Drawbar pull capability

[sportscarclinic]

Good to see he's got a shatterproof visor to protect that helmet, if the supercharger grenades.

 

[beenthere]

Has anyone hooked up a pull gauge to their drawbar to find out the actual pull?


A TBN owned pull scale sent out to trusted people and tested in a standardized way would make a pretty neat spreadsheet on here for future generations.

That information should be available from the Nebraska tests. Drawbar pull was one of those measurements in a "standardized" way.

 

[LD1]

^^This^^ Glad someone finally recognized that weight is a, if not the, key factor.

Weight was mentioned in post 12, 30, 31, 34 and 39. So seems to me a lot of people already recognized it.

 

[LD1]

View attachment 829521

Good to see he's got a shatterproof visor to protect that helmet, if the supercharger grenades.

You mean turbocharger?

 

[LD1]

I think the working load limit of most chain is set around 1/3rd of breaking strength, so those chains would probably have a breaking strength roughly similar to the strap.

Also, I think some strap manufacturers list their "breaking strength" as the webbing alone, ignoring the weak points that are where the webbing bends tightly around a hook at either end. I say this because I've noticed the same rating listed on the same straps, in both hook end and loop end. The stitching could also be a weak area, but I suspect most good brands put enough overlap there to ensure the stitching at least exceeds the strap strength.

Did your strap fail in the middle or where it goes thru the hook? If in the middle, was there prior damage in that area?

Straps WLL is 1/3 break strength. Chain is usually 1/4 though.

 

[WinterDeere]

Straps WLL is 1/3 break strength. Chain is usually 1/4 though.

I guess there's some variability in this, as the first reference I found cited chain at 1/3.

 

[rScotty]

I guess there's some variability in this, as the first reference I found cited chain at 1/3.

There's always going to be variability when it is science versus opinion.

 

[LouNY]

There's always going to be variability when it is science versus opinion.

Or different manufacturing facilities and different batchs of raw materials.

 

[WinterDeere]

There's always going to be variability when it is science versus opinion.

There's no science in setting a working load limit to breaking force ratio, only considerations of risk and liability. Collect breaking force data, analyze the distribution, determine whether you want to live under a 6-sigma or 3-sigma risk regime, and name the working load limit accordingly. Statistics is math, not science!

 

[sportscarclinic]

You mean turbocharger?

"Supercharger" is a generic term that includes both belt driven Roots-type and exhaust driven turbochargers.