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Discussion Starter #1
I'm currently shopping between these 2 tires for a street car whose primary focus is AutoX and DE. 987.1 with 18's.

If the two tires were the same price, which should I go for? How comparable are the grip levels between the two on a stock setup?
 

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I have a 987.2 and prefer the RS3 over MPSS for track. Better grip and seems to me the RS3 tolerates heat/higher pressure better. I also had chunking on the outer edges of the MPSS. The RS3 s were noisier on the highway however.
 

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I have a 987.2 and prefer the RS3 over MPSS for track. Better grip and seems to me the RS3 tolerates heat/higher pressure better. I also had chunking on the outer edges of the MPSS. The RS3 s were noisier on the highway however.
I've heard the same from guys that I do track days with; MPSS for the street, something else for the track. If you're looking for one tire to do it all, the BS Re-11 might be the place to start. Having said that, I used NT-05s for years at the track and auto x and they were not bad; no chunking and wore very evenly.
 

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I've commented in some other threads on tires- my favorite drive to the track DE tire is the Yoko AD08R. Wears well, good grip, good feedback, ok in the wet, little quieter than the RS3 on the road. Nothing bad to say about RE-11s, a good tire too.
 

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If you're going to be autocrossing competitively, your only real choices are RE-71R or Rival S. Both are only a few months old, but rendered every other autocross tire obsolete when they came out. Not sure yet how either do on the track (the next issue of GRM is supposed to have an article about it), but I bet RE-71R would kick *** and wear out very quickly. Dulop ZII* is really quick, too; it's not getting much love from the SRS BZNS people now that the BS and BFG are out, but it's another really good tire and I'd recommend it above R-S3 or MPSS for a dual-purpose 987.

AD08R is a great track tire, but not legal for SCCA autocross anymore.

I ran 255/35-18 front and 275/35-18 rear ZII* on my 987.2S on OEM-sized OZ wheels with great results both autocross and time trial (single lap format). I've only used RE-71R for one event so far (same sizes), but did pretty well on them. The 255/35-18 RE-71R were a bitch to get mounted to 8x18" wheels, though.
 

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If you're going to be autocrossing competitively, your only real choices are RE-71R or Rival S. Both are only a few months old, but rendered every other autocross tire obsolete when they came out. Not sure yet how either do on the track (the next issue of GRM is supposed to have an article about it), but I bet RE-71R would kick *** and wear out very quickly. Dulop ZII* is really quick, too; it's not getting much love from the SRS BZNS people now that the BS and BFG are out, but it's another really good tire and I'd recommend it above R-S3 or MPSS for a dual-purpose 987.
I agree! We ran the RS3's at the Dixie Champ tour and then ran the new BFG-S and what an amazing difference. It seems to be that everyone is in two camps, RE-71R and BFG Rival S. It appears though the BFG S is exhibiting some really good wear characteristics.
 

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I have a 987.2 and prefer the RS3 over MPSS for track. Better grip and seems to me the RS3 tolerates heat/higher pressure better. I also had chunking on the outer edges of the MPSS. The RS3 s were noisier on the highway however.
+1. Did MPSS last year at two track weekends. The rest were on 245/275 18" NT-01s. For track use, NT-01s last the longest and have a lot of stick, but the increased diameter is a bummer. This year I dumped my Nittos for a set of RS3s. I love em. 3 hard, hot track days with no rotation of tires and the left front was a bit blistered but not corded and quite drivable. I drove it 300 miles home and replaced it. The other 3 are fine for a couple more goes. They FEEL better than the Nittos because they are stock size and seem to just work.

I had mine shaved to 6/32" tread depth rather than heat cycling. I'd recommend this.

I used them at 36psi hot...all 4 wheels. It seemed to work pretty well.

I have around -2.5 degrees camber in front and -2.2 in the rear. Could have used a bit more camber in front, to save the left front (It's a clockwise track.)

I have a new torque biasing limited slip rear end that really made a difference on this track and I put it to full use.

Instructor sessions out there are pretty gonzo and passing is allowed anywhere. (Putnam Park in Indiana). My only real nemesis was a pair of E36 325is with full race treatments and M3 engines...one is a race-built M3 engine...Both are the ones with the multiple throttle bodies. (S-52 ?) One is trailered to the track and the other is driven only a short distance (with two sets of spare wheels and tires inside it!!!) These guys, one works at Tire Rack, are about the fastest out there.

A student in C Group had a Lambo Huracan! Gorgeous!

I taught Scott Goodyear's youngest boy, Chris. Dad was there with both sons... Talk about pressure! Lucky for me, he's a natural. We were turning good lap times in his automatic Jetta with stock tires and pretty much passing the field. That's not supposed to happen at a BMW club driver's school!

