Track Tires for Carrera 4

I have a US 2001 Carrera 4 and want to get a set of wheels and tires for the track. I have the 18" Sport Rad wheels with 225/40x18 on front and 265/35x18 on rear. I have the factory sport suspension with Euro sport springs. What size/make/model tires and rims would work best/be recommended as an upgrade for non slick track tires? I understand that wheel circumference particularly on the front is critical on the Carrera 4. Any help would be most appreciated.

You can either use 17's or 18's. If you decide to go for 17's, the Kumho V700 Victoracer is a great tire. For 18" sizes, consider the new Michelin Pilot Sport Cup . 17" 225/45-17 on 7.5" wheels 255/40-17 on 9" wheels 18" 225/40-18 on 8" wheels 265/35-18 on 10" wheels

"I have the factory sport suspension with Euro sport springs." How did you get this combination? Is this an aftermarket change? Did you have the blessings of your dealer when you did the swap?

my car came with the factory sport suspension and then i had the dealer (beverly hills porsche) install the european sport springs. they also corner weighted the car for me. it was on the recommendation of my service advisor. i was told it would not affect my warranty since i used porsche factory springs. the car is dropped a little over an inch and looks great but more importantly on the track handles amazingly. sharper turn in and super neutral. in fact a couple of instructors i've been in the car with have been very impressed with its neutral handling. i will admit that the car is a little harsh driving around town though.

Did you get the warranty issue in writing? My dealer emphatically claims that "any modification" will void the warranty. I hope your dealer wasn't trying to make a quick buck to sell you an aftermarket product. Interestingly enough, Alwyn Singer who now heads Porsche Motorsports founded Andial. Andial sells the factory euro springs, and Customer commitment told me I am going to void my warranty if I swapped the springs. I suppose PCNA has no respect for Alwyn.

I second the Kumhos. They're inexpensive and reportedly perform as well as the Hoosiers (see reference below). I also have an '01 C4 with sport suspension (no Euro springs, though) and my first upgrade (downgrade? from 18" turbo look wheels) was a cheap used set of 17" wheels for the track (which are for sale incidentally). After much research, I settled on the Kumhos even though the rear specification of 255 is very slightly below the stock 265s (in actuality, a very unofficial measuring stick test reveals the Kumho to be equal to or slightly wider than my stock Continentals). My first track day on the Kumhos was a pleasure, the additional offered grip was superb and overall the car felt more communicative. An August 2001 tire comparison in Grassroots Motorsports magazine of Kumhos, Hoosiers and Toyos gave the Kumhos the nod BUT they are very pressure sensitive, so keep the *hot* pressure right around 38 front and 41 rear.

On 17" wheels you can run 245's up front and 275's in the back. Hoosier and Kumho make both of these sizes. Your car shouldn't have any trouble with these tires as their rolling diameter should be very close to the stock set up. As a matter of fact the set up I suggested has equal rolling diameters. Not sure what the stock set up has. No way does changing the springs affect your warranty. How can they void the warranty on your A/C or tranny because you lowered your car to the same specs as a European model. There is a law that prevents a company from doing that. Somebody at your dealer is full of it. Greg

The New Ecsta V700 R compound tires are available in 18's Also in 17's 225/40-18 $175 265/35-18 $185 285-30-18 $195 from tirerack. www.tirerack.com

greg: any advantage to running 18s over 17s or vice versa. grip/feel etc. i'm using 18s on the street. just want to clarify. i can fit 245/45/17s on the front and 275/40/17s on the rear and the kumhos will have the same diameter as stock. what width rims should i use? who makes a good value light rim with the right offset? arthur: porsche cannot deny warranty because of the installation of aftermarket parts unless they can prove that said installation or part directly was the cause of warranty related problem. this is actually law. i also can't see it being an issue given we are talking about a factory porsche part installed by the dealer.

Arthur, you should talk to a lawyer. They will tell you what can and can not void your warranty. It takes more than you would think. If you push, the dealer will fold.

I run Hoosiers and the difference between the 18's and 17's is very noticeable, the side wall is stiffer and there is much less roll over. I also talked with one of the Hoosier reps and he said the 18's were a better tire, (what that means exactly I am not sure) Look at tire racks web site and look at the specs for the Kumho V700 the overall diameter for these two sizes is identical. I would use 8.5" widths for the front and 10" widths for the rears. As far as wheels go, I like Kinesis and BBS wheels, but if I had to get new wheels I would probably get them from www.forgeline.com a friend of mine & PCA Club Race Sponsor owns this company and will give good prices for PCA members, but his 3piece wheel are only in 18" diameters. All of these wheels are forged and none of them are cheap. You can get factory take-offs that would work but they are going to be heavier, and you will probably not get over an 8" width in the front (which won't hurt anything it just isn't optimal). This would be the most cost effective way, since I take it you are not racing or don't have plans to, and would be more than satisfactory. Greg

More Info: You have very specific rights granted by Federal Antitrust laws and the Magnuson-Moss Warranty Act that you must be aware of to keep from being "stonewalled" by a Dealer or Manufacturer. Under Federal Antitrust Laws, the use of parts or accessories that were not purchased from and installed by the Dealer do not affect the vehicle's warranty. Manufacturer's and their authorized representatives, may not condition a warranty on the use of their own parts or service, unless the parts or service are provided free of charge. Also, they may not refuse to honor a warranty unless they can show that an aftermarket part or accessory is the cause of a particular malfunction otherwise covered by the warranty. In other words, warranty coverage cannot be denied simply because such parts are present on the vehicle or have been used. The warranty coverage can be denied only if the aftermarket parts caused the malfunction or damage for which warranty coverage is sought. Normally, these issues boil down to facts and technical opinions, rather than interpretations of the law. Any denials of warranty should be gotten in writing from the Dealer. The Dealer must describe both the failure and how they believe the aftermarket part is responsible. SEMA's website has some useful information about this that can be found at * http://www.sema.org/warranty/