CSG and RCE tag-team suspension Q&A thread! Ask us anything!

[new2subaru]

Originally Posted by RotARy15

So prior to this I was aligning the car with strings but without a way to reduce friction so I was just lifting the car, making a change based on the difference between ground and airbourne measurements, then re-measuring on the ground. Front was no problem. But the rear was a fight I couldn't explain.

Then I finally got some alignment plates and built wheel stands. The amount that rear toe and camber affect each other is giving me flashbacks to working at a shop and trying to align NA/NB Miatas.

Also, holy crap does driver weight affect passenger side camber. First alignment attempt was also without weight and the right front was locked down at -2.5. With driver weight, it measured -3.0. This is on imported STI pink springs. Driver side didn't seem to move as much with weight.

It's a royal pain, isn't it? It lead me to buy rear upper control arms, lower arms and toe arms.

[Racecomp Engineering]

Originally Posted by 2.2Lude

Andrew,

Any experience shims with the Brembos?

FWIW I have the CSG spec Brembo GT calipers on blank rotors and XP12’s.

Not from a reducing noise standpoint.

I don't think you're going to get XP12s consistently quiet on the street with Brembos.

- Andrew

[RotARy15]

Originally Posted by Racecomp Engineering

Not from a reducing noise standpoint.

I don't think you're going to get XP12s consistently quiet on the street with Brembos.

- Andrew

I can't keep R10s quiet on the street. First bedding lasted 300 miles of mostly highway before grinding and squealing returned. Re-bedded them and the noise returned today after about 150 miles (traffic got worse).

[Racecomp Engineering]

For what it's worth...I'm running Endless MX72 Plus and they're quiet on the street and feel awesome. We'll see how they do over the winter but so far so good on the couple of cold mornings we've had. I'm not running brembos though.

- Andrew

[RotARy15]

I wonder where I can get those. Not planning an immediate switch but I am intrigued by the lower friction vs R10s. I prefer standing on the pedal more than the R10s allow.

[Racecomp Engineering]

Originally Posted by RotARy15

I wonder where I can get those. Not planning an immediate switch but I am intrigued by the lower friction vs R10s. I prefer standing on the pedal more than the R10s allow.

We have them.

- Andrew

[RotARy15]

Originally Posted by Racecomp Engineering

We have them.

- Andrew

And the Brembo cuts are cheaper? I feel so appreciated. These are certainly next on my list. Would you agree that they have less friction than R10s? Looking for something closer to stock friction with high heat tolerance. R10s are roughly .6 and the MX72 Plus are around .47. No clue what stock is.

[Racecomp Engineering]

Originally Posted by RotARy15

And the Brembo cuts are cheaper? I feel so appreciated. These are certainly next on my list. Would you agree that they have less friction than R10s? Looking for something closer to stock friction with high heat tolerance. R10s are roughly .6 and the MX72 Plus are around .47. No clue what stock is.

Certainly more than stock but I don't know the exact friction numbers for the OEM pads. Comparing to R10s there's more to it than just the friction but the numbers sound right.

- Andrew

[Spuds]

Looking at the whiteline "antidive" front LCA bushings but I can't figure out how they work. As far as I can see, they rotate the LCA about the vertical axis, moving the wheel slightly forward. The effect is giving up a miniscule amount of camber for half a degree of caster. I would think increasing caster decreases the antidive geometry as opposed to increasing it from what I read. Any thoughts from the gurus?

Also general opinions on replacement front LCA bushings that are not pillowballs are welcome.

[Scargod]

My Guru, unbounded by uncertainty, wants me to ask you what you are doing. I'm not inclined to sift through 5K posts to know where you're headed with your car... or give advice when I know so little... but.
I'm curious because of the questions you ask. I'm late to this game. You seem to know a good bit already so I might learn something.
I think you have it backwards about caster decreasing anti-dive geometry as opposed to increasing it.
Perhaps focus on basic geometry for performance. Anti-dive is relevant for softly sprung suspensions.

