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

[Racecomp Engineering]

Originally Posted by grippgoat

Thanks! I've got cusco upper arms, which I think are all pillow ball. And SPL lower arms with pillow balls at the subframe. So I guess the only rubber left back there is the trailing arm. Does the suspension behave well if everything is pillow balls? Or does it need some rubber somewhere to avoid binding? Does anyone make a pillow ball bushing to go in the knuckle for the trailing link?

EDIT: Maybe these? https://us.gktech.com/products/zn6-8...erical-bushing It says toe arm, but maybe it means the traction / trailing arm, based on the customer pictures.

-Mike

The Cusco upper arms use a hardened rubber bushing (I'd rather a spherical but that's better than poly IMO).

The STI trailing arm is a nice simple piece with a good quality bearing. I use it and combined with the MCA traction mod it's a really nice upgrade. Cusco make a nice trailing arm if you want adjustability.

I think Cusco makes a pillowball for the trailing arm into hub position but I'm not 100% sure. They have them for most locations.

Going to more pillowball bushings can feel pretty good. It'll ask more of your dampers but it reduces bind in your suspension. They get a bad rap sometimes, but that's often because of poor quality bearings. In some cases, they can improve ride quality.

Anyway, I stay away from polyurethane in most cases and I'm careful to only use pillowballs that have enough articulation and use a good quality bearing.

- Andrew

[grippgoat]

Originally Posted by Racecomp Engineering

The Cusco upper arms use a hardened rubber bushing (I'd rather a spherical but that's better than poly IMO).

Interesting. I'll have to take a closer look at them. They came with the car when I bought it.

Originally Posted by Racecomp Engineering

The STI trailing arm is a nice simple piece with a good quality bearing. I use it and combined with the MCA traction mod it's a really nice upgrade. Cusco make a nice trailing arm if you want adjustability.

I was thinking I'd probably end up with SPL if I do trailing arms, because I'm using their stuff for most other things (Rear LCA, rear toe links w/ lockout, front arms, and front outer tie rods). The STI part isn't much cheaper. But I probably won't mess with the trailing arm unless I get a traction mod, which could be a while. MCA isn't available, and GKTech I'm not sure if it's a good design.

Originally Posted by Racecomp Engineering

Going to more pillowball bushings can feel pretty good. It'll ask more of your dampers but it reduces bind in your suspension. They get a bad rap sometimes, but that's often because of poor quality bearings. In some cases, they can improve ride quality.

Hopefully my MCS 2WNR can handle it. My concern was more about whether the geometry of so many links interacting _requires_ some flex somewhere in order to not just completely lock up and stop moving.

Originally Posted by Racecomp Engineering

Anyway, I stay away from polyurethane in most cases and I'm careful to only use pillowballs that have enough articulation and use a good quality bearing.

Yeah, poly is a last resort for me. The Turnin Concepts stuff I had on my 05 STI wasn't too bad. But all the SuperPro and Whiteline stuff I've had on multiple cars has been a bit sus.

So far, I've liked what I've seen from the SPL parts. The rod ends are huge and nice and tight. And I really like the clamp locks on the turnbuckles. It doesn't tend to shift things like jam nuts do, which makes it very easy to get the setting right, and then lock it down without changing the setting or messing up the alignment of the rod ends.

-Mike

[nextcar]

I have a few specific questions regarding the correct installation of stock front end links:

1) The 2022+ torque specification for the end link to sway bar that I found is 55 ft-lbs... this seems high to me; can anyone verify that this is the correct value?

2) There is very little room to tighten the end link to sway bar nut while using a hex key and crow foot. Given the spherical ball nature of the stock end links, is the allen key really necessary while tightening? It would be a LOT easier to use a standard socket on the torque wrench...

Thanks in advance!

[Ohio Enthusiast]

Originally Posted by nextcar

1) The 2022+ torque specification for the end link to sway bar that I found is 55 ft-lbs... this seems high to me; can anyone verify that this is the correct value?

2) There is very little room to tighten the end link to sway bar nut while using a hex key and crow foot. Given the spherical ball nature of the stock end links, is the allen key really necessary while tightening? It would be a LOT easier to use a standard socket on the torque wrench...

1. For 1st gen front is 34, rear is 28. 55 is for the front brackets holding the bushings (22 for the rear brackets). I'm pretty sure 2nd gen would be the same (or very similar).
2. I had good luck tightening by hand with a passthrough socket and an Allen key, then doing final tightening with just a torque wrench.

