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Charade V6 budget hillclimber

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    #46
    Not sure. My instincts say it would need work. Defer to the experts on this one...
    http://www.speedhunters.com/2013/12/...lenge-accepted

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      #47
      Lathe is finally setup and I'm now having a ball making metal streamers. Its an ex tafe colchester triumph 7.5hp with a VSD so I can run it off single phase power. A real beast.
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      One of the first jobs has been the front hubs for the daihatsu. I have gone with holden HZ uprights and made hubs using flangless steel trailer hubs with the flanges from spare camry hubs. Last job on the hubs is to install them on the uprights and set them up between centres in the lathe to take a finishing cut to square everything up... I thought these might be a bit dodgy but its all come up pretty good in the end... anyway the plan is to replace these with aluminium hubs down the track assuming everything works ok.. Ball joint are 68 chev camaro, brake rotors are 330mm commode and calipers willwood w6a.

      Biggest problem I think I have is the scrub radius has ended up being 60mm which based on most of my googling is bad... general consensus seems to be increase the KPI to get it down to around 15mm. Although reading race car dynamics by milliken it says place the lower ball joint as far out as you can, keep the KPI less than 8 degrees and live with the resulting scrub radius... 60mm seems a bit much though. I'm playing around modelling suspension now but I'm thinking I'll probably modify the upright to move the upper ball joint inwards... If I increase the KPI to 16 degrees I can get scrub down to about 20mm.

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        #48
        That disc is the biggest obstacle to getting a low scrub radius asuming the wheel is not on the upper control arm.. Mac strut discs from Commodores have huge offset which is undesirable for all sorts of reasons.
        Get a flatter disc from a Falcon say, and move it as close to the lower ball joint as you can; 3 to 5mm is ok. Remake hubs and adjust control arm lengths to get track. Keep Holden KPI.
        I have done a couple of Holden upright based cars that can run with zero scrub radius- or even positive, admittedly with bigger wheels than you have.
        Claimed horsepower sceptic.

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          #49
          I have been thinking more about this over the weekend and came to the same conclusion about the disc being the main issue. However the problem is the brake calipers i've bought are massively wide hence the reason for the tall discs in the first place.

          I had a look around and a 320mm rotor from an EVO is about 40mm shorter so I made one in mdf to test it out and as I expected the brakes are a problem on the 3 different sets of 17" wheels I had to test... I would need to run probably a 15mm spacer to get it to work. It do go part of the way to fixing the scrub problem but I'm thinking if I go this path I might be better off fabricating new uprights and spindles rather then perservering with the holden ones as im still going to have to increase KPI to get what I want. Also with the holden uprights the flange is going to end up right at the back of the hub which might not be strong enough as the hubs I have are not overly thick at the back, and it also means a lot of the front part of the hub is going to have to stick out thouch the centre bore of the wheel.

          Anyway now I'm doing what I probably should have at the start and am drawing up options in CAD before I do anything else. I'm trying to end up with KPI less than 12 degrees and scrub around 15mm.

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            #50
            My God, I did not see this coming LOL, I thought you liked Charades but I think there maybe a need for a rehab for this illness.
            GURU ENGINEERING PTY LTD

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              #51
              Yeah it is a bit of a sickness.... The count is now 5 including this one. Plenty of space for more though!

              Whiteys still going strong but is now multi coloured after wiping out a roo at 110.

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                #52
                jesus that's cool, subscribed!
                :)

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                  #53
                  I reckon you should have started with a G100, every one knows g200s are poo.
                  Looking good so far.

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                    #54
                    Perhaps consider 330 mm c4 corvette gransport front rotors? They are about 30 mm more shallow than the vr commode front rotors I run onte back of my car. They run my wilwood sl4 front calipers very close to back of rim spokes as you have guessed.
                    Unsure of my front scrub radius, but suffice to say it has a fair bit with no real issues so long as you hang onto wheel...

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                      #55
                      Originally posted by irsa76 View Post
                      I reckon you should have started with a G100, every one knows g200s are poo.
                      Looking good so far.
                      Theres not going to be a whole lot of original charade bits left in the end so I dont think it will really matter.... and the g100's look pretty shit.

                      Decided to go with the 320mm evo rotor and I'll just use spacers to get enough clearance. Will make new uprights to suit as the holden ones aren't going to work easily. Ended up with 12 degree KPI and scrub around 15mm, maybe even a bit less if I can make the spacer a bit thinner.

                      Have been playing around with the suspension in susprog3d but not really sure if what ive come up with is any good... it seems reasonable but i'm a bit surprised how hard it is to find solid guidance on what sort of numbers to shoot for for stuff. I think I have a good handle on the camber change but maybe i've gone a bit too far on the swing axle length as the roll center moves 140mm between full bump and full droop which can't be good.

                      Frt suspension 16_04_13.pdf

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                        #56
                        This is awesome as fuck

                        I really want to see this thing in action when it's done

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                          #57
                          Make sure you set Brakes up as a rear engine car, Large fronts and small rears are no good for you now, same with spring rates.
                          Will all be closer to 50/50 now.
                          GURU ENGINEERING PTY LTD

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                            #58
                            Much win in this thread

                            Rotary Mazda's??? Nah mate I don't know anything about them.

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                              #59
                              Originally posted by Supashake View Post
                              Make sure you set Brakes up as a rear engine car, Large fronts and small rears are no good for you now, same with spring rates.
                              Will all be closer to 50/50 now.
                              I've assumed a 40/60 F/R weight split and played around with few spread sheets to work out the brakes and suspension. Brake balance came out around 60-65% front assuming my guesses are right. Front brakes will be 320mm rotors with 6 piston wilwood calipers and the rears will be standard R33 front rotors and 4 piston calipers. Going to make an unboosted dual master cylinder arrangment so there will be scope to tweak it if need be.

                              Haven't had a chance to do much for months but I might take some time off work to get the front suspension done soon. Its a bit depressing to see all the other cool projects here progessing while spiders move into mine.

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                                #60
                                You should you slackass! even the Datsun is running under its own power....!

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