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Thread: Front Springs for Autox

  1. #41
    Join Date
    Jan 2003
    Location
    Fairfax Station, VA, USA.
    Posts
    166
    Quote Originally Posted by Naumoff
    Next is tires.
    Ah, let the madness begin! There'll be no end to it.
    Gary
    Unique FIA 351W

  2. #42
    Join Date
    Dec 2004
    Location
    Prince Frederick, Maryland, USA.
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    1,561
    I just came back from a test drive with the new front springs.
    It is like night and day. Car even feels more stable at speed and the little shimmy at 65mph is gone.
    And Gary it is funny. when I first put the car on the ground and re-adjusted the car height. I thought I made a mistake with the 650 because it felt so stiff when I pushed down on the car.
    The drive is the proof in the pudding. It felt great and the comfort is not different. The car feels great.( do you think I am HAPPY!)

    Everybody should drive a car with heavier springs just to compare. The springs I took off were 10" 300 lb springs. The ones I put on are 9" 650 lb.
    Tony
    Unique 427 #4279480 Precision Engine Machine Company 427 s/o 483.47 stroker close ratio toploader 3.31 jag rear

  3. #43
    Join Date
    Jan 2003
    Location
    Shepherdsville, KY, USA.
    Posts
    1,725

    Thumbs up Springs

    Your right on Tony.

    The higher spring rates work real well with a big block car.

    My car ran through the mountians better than it ever has, turned real good right and left. We even hit a little stretch of Interstate Saturday AM and it was very stable at 115 MPH, (we were in the rear catching up). I was afraid my passenger (Alan's wife Paulette) would be a little white, not so, she was all smiles.

    My opinion is that all FE's and other big block cars need a minimum of 350# springs front and rear. Dont know what is the effect of 200 PSI charge in the Billstein Shock has on the sping rate but it has to be a factor.

    Glad your satisfied with the changes.
    Rick
    427 S/C , 427 Side-oiler, 4 Speed Close Ratio Top Loader, 3:73 Gear
    #4279405

  4. #44
    Join Date
    Feb 2004
    Location
    Baton Rouge, LA, USA.
    Posts
    100
    Ok, I'm looking to get heavier springs for my FIA. I'm looking at the 550lb QA1 9" springs for the front. What are you guys running in the rear? The same? 9" or 10"? Currently have 10" 300lb springs with Pro shocks all around.
    Last edited by Unique 289_FIA; October 5th, 2006 at 10:21 PM.
    Robert
    Unique Motorcars 289 F.I.A. # 9142
    Southern Automotive 354 stroker

  5. #45
    Join Date
    Jan 2003
    Location
    Fairfax Station, VA, USA.
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    166
    Robert,

    I'm running 8" 300lb springs in the rear.
    Gary
    Unique FIA 351W

  6. #46
    Join Date
    Feb 2004
    Location
    Baton Rouge, LA, USA.
    Posts
    100
    Quote Originally Posted by Silk View Post
    Robert,

    I'm running 8" 300lb springs in the rear.

    Ah, so the rears are 8"? I haven't really checked, I just assumed they were the same as the front. I just recently replaced the front suspension to the more current setup and installed adjustable (height) coilovers in the rear at the same time.

    It's surprising to me that 550lb springs in the front with the stock 300lb in the rear doesn't cause the car to understeer horribly? I'm assuming, since you've autocrossed the setup, this isn't the case? I know my car pushed quite a bit the couple times I've run it (it's been awhile though).

    Let's say I want to stiffen the rear also. Should I go for similar rates in the front? Maybe a little less or more?
    Robert
    Unique Motorcars 289 F.I.A. # 9142
    Southern Automotive 354 stroker

  7. #47
    Join Date
    Dec 2004
    Location
    Prince Frederick, Maryland, USA.
    Posts
    1,561
    A solo II instructor drove my car and said he would lighten up the rear swaybar or heavy up the front just a tad. That is with 650# 9" springs up front and the 4 300# 8" in the rear. I have not weighed the for corners either. Then I will have to redo my four wheel alignment.
    It does get pretty involved with a suspension set up for what you want to achieve. But you also have to have the tires you are going to race with on before you start tweaking the set up to much.
    I would ask Rick how the quad shocks in the rear effect the individual spring rate you would choose.
    Tony
    Unique 427 #4279480 Precision Engine Machine Company 427 s/o 483.47 stroker close ratio toploader 3.31 jag rear

