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Custom rear suspension question (turbo2256b)

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    Custom rear suspension question (turbo2256b)

    If I went with a set of 400 to 450lb/in springs in the rear, how much shock travel would I need? This would hopefully be a coil over shock setup. I may have to build new mouting support off of the frame, but I'll deal with that one when I get there. With the limited info I have, I think there is about 8" travel stock, more than doubling spring rate would put me at less than 4", right? I am currently looking at threaded shocks with about 4" of travel.

    #2
    I have a feeling I will have to go with one of these shocks though. The reason I want such small travel is so I can simply modifie existing mounts to mount the new stuff. But with the heigh of these I need to cut away existing stuff and creat new mounts that allow my to lower the height of the car, but also increat the installed heigh to about 14" as upposed to my current 12" ride or so installed height for my rear springs.

    QA1
    DR5855
    comp.11 5/8"
    ext.17"
    recommended installed height.13 1/4"-14 1/2"
    Springs. 12"

    Comment


      #3
      A little story about to heavy of a spring in the rear. Ponder this.

      I went to the Palm Beach Drag strip (Morso's) one other time. I will try to keep this short. I was building a 351C for my Shelby Mustang my friend a Boss 302 for his older Falcon. The Falcon guy taked me into going to see him run and a olld guy in a 64 TO 67 ish Mecury monclair 4 door stock. Any way I am up in the stands soaking it all in run after run. Finaly Falconman stages with a Nova. The lites start counting down yellow, yellow, yellow ..... I blink. The Nova's half way down the strip. No Falcon in site. Looking to the left to the right no Falcon. Looking at the finish see the Nova's ET and Speed regester on the board. Falcon 's side blank. Looking ddown the return road, scannig over the track .... The next ttwo cars are staging ....the tower is not missing the Falcon no info over the PA. The tower started woundering they were missing the Falcon.. Finaily over the PA the Falcon was found up side down in a very deep dranage ditch on the one side of the track.


      He wasnt hurt, a bit shook up. Cought up wwith him a few days later. This is what he did to cause the accident. He had removed the rear springs and installed 3/4 ton truck springs. He torked the car up launched and as I blinked the energy built up in th springs leap froged him right of the track and into the ditch. Hummmmmmmmmmmm

      This would be a good lead in to the cross bow I bult out of like a 4 yard dump truck spring. Or the recoil spring that shout out of an 8" Howitzer
      Last edited by turbo2256b; 05-18-2006, 12:05 AM.
      Scars are tatoos of the fearless

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        #4
        Yeah Moroso is infamous for their ditches. The bike racers are afraid of going off a corner and landing in there with the gators.
        http://secondhandracing.com/Home.aspx
        http://secondhandradio.com/

        R.I.P. Jason P Harrill 6-12-06

        http://www.grandmarq.net/vb/showthread.php?t=5634

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          #5
          so are the gators
          Attached Files
          Scars are tatoos of the fearless

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            #6
            Well, 400-450 is perfect balance for what I am going for. I am not building a drag car, but a good handeling car. With 925lb springs in the front 450 is about ideal for this car. Since givin current balance it plows like a bitch.

            It sounds like someone did not have the shock to hold back a 3/4 ton spring, the proper suspension to support X level of power.
            Last edited by Blaze86Vic; 05-18-2006, 01:02 AM.

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              #7
              175 is about right for a GM or CV, waggons probably around 200. The rest shoulld be done with bump stops, shock valving and rates. Most drag cars run the same springs as these also. 70 Mustang Trans Am cars ran 175 to 225 in the rear 700 to 780 in the front. Turned low 11s in the quarter. You need to be able to balllance the car on the springs and enough jounce and rebound is needed. Most of your 4 inch stroke shocks are for super speed way stuff outlaws and such.
              Scars are tatoos of the fearless

              Comment


                #8
                175 is what I have now, and it's not right. Doubling the front spring rate is what I am doing. I want the rear to be stiffer than it is now, even without changing the front. So, I have to more than double the rear spring rate to get the desired result while changing the front as much as I am.

