Just joined? Please introduce yourself.
Page 3 of 5 FirstFirst 12345 LastLast
Results 21 to 30 of 45

Thread: Wheels and tires for a 55 C4 conversion

  1. #21
    Banned
    Join Date
    Nov 2015

    Member #:2775
    Posts
    1,426
    BTW sir, I did have a tire on that wheel, but it was a 265/40-17. Stock front size for a Z06, but too short. It was only for a first time trial fit with just something I had available to get a rough idea. Thanks for setting me straight though. I feel much smarter now thanks to you CN.
    Last edited by 55 Rescue Dog; 07-09-2019 at 02:34 PM.

  2. #22
    Registered Member chevynut's Avatar
    Join Date
    Nov 2011

    Member #:115
    Location
    Fort Collins, CO
    Posts
    10,835
    RD, Since you don't seem to understand how a C4 IRS works let me explain what controls the camber curve. Apparently the guy at Morrison 20 years ago didn't understand this either.

    The distance between the inboard u-joint and the lower strut rod inboard pivot point determines the angle between them and the resulting camber curve. You can draw it on a piece of paper using a compass if you don't believe it. With the halfshaft level, raising the knuckle causes the top of the knuckle to move inboard. Since the lower strut rod is pointed down and outboard, raising the knuckle causes the bottom of the knuckle to move outboard. The combination of these movements controls camber. The more the strut rod points downward, the more effect it has on the outboard movement of the bottom of the knuckle. It's simple geometry.

    On the early (84-87) C4 Chevrolet put the inboard strut rod pivot pretty high, and the result was too much camber gain on those cars. This is an early (84-87) C4. Notice how high the inboard strut rod pivot is.





    In 1988 Chevrolet decided to reduce the camber gain on the IRS so they lowered the pivot point. Halfshafts and strut rods were left the same length, and the difference in rearend width is all in the knuckle, specifically the addition of a separate brake caliper mount. Here's a late (88-96) C4 rear, notice the lowered mounting point.




    You can change the camber gain to just about whatever you want to by moving that pivot point up or down. When you narrow a C4 rear you change the angle of the strut rod slightly (makes it steeper), so the camber curve is affected and you get more camber gain. I made my own brackets and modeled them after the late C4 suspension so my camber gain will be slightly more than a late C4 because of the narrowed rearend. I could have lowered that point further if I chose to do so to reduce the camber gain, but it's already less than an early C4 rearend so I didn't worry about it. Also keep in mind that I took 3" out of a 63" wide rearend which is less than 5% change in overall width. Halfshaft and strut rod length changed by about 8%. If I want to change the camber curve in the future for some reason, I'll make new brackets.

    20161215_002.JPG

    20170302_001.JPG

    Now that you understand what effect narrowing a C4 IRS has on suspension geometry, maybe you'll lay off with the uneducated, snide remarks about my project and you won't be so annoying.
    56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension


    Other vehicles:

    56 Chevy 2-door BelAir sedan
    56 Chevy 210 4-door sedan
    57 Chevy 210 4-door sedan
    1962 327/340HP Corvette
    1961 Willys CJ3B Jeep
    2001 Porsche Boxster S
    2003 Chevy Silverado 2500 HD Duramax
    2019 GMC Sierra Denali Duramax

  3. #23
    Banned
    Join Date
    Nov 2015

    Member #:2775
    Posts
    1,426
    That was a great explanation CN on narrowing a C4 rear. Sorry, but until you drive it hard into a corner, it is only an idea at this point, like mine. Everyone could use a test track.

  4. #24
    Registered Member chevynut's Avatar
    Join Date
    Nov 2011

    Member #:115
    Location
    Fort Collins, CO
    Posts
    10,835
    Quote Originally Posted by 55 Rescue Dog View Post
    That was a great explanation CN on narrowing a C4 rear. Sorry, but until you drive it hard into a corner, it is only an idea at this point, like mine. Everyone could use a test track.
    You're welcome, but obviously not much of that technical explanation made it into your "tiny brain" or you wouldn't be making stupid comments like that.
    56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension


    Other vehicles:

    56 Chevy 2-door BelAir sedan
    56 Chevy 210 4-door sedan
    57 Chevy 210 4-door sedan
    1962 327/340HP Corvette
    1961 Willys CJ3B Jeep
    2001 Porsche Boxster S
    2003 Chevy Silverado 2500 HD Duramax
    2019 GMC Sierra Denali Duramax

  5. #25
    Registered Member
    Join Date
    Jul 2017

    Member #:3477
    Posts
    370
    Quote Originally Posted by chevynut View Post
    You're welcome, but obviously not much of that technical explanation made it into your "tiny brain" or you wouldn't be making stupid comments like that.
    Hey CN-

    You have called RD "Tiny Brain" 4 times in this thread. You are starting to sound like that little kid on the playground who throws insults around trying to be cool.

    You don't need to insult another member repeatedly to prove your point. Let your knowledge do that. Notice that RD didn't call you or your project names.

    When you start insulting people all the time you lose your credability.

    I think you are a smart guy who knows alot. I have gone to you when I have a question. You dont need to pick at people or their projects.

    Scorp

  6. #26
    Registered Member
    Join Date
    May 2012

    Member #:625
    Posts
    3,409
    Quote Originally Posted by scorpion1110 View Post
    Hey CN-

    You have called RD "Tiny Brain" 4 times in this thread. You are starting to sound like that little kid on the playground who throws insults around trying to be cool.

    You don't need to insult another member repeatedly to prove your point. Let your knowledge do that. Notice that RD didn't call you or your project names.

    When you start insulting people all the time you lose your credability.

    I think you are a smart guy who knows alot. I have gone to you when I have a question. You dont need to pick at people or their projects.

    Scorp
    He can sure dish it out but cant take it.

  7. #27
    Registered Member
    Join Date
    Apr 2012

    Member #:571
    Posts
    4,671
    RD started that by saying it first. That left the door wide open bouncing off the stops.

  8. #28
    Registered Member
    Join Date
    Jul 2017

    Member #:3477
    Posts
    370
    Quote Originally Posted by Rick_L View Post
    RD started that by saying it first. That left the door wide open bouncing off the stops.
    Sorry. I miscounted the usage of "Tiny Brain" in the thread about tires for a 55 with C4 conversion.

    I guess this thread just causes Tiny Brain-itis.

    Scorp

  9. #29
    Registered Member carls 56 (RIP 11/24/2021)'s Avatar
    Join Date
    Jan 2011

    Member #:33
    Location
    Culpeper, Va.
    Posts
    1,857
    want this great site to grow, name calling not going to help.
    ARMY NAM VET, very proud!

    56 210 4dr

    drive and enjoy them while you work on them, life is to short.

  10. #30
    Registered Member
    Join Date
    Dec 2018

    Member #:4017
    Posts
    176
    Yes I agree stop the snide remarks and stay with the useful sharing. One question. Is the vette suspension going to be any faster in a big car like the Nomad? I would think the much higher CG would see little benefit over a straight axle NASCAR type set up. The group 10 trucks that run in vintage racing are super quick in the turns and have the simplest suspension designs.

Page 3 of 5 FirstFirst 12345 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •