Pics and info on GTM wheels?

[Power Surge]

I didn't find anything on a search (forgive me if one exists), so maybe we could start a thread with people posting their wheel setups, with size/offest specs?

I'm especially interested in wheels that work with C6 Z06 brakes, as that's what I am planning.

I am not finding much online. Would like to do 19s front and rear. Forgestar makes some (like FFR offers), but that's the only option I've found. I don't want to run any Corvette replica wheels.

[crash]

IIRC these are 19" fronts and 20" rears. Maybe 19s all around. Not sure.
IMG_20221125_141825041.jpg
I can contact this individual if you want more info on specifics.

[Power Surge]

IIRC these are 19" fronts and 20" rears. Maybe 19s all around. Not sure.
IMG_20221125_141825041.jpg
I can contact this individual if you want more info on specifics.

That's RR46's car from the other FFR forum, right? I love his build post. Seems he's run 3 or 4 different wheel combos on that car. I would love to hear what brand and specs he's using for his 19/19 and 19/20 street combos.

[Shoeless]

The exact specs you need to run 19/20 combo are available on the FF website.

https://www.factoryfiveparts.com/262...eels-gunmetal/

Front Wheel Size (Diameter x width): 19"x 9"
Rear Wheel Size (Diameter x width): 20"x 12"
Front Wheel Backspace: 6.5" (38mm Offset)
Rear Wheel Backspace: 8.49" (51mm Offset)
Wheel Lug Pattern: GM style 5 lug x 4.75" bolt circle

I ordered these exact specs and confirmed they clear Wilwood brake setup. I can get you the exact Wilwood PN I went with so you can see the clearance charts if you think that will assist you in determining clearance on C6 Z06 brakes. I'm not sure on clearance, but I'd bet they clear. I ended up ordering the wheels very early in my build, broke out the laser level and did a bunch of checking to confirm everything would clear. I didn't keep any of my measurements, but wish I did.

Now that I'm at the point I sent my GTM to Shane to be completed due to medical issues and just an overall great builder, I've gone down the path of looking at 3 piece and carbon fiber wheel. I wish I could justify $20K+ for a set of CF wheels, as they are so damn cool, but just can't swing that at the moment

[VRaptor SpeedWorks, LLC]

Looking at Shoeless's car, the Wilwoods are pretty close on the front with only about 1/4" clearance at the tightest point. I know the C6 calipers are pretty chunky, so not sure if they would clear on these wheels or not? Forgestar might have that info?

For the price, the Forgestars are going to be pretty tough to beat. I know there are other companies that will do custom sizes/offsets, but they're not cheap. I know CCW used to be the "option" wheels from FFR and CCW has the proper offsets on file (or at least used to), so you might check with them on what styles they have available to fit?

One thing to check if you swap brakes is the clearance from the rotor to the lower control arm. On a lot of the "big brake kits" I've installed, the back side of the rotor will interfere with the LCA at the ball joint and you will need to grind the alum back slightly to gain clearance.

[Shoeless]

One thing to check if you swap brakes is the clearance from the rotor to the lower control arm. On a lot of the "big brake kits" I've installed, the back side of the rotor will interfere with the LCA at the ball joint and you will need to grind the alum back slightly to gain clearance.

Now that Shane mentions this, I had to clearance my rear LCAs because of the rotors. Simple Dremel to get just enough clearance.

[crash]

Yes to the clearancing of the LCA. Standard procedure for running the C5 StopTech calipers and rotors.

Our calipers have about a 1/16th of an inch clearance to the rims and don't seem to have any issues. Really will depend on the flex of the rims, but we have not had any issues with CCW rears and C5 ZR1 rears on the fronts. We do run about a 1/16th spacer on the fronts specifically for brake clearance.

[Power Surge]

So FFR's Forgelines they used to sell and recommend are 19x9 with +38 offset, and 20x12 with +51 offset.

I found a C6 Z06 guy with a set of Forgelines for sale... 19x10 with +30 offset and 20x12 with +50 offset.

My calculations say the difference in front rim face would be .8" out more. Anyone see an issue with that?

I also found a set of C7 Grand Sport wheels... 19x10 with +42 and 20x12 with +59

Thoughts?

[Power Surge]

Also.... reading some search posts on wheels, I see mention of 1" wheel spacers supplied with the kit. When FFR specs the Forgestars with +51mm offset, is that intended to be used with these spacers? Or is the +50 offset the proper spec for bolted directly to the hub?

And question for Shane.... I have seen several of your wheel posts where you say you use 19x9 front wheels with +53 offset. But FFR says +38 offset with 19x9s. +53 offset sinks the wheel deeper into the car. Is there a reason you like that spec? I've also read mention of control arm clearance issues.

[Shoeless]

My recommendation, and this is just me and you can do anything you'd like, but if you'd like to do the 19/20 combo, the numbers above will get you there. A set of wheels to these numbers do NOT require you to use the 1" wheel spacers. The rears bolt right to the hub for a clean install.

The price that FF quotes is ridiculous. There are plenty of vendors that will have them build to these exact specs at a more reasonable price. If you are not in a rush, there are plenty of sites that will do Black Friday sales and could save you even more.

Not sure on the question about Shane's numbers on the fronts, he'll have to chime in there.

[VRaptor SpeedWorks, LLC]

The FFR option wheels and offsets listed are meant to be used without the rear wheel spacers. The wheel spacers are provided with the kit to complete the "one donor" idea of using a C5 donor including the C5 donor wheels with the rear wheel spacers.

As for the +53 offset....I'm wondering if you're referring to these?

Rear 19x11.5 - 7.625" Backspace = +35mm Offset
Front 18x9.5 - 7.3" Backspace = +53mm Offset

That was with a 9.5" front instead of 9". That was for the first car we built here:

https://vraptorspeedworks.com/2010/gray-gtm/

At the time of that build, those CCW wheels were the FFR option wheels. If I recall correctly, the FFR option wheels were 9" front. My customer wanted to run Brembo brakes on that car, so I contacted CCW about the FFR option wheels to see if they knew if they would clear the Brembo calipers or not. This is where it get's confusing and I never did understand why, but CCW said that the FFR option wheels would not clear the calipers, but they could make the same wheel for me in a 9.5" width (instead of the FFR option 9"), keep the same "front-spacing" so the wheel would not stick out any farther, and get them to clear the Brembos. So that's what I ended up doing on that car. I never measured the actual offset myself....I'm just going by the specs that CCW provided to me. No, it does not make any sense to me that you can keep the same front-spacing and a 9" won't clear the calipers, but a 9.5" will.....but that's what they told me...and the wheels that they sent fit and cleared the calipers....so that's all I cared about.

[crash]

Shane- I believe it had to do with some machining they likely did to the web area of the rims.

It is so unfortunate that CCW was sold to Weld. John at CCW was "The Man" when it came to truly a custom wheel manufacture. He did things to spec and at a cost that was very reasonable. Weld will still sell you rims that are custom made to order...just at THREE TIMES the price that CCW used to offer.

[doug_porsche]

Does anyone know what Forgestars calls the finish of the F14s?

Mine appear to have a silver background with polished spokes.
For tire availability reasons I would like to go from 18x12 to 19x12 and I sort to want the rears wheels to have the same finish as the fronts.