:cheers:
 

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Discussion Starter #8
Wow, great feedback. Thanks folks.

So to summarize, any of the 200 TW "extreme" category street tires will outperform MPSS in terms of grip and high-heat durability? To be clear, there is NO reason I need to buy the MPSS if my car is not a daily driver and I want the best grip per dollar I can get?
 

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I used to run RE-11's, which are pretty quick and last a long time, but switched to Direzza ZII* Spec for my last set of tires and shaved nearly 3 seconds off my best time at Sebring. (I'm a PCA instructor and my CS is largely stock, other than some brake mods).

The ZII's are clearly quicker than the RE-11's. But I'm moving to the RE-71R's when the ZII's wear out. As good as the RE-11's and ZII's are, from all reports the RE-71R's will likely be quicker. (Probably won't last nearly as long, but hey, life is full of tradeoffs, right?)
 

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Fresh from the mailman: new Grassroots Motorsports article pitting the Rival vs Rival S vs ZII* vs RE-71R on the track @ Harris Hill Speedway! They tested on Andy Hollis' OneLap CRX, and then also tested the RE-71R vs Rival S on a Civic Si to compare how the extra weight impacted these two tires. I'm not going to steal GRM's thunder and copy the results because they're great guys who have given me free food and free beer twice, and I think everyone should all buy their magazine so they can afford to keep publishing articles like this and giving me free beer. It's only $10/year if you catch them at Christmas, so why not?
:cheers:

But after this, I do plan to keep driving RE-71R. Well, at least until I see how bad my local track tears them up, because it's apparently paved with cheese graters. If that's the case, I might go back to ZII* anyhow because I really loved ZII* and got a ton of life out of them.
 

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Wow, great feedback. Thanks folks.

So to summarize, any of the 200 TW "extreme" category street tires will outperform MPSS in terms of grip and high-heat durability? To be clear, there is NO reason I need to buy the MPSS if my car is not a daily driver and I want the best grip per dollar I can get?
The PSS gets its good wet road and aquaplaning characteristics by its out surface being broken into many small blocks with cleverly places space between them for the water to flow off, without the water being able to lift up individual big blocks of tire surface off the road. The problem is that the small blocks can fall apart very quickly under high lateral forces when hot and dry.

I see people report the PSS as being on par with what is sillily labeled as "extreme summer performance" for small track autocross where you only get to go individual rounds of 90 seconds or so with long pauses in between.

So, basic "grip" is probably fine for all conditions with the PSS, with wet grip being much better. But if you rent the entire track and go a couple laps in a row you will pay major $$$, and when ruined the PSS can't possibly perform well.
 

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Wow, great feedback. Thanks folks.

So to summarize, any of the 200 TW "extreme" category street tires will outperform MPSS in terms of grip and high-heat durability? To be clear, there is NO reason I need to buy the MPSS if my car is not a daily driver and I want the best grip per dollar I can get?
Pizza:

If your car is not a daily driver, extreme tires are best. I really liked the Hankooks and they come in stock 18" sizes. Great for me. My PSS ran pretty well too but they don't like the heat as much and feel greasy if they get over-inflated. I still use them on the street, but I like Hankook better for track use.

Go with R tires if you don't get penalized for them. If I were track only, I'd have them. Most R tires don't come in Cayman 18" sizes...I really looked. As I said, my Nitto NT-01s were fast and lasted 3 seasons before they died of old age, but they weren't as entertaining as the Hankooks. Hankooks are more fun than PSS on my car at least.

Hang the lap times, I want to have a good time out there.
 

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Wow, great feedback. Thanks folks.

So to summarize, any of the 200 TW "extreme" category street tires will outperform MPSS in terms of grip and high-heat durability? To be clear, there is NO reason I need to buy the MPSS if my car is not a daily driver and I want the best grip per dollar I can get?
Pizza:

Your car doesn't need to be a DD to enjoy MPSS. They're great and they stick GREAT in corners so long as they don't get too hot. I think they'd be pretty great for autocross use and they seem to last longer than extreme tires. I used MPSS last year for two schools. I'd put some miles on them before either school, so they weren't new. They held up pretty well, but when they get hot, they're not in their element anymore. If you are diligent about dropping the pressures down as the track heats up, they work pretty well...

But the RS3s are better at the track and are a bit cheaper to boot. Same track, same hot temps etc and the RS3s felt really good to me. I blistered one after many very hard sessions and no rotations...and those tires were shaved. Nevertheless, I bought one to replace the knackered one and am good to go. We'll see how long they last, but they really are fun tires.

