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

[marco_mc22]

Traction Mod doesn’t change your motion ratio but decreases anti-squat geometry, that explains why you’re bottoming out even more now, it’s like if you have installed softer rear springs or softened rear low speed compression damping.
You may try raising rear ride height, check your available travel with a zip tie and then if that is not enough stiffer rear springs are required. HKS dampers don’t have much travel tho, in my opinion on bumpy roads you will never have a comfy ride.

[Compelica]

Originally Posted by marco_mc22

Traction Mod doesn’t change your motion ratio but decreases anti-squat geometry, that explains why you’re bottoming out even more now, it’s like if you have installed softer rear springs or softened rear low speed compression damping.
You may try raising rear ride height, check your available travel with a zip tie and then if that is not enough stiffer rear springs are required. HKS dampers don’t have much travel tho, in my opinion on bumpy roads you will never have a comfy ride.

Thanks for the advice @marco_mc22

I'm already 7mm from stock height, as opposed to the default 15mm drop. Recently saw a set of 6k springs up for sale so was wondering if I could combat the bottoming out and the amount of roll I'm seeing on the rears.

[marco_mc22]

Originally Posted by Compelica

Thanks for the advice @marco_mc22

I'm already 7mm from stock height, as opposed to the default 15mm drop. Recently saw a set of 6k springs up for sale so was wondering if I could combat the bottoming out and the amount of roll I'm seeing on the rears.

Assuming that you’re really running out of travel they would help for sure but if you like the actual balance of the car you may want to adjust it with bars later on.
Usually square rates work fine but it’s a matter of driving preference too, you can balance everything from high pitch setups like your to high flat ride.

[Racecomp Engineering]

Right, doesn't affect motion ratio, but does affect anti-squat.

4k is a little soft with a shorter travel suspension. Check with HKS on spring specs (inner diameter and length) for the 6k springs.

- Andrew

[PikachuBRZ]

ok I went back and read through all of this thread plus figured out some classification stuff for AutoX. Here's some back story to give you some idea where I'm coming from. I'm going to be in XSA most likely because I'll hopefully be Flex Fuel by the time AutoX starts up again (Just waiting for my conversion kit to restock and ship) which means I don't necessarily have to stick with a bushed LCA for class rules. I daily the car so I'm worried about the change to a spherical rod end over the bushed one. I still really like the look of the SPL LCAs if I do end up going that route or the RSR if I stay with a rubber bushing. Competitiveness isn't really a concern for me but I don't want to be throwing away my money either. I grew up racing outlaw karts and got up to a worked over CR500 in a rigid chassis that weighed 400lbs with me in it and had a couple Camaros so I'm not completely foreign to adjusting things for handling balance but I am still new to doing so on an IRS car at this level and like the options to have adjustability even if it just means finding the settings I like and sticking with it. My sons are just getting to the age where they can enjoy coming out and tinkering with stuff and I'd like to be able to share this with them and learn how different things affect the handling and ride etc. I already have SS1s and SPC LCAs/Toe arms riding at about 13.5" from wheel centerline to fender. Currently running some Luafenn S Fit AS all season garbage tires because they were $100 for all four thanks to warranty and I figure learning on crappy tires will help in the long run when I step up to something stickier. Now for some questions:

1: would you recommend the RSR bushed or SPL LCAs or another I didn't mention?

2:a: if I got adjustable sway bars I want to verify that the hole closest to the lateral bar is the stiffest and furthest is the softest, correct? I've seen opposing information from different manufacturers.
b: if you fine tune with different setting on each side does that affect right vs. left turns?

3: Can the SS1s work with a 7k/400lb spring?

4: Would trackspec hood vents reduce enough lift that it should be accounted for in suspension tuning? STi Aero? Full splitter/skirts/diffuser/wing? I know autox is relatively slow for aero to be doing a lot but wing tuning was huge in the outlaw kart and it was comparable speeds, plus they're XSA legal.

5: Looking at 17x9 +45 wheels with 245/40 RS4s, how much camber should I be able to get at the lower mount before hitting the shock body?