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                  #9
                  Not completely true. If you put a larger rear swaybar it will help out quite a bit. Similar goes for the front, if you want the car to rotate, put a smaller bar on the front with the higher rate front springs. That way you don't need the super heavy rear springs. Your back will also thank you....
                  Builder/Owner of Badass Panther Wagons

                  Busy maintaining a fleet of Fords

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                    #10
                    I run 175s in the rear now variable rate. Realy would like a straight 175 rate. These springs work just great with good Stock Car style shocks with proper rate and valving. They dont work for beans with your OEM factory style shocks from normal parts places. I need to find out what rare my shocks are at. they didnt send me a rate chart with mine. But there about perfect now. At the first click they were almost like factory shocks. A few notchess up might be better at the track. Since I can adjust compression and rebound for handeling higher rebounnd than compression might help with body roll. Drags lesss rebound might work out better.

                    I dont even have a rear sway bar in the rear yet. Small one in the front . I have tested three different rate front bars, 3 different front springs, Two different rear springs and two different rear sway bars and 3 different shocks front and rear.
                    One reason the rear shocks is there is 275 vaiationns of rates built in to them. Just so I could find what is needed for a certian combo. So for the most part been there and done that. With 175 rate rear springs or heaver you might even have the wrong shocks for your ride height.
                    Scars are tatoos of the fearless

                    Comment


                      #11
                      I am buying the shocks/springs together. I am also mounting them custom. So they will be installed at ideal installed height for what ever ride height I want.

                      I realize just how much of a difference shocks can make, now that I have a set of real shocks in the front. They can make a mushy car handle awesome but still keep some smooth ride. However, I am not looking to keep a smooth ride. I'm looking to take this to the next level, and see what kind of hadling I can really get, not how good I can make stocker spings work. I can see going to 375, but if I do that, it will require more extreme modification to allow the taller shocks to mount under there. Also, if I do that much modding I believe I will be angling the shock/springs inward at the top. If I do this I can put some +-400lbs on there with an effective rate of about 375-350lbs/in.

                      In the interest of rigidity, I also plan to rienforce the front section of the frame. Because it seems somewhat non-rigid once you pass the engine crossover. So somewhere in front of that (probably just behind the radiator, I plan on adding some sort of extra cross member. When I make the mounts for the rear suspension, I will also effectivly have a much stronger cross brace in the back as well.

                      Wether these plans come to fruition of not, I think that now you can see, I'm thinking a little farther outside the box here. Eventualy I plan to rebuild completely, and I am coming to the conclusion, a custom frame is my best bet. Since it will be a little more work than swapping the 03 up frame in, but still be cheaper, and will end up being better.

                      Really, I think I just want to build my own car from scratch, but I would suck when it came time to design a cool looking body.
                      Last edited by Blaze86Vic; 05-18-2006, 09:25 PM.

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                        #12
                        Blaze, me and Tom were talking aobut something like that a while ago. I think the easiest, cheapest, and most effective thing to do would be to buy a GM Metric race chassis, build the suspension using cheap redially available parts, dropping a Ford motor in it, and hanging a Vic body off it like a normal tube-chassis car.
                        http://secondhandracing.com/Home.aspx
                        http://secondhandradio.com/

                        R.I.P. Jason P Harrill 6-12-06

                        http://www.grandmarq.net/vb/showthread.php?t=5634

                        Comment


                          #13
                          Originally posted by DuceAnAHalf
                          Blaze, me and Tom were talking aobut something like that a while ago. I think the easiest, cheapest, and most effective thing to do would be to buy a GM Metric race chassis, build the suspension using cheap redially available parts, dropping a Ford motor in it, and hanging a Vic body off it like a normal tube-chassis car.
                          I agree. Parts are plentiful, and easy to come by...Plus, it's already got a full cage!
                          1983 Grand Marquis 2Dr Sedan "Mercules"
                          Tremec TKO conversion, hydraulic clutch, HURST equipped!

                          Comment


                            #14
                            That's true, but when it comes to this Vic, I am pope like religious about not having GM, Dodge, or Chevy parts on it. And I think I would really enjoy designing my own chassis, being the engineer that I am. Yeah, I know I'm a dork, but it's entertaining some times.

                            Comment


                              #15
                              I hear you on the "no GM shit" preaching... But it's SO tempting...
                              1983 Grand Marquis 2Dr Sedan "Mercules"
                              Tremec TKO conversion, hydraulic clutch, HURST equipped!

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