Aftermarket wheel options for 991 GT3
#16
Instructor
#17
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Yep, when new wheel options hit the market....... New oooooo and ahhhhhhh from people.
Like I said, stock wheels are gorgeous, but there will be other performance wheels available and most future track junkies will downsize to 19" and have a better and cheaper tire selection.
Just add pix here of aftermarket wheels/rims and tire sizes used.
Just a resource for future wheel selection
Like I said, stock wheels are gorgeous, but there will be other performance wheels available and most future track junkies will downsize to 19" and have a better and cheaper tire selection.
Just add pix here of aftermarket wheels/rims and tire sizes used.
Just a resource for future wheel selection
#21
Rennlist Member
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Why would you want to put 19s on a car designed to work with 20s? We're entering a world of software wizardry where back-yard tinkering no longer has a place.
#22
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Been awhile…. hope all is well.
You're too funny my man
But yeah, I also wonder why Porsche Motorsport uses 18" wheels on their 991 cup cars also
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
BTW - I think my friend in LA bought your ex-red beast!!!!!
![burnout](https://rennlist.com/forums/graemlins/burnout.gif)
An old engineer friend wrote this on the why the utilization of smaller wheels:
The weight of the wheels, tires, brakes, etc is unsprung. It's connected directly to the ground without your springs and shocks acting as a mediator. Also, the wheels and tires are spinning and have a certain inertia to their spin, which is directly related to their weight/mass. The motor will have to work harder to overcome that inertia whenever you want to change your speed, and this will be easier to do with lighter wheels/tires. You want your wheels and tires to be as light as possible for the best performance, but need bigger wheels to clear the brakes, and wider wheels to put as much rubber to the ground as possible. Unless you're going for looks, the smallest possible diameter wheel that you can fit over the brakes, with the widest possible width to give you more traction would be ideal.
#23
Rennlist Member
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Hi Serge,
Been awhile…. hope all is well.
You're too funny my man
But yeah, I also wonder why Porsche Motorsport uses 18" wheels on their 991 cup cars also![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
BTW - I think my friend in LA bought your ex-red beast!!!!!![burnout](https://rennlist.com/forums/graemlins/burnout.gif)
OQ991 is correct on all accounts.
An old engineer friend wrote this on the why the utilization of smaller wheels:
The weight of the wheels, tires, brakes, etc is unsprung. It's connected directly to the ground without your springs and shocks acting as a mediator. Also, the wheels and tires are spinning and have a certain inertia to their spin, which is directly related to their weight/mass. The motor will have to work harder to overcome that inertia whenever you want to change your speed, and this will be easier to do with lighter wheels/tires. You want your wheels and tires to be as light as possible for the best performance, but need bigger wheels to clear the brakes, and wider wheels to put as much rubber to the ground as possible. Unless you're going for looks, the smallest possible diameter wheel that you can fit over the brakes, with the widest possible width to give you more traction would be ideal.
Been awhile…. hope all is well.
You're too funny my man
But yeah, I also wonder why Porsche Motorsport uses 18" wheels on their 991 cup cars also
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
BTW - I think my friend in LA bought your ex-red beast!!!!!
![burnout](https://rennlist.com/forums/graemlins/burnout.gif)
OQ991 is correct on all accounts.
An old engineer friend wrote this on the why the utilization of smaller wheels:
The weight of the wheels, tires, brakes, etc is unsprung. It's connected directly to the ground without your springs and shocks acting as a mediator. Also, the wheels and tires are spinning and have a certain inertia to their spin, which is directly related to their weight/mass. The motor will have to work harder to overcome that inertia whenever you want to change your speed, and this will be easier to do with lighter wheels/tires. You want your wheels and tires to be as light as possible for the best performance, but need bigger wheels to clear the brakes, and wider wheels to put as much rubber to the ground as possible. Unless you're going for looks, the smallest possible diameter wheel that you can fit over the brakes, with the widest possible width to give you more traction would be ideal.
Of course it's nice to reduce moment of inertia, but it's not as simple nowadays... You have electronic systems such as the torque vectoring, rear wheel steering, etc which are designed to operate within tight parameters. Once you start changing offsets, wheel diameters (and associated change in tire sidewall response), you no longer have the right software.
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Einmalig (04-20-2020)
#25
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Armbar: This can go on and on and I just merely replied on why a lot of track guys from novice to professional, not speaking of Porsche specifically, use smaller diameter wheels.
I just merely added this thread to have a resource of wheel choices for this new 991 GT3.
I just merely added this thread to have a resource of wheel choices for this new 991 GT3.
#26
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You'll experience every aspect in improvement with a smaller diameter wheel due to less rotating mass and decreased centrifugal force. Acceleration, braking and cornering are all improved. Usually you should select the smallest diameter wheel your brakes and other hardware will allow.
#27
Three Wheelin'
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Ryan
#29
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Wheel diameters. . . WTH. Dunno why you guys are getting your thongs in a bunch. Rolling diameter is what matters. 991 GT3 wheels are forged and while I do like the OP's wheels, I think many of the aftermarket wheels will struggle with reducing weight from stock.
#30
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[QUOTE=armbar;11045696]Porsche Cup cars are one-make according to a homologation schedule done by Porsche Motorsport. Nobody is making Porsche do anything with their Cup cars - if they have 18's on them its because Porsche wants to have 18's on them.