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

[7thgear]

Originally Posted by PRORICAN

Question for the experts. What swaybars do you recommend with the bilstein b14 pss coilovers if any? The stockers may be sufficient but wondering if it would help handling with bigger bars. Thanks

swaybars are a fine tuning device

your choice for coilover spring rate should have been fit for your intended use...

you put thicker/thinner bars on front/back depending on whether you're over/understeering at a specific track or day.

there is NO magical formula, you tune according to what what you desire the car to do.

[CSG Mike]

Originally Posted by PRORICAN

Question for the experts. What swaybars do you recommend with the bilstein b14 pss coilovers if any? The stockers may be sufficient but wondering if it would help handling with bigger bars. Thanks

That depends. What are you trying to achieve? What do you like and dislike about your setup?

[PRORICAN]

Originally Posted by CSG Mike

That depends. What are you trying to achieve? What do you like and dislike about your setup?

Yeah I kinda guessed these questions where coming, lol. I want to autox next season and want to prepare for it, but I'll leave it as is, autox it and figure out what the car is doing good or bad. I guess I wanted to see if anybody has experience with these and figured they needed swaybars for autox. Thanks

[CSG Mike]

Originally Posted by PRORICAN

Yeah I kinda guessed these questions where coming, lol. I want to autox next season and want to prepare for it, but I'll leave it as is, autox it and figure out what the car is doing good or bad. I guess I wanted to see if anybody has experience with these and figured they needed swaybars for autox. Thanks

Sways are used to tune the under/oversteer balance of the car to your preference. In an autox environment, you'll probably want a beefy front sway, since you'll likely value quick transitional speed over sustained cornering speed.

[VADER]

I'm at work and don't have time right now to read through 24 pages to possibly find my answer haha. So, here's my Q...

I currently rub on my rear tires. I am hoping that getting LCA's to adjust the camber will fix this as I have already slightly rolled the fenders. Will I have to also get toe arms with the LCA's? Please tag me in the answer (@vader).

Thanks in advance!

[mike156]

Originally Posted by Fizz

I've just installed coilovers and although the ride height was adjusted equally on the strut body, there was a difference of 5mm in actual ride height between front left and front right (driver side being 5mm lower even without driver).

Originally Posted by Fizz

If I were to readjust would you recommend doing each side equally? I mean raise one side 2.5mm and lower the other side equally. Or just adjust the difference on one side only and be done with it?

This might actually be a quality issue of the springs more than anything else. If you are using good springs (Hyperco and Swift) then you might just be seeing the weight imbalance of the car. If it's Chinese coilovers you are talking about here, it's likely just the springs are junk.

Originally Posted by 7thgear

swaybars are a fine tuning device

Originally Posted by 7thgear

your choice for coilover spring rate should have been fit for your intended use...

you put thicker/thinner bars on front/back depending on whether you're over/understeering at a specific track or day.

there is NO magical formula, you tune according to what what you desire the car to do.

As an alternative here, you can approach this in a scientific manner. Target a natural frequency balance F/R then adjust the swaybars to get roll under control. This is where the "soft spring/big bar" approach ultimately comes from. You run a softer spring so your natural frequency is low enough to make it comfortable on the street then make up for the lack of roll stiffness with the sway bars.


I am curious about this idea that a big front bar improves response though. I recently tested out removing the sway bars all together on another light RWD platform. What I found was a car with instant turn-in and remarkable front grip. It almost felt like the car knew where to go before I even turned the steering wheel...It also over steered so greatly that it slowed the car down considerably. Putting on the front bar balanced the car back out but KILLED the turn-in response up front.

I'm now on a mission to match the no-bar turn in but keep it balanced. My wheel rates are fairly high too with a lot of front bias (580F/380R) with a 53/47 weight balance, yet the car was still crazy loose.

[autobrz]

i think its because the front bar is much stiffer than the rear when motion ratios are calculated. so the balance changed a lot by removing them.

[Fizz]

Originally Posted by mike156

This might actually be a quality issue of the springs more than anything else. If you are using good springs (Hyperco and Swift) then you might just be seeing the weight imbalance of the car. If it's Chinese coilovers you are talking about here, it's likely just the springs are

They're Bilstein coilovers. Anyway I didn't have time to adjust them the other day, so after driving about a few days since installing, they seem to have leveled out evenly. Only about 2-3mm difference between left to right side now. I'll leave them alone for now.

[mike156]

Autobrz, as mentioned, this was not on the GT86 platform. Just another lightweight RWD. I included the wheel rates of the springs alone for comparison purposes. For reference, it was a 680lb/in spring on an 2400 pound E36 BMW setup...LOTS of spring to control roll. Wheel rates of 580/380 should tend towards understeer considering the weight balance of the car, but that wasn't the case.

