CSG Spec Tein Flex A Owners Thread

[timurrrr]

Originally Posted by CSG Mike

Factor in sway and tire grip load, and you'll have a car trying to kill you.

You should ask @sw20kosh about the time I tried 10k/12k on 17 factory sways; it was a death machine and I literally spun out on the first turn at Laguna.

Fair enough, with stiffer rear springs you'd want either softer rear sway bar, or stiffer front, or both. It's normal for "flat ride" setups to have an oversteer balance from just springs, and it's typically corrected via sway bars.

[CSG Mike]

Originally Posted by timurrrr

Fair enough, with stiffer rear springs you'd want either softer rear sway bar, or stiffer front, or both. It's normal for "flat ride" setups to have an oversteer balance from just springs, and it's typically corrected via sway bars.

If the springs are rear-biased, and then neutralized with sways, the net rear wheel rate with independence would be neutral, right?

If you're looking for more rotation, I wouldn't recommend more than 6/7 split.


Most folks consider the 10k/12k race rate setup too loose with 13-16 rear sway.


Are you seeking more rotation at turn-in, mid-corner, or corner exit?

[CSG Mike]

Originally Posted by timurrrr

Why do you want just a +1 kg/mm bump?
I believe the common track-oriented pairings are 6k F / 8k R and 6k F / 9k R.

I honestly don't understand why the CSG spec FLAs use 6k/6k everywhere.
At "street" damper settings the car rocks front-to-back on the highway all the time.
8k or 9k in the rear would be a lot closer to "flat ride", which should also be beneficial at the track.
I wish I knew that before ordering, and ordered custom springs/valving in the rear.

Because these are high performance, high compliance street dampers, that also are trackable.

If you want a track oriented damper, I would recommend considering a JRZ Motorsport, KW Clubsport, etc., something that is specifically designed for track use, with no compromises that originate from being designed for street drivibility.

While not optimal, you can go up to +2kg on the damper; the rebound valving can handle it.

I'm frankly surprised you find this too understeery/pushy for you with a 17 rear sway, as I find it pretty rotation happy, and I'm considered by most to be a very "loose" driver. I'll be the first to complain of a car doesn't rotate.

[Var]

I'm either going to try a 1kg/mm stiffer rear spring, or a stiffer rear sway bar. Problem is that I don't understand how much stiffer they are than stock in terms of overall spring rate.

For example, if a company lists the sway bar is 25% stiffer than stock, how would that compare to a spring rate increase? Would that be the equivalent of a 0.1, 0.5, 1kg/mm? I have no idea. I don't want to install a sway bar and it ends up too stiff on the softest setting or too soft on the stiffest setting. It would be a lot more convenient though as I could quickly set it up for more rotation in the canyons and more stability at the track

[nlopez]

Originally Posted by CSG Mike

Because these are high performance, high compliance street dampers, that also are trackable.

If you want a track oriented damper, I would recommend considering a JRZ Motorsport, KW Clubsport, etc., something that is specifically designed for track use, with no compromises that originate from being designed for street drivibility.

While not optimal, you can go up to +2kg on the damper; the rebound valving can handle it.

I'm frankly surprised you find this too understeery/pushy for you with a 17 rear sway, as I find it pretty rotation happy, and I'm considered by most to be a very "loose" driver. I'll be the first to complain of a car doesn't rotate.

Does pace dictate how the CSG FLA perform? ie. faster/experienced drivers will be more aligned to it's optimal range vs. intermediate drivers may never experience the full benefit of it's performance. Alternatively, how much variance is there in the click settings on the dampers as that may even sway the two users experience with the CFLA in this post.

[timurrrr]

Originally Posted by CSG Mike

If the springs are rear-biased, and then neutralized with sways, the net rear wheel rate with independence would be neutral, right?

The effective spring rate for individual wheels would be neutral? — I believe so.
Although haven't done the math, that's been something I wanted to do for a long time .
Roll resistance at each axle is neutral, yes.

The benefit of "flat ride" is that on bumps that hit both sides (e.g. surface changes on a highway; crests, compression zones on a track, etc.) the chassis reacts with primarily up-down translation movement, and virtually no oscillations in pitch. That happens even when there's little to no damping, as springs themselves have an anti-resonance to such inputs to the chassis.

