wilmywood8455 - 01 October 2008 08:27 PM

What I still (forgive me) don't get, is that the very presence of the blocks, and them hitting the ground first, keeps the plank from wearing. That seems to defeat the purpose of the plank. The wear on the plank is cut down by the blocks hitting first.

The FIA suggests that you can't wear the plank, as getting the car low enough to wear away 1 mm of the plank means it's no longer legal. The block help keep the plank off of the road, keeping the wear to a minimum, therefore keeping the ride height above the non-legal minimum. They could also have used training wheels.
In short, if the blocks keep the plank off the road, they also keep the chassis above the legal minimum, so what's the issue? The plank is safe, the car is high enough.
It doesn't 'defeat' the purpose of the plank, it defines it.

It seems that the FIA is the only group that whines about this-ALMS and Le Mans prototypes have to use a jabrock plank that's 20mm thick, and the ACO's and IMSA's rules that the plank has to be at least 15mm thick at the start of the race, and isn't checked for legality afterwards.

If the FIA is so concerned about this, make 'em run 20mm thick jabrock under there.

I think the point WILMYWOOD is trying to make is that without the rub blocks they would need to run the cars higher to insure against plank wear. The rub blocks work as sort of a suspension stop by keeping the plank off of the track, especially where the momentum of the car hitting a bump and compressing the suspension and the tires would carry the car too "deep".

fastone371 - 05 October 2008 12:07 PM

without the rub blocks they would need to run the cars higher to insure against plank wear.

Run the car higher, stiffen the suspension use rub blocks; all good ways to keep the legality plank within spec. The latter just seems to be the fastest of those three solutions.
As an engineer, I'd have to side with the folks that have gone with the fastest solution.

Why then, at places like Eau Rouge, do we see plank smoke and not sparks? Shouldn't the blocks strike the track before the plank?

ClutchMaster - 05 October 2008 09:54 PM

Why then, at places like Eau Rouge, do we see plank smoke and not sparks? Shouldn't the blocks strike the track before the plank?

The plank is made out of Jabrock, a composite wood (added composites to make it stronger). It is extremely resistant to abrasion and can take an large amount of sanding and pounding to even move a .01 mm of the surface. Eau Rouge is only momentary contact. It may take a full lap of touching the ground at spa to even graze the surface of it. The wood, by itself doesn't spark, only saw dust will be visual. It is the rub blocks that spark.

I thought that the FIA mandated materials similar in weight and density to marine plywood-jabrock is much heavier and denser than plywood.

Chernaudi - 06 October 2008 10:40 AM

I thought that the FIA mandated materials similar in weight and density to marine plywood-jabrock is much heavier and denser than plywood.

Yes it is, the "plywood" construction is made up of composites, layered along with the wood..

I'm of the same opinion. I don't remember the rules permitting anything other than the action of the tyres/wheels/suspension from preventing the jabroc legality plank from contacting the track surface. I thought by 94 they had removed the sparking rub blocks when they narrowed the undertrays?

I was puzzled at that. Could Charlie have secretly issued a "Changing Track Condition" dispensation due to the bumps? Or can someone point at chapter and verse in the technical or sporting regulations giving them a permit?

Though not surprised about the blue exhaust gas glow when not occasionally backfiring.

T2 Cadillac ··············_________············______···········______·····____···__·_·


...name that F1 part...