It would be interesting to see how the twins responded to removing the swaybars while using high spring rates. As I said, the turn-in and front grip was phenomenal without the bars on, maybe the GT86 would respond beter with it's more advanced rear suspension?

[CSG Mike]

Originally Posted by VADER

I'm at work and don't have time right now to read through 24 pages to possibly find my answer haha. So, here's my Q...

I currently rub on my rear tires. I am hoping that getting LCA's to adjust the camber will fix this as I have already slightly rolled the fenders. Will I have to also get toe arms with the LCA's? Please tag me in the answer @VADER).

Thanks in advance!

@VADER

If you're rubbing on the outer edges, then the LCAs MAY help. It depends on the magnitude of the rubbing.

You won't need toe arms.

[autobrz]

Originally Posted by mike156

Autobrz, as mentioned, this was not on the GT86 platform. Just another lightweight RWD. I included the wheel rates of the springs alone for comparison purposes. For reference, it was a 680lb/in spring on an 2400 pound E36 BMW setup...LOTS of spring to control roll. Wheel rates of 580/380 should tend towards understeer considering the weight balance of the car, but that wasn't the case.

It would be interesting to see how the twins responded to removing the swaybars while using high spring rates. As I said, the turn-in and front grip was phenomenal without the bars on, maybe the GT86 would respond beter with it's more advanced rear suspension?

ah... that's interesting... I've always gotten more grip from springs than sways when increasing the same wheel rate. dont know much about e36 suspension though. have you read steve holschier?

[Ouhei]

May as well,

I don't have a BRZ/FRS yet but I'm doing research on them now and plan on buying in March/April. I'm looking at suspension setups and I'm getting a bit lost when it comes to camber setups. I'm coming from a s2000 which has some factory adjustment so I've never had to worry about it (my wheel setup works within factory adjustment at my ride height).

If I want to run 18x9.5 +40 w/ 255/35's all around with a decent drop (not slammed) and I want the car to perform/handle well, what kind of setup would you recommend? I've been looking at the KW v3 and Tarmac 0/2 mostly. From my understanding I'd at least need something like the whiteline camber adjustment kit for the rear.

The car will see mostly street driving with backroads twisties and I'll make it out to an autocross/track every once and a while but not terribly often.

[Racecomp Engineering]

Originally Posted by Ouhei

May as well,

I don't have a BRZ/FRS yet but I'm doing research on them now and plan on buying in March/April. I'm looking at suspension setups and I'm getting a bit lost when it comes to camber setups. I'm coming from a s2000 which has some factory adjustment so I've never had to worry about it (my wheel setup works within factory adjustment at my ride height).

If I want to run 18x9.5 +40 w/ 255/35's all around with a decent drop (not slammed) and I want the car to perform/handle well, what kind of setup would you recommend? I've been looking at the KW v3 and Tarmac 0/2 mostly. From my understanding I'd at least need something like the whiteline camber adjustment kit for the rear.

The car will see mostly street driving with backroads twisties and I'll make it out to an autocross/track every once and a while but not terribly often.

Some may need a camber plate up front for tire clearance, but that may not be necessary with the coilover (fitment gurus help me here). We run a "wide" 245 with coilovers and have plenty of room.

Even without camber plates you'll be able to get plenty of camber. Just the cheap factory camber bolt will get you over -2 with KW or RCE coilovers.

For the rear, rear LCAs or the WL rear camber bushing kit. I like the bushing but it's a pain to install and adjust. I'd recommend rear LCAs, maybe with the nonadjustable version of that bushing.

- Andy

[CSG Mike]

Originally Posted by Ouhei

May as well,

I don't have a BRZ/FRS yet but I'm doing research on them now and plan on buying in March/April. I'm looking at suspension setups and I'm getting a bit lost when it comes to camber setups. I'm coming from a s2000 which has some factory adjustment so I've never had to worry about it (my wheel setup works within factory adjustment at my ride height).

If I want to run 18x9.5 +40 w/ 255/35's all around with a decent drop (not slammed) and I want the car to perform/handle well, what kind of setup would you recommend? I've been looking at the KW v3 and Tarmac 0/2 mostly. From my understanding I'd at least need something like the whiteline camber adjustment kit for the rear.

The car will see mostly street driving with backroads twisties and I'll make it out to an autocross/track every once and a while but not terribly often.

Conveniently, I own and run a S2000.

What kind of suspension did you run on the S2000? You don't necessarily need to have additional adjustability, depending on how you set up the FRS/BRZ. We don't run ANY additional arms, links, etc. on our shop car; we simply don't need them.