IN CASE YOU'RE SEARCHING, OR THINKING ABOUT NEW WHEELS!:
1) OEM Wheels must be used with OEM (or OEM style) lug nuts
2) OEM (or OEM style) lug nuts must be used with OEM wheels
3) Aftermarket lug nuts must be used with aftermarket wheels
4) Lots of aftermarket wheels for our car require extended studs (the stock ones are too short to properly engage 6-7 threads on the nut). Please see illustration below.
5) 50mm studs (such as Z1) will still allow use of OEM wheels and OEM lug nuts with no spacer needed and are long enough for many aftermarket wheels
6) Longer studs >50mm will require either a wheel spacer or open end-converted OEM lug nuts to use OEM wheels
7) 50mm studs are not compatible with the OEM locking lug nuts in the rear of the car due to clearance on the cap of the nut
8) F+R OEM studs have a different part number and differ in length by a few mm but can be interchanged
9) OEM stud thread is 12x1.25
The distance in RED in the picture below is larger on most aftermarket wheels when compared to OEM. Since the distance is larger on aftermarket wheels, this means less stud threads protrude through the face of the wheel and is why I used extended studs for aftermarket wheels.
Open Ended OEM lug nut. Made in a few seconds with a dremel and cut off wheel
Make sure you use proper lug nuts, torque the down correctly, and have enough threads engaging between the studs and nuts. Otherwise this:
rx7 wheels fall off during autocross - YouTube
Replacing Front Studs:
DIY: Front Stud replacement/ Spacer install
Replacing Rear Studs:
DIY: ** Rear 20mm stud replacement spacers
Helpful info on Lug Nuts
Lug Nuts - The definitive guide
Reason For this thread: after installing 50mm studs. I can run OEM wheels with OEM lug nuts with the caps still on, then drive to the track and bolt on aftermarket wheels (in my case 18x10 +34 Forgestars) with no need for changing studs or installing spacers.
Original post:
Does anyone know the OEM (non-nismo) wheel stud length? it's a few mm longer in the front than the rear. I'm getting 40mm rear 42mm front. Also, what is the knurl length and diameter (14mm?)