though? Thanks
19 x 8 is enough for the 235s. The car will be camber challenged anyway. No point in using more wheel than you need. A second is probably right, but if your just running track days you aren't going to need that second unless you have someone particular your trying to keep up with. I would just put the cups on and have fun. You are not going to have more fun with Hoosiers and the Cups are sized better. Do you have ceramic brakes? If not you need pads. the stock ones will get desroyed in one day. Factory brake fluid isn't too good wet either. As to the springs, the car is definitely undersprung for slicks. It may work fine though. I haven't tried slicks. The car is fast enough with Cups that most laps aren't clean anyway. More grip would just mean waiting for more wave bye's.
Yeah, I'm getting the pads changed today (do not have ceramics) as well as the brake fluid. Changing camber on front to -2 degrees (stock is -1) and changing camber on back to -3.25 (stock is -1.5). Changing toe to zero. He spoke with some fellow racing friends of his in the challenge series and got those recommendations. The guy I'm using is pretty adamant about the hooziers. They are really cheap anyway so i'll try them and see what happens. I'll talk to him about changing the wheel order from 19x8.5 to 19x8 though. My brother-in-law who has a z06 and myself rented out the local track here and this guys is coming out with us for the day. He's currently racing in the touring class in the SCCA world challenge series and raced few races in the rolex series so he should be a better judge than me of how the car handles with the new setup and if other adjustments should be made. Thanks again for help.
On the pads, I have found the Porterfield RS-4's to work excellent on the track. They bite pretty hard warm though so you have to adjust your initial pressure. I have also used Pagid Blues. They lasted well, but didn't have the bite like the RS-4. Also, forum sponsor Girodisk is excellent for braking help. P.S. You should get front skid plates if you are lowered at all. You might scrape a bit with slicks under braking.
