BRZ lowered on RaceComp Engineering springs!

[Longhorn248]

Originally Posted by Draco-REX

Well, the car was likely driven through the winter. And besides.. How long are you planning to keep the stock exhaust?

The size difference between the stock and STI rear sways is crazy. A STI bar will be inexpensive, but will likely be really overkill without a matching front.

I love that RCE's camber plates fit! Those are beautiful pieces. I may have to pick up a set to compensate for the lowering. I'm not a fan of aftermarket camber bolts.

I'm a noob, do the lowering springs create negative or positive camber? How do the camber plates correct this?

[7thgear]

Originally Posted by Longhorn248

I'm a noob, do the lowering springs create negative or positive camber? How do the camber plates correct this?

A car's alignment changes when the car is in motion as it goes over bumps, makes turns, brakes, etc. How much depends on the suspension design, commonly referred to as "geometry."

A stock car is generally setup to have little static negative camber. If you lower the car without doing anything else then it's the same as if your car was constantly turning or braking or going over a bump. Ie, if you lower the car 2" without doing anything else, then it's as iff every single wheel has hit a 2" bump.

How it affects camber/toe/caster will be dependent on the car's particular geometry.

In the case of MacPherson struts, deviation from OEM typically creates positive camber, requiring camber plates, ball-joint extenders, lower control arm extenders, crash bolts, or a combination of those things.

Double-wishbone setups typically are not as sensitive to lowering from an alignment point of view, but there are other funky things that happen...

Erm.. hope that helps.

[Longhorn248]

So the camber plates from RCE will compensate for the positive camber and bring the wheels back to an almost neutral setup? I am correct in assuming that without adjusting for the positive camber created with the lowering springs you're going to get uneven wear on the insides of your tires?

[Draco-REX]

Originally Posted by 7thgear

A car's alignment changes when the car is in motion as it goes over bumps, makes turns, brakes, etc. How much depends on the suspension design, commonly referred to as "geometry."

A stock car is generally setup to have little static negative camber. If you lower the car without doing anything else then it's the same as if your car was constantly turning or braking or going over a bump. Ie, if you lower the car 2" without doing anything else, then it's as iff every single wheel has hit a 2" bump.

How it affects camber/toe/caster will be dependent on the car's particular geometry.

In the case of MacPherson struts, deviation from OEM typically creates positive camber, requiring camber plates, ball-joint extenders, lower control arm extenders, crash bolts, or a combination of those things.

Double-wishbone setups typically are not as sensitive to lowering from an alignment point of view, but there are other funky things that happen...

Erm.. hope that helps.

^this.

The front suspension has a single control arm. And in the MotoIQ review, we found that the control arm is pretty much parallel with the ground at stock ride height.

So to better picture what happens when you lower the car, hold one hand out in front of you, parallel with the ground, with your elbow at your side. Now raise your hand upwards by bending your elbow. Your hand comes closer to you as your arm swing upwards. The same thing is happening when the tire hits a bump or your lower the car. Since the wheel and strut are fastened to each other, the only other pivot is at the top of the strut. So if you pull the bottom of the strut closer to you, it tilts outwards, hence positive camber.

The way to fix this is to tilt the top of the strut in towards the center of the car, so that the wheel ends up back where you want it. That's what camber plates do. They let you move the top pivot to tilt the tire back in towards the car to get more negative camber than you could normally get.

The trade-off is that camber plates use spherical bearings instead of rubber bushings, so you get more road noise (NVH) and bumps feel harsher.

[Draco-REX]

Originally Posted by Longhorn248

So the camber plates from RCE will compensate for the positive camber and bring the wheels back to an almost neutral setup? I am correct in assuming that without adjusting for the positive camber created with the lowering springs you're going to get uneven wear on the insides of your tires?

Camber isn't what eats tires, for the most part. It's Toe.



My STI has -2.5 degrees of front camber, but 0 degrees toe, and my tires are fine. Now, combine high camber with high toe and they'll get ground down like cheese on a cheese grater.

It's interesting that the BRZ's front wheels come with 0 camber from the factory, and yet it has so little understeer. I think it'll take very little camber adjustment (-0.75) to dial out any initial understeer and turn it into a grippy monster.

[Dave-ROR]

Originally Posted by Draco-REX

Camber isn't what eats tires, for the most part. It's Toe.

[dsgerbc]

And I had -2.5 degrees of camber on my spec.b with zeroed toe and the tires took a beating pretty quickly. I wouldn't DD anything with over 1.5 degrees of camber, if I cared about tires.

