Spirit of South Dakota Lakester

[SPARKY]

      If you listen to a lot of Patsy Cline songs you might end up with clinical depression.       I love her voice but the lyrics are depressing

I agree with you assement of PC---most of George "NO SHOW" Jones stuffis the same!!

I call it "whiney gri-nee,  you done me wrong" --beer joint songs 

[Tman]

trent, is someone taller than you going to be driving?  if not then you might consider bringing that front hoop down a smidge.  maybe one o.d.'s worth at the flat section between the two bends.  looks like you've got plenty (too much) room to work with.

hate to see you waste tubing but i think a full mock up of spare or scrap material may help you to see how much room you really have.  i usually build a mock up cage piece by piece, bend by bend out of cheap exhaust tubing.  then take your finished multi-piece section over to the bender and copy it with the real material. 

just a thought.  looks good nonetheless.

My brother is a touch taller and we are looking to run the ISP padding on the sides and above the helmet. That said, there is always a reason things are only TACKED. I would like to drop it a couple inches, may just take you up on that since we have room to spare under that plywood. Thanks

[Tman]

Got the front wheel hoops today, MAN ARE THEY NICE! As I was tapping the centers in I realized I could control backspacing and get my scrub radius (something I read on here) better. That is if I knew what teh hell it was about. Did a search, think I know what I am doing but not going to tack these together until I got a good grasp on the concept. Anyone?

[Geo]

Yep, just did mine this summer.  Chalk marks all over the floor. Found the answer to a twenty year question I had as to why the first few years of production called for toe in rather than toe out for all the later years.

There is a line that goes through the piviot points of the front upright.  Spindle rotating line with ball joints or kingpin.  This somewhat verticle line intersects the ground (floor) plane.  The scrub radius is where the centerline of the wheel (tire) meets the floor and if it is inside the piviot point floor intersection at the same point or outside the piviot intersection point.  Seems to not matter unless parking without power steering (no matter to me) or braking!!  That matters a lot.

As you have found it may be easy to set and adjust if you get the wheel center backspacing figured out.  Place the car at ride height.  Run something like a straight edge, length of rod, string along the top to bottom balljoint and on to the floor.  Mark this point.  Place a verticle straight edge on the hub face and mark the floor. See how close you are to the piviot mark. Mark the inner and out points of the wheel width on the floor at positive or no scrub offset or negative offset.  You will now be able to figure the wheel center placement or wheel offset.  Make adjustments if you want to allow for spacer adjustment.

Geo

[Tman]

Thanks Geo, I looked at a sketch by hotshue and confirmed what I was thinking. Since I am building my own axle and wheels I should be able to kep it at Zero or reall darn close!

[landspeed55]

Sounds like you have been busy. Any up to date photos?

[Tman]

Sounds like you have been busy. Any up to date photos?

Nothing that looks any different. Will try and come up with a shot or two.

[JimL]

Zero scrub can sometimes result in "zero feel".  This pic shows typical rear drive scrub compared to typical front drive scrub.  If you choose zero scrub, you may have to put in more toe to keep linkage tolerance reactions in check (for rear wheel drive).  It can sometimes make for difficult steering decisions, when the front wheels are hunting different directions at the same time. 

This happens because the true scrub radius is never constant, unless you run on a billiard table.  If both are a little positive (while "pushing" the front wheels), you'll feel changes in surface drag and smoothness as true pull-feedback in the steering wheel.

This can be useful for the driver.

Regards, JimL

[Tman]

Thanks for that info Jim! nothing on the fronts is tacked, I think I will be a tad positive anyway looking at the components mocked up. Learn something new every day 

[Tman]

More parts pictures. Wheels in question going together.

Previsously posted



New hoops from Rally America, Jimmy Mclean



Fronts almost ready to tackweld, need the dial indicator this weekend. and a rear ready for my welder pal

[Tman]

What I did. I had one REAL nice set of 5x15 wheels. My QC uses wide 5 for the rear so I drilled out the rivets on my set of wheels and saved the 5" hoops for the new Bart wide 5 centers, they are OK centers but I would have been better off having centers cut like Hotshue did (had I seen his post beforehand!). So, 5" hoops for my rears with new centers. This left the Ford centers with 5.5 BP that I needed for the fronts. Since I could not find any good 5 inchers to sacrifice AND my M&H choice for front likes the 4.5s better, I ordered the hoops from Jimmy. Clear as mud? Sometimes checkbook hotrodding would be a heck of a lot quicker and prob cheaper!

[Peter Jack]

I've always liked somewhere between .250"and .5" positive to keep all the front linkages loaded, then use a bare minimum of toe in, especially with radials. The other thing to consider, although it's not really a heavy consideration in lsr is to ensure that if there is any bump steer that it goes to toe out in bump. If it goes to toe in it causes a continuing series of corrections leading to unstable handling.

Pete

[Tman]

Thsnks PJ, we are going rigid to start so should be no bumpsteer.

[Tman]

Nothing photo-worthy but the wheels are tacked and ready for final welding! Small victories but one item each time you hit the shop will see it through. I have the front and rear suspension mounts designed. They are modular and allow height adjustment as well as going from rigid to 4 bar. Time to buy more steel..........sounds like an ongoing theme!

[gas pumper]

Tman, does your wheel center to hoop need to be welded 360 degrees?   Or is that a detail related to the speed the car needs to be legal for?

Frank