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    Results 1 to 12 of 12
    1. #1
      Join Date
      Oct 2014
      Posts
      41
      Country Flag: United States

      Help With New TruTurn Setup to Measure for Wheels/Tires

      Hey all,

      I need some help understanding what's going on with my 1970 Nova. This winter I installed a new rag joint, power steering box, all ridetech (3 pc. MuscleBar, Strongarms, coilovers, and TruTurn). I have OEM subframe, inner fenders, and disc brakes. Now that I'm going to measure for wheels/tires, I'm running into a perplexing issue.

      I rented the wheel-fit "tool" from MCB, and had things all measured out on the passenger side for an 18x9", 245/40R18, which told me I need a 5.875 BS. I set the ride-height as best I could by lowering the coil spring all the way down loose on the coilover, jacked up lower control arm, and had half the sidewall covered by the fender lip; that seemed close enough to get everything done. With the steering wheel cranked all the way to the left, the tire, on the passenger side, almost touches the Musclebar, and I have great clearance at the rear when the steering wheel is cranked to the right. For $hits and giggles, I decided to throw the tool/tire combo on the driver's side. I'm glad I did. With the steering wheel clocked all the way to the right, There is .75"-1" clearance to the sway bar, and with the wheel turned all the way to the left, the rear of the tire on the drivers side is pushed against the inner fender. It's not just "close", it actually flexed the tool mounted to the hub. While both side Tru-Turn steering arm stops don't touch the lower control arm (passenger side does at full lock, drivers side does not), I don't understand why there is a side-to-side variation like this and/or what could be causing it.

      Any ideas?



      I set the tie rod lengths as close to the old stuff I took off, but is that the reason for everything being wonky? I thought that would at least be close to get wheels and tires measured and ordered, and then I would obviously take the car to a shop for a proper, professional alignment. But without this, I can't really appropriately measure for wheels/tires. Not with any confidence anyways. Is there a typical tie rod length, driver side and passenger side?

      Thanks in advance for the help, this site has always been very helpful.


    2. #2
      Join Date
      Nov 2006
      Location
      Mountain Springs, Texas
      Posts
      3,760
      Country Flag: United States
      Did you roughly align the camber and caster? Too much caster can cause problems.

      What caster slugs did you use? Same one in both sides?

      Don
      1969 Camaro - LSA 6L90E AME sub/IRS
      1957 Buick Estate Wagon
      1959 El Camino - Ironworks frame
      1956 Cameo - full C5 suspension/drivetrain

    3. #3
      Join Date
      Nov 2009
      Location
      Austin Texas
      Posts
      544
      Err to the (higher backspace) frame rail side, not the fender side. Its way easier to run a small spacer than to redo your wheels. Im running a 265 on a 10-inch wheel in the front with tru tun and its tight. Also keep in mid your brake kit will affect your offset. Willwood is like .38 out from factory. Kore 2 is like .25 in from factory if I remember correctly.

    4. #4
      Join Date
      Oct 2014
      Posts
      41
      Country Flag: United States
      Quote Originally Posted by dhutton View Post
      Did you roughly align the camber and caster? Too much caster can cause problems.

      What caster slugs did you use? Same one in both sides?

      Don

      Hey Don, I used the standard "street" caster slugs that came with the Strongarms from ridetech; yes, same on both sides. I put the shims back in, in the same spots, from the old stuff I took out. Again, thought all of this would be close enough until I could get the car to a shop for a professional alignment.

    5. #5
      Join Date
      Oct 2014
      Posts
      41
      Country Flag: United States
      Quote Originally Posted by cwylie View Post
      Err to the (higher backspace) frame rail side, not the fender side. Its way easier to run a small spacer than to redo your wheels. Im running a 265 on a 10-inch wheel in the front with tru tun and its tight. Also keep in mid your brake kit will affect your offset. Willwood is like .38 out from factory. Kore 2 is like .25 in from factory if I remember correctly.
      265/35, 40, 45? What backspace? I'm curious to know how you were able to fit those. I'm a tad disappointed I couldn't fit anything over this 245/40, but if all the other geometry is off, I can't confidently determine what will and won't fit. Thanks!

    6. #6
      Join Date
      Sep 2010
      Location
      Martinez, CA
      Posts
      135
      Country Flag: United States
      I’m wondering if the subframe is centered in the body. There always seems to be a little “slop” in these early cars. My 66 Chevelle can be bolted to the frame quite crooked.
      Have you measured from the wheel hubs to fender on both sides?
      1966 Chevelle, 3.6L/217 CI, 4 cam direct injected V6, 6 speed auto, full Hotchkis suspension, 4 wheel Wilwood discs, white w/red interior, cowl hood. 3260 lbs w/full tank. Built for 35 mpg. So far 32.