Lol @3in drop. Way to fuck up the handling. Then again, the 'slammed' crowd doesn't care about that. Inexpensive roll-center correction kits (like sold by Whiteline) barely correct for half an inch out of the 2-3" drop. So with WL RCK or without you're up for one hell of a bump-steery ride. Kits that correct for more are out there, but are expensive and less durable.

[Dave-ROR]

Originally Posted by dsgerbc

And I had -2.5 degrees of camber on my spec.b with zeroed toe and the tires took a beating pretty quickly. I wouldn't DD anything with over 1.5 degrees of camber, if I cared about tires.

Lol @3in drop. Way to fuck up the handling. Then again, the 'slammed' crowd doesn't care about that. Inexpensive roll-center correction kits (like sold by Whiteline) barely correct for half an inch out of the 2-3" drop. So with WL RCK or without you're up for one hell of a bump-steery ride. Kits that correct for more are out there, but are expensive and less durable.

My street car has -2.7 up front and -1.9 in the rear. Currently have about 50% life left on AD08s with about 15,000 street miles and a handful of autocrosses and a few sessions at CMP on it.

You sure there's not something else going on with your setup?

As for the additional 3" drop, that was so stupid that I didn't even bother replying. But hey, if people don't want suspension travel and enjoy their car being approx 1" off the ground, that's not my problem.

[Racecomp Engineering]

The camber plates allow you to dial in more negative camber, which makes a huge improvement in handling. Depending on how you use the car and your set-up (spring rates, tires, etc.) you will want more negative camber than the car comes from the factory. As others have said, toe is the main killer of tires, so you can add a little more camber and get even wear (in some case more even wear than stock). They are not needed to correct for lowering or that sort of thing....they just make the car mo' better. And you can use them on a stock car.

And our camber plates are built in a way that they actually lower the car an additional 3/8th of an inch WITHOUT sacrificing bump travel. A very nice bonus. We use a nice big beefy bearing to keep NVH low, but we've also been experimenting with a little strip of rubber to minimize it even more.

For those that want a huge drop, well....we focus on functional performance upgrades and going lower than this with springs and you sacrifice ride AND handling. That's not our way. Coilovers will get you there though.

Sorry for the lack of details! We'll spill the beans soon.

- Andrew

[dsgerbc]

Originally Posted by Dave-ROR

You sure there's not something else going on with your setup?

Pretty sure, car was aligned at a pace that does tons of them for autox-ers. I was surprised too, since I wasn't expecting significant wear. This wear did not really come from tracking/autox, cause I was checking the thread before/after and for temps during the events. No noticeable issues after I got re-aligned (different tires though and didn't run'em more than a few months before returning to stock). Might depend on road surface/roughness. All I'm saying that it's possible to get significant wear from -2.5 camber, so check it often.

And someone in the know (RCE? pretty please?) would be really helpful if they could draw up a suspension geometry diagram. I wonder where the roll center ends-up when you lower this car.

[pithy_logorrhea]

I've had -3.5 camber up front and -1.5 with 1/4" toe out in the rear on my car for a couple years and my tires never saw extra degradation (from what I can tell anyways).

Andrew/Myles, I'm really interested with what size wheels/tires you can put on. Have you had a chance to play with that yet?

[Racecomp Engineering]

Originally Posted by pithy_logorrhea

Andrew/Myles, I'm really interested with what size wheels/tires you can put on. Have you had a chance to play with that yet?

We do have a few good ideas of what will work, but have not tried too much in that area.

A lot of major wheel manufacturers are working their ass off to have good 5x100 wheels over here soon.

- andrew

[Longhorn248]

Originally Posted by Racecomp Engineering

The camber plates allow you to dial in more negative camber, which makes a huge improvement in handling. Depending on how you use the car and your set-up (spring rates, tires, etc.) you will want more negative camber than the car comes from the factory. As others have said, toe is the main killer of tires, so you can add a little more camber and get even wear (in some case more even wear than stock). They are not needed to correct for lowering or that sort of thing....they just make the car mo' better. And you can use them on a stock car.

And our camber plates are built in a way that they actually lower the car an additional 3/8th of an inch WITHOUT sacrificing bump travel. A very nice bonus. We use a nice big beefy bearing to keep NVH low, but we've also been experimenting with a little strip of rubber to minimize it even more.

For those that want a huge drop, well....we focus on functional performance upgrades and going lower than this with springs and you sacrifice ride AND handling. That's not our way. Coilovers will get you there though.

Sorry for the lack of details! We'll spill the beans soon.

- Andrew

All great info thanks! My car will be almost exclusively street use with maybe a couple days at a track thrown in for fun. From the info that you and everyone else has posted it sounds like I would be okay with just a set of your lowering springs to drop the car the 20mm with the camber plates being optional if I wanted to improve the handling.

[Racecomp Engineering]

^ Exactly.

- Andrew