I prefer the PSS to the OEM P0s my 991C2S came with. No understeer, equal grip, better ride. But then again, I actually have a 991 and PSS so what do I know?

 

Chuck, you are not meant to take this personal. If Your car Works well With Your tires and Your driving style, nothing is better than that.


My information is interesting for a small Group of People, but for those drivers it is important info.


Cheers :-)

 

Unless you are racing, whereby blocking is required. You are better off with slower turn entry and faster track outs. There no appreciable lap time difference between slower turn entry vs. faster turn entry. Entering slower with faster exits will equal faster entry with slower track outs.

I am curious. have you experimented with different tire pressures to compensate for the understeer?

I watched your video again (three times) and five times at your trouble spots. I am by no means an expert, but FWIW I have a comment about your driving at these two turns where the understeer is pronounced (1:31 & 4:01). It appears on both turns there was a late turn in. You tried to compensate by pinching it and then reduced power, causing some drift. I noticed that you didn't have this trouble on other turns. In addition, there will come a point in time where maximum performance summer tires just won't cut it no matter the brand.

Anyway, I am just trying to be helpful in the spirit of good forum etiquette.

 

I have not personally, however while at the PCA track event this weekend saw many cars with Sport Cups. Drivers really like them and are getting nice mileage from them. I have heard a few complaints about the tire spitting out chunks of rubber, but do not know why.

The SC2's are pretty pricey in the high $700 range per tire.

 

I have hear complaints about SC2 from Ring taxi driver at Nürburgring, saying the old cup tire was better in dry conditions, also a lot of graying with the new tire. It is better in wet though and has longer life.
Hopefully the new Dunlop Sport Max Race will be available in many sizes soon, that tire is said to be very good.

Dag

 

Dag,

No offense, but you need to refine your driving technique. I watched your entire video and you often don't have the car settled properly going into the corners. You are not alone, the way you drive is very common with say a fast 'Intermediate' driver. That's why the tires are giving you fits - its your driving style. On a 911, the only way to get a proper 'set' on the car is to be powering through every corner, and its more critical on this car than say a BMW M3 because of the rear weight bias. I see you coasting through several corners and even shifting in the middle of some of them, and that upsets the car and induces oversteer/understeer. Granted, some tires are more sensitive to transitions than others, but 90% of your complaint has to do with your driving style moreso than the rubber on the car. No one likes their driving style critiqued like this, I get that - however I've been instructing since 1996 and refining from where you are now really is the area where you want to focus - that's what is going to matter the most. Stay with it, get your local instructors to show you how to do all your braking before turn-in and then power on through the corners and your whole driving experience will change - AND you'll knock several seconds off your times.

 

Sport Cups are a R-Compound tire, not a street tire - they are for the track only. Most R-Compounds will heat cycle out way before they wear out. Tire chunking is because they are running full tread depth tires on a type of asphalt that is either rough or generates heat. The tire then comes apart. The solution to that is to shave or groove the tire for that particular track. While it may seem counter-intuitive to shave a brand new tire, it can make them last longer on certain tracks. You have to keep records to find out, and experiment with tire pressures and a temperature reader for the tires to get that dialed in for a particular surface.

 

Thanks for the help, and like the previous post says, it is linked to my driving skills (lack of them) also. But with my skills, the Pzero acts more forgiving and grips better. This is a Pzero lap
The pinching and reducing power is because I loose my line, with Pzero there is no need for adjustments, it just grips and steers.

Next year I will have cup tires, even if the potential is in my driving skills!!

Dag :-)

 

I really like your input, I want to improve!!

I am just a tourist driver and have huge potential in improving my driving. Thats why I am one of the few, maybe the only "fast" Ring driver who has not yet bought cup tires.
Last trip I had a pro instructor (Christian Mentzer) and my best lap time went from 7.43,73 to 7.38,19, I am on my way!! The lap you saw was a 7.41 and by far my smoothest.

Have a look if you have time on a Pzero lap, you might see it is smoother.


Thanks for the input again, I will be faster and smoother but it requires me to spend some time in Germany. I will.
The shifting yes, but PDK is so forgiving it might not mean much?

Dag

 

Michelin respectfully disagrees with you. 😀 Their website indicates that they are a DOT approved street able track tire. Having said that, given their cost and intolerance to road debris hazards, I doubt many would use them for anymore than a commute to the tract.

Frank C.

 

The basic premise of this thread is interesting. 'Dangerous' understeer? Understeer is slow, but not dangerous. I agree with many of the observations that what is going on here is either wrong tire pressure or driver technique and not some empirical evidence that Michelin PSS's are inferior to Pirelli PZero's.

I find it amusing that some believe a Porsche N rating is somehow meaningful.

Last, while the thread does have some interesting debate about the actual performance differences of these two tires, 80% of the posts quickly devolved into a laughable discussion of the appearance of the tires. Basically another poseur pissing contest over whether my hips look fat.

 

Well of course they are streetable, otherwise they wouldn't be a DOT approved tire. There are several problems with running an R Compound Tire on the street, I've had at least twenty sets of them over the years.

1) They loose stick with every heat cycle. A heat cycle means warmed up to operating temperature. When the stick is gone, typically before they wear out, they're toast. They turn a blu-ish cast on the tread when they are used up.

2) They are noisy, and pick up EVERYTHING on the road. All the dirt and gravel gets sandblasted onto your underbody and paint near the fenderwells. If you insist on running R-Compounds on the street, better get lots of 3M film on the sides. And some earplugs. Many sound like a circular saw is running under the car.

3) They have very low flat resistance and puncture easily. And once you have a puncture, you toss them away. No repairs.

Not to be presumptuous, but I can probably run my car on its regular street tires around a track faster than most people (but not all) that show up with R-Comps. Why? Just because I have refined my driving technique over 18 years of track driving. Run sticky tires if you want - its a free country and all - but know that they have higher breakaway limits and if you get in trouble they snap quickly, whereas a street tire is more forgiving. I think its most important to get your technique solid first - then go to the go-fast stuff. When you can run your car over your chosen circuit at 10/10ths, and the tires are 'singing' at every corner and the car is in a slight drift - now you have reached the limit of the tire's adhesion and its time to go to R-Comps (that you put on at the track, or trailer to the track with them on the car).

Here's an example of a two well-driven cars. Notice the slight drifts in the corners and the tires are singing...this is how you do it. When you can do this, you have mastered your driving technique. Note that both these 991 Turbos are on street tires...probably Porsche factory drivers....

 

That driving is a sight to see. Looks like a well orchestrated performance.

I guess it's all about how you use it...

 

Way beyond my pay grade!

Frank C.

 

You're right, why would we trust Porsche engineers? They only created the car.