Streetable Track Tire Options
 

Hi,

I want to swap to a set of DOT legal track tires in OEM sizes and I am a little confused with the choices.

There are the Trofeo R tires which are the most expensive and supposedly provide the most grip on track, and the least in ordinary wet conditions.

Attachment 1218374

Let's put those aside for now because they are not complicated to figure out. I had them on my old 15MY Z/28 and they are essentially slicks.

The confusion comes when I try to discern all the different variations of Sport Cup 2 tires. I am also very familiar with these tires as I have them on my current C7Z. I have used over five sets on track and they always performed extremely well. They are 9/10ths the track tire the Trofeo R is but better in ordinary wet driving, but obviously not by much as they are still essentially slicks with token grooves.

So when I do a search for the SC2s on tirerack, it comes up with two options, a Porsche one and a non Porsche one:

Porsche spec:

Attachment 1218375

Non Porsche spec:

Attachment 1218376

So here are my main questions:

1. What is the actual (not suspected) difference between the Porsche and non Porsche specs? Is it a matter of rubber compound or is it that the sidewalls are a different shape, as in the way that our OEM Pirellis slope slightly inwards?

2. Has anyone tried both configurations on track and can tell the difference between the two?

3. You will notice that the for the rears the Porsche spec is actually cheaper ($469), and for the fronts the non Porsche (Ferrari) spec is cheaper ($305). So in an ideal world, if the compounds were the same at the only difference is in sidewall shape, one could mix and match and get four SC2s for $1548, which is cheaper than both of the package options shown above. Anyone see an issue with this strategy?

Sorry for the long winded question, I tried to frame it as clearly as I could. I called tirerack and other than to say that 'Porsche SC2s are engineered specifically for the 911' they had no clue as to the specifics of why and what the differences are between all the versions.

On a last note, my TTS is not my DD, never goes on long trips, and practically never sees rain unless I get stuck in a sudden storm near my house. In short wet performance is very low on my variables list. I want a tire that performs well on track and on dry roads, so for the sake of this conversation there's no need to take wet conditions into account. Also, for now I want to limit the conversation to oem sized tires ... I know that folks run bigger sizes and I'm interested in that option, but for now I want to narrow the discussion to the above choices.

Thanks for any help.

I've always wondered the same thing. Hopefully we get a good answer here. I would absolutely switch to SC2s for $1,550 per set!

- Patrick

Ok so I've been doing some spec comps on the Michelin US site.

If you go there and do a compatibility search for a Porsche 911 2016 Turbo S (Center Lock) the following initial data comes up (which explains nothing):

Attachment 1218373

However, if you're on that page and click on the link that says 'See full details specs' you will get more information. Basically this size tires also work on some Audis and Ferraris. There's a lot of data on that page (I don't want to post all the screenshots so please go there to see it), but so far as I can tell there are only two front versions (Porsche and Ferrari) and the only difference between the two is 0.8 in weight (I assume it's in lbs). Again, no way to tell if it is compound related or if it's just due to the Ferrari sidewall being more straight thus requiring a little extra material. On the rears, the specs are almost identical (0.1lbs variance) in all three versions (Porsche, Audi, Ferrari).

I might have to call Michelin and try to find out if this is a compound issue (which I doubt) or just a sizing issue that results in the weight differences. If it's just weight I'm mixing and matching the cheapest combination of front/back ... if it's compound I might have to do the Porsche spec.

Tbc ...

I have mixed and matched them. i would go with the cheapest combo.:banghead:

Mostly a sidewall issue.

There are, however, differences in compound between N0 and N1.

Well discussed over on the 991 GT3 board.

You mean between N0 and K1?

Do you happen to know what the differences are and how they affect the car?

Thanks

There is also a N1 designation for the most recent Porsche spec.

- Patrick

Do you think the SC2 'Porsche' set sold at tire rack would be the N0 or N1?

Thanks.

At this point almost certainly N0. Switchover to N1 is taking a while.

Regarding difference between N spec and other - very hard to say. I tried K spec rear tires on a GT3 and they had softer sidewalls (bad for rear on track but ok for front, and ok for street driving) and slightly lower grip, but lasted longer. All differences seemed subtle but in a way that I would not go with K spec rears again. I might try K-spec fronts.

Doh, it actually says NO on the screen shot I posted. :)

So if I do it this way (porsche rear/ferarri front) it actually comes out to the cheapest combination ... so that's where I'm leaning.

The only other question is, are the Trofeo Rs so superior to the SC2s on track so as to justify the extra $750 or so per set?

I think the combo you are describing may work well or may understeer a little more than N0 on both axles. I will most likely try it.

Most people I know were not faster on Trofeos than MPSC2. Trofeos have more grip BUT only in a very narrow range of pressures and temperatures, and are a little harder to drive at the limit. So most drivers cannot take advantage of this extra grip most of the time. I would not bother with them unless you are trying to win a bet :D

Ugh oversteer ... I don't want to exacerbate something that's already symptomatic in these cars, so if that's the case I'll just get the N0s and eat the $ difference. Plus my Z06 has the same tires so it will be a good like for like comparison as to what is the performance difference between the two cars.

Thanks for your help Max.

Not every tire that fits will carry a N0 or N1 designation. That doesn't mean it's a bad tire, it's just not Porsche specific.

- Patrick

Difference between N and K, from what I understand, is just the stiffness of the sidewalls.

The difference between N0 and N1 is a difference in rubber composition, making the N1 supposedly an even more stickier tire.

In the end I capitulated and ordered the N0 Porsche package which cost $300ish more than the cheapest SC2 combination. I want to see what they can do without any excuses that they weren't Porsche spec tires.

Once I wear them out I'll get the Trofeo Rs to see how they compare.

Thanks everyone for your input and help.