The theoretical benefit on the track is that both ends of the car compress/droop in sync, causing neutral reaction to such bumps; instead of oversteer/understeer balance oscillations.

Originally Posted by CSG Mike

If you're looking for more rotation, I wouldn't recommend more than 6/7 split.
Most folks consider the 10k/12k race rate setup too loose with 13-16 rear sway.
Are you seeking more rotation at turn-in, mid-corner, or corner exit?

Originally Posted by CSG Mike

I'm frankly surprised you find this too understeery/pushy for you with a 17 rear sway, as I find it pretty rotation happy, and I'm considered by most to be a very "loose" driver. I'll be the first to complain of a car doesn't rotate.

I don't think I ever said it's understeery/pushy?
In fact, the first time I went to the track after installing CSG FLAs, I almost spun out of T3 at Thunderhill driving the way I used to drive with PP suspension. I was using recommended rebound settings for track. Perhaps because of the bumps there? No other changes were made to the car since the previous track day; only coilovers and alignment.
I have since adjusted my driving and tweaked the damping for a balance that I like overall (5 clicks front, 6 clicks rear).

My primary complaints with CSG FLAs are harsh ride in the front on major bumps (has nothing to do with the rear spring rate),
and noticeable pitch oscillations (front/rear rocking) at highway speeds with street settings (8 clicks front, 12 clicks rear).
I don't feel these oscillations on the track using track settings, but there can be other explanations here, such as

• Tracks don't have those ridiculous "ridges" where surfaces change, or on bridges; so the amplitude of oscillations is smaller
• The stiffer dampers help reduce those oscillations quicker, so they are not that obvious
• I'm just too busy paying attention to other things when I'm in a corner

Even if the explanation is that extra damping helps stop those oscillations, that doesn't mean that the suspension works effectively when they do so.

Originally Posted by CSG Mike

If you want neutral spring frequency, use 8/8 clicks or 7/8 clicks. The adjustment knob is there so you can customize oscillation damping frequency to taste.

I'll try these settings. I'm skeptical that it will make spring frequencies "neutral". But if the rear was indeed more bouncy than the front, then perhaps a bit extra damping there will improve the overall situation.
Thanks for the idea!

Originally Posted by CSG Mike

Because these are high performance, high compliance street dampers, that also are trackable.

If you want a track oriented damper, I would recommend considering a JRZ Motorsport, KW Clubsport, etc., something that is specifically designed for track use, with no compromises that originate from being designed for street drivibility.

It's funny you mention that they are primarily street coilovers, given that my main complaints are about street performance.

I haven't tried 6/8 or 6/9 on the street, but my friends who have those setups street drive their cars too.
I understand that stiffer rear springs will make the rear stiffer (duh).
But given that the front is already much more harsh than rear, making the rear stiffer might not really make much of a difference to the overall comfort.
Especially given that "flat ride" is exactly all about having similar effective suspension stiffnesses at both ends of the car.

Originally Posted by CSG Mike

Factor in sway and tire grip load, and you'll have a car trying to kill you.

I guess the thing you're implying is that when designing FLAs, TEIN picked the spring rates to match the factory sway bars.
This is a good strategy to make buying these coilovers "cheaper" initially. But I wonder if CSG FLAs could provide an optional alternative spec designed to work with specific aftermarket sway bars instead.
After all, sway bars are some of the easiest to change and adjust components in the suspension; and given that CSG FLAs were so popular among 86DC participants.

Sorry for a longread, but if this helps in development of any future CSG Spec coilovers I'd be very happy!

[timurrrr]

Originally Posted by Var

Problem is that I don't understand how much stiffer they are than stock in terms of overall spring rate.

For example, if a company lists the sway bar is 25% stiffer than stock, how would that compare to a spring rate increase? Would that be the equivalent of a 0.1, 0.5, 1kg/mm? I have no idea.

I don't know a simple answer, especially now that you have non-standard geometry in the rear, that changed motion ratios.

A complicated answer that I do know is:

1. Find out the Nm/º stiffness of the sway bar (may be able to calculate from its diameter)
2. You calculate how much leverage the end links have on the sway bar at ride height (accounting for the angle between the sway bar and the end links)
3. You account for the motion ratio of the end link
4. To answer "how much spring is this equivalent to", you also need to account for the motion ratio of the strut

Something like this super-complicated calculator might help if you find all the right measurements for your car.

