What's up everyone,

I figured I'd post this here since there are quite a few guys in this forum that know about tires and alignments. I have 2nd Gen GS400 lowered on Tein Flex's and my tires are wearing excessively on the inside due to too much negative camber. My car isn't slammed all the way, but it's sitting right on top of the tire, not tucked. I just bought new Michelin Pilots for the front and prior to putting them on I'm considering buying the RCA lowering blocks: http://www.exactmotorsports.com/GScamberkits.html which supposedly allow you to get your alignment within spec.

Anyone have these and can confirm from personal experience that they do in fact work.

Thanks in advance,

Slo

 

Of course they work by the principles of physics and geometry.

But just because they're RCA blocks doesn't mean you can get back to "OEM specs". I only say this because there are far too many people who have high expectations of getting their 4" drop to align like a stock car. The amount of correction depends on how thick the blocks are (at least for the front).

I think EXACT's blocks is 3/4" thick. Imagine you've just raised your height by 3/4"...that's the amount of camber you'll have, except you'll be able to keep your existing height. In another words....

If I bought springs that lowered 2", and you are lowered 3" on coilovers with 1" RCAs, we'd have virtually the same amount of negative camber. If you are slammed like some people I know, RCAs will help, but it doesn't automatically fixed it 100%. But since you're not riding that low, these RCAs will help you out tremendously. It's sure a lot better than having excessive negative camber. The money you save on tires by getting the RCAs is totally worth it.

 

how much negative camber have you got? as everyone always says, toe kills tyres alot more than camber does, camber just decides where they wear out and focusses the wear more. Make sure Toe is set up as neutrally as possible relative to your drop.

 

Gsteg: Thanks, I appreciate the reply. Are there any other RCA's that are a little thicker than the ones from Exact? Only asking because I wouldn't mind buying some a little thicker to ensure that my alignment will be fine. On the other hand I should be ok since I'm not really that low.

Ant: Thanks as well, not really sure how much negative camber I have. I wanna say that it really wasn't too far out of spec. Hmm, what exactly do you mean by making sure that toe is set up as neutrally as possible relative to my drop?

Thanks again

 

I dont know anyone who makes thicker RCAs. There is a downside to having the block too thick. Your upper control arm will be hitting the fender all day long, and your suspension geometry will be way out of place. If you want to further correct camber, you need to resort to adjustable front or lower control arms. The original intent of these blocks was to alleviate bumpsteer due to the roll center being out of place. It just happens that you were able to reduce negative camber as a perk.

 

Ok, thanks for that info. I'm sure, well hopeful, that Exact's RCA's will allow me to adjust my camber to the point where my tires aren't wearing out so fast anymore.

 

wait a minute... lets think this through for a minute... how fast are your tires wearing???

was the car aligned at all since it was lowered? Has it changed at all since it was aligned last?

Reason being that excessive negative camber is bad, but it's not horrible... however, toe, is a very fast wear suspension angle... when you change a cars ride height, you also change the toe setting (most cars at least)...

If you have -2.5 to 0 degrees camber, you shouldn't be wearing tires all that fast... I ran -2.5 for two years and 30k miles on a set of BFG KDW's and they were not completely worn out when I replaced them... Here, toe is the key factor again...

 

Definitely. Toe is the biggest contributor to inner tire wear unless you're at extreme negative camber.

Make sure you get your caster arm bushings checked out. It's a common issue on 2nd gen GS. If your caster is changing all the time, your toe will be doing the same thing.

 

The last time I had an alignment was after I replaced the ball joints, tie rod ends and radius arms, so I hope that my suspension components are pretty tight. The tires wore out on the inside within just a few months. How can I ensure that my alignment guy is setting the toe properly?

Thanks guys

 

get a print out, ideally, watch him print out the specs... (sometimes, alignment guys will cheat the machine - its quite easy if you know how it works, but it's also quite obvious)

so long as you aren't driving 10k miles a month, there is no reason they should wear out in just a few months, even if the camber is as much as -3.0 degrees all the way around, again, so long as toe is good...

my money says toe was either out of spec, or at the high range of the spec, which is just as bad... it really needs to be within .05 degrees front and rear... most alignment machines will give you .10 or more and it still be "within spec" but the reality of it is that .10 on both sides is .20 total and that can be fast tire wear... might not be horrible on a car with not a lot of negative camber, but on a car with lots of negative camber, it is imperative that toe is spot on...

 

Lower ball joints can cause inside wear for the front tires. Just a thought.