6: For starting point on alignment how does -2.3F/-1.8R with 1/16" toe in rear sound for minimal daily wear but still nimble enough?

[Racecomp Engineering]

Originally Posted by PikachuBRZ

1: would you recommend the RSR bushed or SPL LCAs or another I didn't mention?

2:a: if I got adjustable sway bars I want to verify that the hole closest to the lateral bar is the stiffest and furthest is the softest, correct? I've seen opposing information from different manufacturers.
b: if you fine tune with different setting on each side does that affect right vs. left turns?

3: Can the SS1s work with a 7k/400lb spring?

4: Would trackspec hood vents reduce enough lift that it should be accounted for in suspension tuning? STi Aero? Full splitter/skirts/diffuser/wing? I know autox is relatively slow for aero to be doing a lot but wing tuning was huge in the outlaw kart and it was comparable speeds, plus they're XSA legal.

5: Looking at 17x9 +45 wheels with 245/40 RS4s, how much camber should I be able to get at the lower mount before hitting the shock body?

6: For starting point on alignment how does -2.3F/-1.8R with 1/16" toe in rear sound for minimal daily wear but still nimble enough?

1. I prefer spherical bearings over poly in pretty much every scenario. Cusco work well since the bearing is protected from the elements with a rubber bootie, otherwise SPL are great. No experience with RSR...are they rubber or polyurethane bushings?

2. a. yes the closest hole to the center means stiffer. Shorter bar means stiffer. longer bar means softer.
b. different settings left/right doesn't mean different effect on left vs. right turns. You could preload the bar to do that, but that's not really recommended unless you do circle track stuff.

3. Yes.

4. Short answer is that you need to get into big wings and front splitters before you need to worry about that. Hood vents and basic "street" splitters and "street" diffusers not as much.

5. With the OEM crash bolt maxed out you won't hit the shock body.

6. That's great for a daily, but you'll want a lot more for auto-x! Could push it a bit more than that unless your commute is a lot of highway driving.

- Andrew

[Ohio Enthusiast]

Originally Posted by PikachuBRZ

I know autox is relatively slow for aero to be doing a lot but wing tuning was huge in the outlaw kart and it was comparable speeds, plus they're XSA legal.

If you put an outlaw kart wing on a Twin you'll get effective downforce at autocross speeds (with a lot of drag at higher speeds). Large wing (or even multiple wing elements), aggressive angle and large end plates are the ticket - Lotus Talk had a nice discussion on this.

[Tatsu333]

Originally Posted by Racecomp Engineering

1. I prefer spherical bearings over poly in pretty much every scenario. Cusco work well since the bearing is protected from the elements with a rubber bootie, otherwise SPL are great. No experience with RSR...are they rubber or polyurethane bushings?

2. a. yes the closest hole to the center means stiffer. Shorter bar means stiffer. longer bar means softer.
b. different settings left/right doesn't mean different effect on left vs. right turns. You could preload the bar to do that, but that's not really recommended unless you do circle track stuff.

3. Yes.

4. Short answer is that you need to get into big wings and front splitters before you need to worry about that. Hood vents and basic "street" splitters and "street" diffusers not as much.

5. With the OEM crash bolt maxed out you won't hit the shock body.

6. That's great for a daily, but you'll want a lot more for auto-x! Could push it a bit more than that unless your commute is a lot of highway driving.

- Andrew

Another question RE SS1's and camber bolts - am I better to run the OEM crash bolts in the top slotted holes, or run the stock 16mm bolts there and 14mm camber bolts in the lower holes?

I have an alignment coming up in two days, and I have the SPC 81260 camber bolts on hand (I used them before the swap to the SS1's without any issues with slippage, etc.) and am trying to source the crash bolts locally, but haven't heard back on availability yet, so really I guess I want to know a) would it be "bad" to run the camber bolts on the SS1's and b) if I can get the crash bolts in time, am I better to use those?