[Var]

Originally Posted by timurrrr

I don't know a simple answer, especially now that you have non-standard geometry in the rear, that changed motion ratios.

A complicated answer that I do know is:

1. Find out the Nm/º stiffness of the sway bar (may be able to calculate from its diameter)
2. You calculate how much leverage the end links have on the sway bar at ride height (accounting for the angle between the sway bar and the end links)
3. You account for the motion ratio of the end link
4. To answer "how much spring is this equivalent to", you also need to account for the motion ratio of the strut

Something like this super-complicated calculator might help if you find all the right measurements for your car.

Aren't the motion ratios preserved if the lengths of the arms and pickup points are the same? The RLCA has 3 holes to choose from to mount the shock. I believe middle hole provides stock leverage, but I'd have to go read through the manual to be sure. Unless something else changes the motion ratios?

[timurrrr]

Originally Posted by Var

Aren't the motion ratios preserved if the lengths of the arms and pickup points are the same? The RLCA has 3 holes to choose from to mount the shock. I believe middle hole provides stock leverage, but I'd have to go read through the manual to be sure. Unless something else changes the motion ratios?

Yeah perhaps the middle point has the same motion ratio. I was just pointing out that you should double check that.

[itschris]

Originally Posted by Var

I'm either going to try a 1kg/mm stiffer rear spring, or a stiffer rear sway bar. Problem is that I don't understand how much stiffer they are than stock in terms of overall spring rate.

For example, if a company lists the sway bar is 25% stiffer than stock, how would that compare to a spring rate increase? Would that be the equivalent of a 0.1, 0.5, 1kg/mm? I have no idea. I don't want to install a sway bar and it ends up too stiff on the softest setting or too soft on the stiffest setting. It would be a lot more convenient though as I could quickly set it up for more rotation in the canyons and more stability at the track

My notes say 141 lb/in front 113 lb/in rear for 2013-2016 sways, .964 front .59 rear sway bar motion ratios (stock, not sure if this applies to wisefab). With these numbers, a 25% stiffer rear would be about 0.3 kg/mm more. It would be good to check with the manufacturer if the 'stiffer than stock' measurements are based off 13-16 or 17+ sways.

Ride height will have a noticeable effect on the car's balance. It would be good to keep in mind if you're planning major changes there.

[CSG Mike]

Originally Posted by timurrrr

The effective spring rate for individual wheels would be neutral? — I believe so.
Although haven't done the math, that's been something I wanted to do for a long time .
Roll resistance at each axle is neutral, yes.

The benefit of "flat ride" is that on bumps that hit both sides (e.g. surface changes on a highway; crests, compression zones on a track, etc.) the chassis reacts with primarily up-down translation movement, and virtually no oscillations in pitch. That happens even when there's little to no damping, as springs themselves have an anti-resonance to such inputs to the chassis.

The theoretical benefit on the track is that both ends of the car compress/droop in sync, causing neutral reaction to such bumps; instead of oversteer/understeer balance oscillations.

Great theoretical exercise, but in actuality, the front wheels will always hit the element first, before the rear wheels. Even if damping frequency was identical in a theoretical situation, in reality, the front oscillation starts and ends first, unless you can magically make both axles hit the element at the same time

Originally Posted by timurrrr

I don't think I ever said it's understeery/pushy?
In fact, the first time I went to the track after installing CSG FLAs, I almost spun out of T3 at Thunderhill driving the way I used to drive with PP suspension. I was using recommended rebound settings for track. Perhaps because of the bumps there? No other changes were made to the car since the previous track day; only coilovers and alignment.
I have since adjusted my driving and tweaked the damping for a balance that I like overall (5 clicks front, 6 clicks rear).

Typically wheel rates are considered for balance. Wanting more rear spring or sway is normally a desire for more rotation

Originally Posted by timurrrr

My primary complaints with CSG FLAs are harsh ride in the front on major bumps (has nothing to do with the rear spring rate),
and noticeable pitch oscillations (front/rear rocking) at highway speeds with street settings (8 clicks front, 12 clicks rear).
I don't feel these oscillations on the track using track settings, but there can be other explanations here, such as

• Tracks don't have those ridiculous "ridges" where surfaces change, or on bridges; so the amplitude of oscillations is smaller
• The stiffer dampers help reduce those oscillations quicker, so they are not that obvious
• I'm just too busy paying attention to other things when I'm in a corner

Even if the explanation is that extra damping helps stop those oscillations, that doesn't mean that the suspension works effectively when they do so.

