Jay Griffin
Well-known member
Or more specifically, how would you ‘properly’ measure this in a tech situation?
My reason for asking is twofold.
First, I recently discovered that I have been running my car for the past several years at a narrower track width than I thought I was. Just made some stupid simple math mistakes. And I felt pretty stupid when I realized it too. So now I am striving to run it at, or near the maximum allowed figure.
Second, since I am also running the new Hoosier radials, I need to add quite a bit more negative camber than I ever did with the bias plys.
This, depending on where and how the track is measured, could potentially make the track width measurement appear wider than what the maximum allowance is.
It’s been several years since I have seen any track width measurements at any races here in the SEDIV but the last time I had it done the inspectors used a tool that measured from the inside edge of one wheel and the outside edge of the opposite wheel. This measurement was taken at or near the bottom edge of the wheel, closest to the ground. The only thing I see wrong with that is that when I set up my car (now) I start with the distance between either hub face at the horizontal centerline. Then, knowing what my wheel offset is, add whatever spacer(s) I may need to get the track width to my desired goal.
The problem with this is, if a tech inspector were to use the above described method to measure track width, it would measure beyond the allowed maximum. The amount over would be directly related to how much negative camber the car may be running. For example if it were -2.2⁰ with 13” wheels and 20.8” tall tires (according to Hoosier) I figured the track width would come out to be roughly ½” wider than what it would measure at the height of the wheel/tire centerline.
So, what do you think? I know how I think it should be done (centerline height) but I’m just one guy and not a tech inspector (even though I have volunteered to help in the past).
My reason for asking is twofold.
First, I recently discovered that I have been running my car for the past several years at a narrower track width than I thought I was. Just made some stupid simple math mistakes. And I felt pretty stupid when I realized it too. So now I am striving to run it at, or near the maximum allowed figure.
Second, since I am also running the new Hoosier radials, I need to add quite a bit more negative camber than I ever did with the bias plys.
This, depending on where and how the track is measured, could potentially make the track width measurement appear wider than what the maximum allowance is.
It’s been several years since I have seen any track width measurements at any races here in the SEDIV but the last time I had it done the inspectors used a tool that measured from the inside edge of one wheel and the outside edge of the opposite wheel. This measurement was taken at or near the bottom edge of the wheel, closest to the ground. The only thing I see wrong with that is that when I set up my car (now) I start with the distance between either hub face at the horizontal centerline. Then, knowing what my wheel offset is, add whatever spacer(s) I may need to get the track width to my desired goal.
The problem with this is, if a tech inspector were to use the above described method to measure track width, it would measure beyond the allowed maximum. The amount over would be directly related to how much negative camber the car may be running. For example if it were -2.2⁰ with 13” wheels and 20.8” tall tires (according to Hoosier) I figured the track width would come out to be roughly ½” wider than what it would measure at the height of the wheel/tire centerline.
So, what do you think? I know how I think it should be done (centerline height) but I’m just one guy and not a tech inspector (even though I have volunteered to help in the past).
I understand the info is on GCR page 173. My point is that in previous years when one looked in the GCR index under Measurement, one found "Measurement Standard" which directed one to the correct page for Measuring Track width. In the 20112 GCR nothing in the GCR index directs the reader to GCR page 173. If one doesn't remember where the info is from the previous year or if the GCR location for the information changes places again without the information shown in the GCR index will be required to hunt & peck to find the information. Or maybe I have the one queer GCR which is missing the index information for Measurement Standard. :roll: