Jacking Point Position with diffuser

[peterPan]

Hello,

I have a question about the rule B6.6.1 concerning the position of the Jacking Point. The rule states "[the jacking point] must be provided at the very rear of the car."

How is this rule affected by the exploitation of rule B12.2 (Location of Aerodynamic devices). If you build a car which has a diffuser "extending 305 mm (12 inches) rearward of the rear of the rear tires", must the jacking point be located at the rearmost part of the (space)frame (position 1) or at the rearmost part of the diffuser (position 2)?

[peterPan]

Hello,

I have a question about the rule B6.6.1 concerning the position of the Jacking Point. The rule states "[the jacking point] must be provided at the very rear of the car."

How is this rule affected by the exploitation of rule B12.2 (Location of Aerodynamic devices). If you build a car which has a diffuser "extending 305 mm (12 inches) rearward of the rear of the rear tires", must the jacking point be located at the rearmost part of the (space)frame (position 1) or at the rearmost part of the diffuser (position 2)?

[MegaDeath]

I think the jacking bar rule also states that it must be visible standing 3 feet away at a 60* angle or some specified height. So regardless, you have to make sure that it fits the "visibility" part of the rule whether the diffuser stick out 12" past the rear tires or not.

To answer your actual question, for the past two years, our jacking bar has been located directly under the diff, not extending past the rear wheels.

I think this would be one of the "Intent of the rule not the letter of the rule" scenarios.

[Tech Guy]

PeterPan,
As you said, the rule says now, it has to be "at the very rear of the car". Sounds clear to me. And MegaDeath is correct, the first bullet of 6.6.2 says the jacking point "must be visible to a person standing 1 meter (3 feet) behind the car". I believe the these changes were added a couple of years ago because some teams were putting mufflers and radiators behind and over the jacking bar so they could not be seen. The course workers need to see the jacking point to use it. So if the tech inspectors cannot see the jacking bar or it will not do the intended job, they will not pass it and won't give you a tech sticker. Simple as that!

So for teams who want an extra long undertray, the new rear aero rule is going to force the jacking point 12 inches further rearwards!

[Michael Royce]

I agree with the Tech Guy. I wrote the rules change adding the "very" and the visibility requirement, along with the need for orange paint for the 2009 Rules. I did it for exactly the reason the Tech Guy listed. The tech inspectors got fed up of explaining to the teams that if the corner workers could not see the jacking point and used the quick jack on a suspension member, a muffler or a radiator, then it was the team's fault, not the corner workers!

For those that do not know what a quick jack looks like, there are some photos of one and how it is used on the official SAE web site under Rules & Important Documents and Competition Operations.