Page 8 of 12 FirstFirst 1 2 3 4 5 6 7 8 9 10 11 12 LastLast
Results 71 to 80 of 120

Thread: The Suspension Setup Thread

  1. #71
    Senior Member sr_rolla's Avatar
    Join Date
    Dec 2008
    Name
    beau
    State
    NSW
    Location
    Bathurst
    Country
    Australia
    Posts
    435

    Default


    TO REMOVE ADS, PLEASE
    REGISTER OR SIGN IN
    (quote old thread ru-iki)

    Love the pics of the hot race car suspension, but the rusty old stilsens on the ground for adjustments.



    My mechanic only worries about bump steer once the lower control arm on my ke gets above horizontal. At this point, its beyond the range of motion its designed to exist in and bump steer becomes evident.

    Every steering system must have some geometric variation as the suspension is compressed and rebounded (as evidenced by the pivots discussed above in the trd stuff). Perhaps the trick is to get it pivoting from just below to just above the horizontal position, being that the tie rod end and lca are parallel in the system. Lets call this variation x, which is in this case + or - above the horizontal. Meaning the total variation in geometry is only half what it could be.

    If you went a bit lower and the lca was horizontal to begin with, upon the same compression as above, it would displace a distance of +2x.

    Make any sense? If you know what Im on about Dave, id love to see a diagram. Feel free to pick me to pieces I'm thinking out loud here..

    ...top thread, finally some nitty gritty..

  • #72
    Senior Member sr_rolla's Avatar
    Join Date
    Dec 2008
    Name
    beau
    State
    NSW
    Location
    Bathurst
    Country
    Australia
    Posts
    435

    Default

    (quote old thread ru-iki)

    The other thing that hasn't been touched on yet, is what happens when the suspension compresses while you are tuning, displacing the steering sideways and altering the angle between the lca and tie rod. This must have a more drastic effect than anything in a straight line. I've always worried about the bump steer I feel when turning, not really in a straight line.

  • #73
    Senior Member sr_rolla's Avatar
    Join Date
    Dec 2008
    Name
    beau
    State
    NSW
    Location
    Bathurst
    Country
    Australia
    Posts
    435

    Default

    u wont feel true bump during turning as toe changes whilst turning due to ackerman angle anyway, what u feel is scrub radius problems. as u hit a bump (in a rolla/sprinter at least) the wheel is forced backwards from its pivot point so it fells like its trying to steer. Alot of older cars have this problem as the balljoint is to far inboard from the tyre contact patch. This is y most new cars run a system where the balljoint is basically in the wheel.

    In a rolla u have 2 basically deal with it, im gonna be workin on some ways to improve it a little but unless you completly redesign the front end theres not alot u can do

    u have 2 lose the deep dish wheels aswell

    And back to the 1st point, that is true if the arms are all parrelell to each other and the ground it should work fine, and usually this is a fine rule to work to normally

    But lets face it, if your here your not normal tongue.gif

    if u run that level setup u dont have enough front roll center hieght, hence RCA's being so popular. However, because the RCA's go between the steering arm (where the tierod and balljoint are mounted) and the strut it doesnt affect the bump characteristics, if the bump is wrong then the tierod must be raised/lowered in relation to the LCA by either changing the tierod mount on the steering arm or raising/lowering the rack

  • #74
    Senior Member sr_rolla's Avatar
    Join Date
    Dec 2008
    Name
    beau
    State
    NSW
    Location
    Bathurst
    Country
    Australia
    Posts
    435

    Default

    (quote old thread slydar)

    ill have this to add. helper springs. win. my car is set up with a good 3" of droop now, and some helpers springs. everything else is fairly "normal" but wow, big difference. car just as way better manners. havent even had a wheel alignment yet.

  • #75
    Senior Member sr_rolla's Avatar
    Join Date
    Dec 2008
    Name
    beau
    State
    NSW
    Location
    Bathurst
    Country
    Australia
    Posts
    435

    Default

    (quote old thread biggo)

    I have a few things to add too,

    AE92 shocks are a no no for droop

    A nifty rule i got the other day 1mm = 1/4* deg in toe in/out terms, this is not the be all end all tho.

  • #76
    Senior Member sr_rolla's Avatar
    Join Date
    Dec 2008
    Name
    beau
    State
    NSW
    Location
    Bathurst
    Country
    Australia
    Posts
    435

    Default

    (quote old thread mattyn)

    hey suspension team.

    Situation => I'm going to change bushes in the very near future and i was hoping for some guidance. I was looking to go for Poly Urethane… Given availability Super Pro seemed the best option. 2 issues here..

    Issue 1:
    QUOTE
    don't replace the bushes in the top passenegr side trailing arm to the diff at each end, the rest of the 5 link is good.

    with all the bushes in the rear changed the diff cant pivot properly and to make it do that you need to either remove the top passeneger side bar (not recomended) or drill multiple holes through the rubber bushing.

    Im wondering where these notes from another thread will apply.. not sure about this one..


    Issue 2:
    there are a pair of rose joints at the front end of my car, (name of arms escapes me, they attach from the torque box to the LCA, sorry.. .maybe castor arms??)
    is this what you refer to here..
    QUOTE
    is get some nice bushes, some corona front arms, some RCA's and a rosejointed castor arm arangement.
    I’ve got level LCA’s done with RCA’s and I think if I’m using the right name I’ve done the rose joint you refer to.
    So the question is:
    If I was to Leave the control arm bushings and only do the rear would this have a negative (perhaps unbalanced) effect.. IE: would it start to feel sloppy at the front once the rear is done????

