vdar

Hi everyone,

I had just dropped off my GT4 this morning for a basic track suspension setup including toe links, front monoball camber plates, corner balancing etc. The owner called to say they didn't have the camber plates in yet because the part was being re-designed to include caster adjustment as well and would not be available for another couple of weeks. I know it's a popular upgrade and was wondering if anyone else had heard about this. Couldn't find anything on Tarett's website yet either... just this part that a lot of people already have/recommend:

http://www.tarett.com/items/986-987-...9#ITEM_7054732

thigos

Interested in this as well. I was about to order the set shown in your link.

ShakeNBake

I don't know about this iteration, but I'm not surprised. Caster is a very important adjustment and the position of the top of the strut will change it. The position on an axis that is perpendicular to the camber adjustment was fixed before, but I can see how they would add the ability to allow for adjustment.

The first generation of camber plate had an unfavorable strut top location for caster on the GT4 - it removed caster. Tarett revised it to help maintain caster. Now they appear to be allowing you to adjust it, which is probably helpful if your other degrees of freedom for adjusting caster (thrust arm bushings/thrust arm/shims) are limited by a constraint such as the wheel's forward position in fender.

Alan C.

I've seen adjustable camber/caster plates for other cars. Not a bad idea to have them.

Tarett Engineering

To avoid any confusion, here's a little history and update on our 991/981 camber plates. We have two very different camber plates for the 991 and 981. Our Club-Sport design is compatible with the standard OEM struts and similar designs like PSS10’s and JRZ RS Touring’s, and our Race design that works with the GT3/GT4 and other race style coil over kits. We determined that two different designs would be needed to optimize the designs, and avoid compromises that we did not want to make.

The basic idea was to add more camber and keep the caster the same, just like we’ve done on previous camber plates designs over the years. Both designs added about -1.1 degrees of camber, and were a nice improvement over stock. We’ve been selling them for a while and everyone liked the increased camber they provided, including GT4 customers. The GT4 came along after we did our original design, and their plates had added caster, but with the camber still unchanged. Next, the RSR came along with both camber and caster added. Working closely with several race teams, we decided that adding caster too would provide an additional improvement to the design.

The camber and caster increases are hard machined into the plates. Camber is still adjustable through the slots in the chassis, and caster is fixed in the plates, similar to the RSR design. Due to design constraints, we were able to squeeze a bit more camber and caster into the Race design verses the Club-Sport design, which was appropriate considering the different applications. We’ll have more details of the actual amount, listed up on the website shortly.

The new design has been implemented on the Race plates for a while now, and it has worked out well. We just recently revised the Club-Sport design to include the caster addition as well. We are currently out of stock for both the Club-Sport and Race designs, but are just now finishing builds of both and expect to have them available to ship tomorrow.

Hope that explains and clears things up. As usual, please always feel free to contact us with any questions.

Thanks!
Ira

Mech33

Thanks. How much caster gets added on the GT4 with the race plates?

ShakeNBake

That clears up a lot Ira. So you're saying the GT4 plates (race) have not been updated since last summer right?

We're liking the revised plates that have the increase in caster. We put them on last summer and got the alignment much closer to where we wanted it.

ExMB

The term "increases the caster" has me confused. An increase to me means that the angle increases. But isn't an angle increase the cause of rubbing. Wouldn't it therefore make more sense to reduce the caster (angle) with increasing camber to keep the wheel centered?

Tarett Engineering

That's a good question. If you increase the caster from the bottom (LCA), then it moves the wheel forward and can cause the rubbing issue you are describing. Increasing it from the top (camber plate) will move the wheel back, like the GT4 and RSR plates do.

Ira

Tarett Engineering

Correct, We've only done the one upgrade, and it was in July of last year.

ExMB

Thanx.

And now for the catch 22.

Since the top only gives you so much you will need to add at the bottom to increase your "go to" camber.

How much caster angle change does your top give for max camber its designed for? Unless that is too proprietary.

vdar

Ah the power of Rennlist. Thanks for the detailed info Ira. So the rev to the club sport version with built in increased caster in addition to the previous -1.1 camber is what's new. Looking forward to having them on my car soon!

jreifler

Sorry to revive, but have been sitting on a pair of the Tarret Clubsport plates for my GT4 and wanted to install this weekend. Looked around and haven't found any good instructions or installation threads. I'm sure it's relatively simple, but would love some backup.

Thanks!