[Racecomp Engineering]

Originally Posted by Tatsu333

Another question RE SS1's and camber bolts - am I better to run the OEM crash bolts in the top slotted holes, or run the stock 16mm bolts there and 14mm camber bolts in the lower holes?

I have an alignment coming up in two days, and I have the SPC 81260 camber bolts on hand (I used them before the swap to the SS1's without any issues with slippage, etc.) and am trying to source the crash bolts locally, but haven't heard back on availability yet, so really I guess I want to know a) would it be "bad" to run the camber bolts on the SS1's and b) if I can get the crash bolts in time, am I better to use those?

How much camber do you want? I think you'd be fine either way, I just prefer the OEM crash bolts.

- Andrew

[PikachuBRZ]

Originally Posted by Racecomp Engineering

1. I prefer spherical bearings over poly in pretty much every scenario. Cusco work well since the bearing is protected from the elements with a rubber bootie, otherwise SPL are great. No experience with RSR...are they rubber or polyurethane bushings?


6. That's great for a daily, but you'll want a lot more for auto-x! Could push it a bit more than that unless your commute is a lot of highway driving.

- Andrew

Thanks for the help!
1: I'm not sure on the RSRs. None of the places I looked had a material type. Maybe CSG knows since they sell them? Thanks for the input on the cusco. I didn't realize they protected the bearing. Now I have another contender to puzzle over haha.

6: If I take the fun route it's a little highway and mostly curvy back roads. If weather is crap it's mostly highway/city driving.

[strat61caster]

What’s wrong with the spc control arms?

Also you can run e85 in ESP-LP, easier pax then XA even if you don’t buy Hoosiers.

17x9 +45’s rub in the front at full lock, I have a 5mm spacer on my car.
I’m at -4.3F and -2.5R camber for stx and I want to bump up to -4.5 in the front, still daily it, my ecs are finally done after like 20k miles with that alignment. -3F/-2R would be the minimum imho.

[PikachuBRZ]

Originally Posted by strat61caster

What’s wrong with the spc control arms?

Also you can run e85 in ESP-LP, easier pax then XA even if you don’t buy Hoosiers.

17x9 +45’s rub in the front at full lock, I have a 5mm spacer on my car.
I’m at -4.3F and -2.5R camber for stx and I want to bump up to -4.5 in the front, still daily it, my ecs are finally done after like 20k miles with that alignment. -3F/-2R would be the minimum imho.

I've already had the SPC arms lose their alignment on me once after some spirited driving. I don't trust them if I'm going to be adding more grip and lateral loads.

Not worried about PAX but I am pretty set on hood ventilation which is still not allowed in ESP. I live where the desert meets the mountains and have altitude densities 2-3x lower than actual altitude so normal cooling methods aren't as effective. That's part of why I'm switching to e85 as well.

I'm aware of the rubbing. That's why I asked about clearance to the strut. I'm figuring less tophat adjustment will give more wiggle room. Also debating between verus steering limiter and spacers/studs. I already know I want better studs after my Legacy broke 6 last summer but I hear people say you never notice the limiter. Trying to find reports on H&R stud spacer combo. For the alignment, I figured I'd adjust according to wear but wanted a good baseline. Thanks for the tips.

[Tatsu333]

Originally Posted by Racecomp Engineering

How much camber do you want? I think you'd be fine either way, I just prefer the OEM crash bolts.

- Andrew

I'm planning on somewhere in the -2.2 to -2.5 range, so it's likely do-able without either option if I use the camber plates, but I recall you saying somewhere that you prefer to max out camber at the knuckle first (presumably to not change SAI / KPI and minimize changes to scrub radius).

I was at -2.2 with the camber bolts on PP struts before, and rear was at -2.1 on stock LCA's (I.E. non-adjustable) with the 1.25" drop from my springs, which I have matched with the SS1's. I was actually pretty happy with that on the road (which is the primary use for my car).

[Racecomp Engineering]

With the OEM crash bolts maxed and the SS1 camber plates in the center position, I was right at -2.2.

- Andrew