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Suspension and spring rates for my race car

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  • Suspension and spring rates for my race car

    Hi Everyone!

    I am at that point now where I need more input on my car. I have had the opportunity to spend a fair amount of time in other racing cars and it becomes quite apparent almost immediately that my car leaves something to be desired in the suspension department.

    My questions are very simply:

    What spring rates will be best? Where do I get them? Mine are at a claimed by the manufacturer 550 lb front and 450 lb rear. I know some cars comparable in weight to mine are using 800 lb to 1000 lb springs pretty effectively. Mine are way too soft at this point. I need my car as low as possible and have little chassis roll.

    What dampers to go with them? Mine are Tein RS which I was going to have revalved for the spring rates to be used but these are only double adjustable.

    My car weighs 2530 with a half tank and 2730 with me and my stuff in it.

    Lap times and being fast are the only goal.

    Any thoughts anyone may have will be greatly appreciated.

    Def I also want those bearing sets you're making. Over the winter is when the suspension changes will happen.

  • #2
    I'd love to see dyno plots for those RS when you pull them off Steve. (I'll pay for it even=)

    The most I'd run on my stuff (8611) w/o revalving would probably be 750-800 for the fronts. Revalved you could probably squeeze 1000 or so.

    What kind of budget are you willing to work with would be the next question?

    I know when we planned out your stuff last time it was gone through all adjustable arms, so it should just be the dampers and upright bearings you'd need.
    Last edited by veilside180sx; 08-31-2008, 07:16 PM.
    Between rides...unless you count a WD21...


    • #3
      What's the front/ rear weight bias on the car? I'm running 700# fronts and 400# rears atm, with a 55/45 weight distribution.


      • #4
        i think i should add for Steve that he will be Racing with NASA ST class, hes up to about 400whp meow an i believe 295 Hoosiers out back if not more. So any suspension suggestions are to give him the cutting edge for aggressive tracking to make those fast lap times and help put the power down.

        Are you looking to actually make it to a NASA event this year steve? so far i think ever entry list was lacking that one red 240sx that could terrorize the tracks.
        NASA HPDE Instructor


        • #5
          Man you need to post some o your sexy car pics

          And more specs on your car, parts, alignment, everything, etc... its a hot car

          Last edited by a_ahmed; 09-01-2008, 08:50 AM.
          "hexa-dodecahedron-triple-threaded-super-eleventy-way-adjustment-spec" dampers. -Def


          • #6
            it doesnt look like that anymore..oooollllddddd pics from like early 2006.

            i know he has new sponsor things on the car, and possibly wide fenders and FRP hood and aero, spiller etc....

            I used to see steve at events and talk often, we have lost touch this past year so im hoping once he gets back into racing i can get some photos of the car and footage to put up. His traffic times are avg. 5 sec faster than my clean laps before the big turbo upgrade.
            NASA HPDE Instructor


            • #7
              I wana see more in car videos like that one i posted. Totally awesome track, awesome car, awesome driving.

              It's a beautiful thing to see triple digit x thousand dollar double horsepower and technology vehicles being owned by our beloved s chassis cars
              "hexa-dodecahedron-triple-threaded-super-eleventy-way-adjustment-spec" dampers. -Def


              • #8
                Hey Casey! I don't think I am going to be running any NASA events this year. The car still needs so much sorting and will probably need a motor freshening. I can't believe the motor is 5 years in use next April and never been apart other than for cams.

                Anyway with my exposure to a number of different cars in the past two seasons it's pretty easy for me now to pinpoint my cars weaknesses. It needs to be lower and stiffer to start.

                It carries 53% of the weight in the front with me in it. It has high speed push with the rear Progress bar set at full stiff and the front at full soft. My tire stagger is significant. 275-295 in the rear and 245's or 255's in the front.

                I was thinking having sets of springs in 50 lb increments so I can tune the car to an attitude that works well and also have some abaility to make changes for different track conditions. Like 550 to 750 for the rear and then 650 to 800 for the front. Then I need a damper valved properly so that it can work within those ranges.


                • #9
                  interesting. You run stiffer rear sway and softer front, and want to run softer front springs and stiffer rear. This is like against norm of what we've been discussing on forums here (like no rear, or tiny rear, stiff and big front sways + stiff front springs and soft rear)
                  "hexa-dodecahedron-triple-threaded-super-eleventy-way-adjustment-spec" dampers. -Def


                  • #10
                    Steve - I sent you a PM.

                    Originally posted by a_ahmed View Post
                    interesting. You run stiffer rear sway and softer front
                    I'm doing this now and will probably stick with it. The car rotates nicely and I can still throttle out of the turns without the backend stepping out (lower power than Steve is at of course and).

                    ...and want to run softer front springs and stiffer rear.
                    I think Steve was stating that he was going to get several sets of springs for the front/rear and just play with them... not actually run stiffer springs in the rear -vs- front.

                    This is like against norm of what we've been discussing on forums here (like no rear, or tiny rear, stiff and big front sways + stiff front springs and soft rear)
                    Steve is not the 'norm'
                    Last edited by McCoy; 09-01-2008, 11:59 AM.


                    • #11
                      lol me want to hear more from steve and his crazy ways then haha. The video speaks for itself, me likey.

                      Steve wana share some bed time stories and car specs + new pix/info on the sexy beast.
                      "hexa-dodecahedron-triple-threaded-super-eleventy-way-adjustment-spec" dampers. -Def


                      • #12
                        You need less rear tire or more front tire(I vote for less rear tire width to get the car lower), plus more front downforce. It's easy to add rear downforce on the a door slammer, but usually harder to add front downforce so typically the center of downforce moves way too far back at high speed.

                        The rates could likely go up a hair, and I"d get your shocks dyno'd before making a move with that.
                        '18 Chevrolet Volt - Electric fun hatch for DD duty!

                        DefSport Koni Sleeve and Spring Perch Buy!!!


                        • #13
                          What would be the best way to add more front downforce? I already use a 3 1/2" splitter. I have been looking into a front end that is lower so the splitter sits lower to the ground like the new Nascar COT cars.


                          • #14
                            Lower helps A LOT. Plus maybe think of some dive plates and a vented hood if you don't have one. A new trend in car design that seems to work well with a little front downforce and reduced drag is to vent the engine bay out past the front wheels. Helps cut down on turbulence, vent the engine bay, and reduces lift by reducing pressure in the bay. A vented front hood helps reduce bay pressure as well.

                            If I don't get a fiberglass front hood I might gut the support off my stock hood and vent it for better cooling and a little less front end lift. I still think it'd be too heavy though.
                            '18 Chevrolet Volt - Electric fun hatch for DD duty!

                            DefSport Koni Sleeve and Spring Perch Buy!!!


                            • #15
                              Already have the vented hood and have seen some advantages but mainly cooling. Hard to say from a downforce standpoint as I have nothing to measure it with other than corner entry speeds. They have gone up but I have made so many changes to the car so it's hard to pinpoint what's doing it.