[nextcar]

Originally Posted by Ohio Enthusiast

1. For 1st gen front is 34, rear is 28. 55 is for the front brackets holding the bushings (22 for the rear brackets). I'm pretty sure 2nd gen would be the same (or very similar).
2. I had good luck tightening by hand with a passthrough socket and an Allen key, then doing final tightening with just a torque wrench.

BTW - attached are the 2022 specs I found...

[nextcar]

Originally Posted by nextcar

BTW - attached are the 2022 specs I found...

Of course, this document gives a conflicting value of 44 ft/lbs...

[Ohio Enthusiast]

Originally Posted by nextcar

BTW - attached are the 2022 specs I found...

Originally Posted by nextcar

Of course, this document gives a conflicting value of 44 ft/lbs...

Yeah, that's confusing. The 2017 service manual has this to say.
I'd probably opt for the second PDF with the diagram and 44 ft-lb, at least there there's no confusion about which part is which. Plus it's closer to 34 ft-lb spec for the 1st gen...

[dragoontwo]

The FSM in my sig calls out 44.3 ft/lbs

[cmiovino]

I have a 2017 BRZ wit RCE SS-1's and SPC RLCA/SPC front camber bolts in the lower slot. Camber is -4 up front, -2.2 in the rear with 1/16" toe in. Perrin 19mm front swaybar and endlinks. Tires were 225/45/17 A052's - rather heavily worn with 170+ runs.

Ride height in the front is 13.5" hub to fender and 14" in the rear. I do realize this is a bit higher than most and is only a hair lower than stock (Thanks to my driveway).

Finally got the car out to an autocross test event yesterday and the rear end was terrible. On longer sweepers, trying to put the power down, it felt like the rear end was skipping or hopping around. Almost like the rear diff was doing rear diff things searching for grip. This never happened on the stock suspension at all. Video below, but it felt more violent in the car than the video shows.

My settings were on the recommended street/comfort mode of 14 clicks from full stiff in the front, 16 from stiff in the rear. After about 3-4 runs, I upped the settings to only 2 away from full stuff in the front and 3 away from full stiff in the rear. This noticeably helped the the issue, but didn't fully fix it.

If I can wrap my head around it, I'm thinking on the soft settings the car wasn't staying flat enough and I was actually slightly lifting the rear inside wheel, making the diff kick in on power. Stiffening things up helped keep it more level and it didn't skip around as much. Or possibly the car was just bouncing because there wasn't enough dampening for the springs for those conditions.

So, what exactly is the solution here? I can't really change the rear ride height and feel like it being high is goofing with the suspension travel. I can try putting it to full stiff in the rear and tailoring the front the match, but this feels wrong as the recommended 'track' settings are more or less in the middle of the adjustment range. Extra side note, at 3 clicks away from full stiff in other areas of the course, the rear end was more lively than I wanted.

For what it's worth, I actually felt like the car drove better on the street with the stiffer settings on the way home. I have a fresh set of A052's in 245/40/17 on 9" wheels going on this week for the first official event. My guess is the car is going to drive and react completely differently than on the heavily worn tires.

Any suggestions on settings would be highly appreciated. The suspension rides GREAT on the street even on the much stiffer settings.

[autoracer86]

Originally Posted by cmiovino

I have a 2017 BRZ wit RCE SS-1's and SPC RLCA/SPC front camber bolts in the lower slot. Camber is -4 up front, -2.2 in the rear with 1/16" toe out. Perrin 19mm front swaybar and endlinks. Tires were 225/45/17 A052's - rather heavily worn with 170+ runs.

Ride height in the front is 13.5" hub to fender and 14" in the rear. I do realize this is a bit higher than most and is only a hair lower than stock (Thanks to my driveway).

Finally got the car out to an autocross test event yesterday and the rear end was terrible. On longer sweepers, trying to put the power down, it felt like the rear end was skipping or hopping around. Almost like the rear diff was doing rear diff things searching for grip. This never happened on the stock suspension at all. Video below, but it felt more violent in the car than the video shows.

My settings were on the recommended street/comfort mode of 14 clicks from full stiff in the front, 16 from stiff in the rear. After about 3-4 runs, I upped the settings to only 2 away from full stuff in the front and 3 away from full stiff in the rear. This noticeably helped the the issue, but didn't fully fix it.

