Trackwidth

[erikshallbetter]

Where do most of these TTB Broncos end up for outside track width.

In the 2006-2010 rule book it says stock width +/- 4". Where do they measure track width from? (i.e. Outside to outside? Wheel mounting surface?)

Thanks in advance for any answers.

Erik S

[retroblazer]

Last year's Class 3 SCORE Class 3 Donohoe FJ had to change its track width from +7" down to +4". Savage commented on the issue, but I don't recall exactly what he used as a true reference point.

[3amigo]

As I understand it trackwidth is measured from the center of tire tread to the center of tire tread. This is the way the manufactures measure it. Score would look at the published track width for a vehicle and base the +4" off of that.

[Grimm]

I always thought it was WMS to WMS. UH OH

[Blanco]

As I understand it trackwidth is measured from the center of tire tread to the center of tire tread. This is the way the manufactures measure it. Score would look at the published track width for a vehicle and base the +4" off of that.
That is correct!
I called SCORE tech on this awhile back & thats what they told me. :cool:

[erikshallbetter]

Thanks guys! That answers it!

[retroblazer]

Now I recall. It also reminds me of why I don't like using that reference. It makes it a little cloudy when there is a difference on what tire and wheel selection was an option for any given model. So wheel offset becomes critical. It means that possibly the Donohoe FJ could have become compliant by changing wheel offsets to make up for wider front arms. In that same respect how does it affect a ttb ? How much wheel offset will could be used versus how much wider can you make the arms?

[straightaxle]

Now I recall. It also reminds me of why I don't like using that reference. It makes it a little cloudy when there is a difference on what tire and wheel selection was an option for any given model. So wheel offset becomes critical. It means that possibly the Donohoe FJ could have become compliant by changing wheel offsets to make up for wider front arms. In that same respect how does it affect a ttb ? How much wheel offset will could be used versus how much wider can you make the arms?

In fact the FJ showed up with new wheels after only one race. I believe they advertised the arms they were using on their website as being 4" wider on each side. You're not going to gain anything doing this with a ttb, but could get a little more travel with a sla setup. With a ttb, you will only change the scrub radius a little bit, but on a sla, you will get a slightly longer half shaft that will allow a little more travel.

[erikshallbetter]

I wasn't really thinking of doint it, it was more food for thought. Everyone says the 4+ beams are not class 3 legal. I was wondering if you could make trackwidth running 4 over beams and a wheel with like 6 or 7" BS. I have not looked into any other clearance issues (i.e. brakes, shocks, ect.) to know if it was even possible.

[straightaxle]

You could probably make the trackwidth rule with 17" wheels and a crazy backspacing. Only reason I could see doing it was if you had a truck that was C3 legal every other way, and wanted to run it in a race. Otherwise it would be a complete waste of money on longer axles, more weight, etc. Of course if you brought it to SCORE, you would have to bring your own tape measure AND teach the SCORE tech high schooler's how to use it.....