Summer Max Performance Tires

[mjw930]

Be carefull and consider want out of the tires. Everyone wants to jump on the PS2 bandwagon but for many, me included, they are not the proper tire for the Boxster if you want to maintain or enhance the balance of the car, especially at the limit.

The PS2 is part of a new breed of tire that attempts to increase the comfort level while still maintaining reasonable directional stability and precision. This results in a tire with a hybrid sidewall construction that can work very well in some applications and horribly wrong in others. I have found that the Boxster is very sensitive to sidewall construction and doesn't really like the PS2's in the 18" configuration (you didn't mention the sizes you are shopping). Although the highway ride was very nice and the absolute grip these tires produce is excellent the loss of precision upon initial turn in and when they are subjected to varying side loads within a turn makes the driving experience less enjoyable for me. I switched back to the PS Rib (Pilot Sport N1) and although the ride is harsher the handling and feel of the car is much more to my liking. The overall grip is still very high and I find that I don't lose anything on the track or at the autoX.

You might want to consider the tried and true Bridgestone SO3's. They have been the standard bearer for many P-Car owners who track their cars regularly for the last few years.

[MikenOH]

do you think this due to a softer sidewall? I haven't driven my car with PS2's enough to get a feel for steering response relative to the Kumho's I had on the '99' but when I went from the Michelin MXX3 to the Kumho, I immediately noticed the less immediate response to steering inputs.
The ride was softer in the Kumho's and it still had lots of grip, but the "hardwired" feel of the MXX3's was not there.

A good friend that used to be a Goodyear tire engineer explained all the compromises you have to make, depending what you want the tire to do for you. I'm wonder if the loss of turn in response is a result of getting a softer ride.

[Adam]

I like the initial turn in on my PS1's. Are the PS2's less responsive than the originals? What do you guys think of those Yoko Advan Novus tires?

[Ghostrider 310]

Great feedback from everybody, I made a mistake in my post in identifying the Michelin tire. I'm looking for max performance street use only. I was shocked to see C&D magazine choose a Goodyear product. I have always found the Pirelli's and Michelin tires performed very well. Things have certainly changed, it sounds like that Yokohama product is a great choice now. I was surprised the Michelin pilots didn't score better in the comparison. My '98 has the optional 17' wheels, it's a non S 2.5L.

[Rail26]

I have long sweeping turns where I live that I usuall negotiate between 80 and 100. Sometimes the car wiggles under hard cornering. It almost feels like the sidewalls are rolling over. What might be causing this? I am running Bridgestone Potenza's that came with the car.

[Adam]

Originally Posted by Ghostrider 310

Great feedback from everybody, I made a mistake in my post in identifying the Michelin tire. I'm looking for max performance street use only. I was shocked to see C&D magazine choose a Goodyear product. I have always found the Pirelli's and Michelin tires performed very well. Things have certainly changed, it sounds like that Yokohama product is a great choice now. I was surprised the Michelin pilots didn't score better in the comparison. My '98 has the optional 17' wheels, it's a non S 2.5L.

Remember, C&D rated the tires in the wet and dry and then took cost into consideration. The Goodyear is not the best "dry" performance tire in that group. It just gave consistent performance in the wet and the dry at a resonable cost. The best dry tire appears to be the Yoko's.

Rail, what PSI are you running in the tires? I'm running 33 up front and 36 on the back and have been very happy with that setup for street use.

[mjw930]

Originally Posted by MikenOH

do you think this due to a softer sidewall? I haven't driven my car with PS2's enough to get a feel for steering response relative to the Kumho's I had on the '99' but when I went from the Michelin MXX3 to the Kumho, I immediately noticed the less immediate response to steering inputs.
The ride was softer in the Kumho's and it still had lots of grip, but the "hardwired" feel of the MXX3's was not there.

A good friend that used to be a Goodyear tire engineer explained all the compromises you have to make, depending what you want the tire to do for you. I'm wonder if the loss of turn in response is a result of getting a softer ride.

In a nutshell, yes. The Kuhmo's are known to be a softer tire, that's how they were engineered. The PS2 has a very soft sidewall as well but to be fair, the sidewall in the PS2 is very sophisticated, it's not simply softer. It's designed to combine the softer sidewall with an outside tread density that should allow for very precise turn in and in the proper application the PS2 is a killer tire. I run a 17" version on my V70R and it transformed that car. The ride is superb and it can generate A LOT of corning force. To be fair, the suspension on the Volvo is geared for a softer tire so it takes the PS2's very well. The 986 suspension, OTOH is designed around a tire like the Yokohama AVS Sport, Pirelli P-Zero or the Michelin Pilot Sport 1 (derived from the MXX line of tires), all of these tires have a much stiffer sidewall and less tread squirm than the PS2 and certainly more than the Kuhmo's.

If you care about staying with an N-Spec 17" tire then the Michelin PS Rib (N2) seems to be the hot ticket. If you want to try something a little more geared for street/track then I would seriously consider bumping the fronts up to 225/45's and look into Bridgestone Potenza S-03 Pole Positions or the new Yokohama ADVAN Neova AD07.

With all that being said there are a lot of people quite happy running the Kuhmo MX's in 17's on their Boxsters but I doubt they are tracking the car reguarly OR they do track it and got tired of paying $200+ per tire after destroying them on the track in one season.

[MikenOH]

Regarding dedicated DE tires, I've drive the MX on a track and it's clear the tread needed to be shaved. One magazine that tested the tire put it right up there with the BFG KD in a short auto-X course with shaved tread. When I drove it on a 90 degree day, the tread was getting greasey after several 1/2 hour sessions but when I got it home the tread wear was uprisingly minimal. I'm thinking that if the tread was shaved to 5/32 there would be more traction, less heat from squirm and less tread flaking off.

What i'm thinking about is going with 17" tires for DE's on a 987 for $ reasons and using a shaved tire like the MX or G force Sport because they do give good performance--as opposed to great--cheap to replace (Est. $120/tire) and can be flipped if one side wears. Also, since I have to drive a good ways to a track, I'll actrually have a tread pattern in case I get caught in a shower.

TR has quoted me $100 to shave a set so a delivered MX set would be around $650

[mjw930]

Just for grins I ordered a set of Falken Azenis RT-615 from Discount Tires Direct to try out on my 17" rims. These tires seem to have quite a following with the Autocross and drifter crowd and considering their price I figured they were worth trying as track/autocross tires. I went with the 225/45x17 and 255/40x17 sizes, my wheels are 7" an 9" widths so these should fit perfectly.

Once I get some track time on them I'll post some reviews.

[MikenOH]

What year Boxster do you have and which wheels are you using?

After all the chatter recently about the larger OD on the rear wheel of the 987 and how you need to stay in a certain range of tire size ratio--front to rear--what you've got just might work on my car( using the 245/45/17 size) and be relatively inexpensive.

Let know how it works out.

[mjw930]

Mike,

It's a 2003 S, soon to have the RoW M030 suspension installed. They are going on a set of Mille Miglia turbo twist replicas, 17x7" and 17x9". I know, these are heavier than the factory wheels but they are all I have in 17's and they aren't really bad wheels. If you were to go out and buy a second set of track wheels and tires the package would be very reasonably priced, somewhere around $1800. That's for the entire set of wheels and tires OR about what I paid for the rear set of 18" wheels (minus tires) that are on the car now