If I can wrap my head around it, I'm thinking on the soft settings the car wasn't staying flat enough and I was actually slightly lifting the rear inside wheel, making the diff kick in on power. Stiffening things up helped keep it more level and it didn't skip around as much. Or possibly the car was just bouncing because there wasn't enough dampening for the springs for those conditions.

So, what exactly is the solution here? I can't really change the rear ride height and feel like it being high is goofing with the suspension travel. I can try putting it to full stiff in the rear and tailoring the front the match, but this feels wrong as the recommended 'track' settings are more or less in the middle of the adjustment range. Extra side note, at 3 clicks away from full stiff in other areas of the course, the rear end was more lively than I wanted.

For what it's worth, I actually felt like the car drove better on the street with the stiffer settings on the way home. I have a fresh set of A052's in 245/40/17 on 9" wheels going on this week for the first official event. My guess is the car is going to drive and react completely differently than on the heavily worn tires.

Any suggestions on settings would be highly appreciated. The suspension rides GREAT on the street even on the much stiffer settings.

I don't see why the ride height would effect anything at least I hope not as I also run near stock height 20mm drop all around but I run stiffer spring rates 7k/8k and stock sway bars the SS1 are listed as 6k/6k.

Maybe look into higher spring rates if the valving on the SS1s can handle it

[Racecomp Engineering]

dbl post

[Racecomp Engineering]

Def stick to the stiffer settings for auto-x. It's okay to be on the stiffer side with SS1s.

The tall rear ride height isn't helping since you're reducing your droop travel. If you can get away with just a little lower, that's going to help.

Yes it will be a little different on the fresh tires so I would wait before adding new parts until you can diagnose with the new set up.

- Andrew

[strat61caster]

@cmiovino assuming it's not a typo running toe out in the rear would be my first guess at a problem putting down power on corner exit. Literally never seen anyone succeed with that on an 86 even with CS/DS setup shenanigans. Hell, I've seen fast times put down with 1/4" toe in in the back.

Edit; always rear toe in on this car imho, you can be very small with it 1/32" on each side for 1/16" total, but I've done zero and it sucks on the freeway and nets you nothing on course. I've done toe out on accident and that's how we finished bottom 10 at nats despite being top half at the ProSolo Finale two days prior.

[cmiovino]

Originally Posted by strat61caster

@cmiovino assuming it's not a typo running toe out in the rear would be my first guess at a problem putting down power on corner exit. Literally never seen anyone succeed with that on an 86 even with CS/DS setup shenanigans. Hell, I've seen fast times put down with 1/4" toe in in the back.

Edit; always rear toe in on this car imho, you can be very small with it 1/32" on each side for 1/16" total, but I've done zero and it sucks on the freeway and nets you nothing on course. I've done toe out on accident and that's how we finished bottom 10 at nats despite being top half at the ProSolo Finale two days prior.

Typo, it's 1/16" in, per RCE's recommendations and what I was seeing on the STX threads over the years. Although I zeroed front and rear toe when I drove the car in DS for years. If anything I was really thinking crap, good thing I went with at least a bit in with the rear on the alignment or I'd really be all over the place at zero.

I think more of this is a dampening setting issue. The car's not dialed in at all. I had 3-4 runs in and just cranked it up to near the stiffer limit to see if that would change anything. It certainly did make a big difference in the rear turning it up.

I've never had coilovers and didn't think there's be a big difference in settings. I've even second guessed going with the SS-1's now in the fact that there might not be enough dampening... but I haven't maxed it out just yet. Just feels weird being that high up in the settings just to get it to work with the provided 6k springs.

The more I watch the video, I'm not thinking it's a ride height issue or that I'm picking a rear wheel up, but more that the dampening was so soft it was literally not working with the spring properly and kinda working like a blown strut in the rear.

It could be like Andrew's saying that you generally need to be much more on the stiffer side of the settings on the SS-1's for autocross specifically. I mean, they did choose the dampening after all.

Not ruling out the tires and colder temps. The first run was at 40 degrees and the later one was at 55. Fresh rubber might also fix the issue. 170 runs and sat on the car in my garage over winter didn't help.

Doesn't help that nobody runs STX locally. Most guys around here are street class only, even in other cars.