  8. #48
    Join Date
    Jan 2003
    Location
    Fairfax Station, VA, USA.
    Posts
    166
    Robert,

    As Tony noted, with quads in the rear, it's much different than having just a single 300lb spring at each rear corner. I've adjusted my spring rates based on actual performance, and I've found that moving up the rates in front helped significantly with dive and roll. The 300lb rears seem to be working well for me. I'm sure someone with real expertise in suspension geometry could determine whether this is the optimum setup, but I haven't gotten that serious about things (yet).

    The good news is that springs are relatively cheap and easy to swap out, so you can always try a different setup and see if you like the results. At worst, you'll be like a lot of us and have a nice array of different spring lengths and weights sitting around on the garage shelf.
    Gary
    Unique FIA 351W

  9. #49
    Join Date
    Feb 2004
    Location
    Baton Rouge, LA, USA.
    Posts
    100
    I agree that it's different with the paired spring setup in the rear, there's also a much longer lever arm which I'm sure also affects it. I also don't have a rear swaybar and am using a 3/4" front bar. What we should probably be comparing is wheel rates, but I was looking for some empirical evidence for a good setup and whether I should keep the rates similar f/r. The rear on my car feels realllllly soft, in fact, I suspect the rear tires are bottoming out and occasionally hitting the fenders (275/60's, so they are kinda tall (measure about 27 3/4")). I think I will just try some 400's in the rear and 550's in the front and see how that works. I don't mind a firm ride at all (my old MR2 with modified suspension was muuccchhh stiffer). The QA1 springs are only $36 each at Jegs and Summit.
    Robert
    Unique Motorcars 289 F.I.A. # 9142
    Southern Automotive 354 stroker

  10. #50
    Join Date
    Dec 2004
    Location
    Prince Frederick, Maryland, USA.
    Posts
    1,561
    I am running a shorter tire. A 295/50 15 which is 26.5 inches tall.
    3/4" front and rear sway bars.
    This winter I am doing tire research and will be purchasing some 17" wheels just for AutoX The tires are shorter than the 15" go figure. They are about an inch shorter than my 50s.
    Tony
    Unique 427 #4279480 Precision Engine Machine Company 427 s/o 483.47 stroker close ratio toploader 3.31 jag rear

  11. #51
    Join Date
    Feb 2004
    Location
    Baton Rouge, LA, USA.
    Posts
    100
    Interesting bit of info. I went to double check the length of the springs on the f/r. Turns out I have 10" in front like everybody else, but the rears are 9" instead of 8". Wasn't expecting that. I checked all four, with the springs in unloaded state, and they are all clearly 9".

    This works for me, as the QA1 9" powdercoated springs are the cheapest. Just ordered 2 550lb for the front, 4 400lb for the rear. I'll let you all know how it works.
    Robert
    Unique Motorcars 289 F.I.A. # 9142
    Southern Automotive 354 stroker

  12. #52
    Join Date
    Mar 2006
    Posts
    75

    WTB rear coil-overs

    Looking to buy some used rear coil-overs - PM me - thanks peter

  13. #53
    Join Date
    Feb 2004
    Location
    Baton Rouge, LA, USA.
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    100
    Quote Originally Posted by peter View Post
    Looking to buy some used rear coil-overs - PM me - thanks peter
    PM sent.



    {Gotta make the message at least 10 characters, so this ought to work.}
    Robert
    Unique Motorcars 289 F.I.A. # 9142
    Southern Automotive 354 stroker

  14. #54
    Join Date
    Dec 2004
    Location
    Prince Frederick, Maryland, USA.
    Posts
    1,561
    Cool Robert,
    Keep us posted on how they work for you.
    Remember to set the ride height the same unless you plan on doing another alignment.
    Tony
    Unique 427 #4279480 Precision Engine Machine Company 427 s/o 483.47 stroker close ratio toploader 3.31 jag rear

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