Wheel & tire selection double check

Discussion in 'Suspension, Steering, Brake & Wheel Topics' started by Jeep43, Feb 11, 2019.

  1. Jeep43

    Jeep43 Veteran Member

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    I want to buy some good street/occasional auto X rolling stock and don't want to break the bank but also don't want to compromise on fitment by opening up my options to less backspace. I am about to pull the trigger on the following:

    BG rodworks Old School wheels and Falken Azenis RT615K+ tires in these sizes.

    Front
    17x8 4.75" BS with 245/45
    Rear
    17x9.5 5.5" BS with 275/40

    The calculator I am using shows that both sizes have the same offset as the stock steel Z28 wheels so the extra size is split 50/50. Fronts are .2" closer to fender lip and same to the suspension side and the rears are .8" closer to fender lip and same toward the leaf. The car is lowered about an inch with Hotchkis springs and spacers/shackles. Front suspension geometry is stock other than tall upper ball joints which should only help with the more aggressive camber change.

    I tried to do my homework especially from the guys who drive their cars hard and this seems to be a pretty safe combination I believe. I plan to compare these numbers to the clearance around my 15" combo I have now but does anybody see anything wrong with this selection?

    The attached pic is an RS with the style wheel I am looking at.
     

    Attached Files:

    Last edited: Feb 11, 2019
  2. sandiego74

    sandiego74 Veteran Member Lifetime Gold Member

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    That should work perfectly. I had the exact setup on my car and it handled like a dream. The front hardly ever lost grip, and the rear would rotate when I wanted it to.

    As much as I love the Falken’s, however, look at the Bridgestone RE71’s. They are, from what everyone at autocross has been saying, the best 200 treadwear tire right now, and they aren’t much difference in price with the Falken’s.

    Good luck!
     
  3. Jeep43

    Jeep43 Veteran Member

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    That's good to hear. Any need to clearance anything like rolling fender lips or hammering the seat belt hump? I don't want to do any of that which is why I'm not trying to squeeze every last mm of tire in there.

    I will definitely look at tires again.

    Goodwrench1965. Thanks for the input, no traction bars on this car.
     
  4. sandiego74

    sandiego74 Veteran Member Lifetime Gold Member

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    I drove my car hard, so it rubbed a bit on the frame up front and on the seat belt humps in the rear under hard cornering, but nothing I could notice while driving.
     
  5. Jeep43

    Jeep43 Veteran Member

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    I can tolerate a little rub on the inboard side as long as it isn't shaving any rubber off.
     
  6. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

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    Your measurements are solid.
    I would tend to push the fronts to 5" of backspace, but you'll be ok at 4.75"

    Out back: measure your rear end to make sure it's centered These cars can be shifted up to 1/4" to the side.

    I HIGHLY recommend going to 18" or larger wheels. The 17" size is dying fast as no OEM is using them for performance vehicles anymore. Corvette hasn't used a 17" since 2004
     
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  7. C4Racer

    C4Racer Veteran Member

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    18's also gives you more clearance to things like UCA and tie-rods and enables you to run more BS to push the wheel inboard on the front.
     
  8. sandiego74

    sandiego74 Veteran Member Lifetime Gold Member

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    I would also suggest 18” for the exact reasons listed above.
     
  9. Abhigrt1

    Abhigrt1 New Member

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  10. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

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    The 17x11 on the rear can work,but you’ll need to do some clearancing on fend lips seatbelt hump etc
    If the rear end is square in the car and the body panel God’s smile upon you a 5.75” backspace should fit

    But, as said above, I no longer recommend the 17” size
     

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