    7. #7
      Join Date
      Oct 2014
      Posts
      41
      Country Flag: United States
      Quote Originally Posted by 67-LS1 View Post
      I’m wondering if the subframe is centered in the body. There always seems to be a little “slop” in these early cars. My 66 Chevelle can be bolted to the frame quite crooked.
      Have you measured from the wheel hubs to fender on both sides?

      I can check that tonight. But, even if I had all of the body panels off the car, the front of the tire on the passenger side would still hit the sway bar, and the rear wouldn't hit inner fender/frame, but on the drivers side the front of the tire wouldn't hit the sway bar, and the rear would definitely hit the inner fender/frame. All the ridetech stuff is mounted on the subframe. Does that make sense?

    8. #8
      Join Date
      Nov 2006
      Location
      Mountain Springs, Texas
      Posts
      3,760
      Country Flag: United States
      Quote Originally Posted by Steel409 View Post
      Hey Don, I used the standard "street" caster slugs that came with the Strongarms from ridetech; yes, same on both sides. I put the shims back in, in the same spots, from the old stuff I took out. Again, thought all of this would be close enough until I could get the car to a shop for a professional alignment.
      Still sounds like too much caster. Try removing a couple of shims on the rear control arm bolt.

      Don
      1969 Camaro - LSA 6L90E AME sub/IRS
      1957 Buick Estate Wagon
      1959 El Camino - Ironworks frame
      1956 Cameo - full C5 suspension/drivetrain

    9. #9
      Join Date
      Nov 2006
      Location
      Mountain Springs, Texas
      Posts
      3,760
      Country Flag: United States
      Quote Originally Posted by Steel409 View Post
      265/35, 40, 45? What backspace? I'm curious to know how you were able to fit those. I'm a tad disappointed I couldn't fit anything over this 245/40, but if all the other geometry is off, I can't confidently determine what will and won't fit. Thanks!
      In my experience you have to run a lot of negative camber to fit wide tires with TruTurn. -1.5 degrees or so.

      Don
      1969 Camaro - LSA 6L90E AME sub/IRS
      1957 Buick Estate Wagon
      1959 El Camino - Ironworks frame
      1956 Cameo - full C5 suspension/drivetrain

    10. #10
      Join Date
      Jul 2008
      Location
      Summerfield, NC
      Posts
      220
      Country Flag: United States
      If it's anything like my 64 Chevelle there's a hump in the rear of the driver's wheel well for the parking brake cable exiting the firewall. I've dialed in so much caster on my car the wheels are off center in the wheel well, it's not pretty, but gets the job done.
      *Jeff*
      Project Salty - 1964 4 door Malibu, beaten, neglected, red headed foster child
      Cammed LQ4 / T56 Swap Project Thread <-click to read! 😁

    11. #11
      Join Date
      Oct 2014
      Posts
      41
      Country Flag: United States
      Quote Originally Posted by dhutton View Post
      In my experience you have to run a lot of negative camber to fit wide tires with TruTurn. -1.5 degrees or so.

      Don

      Hey Don,

      Do you mean add shims at the upper control arm bolts? Thus moving the UCAs in towards the engine? The previous suspension had two shims at the back, one at the front. In some of the pictures of other pro touring rides, it looks like there are a LOT of shims between upper control arm and frame, which I thought = lots of negative camber, and thus allowing additional tire clearance at top of fender.

      Thanks for clarifying... Obviously my first suspension overhaul!

    12. #12
      Join Date
      Nov 2006
      Location
      Mountain Springs, Texas
      Posts
      3,760
      Country Flag: United States
      Quote Originally Posted by Steel409 View Post
      Hey Don,

      Do you mean add shims at the upper control arm bolts? Thus moving the UCAs in towards the engine? The previous suspension had two shims at the back, one at the front. In some of the pictures of other pro touring rides, it looks like there are a LOT of shims between upper control arm and frame, which I thought = lots of negative camber, and thus allowing additional tire clearance at top of fender.

      Thanks for clarifying... Obviously my first suspension overhaul!
      Yes adding shims on both bolts adds negative camber. Adding shims on just the rear bolt adds negative camber and positive caster. That’s why I suggested removing a rear shim to reduce caster. So in your case you could also try adding some shims to the front bolt to add negative camber and reduce caster.

      Don
      1969 Camaro - LSA 6L90E AME sub/IRS
      1957 Buick Estate Wagon
      1959 El Camino - Ironworks frame
      1956 Cameo - full C5 suspension/drivetrain