We rebuilt the rear axles in my M3 - probably had right at 300,000 miles on it at the time. It was either $200 for the rebuild kits or $1200 for replacements.
You could tell there was some wear on the cages and bearings, which there should have been at that point, but nothing that looked or felt worn.
Based on that experience, I would say the only reason the cages may get modified at all is to make the reassembly, especially on the blind, or closed axle stub end, easier.
My early thought is the rule was exploited though I'm not convinced it created an advantage, but my experience is no wear would open up the cage enough for a bearing to pass through. To be fair, the Miata joint could be a different enough design.
And I can't imagine having to drag a tub onto the open trailer to get the race car home.
#39 CMC Camaro
Orange is Fast!
CMC-NT01 FTW!
Anyone know if this was a true competitive advantage over stock parts or just simply not stock parts?
James Proctor
http://www.jp-motorsports.com
Wow...All the issues with the dyno sound pretty good right about now.
On the mazda racers forum someone referenced an SAE paper that measured efficiency of these types of ball joints at 99.5% at 5 degrees angle. Not sure how much angle an SM puts on these but in any case it aint much.
Al Fernandez
Yeah maybe .13 hp. Maybe they had larger ball bearings? I did read that guys long post last night and it was interesting. You can reman or get reman axles but there isn't a spec on what can be done. Would love to know if it was an actual witch hunt and what the SM communities opinion is of all of this. If I remember even the winner had a DQ for the axles. Good point was asking did the subsequent winner get his axles checked and the same teardown?
Does anyone know why they even send the Miata's to the dyno? I thought it was basically an unlimited class as far as power and why they spend so much on drivetrain.
Guess a little different tech than dealing with quarter glass windows.
Bryan Leinart
CMC #24
Danny (official winner) put his tub in the trailer with a forklift. Sooo yah he got scrutinized too. But here is SCCA’s response since the runoffs are a couple weeks out.
https://dk1xgl0d43mu1.cloudfront.net...pdf?1538744727
“A man with no enemies is a man with no character.”
― Paul Newman
Now the tinkering begins in earnest...
#39 CMC Camaro
Orange is Fast!
CMC-NT01 FTW!
I've never thought I'd ever give the SCCA praise over doing something better than NASA, but wow, in a few short sentences they just called NASA out on their BS:
Given recent events, the SCCA CRB makes the following change to the GCR effective
immediately for the remainder of the 2018 Spec Miata season. The CRB acknowledges that
Spec Miata OEM, re-manufactured or rebuilt axles do not have a published specification nor
are the axles a serviceable item. As a follow-up the CRB has asked the SMAC to provide a
recommendation for 2019 for Spec Miata axles.
Add to section 9.1.7.C.2
“i. The half-shaft CV Joints shall be an OEM or OEM equivalent part. The internal cage and
bearing dimensions are unrestricted. This rule is effective until 12/31/18.”
Bookmarks