Rear axle set up question(s).

[deadlew]

Just picked up a cheap 89 Firebird with the intentions of LSR.  No lofty goals yet.  Just make it safe and have fun with it.  Since the rule books aren't available till March, I need to get a couple of questions answered about the rear axle, brakes, wheel studs, wheels and so on.

What are the requirements for rear axle?  Are C-clips not allowed, semi floater minimal equipment, type of diff (locker, spool, lsd), size and length of wheel studs.

Front end? what size wheel studs/length and any other suggestions.

Wheels requirements?  I know about the speed ratings, what wheels are required/recommended width?

Thanks for the info.

PaulC

[Milwaukee Midget]

Greetings, Chief -

Thumbing through the SCTA book, we're looking at this.

C Clips are NOT allowed (Section 2.E).
Spool, locker or open diff - doesn't matter - whatever works best for you.
If the class you're competing in has a record of over 200 MPH, you'll need 1" studs.
No acorn nuts, only open ended wheel nuts.
5 studs required.
Narrow wheels and tires give you the least rolling resistance, but most speed rated street tires are wider than you'll probably want.
Avoid Magnesium wheels - see the rule book.

I suspect you didn't get any replies to this point because we'd be typing out the rule book for you.  I've condensed it for brievity, but once you have the book, all of these questions will be answered.  All of the points you brought up are important, and I hope this helps.  Welcome aboard!

Cheers!

[Stan Back]

MM --

1-inch lug nuts (not 1-inch studs).  Let's not scare him away.

Stan

[hitz]

  That is always confusing. The lug nuts have to be 1" across the flats or better yet "they fit a 1" hex socket. If the record in the your class is over 200 mph, you need 5 wheel studs at least 1/2" diam. to put them on. A minimum of 5/8" of the nut thread mus be engaged must be engaged with the wheel studs. Make it easier on the inspector and have a thread showing out of the nut. Over the 200 class and the requirements change for the wheels too.

  I haven't been through inspection yet but still worry that I might miss something. Hope to get the car inspected this year.

  I find something else to look for every time I read the rule book.

  Good luck.

  Harvey

[Milwaukee Midget]

Thanks for setting me straight on that - The rule book's tough enough without me misinterpreting it for others.

Yeah, now that I think of it, 1" studs would fall into the John Deere category.

And another racer clarified the 5 stud issue with me personally.

See, this is why it took so long for deadlew to get a response - everyone's waiting for someone else to step in it.   

[Sumner]

  ................. If the record in the your class is over 200 mph, you need 5 wheel studs at least 1/2" diam. to put them on...................Harvey

Harv not exactly right as far as I know.  You only need the 5 wheel studs if your wheel is over 17" in dia. and/or the tire diameter is 29 inches or greater.  I called John Bjorkman who has been the Special Construction Category Chair last night to make sure and he said that is the correct interpretation of the rule.  I have worried about this as my rear end is basically a Datzun Z IRS rear with 4 lug wheels.

If someone thinks otherwise I would sure like to hear from you,

Sum

[hitz]

 
  Sum -- Your right the rules don't say you have to have 5 studs if you are running smaller wheels. It does say you have to have 1" lugs so I guess you can have 2 studs and be legal.

  You did the right thing calling John Bjorkman. He's top notch help when you need it. Sorry, I didn't mean to get you worried. I type very slow but I even think slower.

  Carry on, only 176 days till speed week.

  Harvey

[1212FBGS]

if your plannin on runnin faster than 200 ya better have 5 if them hex thingys..
kent

[Sumner]

if your plannin on runnin faster than 200 ya better have 5 if them hex thingys..
kent

Is that a requirement or a good idea??

Sum