49 replies to this topic

[Ron Alan]

Please, what measuring process did tech use which was not repeatable???

Those mm's on the tape measure look like 1 blurry black line 

[Bench Racer]

Those mm's on the tape measure look like 1 blurry black line 

Ron, I'd like to know the process Brandon/tech/SMAC used. I'd like to know the variance of their dimensions. Hard to improve a process without knowing the process

[Jim Drago]

Ron, I'd like to know the process Brandon/tech/SMAC used. I'd like to know the variance of their dimensions. Hard to improve a process without knowing the process

Rich powers documented early on, I believe in this thread

[Tom Sager]

Make 24mm offset wheel with no spacer the max allowed width.  Going any wider does not offer any benefit to class as has been stated by others.  Have a heart for the ball joints and bearings that are doing their best to hang on. 

[Steve Scheifler]

Make 24mm offset wheel with no spacer the max allowed width. Going any wider does not offer any benefit to class as has been stated by others. Have a heart for the ball joints and bearings that are doing their best to hang on.

That leaves the NA with significantly less max rear track. Would you permit an update of the rear upright, or spacers to equal things out?

[Johnny D]

That leaves the NA with significantly less max rear track. Would you permit an update of the rear upright, or spacers to equal things out?

 

Isn't smaller the offset number the more the offset is ?

30mm is less offset than 25mm correct ?

J~

[Tom Sager]

That leaves the NA with significantly less max rear track. Would you permit an update of the rear upright, or spacers to equal things out?

Alright, spacers on the rear only to equalize track with NB's.  

[Ron Alan]

That leaves the NA with significantly less max rear track. Would you permit an update of the rear upright, or spacers to equal things out?

Currently the max track width front and rear is the same on all cars. Steve makes a good point a max offset wheel# would change this. Currently you can run 25mm wheels with 5mm spacers on the NA to get to max width. I will let someone else comment if this is a benefit or not!

[Jim Drago]

That leaves the NA with significantly less max rear track. Would you permit an update of the rear upright, or spacers to equal things out?

 

I dont see anyone against this.. I am certainly not.   Allow all cars the same track, if that means NA cars get an extra spacer, thats fine by me as well

[Bench Racer]

 

 

The rule change proposal as written was an attempt to get away from the 1450mm Frt/1475mm Rear Track width specification (which is not easily measured at the track in an efficient an accurate (i.e likely not to be disputed) manner.

 

 After thoroughly reviewing the GCR definition I came to the conclusion that I already had the perfect tool to easily and accurately (within 1 mm) measure the front and track width of our car.

 

Per the GCR, the definition and a method by which track is measured is provided in Appendix G. Facts, Formulas, and Measurement Standards.  Measuring Track is defined in paragraph 4. and reads as follows;

"Track is the distance between the centerlines of the wheels as raced, without driver, measured at a horizontal plane through the wheel hub centerline.  Alternately, it may be measured from the inside of one wheel at the hub centerline height to the outside of the other wheel, then conversely from the outside of the first wheel wheel at hub centerline to the inside of the second wheel.  The 2 dimensions obtained are to be added together and divided by 2 to obtain the average.  Measurements are to be taken at both front and rear of the wheels and averaged to compensate for toe-in/out. Under certain circumstances it may be preferable to measure from the outside of one wheel to the outside of another and from this dimension deduct the thickness of one wheel. This should be repeated 180 degrees opposite to the first measurement and the two dimensions averaged."

 

The device I've see used in the CenDiv is a take off of a toe stick. Two probes bent in the same direction
(to reach around tire bulge), one fixed to a square tube, the other probe slides along the square tube.
There is a fixed measuring scale which the sliding probe passes over with a clamp to secure after
measurement is complete. Measure from outside of rim to inside of rim at horizontal center.

 

Dave Wheeler, do you have a contact number for Dennis tech guy? Going to borrow CenDiv/may be Region track width tool and see if accuracy/repeatability is within 1mm or .040 inch.