GT3 LCA Build

[Robert986]

Originally Posted by Quadcammer

Im installing a set of these right now. Nice pieces with endless adjustment

Nice stuff, but what the heck do they mean by: " this no compromise design the center geometry can also be adjusted to correct for lower ride heights."

On McPherson, when ride hight is lowered beyond the point where the LCA are vertical you will get a positiv (not good) effect on camber, also the roll center will become higher.
How will those Tarrett control arms compensate for that, Idon´t see that it is possible.

Educate me..

[jaykay]

Originally Posted by Robert986

Nice stuff, but what the heck do they mean by: " this no compromise design the center geometry can also be adjusted to correct for lower ride heights."

On McPherson, when ride hight is lowered beyond the point where the LCA are vertical you will get a positiv (not good) effect on camber, also the roll center will become higher.
How will those Tarrett control arms compensate for that, Idon´t see that it is possible.

Educate me..

I believe they are referring to roll centre. I have not reviewed the component or its adjustments but you would have to be able to change the position pivot (up or down) points to affect roll centre position.

No one ever talks about this adjustment but theoretically it will have a massive influence on a vehicles handling during cornering as it is essentially the roll axis of the vehicle. Its position relative to the CG is what is critical. You want to aim the arm such that the roll centre is closer to the CG. This will yield a reduced roll moment.

Edit: I just had a look and they do mention roll centre at the very end of the description; I cant quite see but I would think the pivot position adjustment would some how be incorporated at the outboard end with a spacer of some sort

[P_Carfahrer]

I am getting close. Everything is done but the inner bearing housing. Starting to cut them this weekend hopefully.

Outers/Inners are 7075-T651 with FK Com12T-F1 spherical bearings. All bushings are 4340 which along with fasteners I will nickel/cobalt plate and relief bake. The outers are modeled directly from stock 996 GT3 arms incorporating spherical bearings with one additional stiffening rib on the under side between the thrust bushing and bearing bore. Outers will be hard anodized black with the inners hard anodized red and blue.

Outers incorporate 14mm hardware.

Shims are hard anodized 6061 aluminum.

Thrust bushings are hard anodized red/blue and have 1/4" drive holes to use to rotate the bushings for caster adjustment.

Some pics.

[Gilles]

Originally Posted by P_Carfahrer

I am getting close. Everything is done but the inner bearing housing. Starting to cut them this weekend hopefully.

Outers/Inners are 7075-T651 with FK Com12T-F1 spherical bearings. All bushings are 4340 which along with fasteners I will nickel/cobalt plate and relief bake. The outers are modeled directly from stock 996 GT3 arms incorporating spherical bearings with one additional stiffening rib on the under side between the thrust bushing and bearing bore. Outers will be hard anodized black with the inners hard anodized red and blue.

Outers incorporate 14mm hardware.

Shims are hard anodized 6061 aluminum.

Thrust bushings are hard anodized red/blue and have 1/4" drive holes to use to rotate the bushings for caster adjustment.

Wow, these control arms look beautiful, exotic, and expensive..
How is their weight compared to the GT3 arms?

[P_Carfahrer]

Originally Posted by Gilles

Wow, these control arms look beautiful, exotic, and expensive..
How is their weight compared to the GT3 arms?

Machined aluminum like this is to me what diamonds are to women. I can't stop looking at it.

Cost has been a few hundred bucks for material and pizza and beer money while with my friend at his machine shop over some nights/weekends with plating in my garage and for you Gilles half price.

Weight should be comparable to stock but I don't have the stock arm anymore as I borrowed it to make the models and can't find where I noted how much they weighed. It might be a little more with the bottom outer misalignment spacer.

Next builds after LCAs are done and ready to go.

[P_Carfahrer]

Look what Halloween raised from the dead....

I was able to get to the last NASA event at Utah Motorsports Campus a few weeks ago and it was awesome to see cars and hang with great people.

It has now been a year since I was really on the forum. Winter projects and skiing with the kids consumed my time until mid March. Since then dealing with Covid in my business has been a like adding a second job to my work and I essentially put everything on the shelf from then on.

Well, attending the last day at the track this year has served as a bit of a renewal of sorts to get everything done and on the track next year. Covid be damned...

Before Covid hit I finished the LCAs and they have sat on my shop shelf.

I also finished the toe-control arms and caster arm forks. Tie-rods are almost done.

Here are some pics of the finished LCAs. As soon as the snow flies here, the car is going up on stands and the tear down and rebuild begins. Blue and red represents a sample of the sets I built. The blue has a 10mm spacer and the red has a 15mm spacer.