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I see that the new GT4 will have 20x11" wheels with 295 tires but I measured my 20" wheels and wheel well clearance and couldn't see how it would fit. I also asked Wheel Enhancement and they said they couldn't fit 11" wheels either. I don't see any mention of flares on the GT4 so any idea how they're doing it?
 

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Check the offset specs for the GT4 wheels once they get released, they probably pulled them inboard towards the car relative to the standard 981. The inboard clearance limit is usually strut to wheel or tire. You only need around 1/4" of clearance for an aggressive fitment. More negative camber on the rear by moving the upper mount inboard will help too. I use all these tricks on my 987 to fit 315's on 11" wheels.
 

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If you are willing to run a slight poke, and a little stretch (295s on 11" rims) you can fit 11s on a 981. You might however get some heavy rubbing on that silly tab that holds the lower rocker panel to the rear fender in front of the tire (even people running 15mm spacers run a slight risk of rubbing this especially if the tire has a squarer shoulder.) I would guess you could remove that tab, but how to hold the two panels together then becomes a new problem. I'm sure the GT4 has hubs placed further inboard as others have said. It's a completely new suspension. Shorter drive shafts too.
 

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Brochure I downloaded from Porsche website for GT4 wheels and tyres has following info ( includes offset detail)

Front: 8.5 J x 20 ET 61, Rear: 11 J x 20 ET 50
Front: 245/35 ZR 20, Rear: 295/30 ZR 20 (sports tyres)
 

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As K-Man said, completely new everything back there, including inverting the shocks so the springs are now on the bottom. Just came back from the dealer where my tech showed me the additional info they have so far. Car is also slightly wider, longer, and lower than the 981S. Good news is, in the GT4 both TC and PTV can be completely turned off.
 

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As K-Man said, completely new everything back there, including inverting the shocks so the springs are now on the bottom. Just came back from the dealer where my tech showed me the additional info they have so far. Car is also slightly wider, longer, and lower than the 981S. Good news is, in the GT4 both TC and PTV can be completely turned off.
PTV? With the ESC+TC button?
 

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As K-Man said, completely new everything back there, including inverting the shocks so the springs are now on the bottom. Just came back from the dealer where my tech showed me the additional info they have so far. Car is also slightly wider, longer, and lower than the 981S. Good news is, in the GT4 both TC and PTV can be completely turned off.
Do inverted shocks reduce unsprung weight? At more risk of leaks?
 

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Do inverted shocks reduce unsprung weight? At more risk of leaks?
Don't know but my service mgr. said it made the suspension more "sensitive" which I interpreted as better.
The dealers don't have all the info on this car yet, but they have way more than we do. I saw the parts schematic but no prices yet.
 

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Don't know but my service mgr. said it made the suspension more "sensitive" which I interpreted as better.
The dealers don't have all the info on this car yet, but they have way more than we do. I saw the parts schematic but no prices yet.
Could be. I don't think they'll help the handling if someone inverts the car.;)
 

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Do inverted shocks reduce unsprung weight? At more risk of leaks?
if they put just the rod at the bottom with the housing and end of spring fixed to the chasis, my engineer's intuition says yes. Unsprung weight is less. That is simple logic. But isn't that the way most coil-over spring/shock assys are designed?
 

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Cant you just add 19mm spacers like I do for 295 rubber on 987.2?
 

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I run 20x11 wheels on my 981 without any issues. They are actually tucked a little bit and can add up to 15mm spacers to fill in the wheel well better. Tire size I've run are 265/35/20 and also ran 295/30/20. Both sets worked well without any fitment issues.
 

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Car is also slightly wider, longer, and lower than the 981S. Good news is, in the GT4 both TC and PTV can be completely turned off.
I know this is an old post, but wanted to update that the 981S and GT4 are the exact same size width and length. Not sure what your tech pulled up that showed anything that made the GT4 a larger car.
 
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