[Spuds]

Originally Posted by Scargod

My Guru, unbounded by uncertainty, wants me to ask you what you are doing. I'm not inclined to sift through 5K posts to know where you're headed with your car... or give advice when I know so little... but.
I'm curious because of the questions you ask. I'm late to this game. You seem to know a good bit already so I might learn something.
I think you have it backwards about caster decreasing anti-dive geometry as opposed to increasing it.
Perhaps focus on basic geometry for performance. Anti-dive is relevant for softly sprung suspensions.

Just curious since I'm considering the remainder of 12-year-old bushings I can replace with stiffer versions.

For reference I have an autocross DST build. RCE T2s with the standard 400/400 springs. I already have an extra degree of caster from camber plates. Rules seem to let me use offset bushings of the same type (material compliance). Do I need more caster, probably not. I could use a bit more antidive geometry since occasionally I hit the bumpstops up front on a bumpy/undulating course. I could also fix that with springs, but I'm pretty comfortable with the 400s, plus that doesn't get me a fancy new bushing lol.

There are obviously other options, I'm just wondering if anyone understood why it's marketed as "antidive".

[Racecomp Engineering]

Originally Posted by Spuds

Looking at the whiteline "antidive" front LCA bushings but I can't figure out how they work. As far as I can see, they rotate the LCA about the vertical axis, moving the wheel slightly forward. The effect is giving up a miniscule amount of camber for half a degree of caster. I would think increasing caster decreases the antidive geometry as opposed to increasing it from what I read. Any thoughts from the gurus?

Also general opinions on replacement front LCA bushings that are not pillowballs are welcome.

I've got some opinions on the ol' WL anti-dive/lift kit lol.

Okay the bushing has 3...let's call them "features."

1. The polyurethane bushing itself. Stiffer. Tends to be a good thing, however I personally really dislike poly for bushings that pivot on more than 1 axis or twist against the axis. That bushing in particular isn't suited to poly in my opinon. Whiteline designs in some deflection which is good. Still don't like it. That said, it is likely an overall performance improvement.

2. The caster. This is done with the lateral relocation of the bolt/axis. It's no longer right through the center and it moves the wheel forward as you said. It's nice to have a little more caster.

3. The anti-dive feature. This is done with the vertical relocation of the control arm point. That might be helpful for you...I'm not sure exactly how much it changes the anti geometry though and Whiteline is not clear about that at least for this chassis. If I recall, Jackson Racing also makes a part that adds anti-dive that can be used with an OEM bushing.

- Andrew

[Spuds]

Originally Posted by Racecomp Engineering

I've got some opinions on the ol' WL anti-dive/lift kit lol.

Okay the bushing has 3...let's call them "features."

1. The polyurethane bushing itself. Stiffer. Tends to be a good thing, however I personally really dislike poly for bushings that pivot on more than 1 axis or twist against the axis. That bushing in particular isn't suited to poly in my opinon. Whiteline designs in some deflection which is good. Still don't like it. That said, it is likely an overall performance improvement.

2. The caster. This is done with the lateral relocation of the bolt/axis. It's no longer right through the center and it moves the wheel forward as you said. It's nice to have a little more caster.

3. The anti-dive feature. This is done with the vertical relocation of the control arm point. That might be helpful for you...I'm not sure exactly how much it changes the anti geometry though and Whiteline is not clear about that at least for this chassis. If I recall, Jackson Racing also makes a part that adds anti-dive that can be used with an OEM bushing.

- Andrew

Yeah, #1 seems a bit strange in my mind, but I think those little holes probably work fine for the relatively small deflections it sees. I didn't realize it made a vertical adjustment to the LCA. Hard to tell from pictures lol.

Not sure if that vertical change is DST legal. Seems like a grey area but I'll have to read the rules again. I am pretty sure the JR solution isn't DST legal because it relocates a mount point.

Edit: Looks like the ST rules specifically allow for this part in 14.8 (B and K). Might try it...