il pirata

The Spyder has a lot more torque/HP. It is also a lot easier to get the rear end loose than the GT4 or a 911. From the reviews I have read by writers who I believe have great driving skills this was the design intention.

Generally on a mid engine if you put wider tires on the back without increasing the front width I believe you are going to create more understeer...not the best ideal.

You might want to drive the car for awhile before mucking with the suspension...it really is one of the best you can buy "off the shelf".

You want to try something different, get more aggressive tires...of course the more aggressive tires will have limits in rain, wear a lot faster, etc, etc. If it was me, given the three OEM tires currently shipping, I would switch to Michelin PSS (non OEM) at some point. The Cup 2s mentioned earlier are fantastic but for street driving are a pass for me.

Underblu

My first Porsche back in the 90s was a used 84 targa Carrera, that was probably the only car that every scared me at some points. The 993 was significantly better and the 997 felt very stable for a rear engine car. But nothing felt more stable to me than the midengine Boxsters starting with the 986 up to the 981BS I currently own. I never felt thwt 50 more hp would in anyway unnerve the balance of the 981BS so this is surprising to me. especially since the Spyder is lighter and has a sportier setup with x73 ptv lsd etc. I mean don't get me wrong, I felt the first Boxster had too much under steer and was nearly impossible to throttle steer. I like a tossable car but not snap oversteer or a nervous rear end. Therefore I find it interesting that a few people have mentioned this. Is the 981 Spyder the 930 turbo of the bunch?

il pirata

No...it;s the opposite.

I think your taking it out of context, the OP was looking at putting larger tires on the Spyder, and with that, you could introduce changes in how the car drives.

CAlexio

the rear tires on my spyder are shot, but the fronts are still quite good tread.. lots of life left in them. I'd like to go slightly wider in the back without having to change my fronts yet.. is that going to throw off the diameter.. does it have to remain the same or is there some leeway with this?


currently there is already a difference:
front diameter on 235/35/20: 26.5 inches
rear diameter on 265/35/20: 27.3 inches

i wouldn't want the rear diameter to get smaller.. would want it similar so that takes me to:
295/35/20: 27 inches even (0.3 inches smaller)...

would that 295 fit on the stock wheel, and would it be too big of a difference width-wise with the original 235 in front?

il pirata

The stock OEM size has a variance just over 3%

http://www.1010tires.com/Tools/Tire-...5R20/265-35R20

Interesting in that most of the info I have seen says stay within 3% so as to not upset the electronic nanny's, if it's AWD on a Porsche then usually a negative number for the rear.

If everything else stays the same and you increase the rear tire width you will increase understeer, whether or not you notice it's not the direction I would go in.

Other than looks why are you considering this?

Frankly I would put better tires on the car if I messed with anything, HOWEVER, pickings are slim, at least according to what's available on Tire Rack. All of the MPSS tires shown are outdated, or a mix of specials for different car makes. Michelin is suppose to have the new Pilot Sport 4 S out in March in the US with OEM sizes...if they are available the Pirellis get tossed.

Tremelune

For playing around with different sizes: https://tiresize.com/comparison/