<VV> Looking for a 1965 posi-traction differential --No further info needed.

[Scott Ralston]

I'm really impressed with the responses from this post on VV.  I did get info on available parts, but I ended up with more advice on why to keep the open differential (it was coded as a 3:55 posi but someone removed the posi).  I wasn't expecting those kinds of responses, but they are greatly appreciated.  Many of you have asked if I have had traction problems in the corners.  I do have a problem in one right hand corner and I do lose drive, but I'm tending to overdrive that corner anyway.  Otherwise I don't notice any other problems.  Because of all of the advice I've been given, I'm going to keep the open differential and not convert it back to a posi.  No further info on this post is required.  You've given me all the info I need.

I need to change in my head motorcycle riding vs. car driving.  With the rear engine, they are similar in many ways, but you have much more control and can change techniques on the fly riding a motorcycle.  I think in my head I'm still trying to drive the car like a motorcycle.

My motorized background is teaching intermediate to expert class club racers the finer points of high performance motorcycle track skills.  In that realm, you set the turn with with countersteering and trail braking, and the rest is done with throttle.  If you didn't get your turn-in and trail braking correct, most of the mid corner adjustments come from throttle.  Ideally you should be able to constantly increase throttle through the turn.  Go in slow and come out fast.  In the tighter stuff it helps to spin up the rear tire a little to "free up" the bike and help it turn in.  Maybe this is what I'm trying to get the car to do, but it's power isn't enough to break both tires loose with throttle like on a motorcycle. The other way to help turn in is to point your inside toe on the foot peg with your knee on the ground, basically manually pushing the rear tire loose. I'm not going to try that with the Corvair :)

Thanks for all your help, and keep the rubber side down.

Scott
  ----- Original Message ----- 
  From: Scott Ralston 
  To: Virtual Vairs 
  Cc: Scott Ralston 
  Sent: Thursday, October 25, 2012 9:36 AM
  Subject: Looking for a 1965 posi-traction differential 


  Greetings,

  My father-in-law (Bob Dunahugh) is rebuilding the entire drive train of my 1965 140hp 4spd convertible.  The cam timing gear let go, and when he got inside the motor there was significant damage from pre-ignition.  We have no idea how that could have happened without noticing it.  It's still a mystery.

  I have this car set up as a street/go-kart track race car.  Heavy duty springs and shocks, poly bushings everywhere, etc.  This car will have the snot beat out of it.  The goal of this rebuild is to NEVER have to pull the drive train apart again, so we haven't skimped on anything.  We've got about $3k in it so far for parts.  The differential has already been done, and as soon as the motor is finished it will all get put back together.

  I've been wishy-washy on whether to leave it an open differential or change to a positraction unit.  I need to make the decision quick.  I had Clark's identify the parts to switch my differential over to posi, and it was around $800 with one of the parts not available.  That's an insane price for what I'm doing with this car.  So I thought I'd post this on VV and see if anybody can help.

  Does anybody have a 1965 posi-traction differential they'd like to sell?

  Thanks,

  Scott Ralston