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Thread: First of many questions- wheels

  1. #1
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    First of many questions- wheels

    Hey! I'm taking delivery of a kit next week! Built a roadster with one son 8-10 years ago, and now building a GTM with his younger brother. It'll have a lightly upgraded LS3 with a G9650. Lots of add ons from Shane, etc.

    Question about the FF GTM wheels. In looking back over the million posts over the years it looks like everybody has 18" fronts and 19" rears with the FF wheels. They now have 19" x 9" wide fronts and 20" x 12" wide rears. Has anybody built with this combo yet? They also have some 18" fronts still. Do the 19s work ok on the front fender clearance? I assume there is plenty of room for the 20s on the rear? Even if you haven't built with the larger combo, I'd appreciate any feedback you have.

    Many thanks
    Butch

  2. #2
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    Welcome to the madness Butch. Looks like you and I will be pretty close together on our builds. I took delivery in October and have been working on sheetmetal fitment and am almost complete and ready for coating of panels. Just waiting for some parts from Shane before I drill my final holes. I plan on setting up a temp paint booth and coating panels over my Christmas break if all goes well.

    As for wheels, I wanted to go with the largest possible and same with the brakes, the largest possible. I ordered the 19x9 and 20x12 Forgestar F14 from ModBargins.com per the exact specs that are shown on the FF website and got them for about $2k. It was a 10 week lead time, but their customer service was excellent and the tech guy helped me with the Wilwood brake packages that would not work with my setup. I say would not work as we pretty much narrowed it down to a couple brake packages that would work with small spacers up front. After talking with Gordon Levy, he stated they used spacers all the time to get nice fitment and finish so I am not worried about the brakes at this moment.

  3. #3
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    Welcome, Butch. I have the wheels from FFR with tires mounted and a standard break set up. I can't say for clearance at this time as I do not have the body mounted.

    Enjoy the build.

  4. #4
    VRaptor SpeedWorks, LLC's Avatar
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    Sounds like you have a great place to start there....you'll love that G9650.....IMO, the slickest shifting trans for the GTM you can get.

    As for the wheels, I didn't even realize that FFR changed their "option" wheels. Last I checked, the optional wheel package from FFR was 18" all around and they were running 335's in the rear. As for running 19's and 20's, we've done that here before. Lot's of the cars we've built had 19's on the front with no problem. Apparently the 20's work, or FFR would not offer them as an option.....although, to me it seems like they're going to fill every bit of available space.
    Shane Vacek
    VRaptor SpeedWorks, LLC
    www.vraptorspeedworks.com
    Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
    Offering a full line of GTM Upgrades and Custom Parts

  5. #5
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    I'm also unsure what to choose. The manual says "Wheels and Tires: See the appendix for complete recommended sizes.", but I don't see anything in the appendix about it.... hmmm.... (at least, I couldn't find it)

  6. #6
    VRaptor SpeedWorks, LLC's Avatar
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    Quote Originally Posted by Perkster029 View Post
    I'm also unsure what to choose. The manual says "Wheels and Tires: See the appendix for complete recommended sizes.", but I don't see anything in the appendix about it.... hmmm.... (at least, I couldn't find it)
    In a nutshell, you're either going to have to pick some wheels that are made to fit a C5 and use the provided wheel spacers in the rear, or you're going to have to buy wheels with the same offsets/backspacing as the FFR option wheels....and note that if you choose wheels of different width than the FFR option wheels, you're going to have to do the math to figure out what the offset should be based off of the width/offset of the FFR option wheels.
    Shane Vacek
    VRaptor SpeedWorks, LLC
    www.vraptorspeedworks.com
    Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
    Offering a full line of GTM Upgrades and Custom Parts

  7. #7
    Senior Member jamesfr58's Avatar
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    I used a staggered set up with 19” front and 20” back wheels. They are IPW Front wheel is 19X8.5 and the back are 20X10 with the C5 bolt pattern 5X4.75. They had the right offset to fit my Wilwood Big Brakes 6 piston fronts with 4 piston backs using EDC racing rotors – BSD Series Sport w/Ultra Quite V Slot configuration. You can see the wheel offset clears the big brake caliper but it is close. Was hard to find a wheel with right offset using the Wilwood brakes as they are considerable larger that the corvette brakes. Making sure you have right wheel offset to clear your brake caliper is an exercise if not using the corvette wheel. VRaptor is right in is a big deal to make sure the offsets / backspacing are correct and will fit your hubs and brakes.
    IMG_1462.JPGIMG_1464.JPGIMG_1467.JPG

  8. #8
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    Quote Originally Posted by jamesfr58 View Post
    I used a staggered set up with 19” front and 20” back wheels. They are IPW Front wheel is 19X8.5 and the back are 20X10 with the C5 bolt pattern 5X4.75. They had the right offset to fit my Wilwood Big Brakes 6 piston fronts with 4 piston backs using EDC racing rotors – BSD Series Sport w/Ultra Quite V Slot configuration. You can see the wheel offset clears the big brake caliper but it is close. Was hard to find a wheel with right offset using the Wilwood brakes as they are considerable larger that the corvette brakes. Making sure you have right wheel offset to clear your brake caliper is an exercise if not using the corvette wheel. VRaptor is right in is a big deal to make sure the offsets / backspacing are correct and will fit your hubs and brakes.
    IMG_1462.JPGIMG_1464.JPGIMG_1467.JPG
    Damn that's close, but looks great!!!!

    I am about to pull my Forgestars out of their boxes again and do my final measurements to order my Wilwoods. For what I am looking at, it looks like I will need a .200 spacer up front and no spacer in the rear for the Wilwood Big Brake set up. What I realized is that there would be more interference if you go with the smaller Wilwood option due to the way the Forgestarts spokes are. I'll post everything when I get to that part of my build, which will be shortly.

  9. #9
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    I have fought with wheels for years. I would not recommend 20" wheels at it requires a very low profile tire and you will be very limited on tire options.

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