titleistaddict87

This is where I'm leaning, thanks for the confirmation. Like I said, great tire on my 991 so why rock the boat on a good thing?

Suicide Jockey

Guys, the car is under-tired by design! That's one of the rare, unique and special features of the 981 Spyder. Anyone seeking out more grip through wider/stickier rubber is IMO (and perhaps unwittingly) tampering with one of the car's most endearing qualities -- the ability to get the rear unglued. Tire selection obviously affects grip, so why do you think Porsche went skinny? Because it was trying to cut corners? Save a little money? Hell no. A lively rear-end is something Porsche intentionally baked into this car's DNA when it chose thinner shoes over much more aggressive rubber. This isn't a design flaw meant to be corrected, it's an inspired "less-is-more" decision to be celebrated. Porsche made this car so the rear can dance and bravo to them I say for not sacrificing this ability at the altar of maximum lateral grip.

More than one commentator has pointed this out much more eloquently than I. From Pete's Sept. 2015 Panorama review:


"The 981 Boxster with X73 was previously tested . . . and it proved to be outstanding even after the high bar set by the 2011 987 Boxster Spyder. Perhaps our greatest lament was that the car felt so planted that we longed for more power. Porsche addresses that issue in the Spyder with a 3.8 litre, large-displacement long block from the 991 Carrera S. The intake, throttle body, and sport exhaust are all shared with lesser, 3.4-litre 981s however. Breathing through these relative straws cuts peak power from 400 hp in the Carrera S to 375 here.

That's a 42% bump in power from the base Boxster, yet against its typical practice Porsche has chosen to leave the tire widths and suspension alone. The result goes beyond addressing criticism that the Boxster is underpowered -- the Spyder is now, on paper, more overpowered for its tires than any factory Porsche short of halo models and supercars. This is a factory hot rod, and 375 horsepower pushing through skinny, non-R compound 265 tires with relatively light weight over them means you end up with more ability to steer with your right foot than with all but a handful of legendary Porsches."


Why would anyone want to dial that out?

I'm telling ya, go aggressive on the rubber and you're messing with the secrete sauce! Think twice before stripping this masterpiece of one of its most defining characteristics. Would you paint a toothy grin on the Mona Lisa because you thought Leonardo erred in making her expression too subdued? Absolutely not because that subtle expression goes right to the core of what makes it a masterpiece. Tamper with the rubber on the Spyder and the act is arguably no less blasphemous IMO. Unless you track, I just don't see the point.

Not trying to talk anyone out of a tire change. Just explaining why it's a head scratcher for me -- as are so many other things!

NelsonF

Well said SJ! I couldn't agree more and one of the reasons I chose the Sypder, a very unique Porsche offering. Enjoy! Still tempted by sport headers though!

il pirata

Don't disagree at all about staying with the current Spyder tire sizes, however I would suggest if your Spyder came with the P zero N0 version that going to PS4S will offer lots of improvement without sacrificing the design intent. If you have not tried it hard to criticize what's going to happen. And in any case, each to his own.

titleistaddict87

digitalrurouni

Your passion is quite evident in your post! And you are probably right! At most I would go with the Michelin 4S especially since Porsche is now making an N spec version for our cars when I need new rubber. However the other curious part of me is also like what would it be like with RE-71r tires?! I do track my Spyder after all!

tq.3z

Have you done any mods to prepare the car for track use? Would love to hear which ones, if any and how you like the car on track.

il pirata

Here's a thread from texasviany (which if you do not know is/was a professional race drive and is very good) driving a Spyder with stock P zero, short shifting (engine not broken in yet) and passing GT4's at COTA (forward to around 415). Has a couple of comments on suspension set up for track.


https://rennlist.com/forums/showthread.php?t=917473&referrerid=93689

digitalrurouni

Great thread! And I loved seeing a Spyder being thrashed around 'mildly' on track. He looked so relaxed lol! Impressive while short shifting!

My car is stock. I just added some spacers to get the stance looking a bit better. I however as mentioned in the other thread got a proper alignment done. Maxed out the cambers as he also mentioned. Definitely improved the street handling too imho. I used to get understeer very easily now it's just about a thing of the past. Sure if I carry a ton of speed in it will plough the front but now the rear also likes to step in to help neutralize the front and I can rotate the car now though can't do it whenever I feel like it cause lack of *****. But at Road Atlanta I was doing mid 1.40s and short shifting but did hit a 140 mph in the back straight. I had my roof up though lol too chicken to do it roof down and it was over a 100 degrees in July! Also I agree the stock P Zero PSIs went up FAST! I already went to the track day with lower than normal PSI but yeah gotta keep an eye on those pressures! I gotta say car was phenomenal. Felt super stiff but as I kept getting quicker and quicker and carrying more corner speed especially in to turn 1 and the final corner before the back straight I felt like maybe I would prefer the car to be a bit flatter. I was in the novice class and there were Corvettes that would be really surprised cause I would not floor it down the back straight like they would cause my engine was still like barely 1500 miles but I would destroy them in the corners. No joke. I would claw back all the ground in a flash in the corners alone. Next time I track (Mar 9th) I hope to capture some data of my laps and see how fast I really am going. The Spyder is a great track day car. I am sure the GT4 is better no doubt so I am actually looking forward to getting a 718 GT4 and swapping this out for it. Brakes never showed a sign of fade for my driving style. Just would prefer a little less roll (perhaps its in my mind) in some of those corners I mentioned. Definitely get an aggressive alignment it does wonders!!

4PTZERO

If not tracking, PS4S and while you're at it upsize wider a tad (see below). If you're only driving in temps above 55 F everyday (no early morning drives), I'd go with Cup 2s for the extra performance, but think Bay does dip in temp enough where you wouldn't worry about that stuff.

https://rennlist.com/forums/987-981-...or-spyder.html

titleistaddict87

Straight copy of CAlexio post from the linked thread above. Summary: I think I'm going to go with the Cup2 tires in the sizes he mentions below when the time comes!

-------------------------------------------------------------
stock is:
235/35/20
diameter: 26.5

265/35/20
diameter: 27.3

stock ratio front to rear: .97

my new setup is:
245/35/20
diameter: 26.75
delta: 0.25 inches

285/35/20
diameter: 27.8
delta: 0.5 inches

new ratio front to rear: .96

so the ratio delta between stock and going up to 245/285 FR is 1% off, that's the closest I could get it, and is closer than the 295 rear which i believe might actually be too wide for the Spyder rear wheel. I took it very a spirited drive in the mountains and perceived a slightly heavier feeling steering, definitely more compliant ride over bumps, and a much better grippiness.. less skittish car. Of course, all this is subjective, as is the looks which I feel have improved greatly with the wheel well filling out more as well as the wheel/tire fitting more flush to the side, almost as if i had spacers.

if there is a good reason why porsche didn't go with this size as standard to begin with, then I don't perceive it. I'm 100% happy with the changes.