    Thanks for bearing with me on this one..
    Matt.

  • #77
    Senior Member sr_rolla's Avatar
    Join Date
    Dec 2008
    Name
    beau
    State
    NSW
    Location
    Bathurst
    Country
    Australia
    Posts
    435

    Default

    (quote old thread konakid)

    QUOTE (mattyn @ Nov 18 2008, 01:29 AM) *
    hey suspension team.

    Situation => I'm going to change bushes in the very near future and i was hoping for some guidance. I was looking to go for Poly Urethane… Given availability Super Pro seemed the best option. 2 issues here..

    Issue 1:

    Im wondering where these notes from another thread will apply.. not sure about this one..


    I have had Super Pro throughout my car for 40,000km, they are still as new today, made in Japan, very good quality bushes dude, got them from AJPS, full bush kits are about 370 i think.

    As for the issue for not replacing those bushes, i just replaced all the trailing arm bushes and the rear end now feels tight. It sounds like a bit of an old racing tale to be honest, too many companies offer full rose jointed 5 links for it not to make enough difference if the rear end has no movement.

    That said, poly bushes still offer some give.

    QUOTE
    Issue 2:
    there are a pair of rose joints at the front end of my car, (name of arms escapes me, they attach from the torque box to the LCA, sorry.. .maybe castor arms??)
    is this what you refer to here..
    I’ve got level LCA’s done with RCA’s and I think if I’m using the right name I’ve done the rose joint you refer to.
    So the question is:
    If I was to Leave the control arm bushings and only do the rear would this have a negative (perhaps unbalanced) effect.. IE: would it start to feel sloppy at the front once the rear is done????

    Thanks for bearing with me on this one..
    Matt.


    Sounds like rose jointed castor rods and brackets? Those rods that reach diagonally and connect to the lower radiator support chassis rail are castor rods.

    A rose joint looks like this, basically a bearing in a carrier

    Reduced: 73% of original size [ 700 x 305 ] - Click to view full image


    It would feel less direct in the front end if you only did the rears, id recommend definately doing it all at once to make the car feel tighter and more responsive. The front end is equally important as it effects how direct your steering is and feels.

  • #78
    Senior Member sr_rolla's Avatar
    Join Date
    Dec 2008
    Name
    beau
    State
    NSW
    Location
    Bathurst
    Country
    Australia
    Posts
    435

    Default

    (quote old thread ajps)

    just clearing up one thing kona kid said

    super pro (imho) worlds best urethane is made in australia and is exported to the world - it is often sold in different colours and with different packaging.

    It is also used and often favoured over rubber (which japanese typically used to ALWAYS use) and they advertise in JDM mags - although i think that is resellers in japan advertising (perhaps where the made in japan thing came from)?

  • #79
    Senior Member sr_rolla's Avatar
    Join Date
    Dec 2008
    Name
    beau
    State
    NSW
    Location
    Bathurst
    Country
    Australia
    Posts
    435

    Default

    (quote old thread mattyn)

    yeah, cheers for that kona kid, i was getting it mixed up as sometimes i've heard it called a strut bar. but yeah same thing with two names ive now discovered.
    cheers for the heads up on the longevity also, good to hear yours are lasting a decent period.
    will go through with the front also, shouldn't make the job too much bigger since ill be under there with penetrating oil and a breaker bar anyway.. tongue.gif


    If anyone has heard anything else about this

    QUOTE
    don't replace the bushes in the top passenegr side trailing arm to the diff at each end, the rest of the 5 link is good.
    with all the bushes in the rear changed the diff cant pivot properly and to make it do that you need to either remove the top passeneger side bar (not recomended) or drill multiple holes through the rubber bushing.

    let me know.. cheers!!

  • #80
    Senior Member sr_rolla's Avatar
    Join Date
    Dec 2008
    Name
    beau
    State
    NSW
    Location
    Bathurst
    Country
    Australia
    Posts
    435

    Default


    TO REMOVE ADS, PLEASE
    REGISTER OR SIGN IN
    the theory is that because the upper and lower arms are at different lengths the diff will try to twist itself as the left and right ends move in different directions (ie: the left moves up and forward while the right trys to move back and down). When u convert the rear end to more solid bushings the diff can no longer pivot in its bushes so the car has a tendency to lift wheels and push understeer. If u drill out the upper bush as u described the diff can pivot as it is meant to do.

    What i would suggest doing is trying the drilled out upper arm 1st and if u feel its a problem later on, get some new bushes.

  • Page 8 of 12 FirstFirst 1 2 3 4 5 6 7 8 9 10 11 12 LastLast

    Similar Threads

    1. (SA) *E7*/86 BC/AJPS Rear Suspension setup/ 2871r turbo setup
      By sleeper_13 in forum Car Parts For Sale
      Replies: 3
      Last Post: 25th July 2012, 01:06 AM
    2. Need Help With Suspension Setup
      By ArbPotatoes in forum Technical - Questions
      Replies: 22
      Last Post: 30th June 2009, 10:51 PM
    3. The Suspension Setup Thread
      By sr_rolla in forum Technical - Articles
      Replies: 84
      Last Post: 16th August 2008, 02:15 AM
    4. suspension setup
      By AE86_4life in forum Technical - Questions
      Replies: 9
      Last Post: 1st November 2006, 08:43 PM

    Posting Permissions

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