Ubermensch

Why wait for 20” when 19” will clear and has cheaper tires? This is a genuine question. I’m not sure why you think changing wheel diameter changes your alignment. If the overall tire diameter changes the toe will change a tiny bit but honestly not in a meaningful way.

qil

Fair question. I don’t like the tight clearance of the 19” over pccb. it’s technically feasible but over the 20” it’s tight enough as is.

enduro

Don't see how it'd change toe or any of the alignment params measured on the machines, but depending on the offsets, track and scrub radius will change. I haven't checked how the offered offsets will or won't change these. Also, most of the available tire diameters I've looked at will be smaller. That said, I'll be running 19s as soon as I can get the tires I want in the sizes I want.

Reedy

I just want to keep the car as close to factory spec as possible. Firstly I haven't ruled out swapping to Surface Transforms and that needs the 20's for clearance. But my main reason is wanting to keep the offsets identical to the OEM wheels because that does have an effect. Every off the shelf wheel on the market widens the track up front slightly and I want to be able to use my OEM and aftermarket wheels interchangeably without affecting the geometry in any way. It also tweaks rolling diameters slightly which alters the ride height and my car already scrapes getting in and out of my driveway.

sgreer78

You only need more clearance if you switch to PCCB calipers.

Westcoast

Regarding the VS-5RS: from the Apex site, they will have 20" available in July and although the rear appears to have the same OEM spec for fit the front has a slightly different offset, OEM 20x8.5 ET61




My question to @APEXRaceParts what is the fitment and clearances for the OEM PCCB brakes on the GT4 and Spyder on the VS-5RS front and rear wheels, please let us know if they accommodates these brakes.

Specifically is the clearance equal to or better than what we currently have with the OEM wheels?

Ubermensch

Totally reasonable! I'm pretty sure Apex specifically indicates that 19" wheels just won't clear PCCB despite their best efforts. The Problem with 19” Wheels and 410mm Porsche Ceramic Brakes – APEX Race Parts Blog

"Don't see how it'd change toe or any of the alignment params measured on the machines, but depending on the offsets, track and scrub radius will change. I haven't checked how the offered offsets will or won't change these. Also, most of the available tire diameters I've looked at will be smaller. That said, I'll be running 19s as soon as I can get the tires I want in the sizes I want."

Agreed. As measured by any machine there won't be a difference. I was trying to be open minded and give the previous poster the benefit of the doubt that maybe they meant toe as measured at the front and rear edge of the tires which would change slightly if the tire diameter changed.

Apex Wheels

We would be happy to reach out to you directly when the 20" Group Buy is going live. Feel free to PM me your email address, or you can visit our website and sign up for our email list (bottom of the home page, blue box titled "Stay on Track".


Thanks for providing the link to our blog article on the topic, @Ubermensch.

We recommend our 20" wheels for GT4s equipped with the 410mm PCCBs, as they will provide approx. 11mm of clearance between front caliper and wheel barrel (thats a very healthy amount).

We engineer our wheels to offer massive brake clearance, however, the 410mm PCCB package is extremely large and although a few wheel companies seem to actively sell 19" wheels to owners with PCCBs, we have seen (and experienced first hand) a lot of damage to both the calipers and the wheel barrels as a result.

- Ryan

Apex Wheels

- Ryan

Westcoast

Thanks for replying Ryan, 11mm is very good to the barrel, what about the spokes, that is where it can also be very tight?

Also can you comment why Apex changed the front offset for the 20x8.5 on the VS-5RS from the OEM spec? And the effect of the offset on the 20x9?

BTW, PM sent!

unclemat

I like those 5RS.

To confirm, so these are real forged wheels, not "flow forged" (which means cast, really)?

unclemat

So interested in 5RS set in 19". Any reason to get 11" wide rear rim over 10.5", if max tire would be 285? Seems both would be fine.

EDIT: Would even 11" fit 718 GTS 4.0? I am reading that stock Spyder/GT4 wheels (11") do not.

Apex Wheels

20" spoke to PCCB caliper clearance is 5.1mm. Internally, our minimum requirement for a safe tolerance is 3mm.

That is correct. These Sprint Line wheel designs are fully forged wheels constructed from 6061-T6 aluminum and a 10,000 ton press leveraging our custom designed motorsport forged blanks.

We're very big on wheel education and transparency, which is why our flow formed wheels are called just that - flow formed wheels. We're proud to offer wheels from both manufacturing methods, as that allows us to deliver quality, lightweight motorsport oriented wheels to all types of customers depending on their performance and budgetary needs.

You can visit our website, review the original post in this thread, or watch this tech video we made for more info on our new forged line of wheels:



We offer both 10.5" and 11" rear wheels, as that allows drivers to choose the best solution for their personal needs. The 10.5" rear wheels are suited best for 285/35-19 and 295/35-19 that run true to size, while the wider 11" wheels are better suited for 295/35-19s that run wide, in addition to 305/30-19.

The 11" wheels will fit any 981/718 Cayman Boxster including your GTS 4.0.


- Ryan

Westcoast

Regarding the above question? The 8.5" wide OEM front wheel has an offset of ET61...

Apex Wheels

Apologies for missing that. Our objective with the 8.5" wheel was not to mirror the stock offset.

The 8.5" ET54 offset we honed in on is within 7mm of the stock offset which makes it legal for AutoX enthusiasts participating in the stock/street class. It also widens the track width up front just a bit, and sits a touch more flush to the front fenders without requiring any modifications.

Last, the higher the offset, the more convex the wheel spokes need to be to clear brakes. Our engineers prefer to run with a lower offset so they can further optimize the wheel for strength to weight. As an example, if we went with the stock ET61 offset the spoke depth would be compromised for the sake of brake clearance, and that would result in fatter/shallower spokes.

- Ryan