Heard that these are necessary to run larger (17 or 18") wheels on our cars. How come? What do they do? How much do they cost? What's involved in installing them? Anyone have a set kicking around they want to get rid of?

TIA!

 

Don't know about the wheel reason but they are 75 bucks a piece. So bump for an answer to the wheel question.

 

$75 from the dealer, or can you source them from Paragon or the like?

 

lol...that IS the price from Paragon. 74.67. each.

 

All I can say is that they are needed when running larger wheels. I think that it is because of the extra strain put on the wheel bearings maybe? Or maybe thats when you lower the car, lol. I am not sure. But they are very easy to install. Just be sure not to overtigthen them. I have heard of people having problems when they overtighten them and strip out the nut that is inside the frame. Other than that, it is very straight forward.

 

Installation is straight forward. Mark the current location of your castor blocks to preserve alignment. Remove the two bolts holding it to the car and the one large nut on the end of the a-arm. Say 30-45 min per side if you take your time?

The stock bushing has a ton of rubber and the increased leverage of the 17" rim will put extra strain on it causing the rubber to crack or deform badly. I'm not sure why Porsche sees it as a safety issue, but I got mine from Sunset Porsche for around $45 each.

 

So I'd need 4 of them, one for each corner, or only two for the front? Does it matter that the 18" wheels I'm putting on weigh less than the 16's the car came with? Less unsprung weight, so less stress?

 

FWIW I've been running 18's with stock caster blocks for a good while now. Replaced the original 1986-vintage blocks few years ago (they were completely busted by then) with similar new ones and it's been working fine.

The 968 block is superior no doubt but it's not like you absolutely have to have them right away when upgrading the wheels.

You need two, one for both front control arms. The caster block is essentially the piece that mounts the rear end of the control arm to the car body.

 

I upgrade to 968 blocks even with stock wheels - they reduce the alignment change when cornering by a significant amount.

Sam

 

Can you order online from sunset? When I was looking a while back, all where around $100.