Double check your preload, and minimize it. Raise the height a bit. It takes VERY LITTLE effort to unintentionally add too much preload, due to the mechanical torque multiplication of turning a collar.

Recommended settings are a blend of functionality and aesthetics. The As you previously mentioned, you get a lot of HBS engagement on the street.
Raising the car will reduce that.

There are quite a few adjustable settings on the dampers, and it's definitely not a 1 size fits all.

Originally Posted by timurrrr

I'll try these settings. I'm skeptical that it will make spring frequencies "neutral". But if the rear was indeed more bouncy than the front, then perhaps a bit extra damping there will improve the overall situation.
Thanks for the idea!

Real world trial and error is how you validate/invalidate. Even with the best suspension models, real world testing still trumps all. Doing this testing will allow you to reach the settings that are best for you!

Originally Posted by timurrrr

It's funny you mention that they are primarily street coilovers, given that my main complaints are about street performance.

I haven't tried 6/8 or 6/9 on the street, but my friends who have those setups street drive their cars too.
I understand that stiffer rear springs will make the rear stiffer (duh).
But given that the front is already much more harsh than rear, making the rear stiffer might not really make much of a difference to the overall comfort.
Especially given that "flat ride" is exactly all about having similar effective suspension stiffnesses at both ends of the car.

I guess the thing you're implying is that when designing FLAs, TEIN picked the spring rates to match the factory sway bars.
This is a good strategy to make buying these coilovers "cheaper" initially. But I wonder if CSG FLAs could provide an optional alternative spec designed to work with specific aftermarket sway bars instead.
After all, sway bars are some of the easiest to change and adjust components in the suspension; and given that CSG FLAs were so popular among 86DC participants.

Sorry for a longread, but if this helps in development of any future CSG Spec coilovers I'd be very happy!

Actually the 6/6 was picked for a combination of compliance and balance. with a 13-16 rear sway, its pushier, whereas with a 17+ rear sway, the balance is closer to neutral. THis gives the end user a $75 option to adjust balance.

The damping combined with a 6/6 rate ultimately nets more performance than stock, combined with a nicer ride than stock.

[CSG Mike]

Originally Posted by Var

Aren't the motion ratios preserved if the lengths of the arms and pickup points are the same? The RLCA has 3 holes to choose from to mount the shock. I believe middle hole provides stock leverage, but I'd have to go read through the manual to be sure. Unless something else changes the motion ratios?

The motion ratio is preserved if the lever ratio is preserved

for example, the SPL RLCA changes motion ratio when you adjust camber by making the RLCA longer or shorter. This also changes the lever ratio.

The vast majority of folks out there neither feel or realize this, because the net effect is miniscule.

You also change rear motion ratio when you change wheel offsets, but most people don't notice that either.

A few eagle-eyed folks have noticed I run lower offset front than rear.

[CSG Mike]

Originally Posted by nlopez

Does pace dictate how the CSG FLA perform? ie. faster/experienced drivers will be more aligned to it's optimal range vs. intermediate drivers may never experience the full benefit of it's performance. Alternatively, how much variance is there in the click settings on the dampers as that may even sway the two users experience with the CFLA in this post.

With proper setup adjusted to each driver's taste, the CSG FLA should feel intuitive.

Each click is meaningful in damping adjustment. However, individual drivers' preferences will vary, regardless of speed or experience, as well as other components on the car.

[CSG Mike]

Originally Posted by Var

I'm either going to try a 1kg/mm stiffer rear spring, or a stiffer rear sway bar. Problem is that I don't understand how much stiffer they are than stock in terms of overall spring rate.

For example, if a company lists the sway bar is 25% stiffer than stock, how would that compare to a spring rate increase? Would that be the equivalent of a 0.1, 0.5, 1kg/mm? I have no idea. I don't want to install a sway bar and it ends up too stiff on the softest setting or too soft on the stiffest setting. It would be a lot more convenient though as I could quickly set it up for more rotation in the canyons and more stability at the track

Springs affect overall stiffness, sways only affect roll stiffness and decrease independence.