Some of the tires being discussed here, like Goodrich Rivals, don't come in stock Boxster/Cayman sizes.

Make sure you don't go too far with changing tire diameters front to rear. If they're way off, it'll confuse the PSM and you can have a lot of issues. Search "Ice Pedal" for some info on that. If you increase or reduce the OD or Rolling RPM of the front, try to do the same for the rear so they stay proportional in diameter. One percent or so won't make much difference, but increasing the front while decreasing the rear can make some problems.

Have used 245/40/18 front 275/40/18 rear. This increases diameter of both wheels proportionately. It didn't affect my PSM, but I didn't like the longer effective gear ratio. I'm using stock sizes now.

Autocross doesn't heat up the tires like track days, so you are not going to have the same issues with MPSS at autocross.

If your focus is autocross, you should check rules for tire size penalties etc and get something that comes in the sizes you need.

I do like the Hankooks but MPSS are really better on the street. I don't drive my car daily but it gets plenty of exercise on the street on weekends and on one weekday evening. I have a set of MPSS for that and use Hankooks for track days until something better comes along in stock sizes.

:cheers:
 

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Just to reinforce consensus: MPSS is an awesome tire for street and occasional auto sport. For DE it is problematic because you WILL get them hot and they get greasy at high pressures. you can manage that by lowering the pressures accordingly, but then their relatively soft sidewall becomes a problem = premature wear. you might be able to manage that with a ton of negative camber, but at more than a couple track days you are better off with one of the many other choices. Lots of DE folk like AD08R and RE-11s. Both have stiff sidewalls, last a while, communicate well ;) are fun, and are available in 987 stock sizes.

No experience with some of the newer tires so can't comment there. I have a used set of CR stock 19" wheels shod with MPSC2s and can't wait to try them this Monday!

-Edit-
Well I just looked at the sizes available for the RE-71R and the Rival S (at least from Tire Rack). Nothing even close for the rear tires of a 987 for the Rival S. Not much better for the RE-71R. Am I missing something? Why are they being recommended on a 987 cometition forum?
 

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-Edit-
Well I just looked at the sizes available for the RE-71R and the Rival S (at least from Tire Rack). Nothing even close for the rear tires of a 987 for the Rival S. Not much better for the RE-71R. Am I missing something? Why are they being recommended on a 987 cometition forum?
Because they are "the tires to have" and are considerably faster than now-obsolete tires like RE-11 and R-S3. Anything else, and you're not going to be competitive. And to reiterate: MPSS is not a competitive autocross or track tire; it's a luxury performance DD tire designed more for people that complain Porsche suspensions are too stiff than for people who actually drive fast. It's a good DD tire, but not a competition tire. If anyone thinks MPSS is grippy for autocross or track, you owe it to yourself to try on an actually sticky extreme performance tire :)

For RE-71R, ZII & ZII* on my 987S, I've had great success with 255/35-18 front and 275/35-18 rear on OEM-size 8x18 & 9x18" wheels. This matches the OEM rake very closely, drops the car a few mm, and improves the shape of the contact patch vice OEM tire sizes, allowing for grip at higher slip angles. Due to poor availability in some sizes, 997 drivers right now are running RE-71R in the front and Rival S in the rear which may sound scary to people who worry about mixing N1 and N2 (lol), but it's a really quick combination.
 

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The 255/35-18 has a min specified rim width of 8.5" and is proportionally taller than the 275/35-18 on the rear (compared to stock proportions), so I'm not as comfortable with it for DE use. Have people run that combination on the track (not autox) much?

Love that new compounds are coming out so quickly and am eager for wider size ranges.
 

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Trying to win your run group, huh? If you're not limited to 200TW, you'll want to look at Hoosier R7 instead. Or even bias-ply racing slicks. The RE-71R and Rival S are needed to compete in 200TW series (track or autocross) because your competitors will be on them, but for DE... just run whatever you want. Original Rival and ZII* are other great high performance DD/track tires will still be fast and fun and will last probably 50% longer.

As to the tire sizes, the rake I run differs 1/4" front-rear from OEM ratios (1/8" smaller than OEM in front and 3/8" smaller in rear), and is less than the difference you'll see between new and worn tires. I've had zero issues from PSM or ABS. It's only slightly over-tired, and you need to go 255/35-18 to match the rake of 275/35-18. I haven't done any DEs with these size tires, but I did two time trials on it at my local track- took 2nd place (overall) on ZII and won (overall) on ZII*. I haven't tracked yet on RE-71R because I just mounted them 3 weeks ago.
 
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