Jump to content
HybridZ

clarkspeed

Members
  • Posts

    840
  • Joined

  • Last visited

  • Days Won

    29

Posts posted by clarkspeed

  1. I used a more simple and elegant design that I blatantly lifted from this website.  I slightly modified Tube80's design using a stock control arm from page 4 of this old rear control arm design post.  Used a 3/4x5/8 rod end for the forward one.  I recently sourced some oil impregnated bronze bearings for the inner pivots instead of polyurethane which falls apart if you get oil on it .  Works well and my rear RC is where I wanted it anyway.  Being able to adjust rear toe transformed my car, it went from a darty unstable handful at 120+mph to rock steady at 140 on the banks of Daytona with one hand out of the window waving to the crowd.

     

     

    http://forums.hybridz.org/topic/62776-yet-another-rear-control-arm-design/page-4?hl=%20rear%20%20control

  2. The Bilstein P30’s work ok with the stock valving.  I ran a couple races with them before I had them revalved.  I really liked the “feel” of them which is purely related to their low speed performance in transitions.  I initially had them revalved 100/300 which was too stiff and killed the transitional feel of the car.  I then worked with a Bilstein engineer to revalve again based on my measured data. Turns out my current valving is not too far off the stock numbers.  My car weighs 2450# wet with me in it.  I think if you were around 2100-2300# the stock valving would be really close.  My comments are for road racing of course.

  3. Depending on what cam you have you may be chasing the fuel values. Under WOT you may find a spike at 2500-4000 rpm where the engine wants a lot more fuel under load. To counteract this with SDS I had to create a rich condition before the spike and then pull it back out after the spike.

  4. Wow, 13" rear rotor, really? I've taken rotor temps at the track and could not imagine ever needing anything close to that, especially on the rear.

    I think you may be missing my point, nothing wrong with upgrading brakes IF YOU NEED TO. But if you are going to spend $700-800 on an axle, why is giant better than just a little bigger? All those big brake kits sold could be even lighter if sized more reasonable. Every pound counts out on the corners.

  5. Keep in mind, tires make your car stop, not the brakes. I havent posted that in awhile. Kits with 12" rotors and Wilwood calipers are pure overkill, and having designed a set for myself using smaller and lighter components, I can say it is not cheap going the Wilwood route, regardless of size. I haven't purchased from them, but the Silvermine stuff looks attractive to me for anything under 150mph.

  6. I never knew that phenomena existed or ever thought about it. You would that SAE and automakers would have plenty of data on the subject.

     

    As far as cooling, I run a Ford double pass radiator with the oil cooler mounted in front of it. After I sealed off the front, my water temps went to 150 at Daytona on a 95 degree day. I installed another 190 thermostat with 1 hole drilled instead of 2, blocked 1/2 the grill, and got the temps rock steady at 190. I have been taping off the grill to block as much air as possible from going into the box and still keeping the 190, barely. However my oil temps have remained steady this entire time at around 240-250. They seem independent of water temp.

  7. I was running stock efi and cam in an 82 ZX with a ported out 75 manifold. Everyone who drove it was amazed at the power it had.

     

    I would keep the compression low and run cheap gas for daily driving.

  8. That's a good set up. I built one to drive 140 miles a day with a P79. Just fresh engine, blended the ports into the valves, port matched the manifold, weber big throat, headers, 2-1/2 exhaust with cheap 3" Catalytic converter. Ran like hell on 87 octane. 23mpg.

  9. I sprayed mine with a gun and industrial paint. Didn't prime first and still get a lot of chips in it. But you don't need expensive paint since UV protection is not an issue.

     

    Painting a cage is the hardest thing I have ever painted. Impossible to keep the gun distance even, get 360 degree tube coverage, while paint is blowing back in your face. You will not want to do multiple coats. Plan on taking some time to do it. Powder coating is the way to go for pro results.

  10. Not trying to derail this thread but a number of us in the NW were running around 3 hz with the front 5 to 10% higher.  What was odd to me was that as we started to develop setups that were mostly spring and little to no bar we didn't need to change much with grip changes.  When we ran more bar and a lot softer in the springs we'd have to chase the track.  And when it was cold or wet the bars had to come off and often the car wasn't very much fun to drive.  

     

    I got this chart from Eric Purcell a number of years back.  When I first heard about it I thought people were smoking something.  But having tried this it's worked very well for me.

     

    Spring rate based on corner weight.

    Sedans and radial DOT tires  -- .5 to .7 

    Production and light GT cars -- .8 to 1

    Medium weight, 200 to 300 HP cars GT cars -- 1 to 1.3  (FP)

    Heavy high HP GT cars -- 1.3 to 2 (XP/EM)

     

    Hope this helps,

    Cary

    Not sure I understand.  Wouldn't motion ratio factor into this? 

     

    Interesting that the spring rates go up when the tire spring rate goes up.

×
×
  • Create New...