Question about CS Rear Shocks

[iammike]

@CorkSport;

I recently installed a set of Swift springs and your dampers and after some interesting times getting them dialed in, I had a question.

Your rear shocks do not use the OEM bumper but most rear springs, including yours I would think, were designed with the added spring rate from the bumper in mind.

My current experience is that the rear of the car feels very soft now and this would make sense if the Swift spring rates were expecting the bumper to assist.

How was this factored into the shock design? What are your thoughts? I'm sure in the designing of the shocks it must have been brought up for discussion.

Just looking for more info. I have things working pretty well now but I have the rear shocks cranked all the way up because otherwise, the rear suspension just compresses way too easy. 11 on the front and 15 on the back seems to have balanced out the feel but only to a degree.

[iammike]

Just some further thoughts after putting about 3000 miles on these dampers mated with Swift springs.

1. At this point I have all 4 corners turned to their hardest setting and it's still not really super firm. My only problem is that the rears still seem like the suspension is moving around a lot. See #2

2. Today I reached up there while the car was resting in a neutral position and there is, best guess, about 3 inches between the top of the shock body and the bump stop that sits under the adjustment knob. Considering the OEM jounce bumpers darn near ride the top of the shock this would explain the soft feeling in the rear. I'm just not sure I understand the decision to do this considering as far as I can tell, all spring options for our cars counts on that jounce bumper for added spring rate.

I've had a lot of problems with the rear suspension compressing further than it ever did on CS springs and Koni Yellow's resulting in some rubbing on things I've never rubbed on before.

Thinking about adding some packers on top of the shock body to engage the bump stop on the shock sooner.

[SpencerC]

I don't really understand what you are asking. Are you simply curious if the design of the rear shocks was created to utilize the stock back bump stop even though we replace it with our own?

You could always try using a larger bump stop if you wanted. This might limit the movement you get in the rear as you state and could be helpful.

[iammike]

I'm sorry, suspension, to some degree, is still a black art to me thus I'm having a hard time putting all this into words.

To put it as simple as I can, the rear seems to be really weak on compression damping causing the rear to compress quite a lot compared to the front causing an unbalanced feeling in many cases. While changing the rear bump stop or adding packers would reduce travel, I fear the other impacts might make it an undesirable path to take especially if the rubber bumpers on the CS shock are designed as stops and not a progressive spring assist.

Impacting the rear jounce bumper (spring assist) on the OEM setup was akin to adding spring rate to the rear spring. The real bump stop is on the LCA.

Some things I'd love to know from you guys if you can release such info would be the following.

1. Is the rubber bumpers on the CS rear shock designed to act as a bump stop or a jounce bumper (spring assist)?

2. There are two rubber bumpers on the CS rear shock. One above the adjustment knob and one below. The one below is obviously impacted by the shock body if it compresses enough, does the top one also compress with impact from the shock body? Not sure if it does or not considering the adjustment knob and housing rest between these bumpers.

3. Has CS ever released shock dyno's for these dampers? Would go a looooong way to understand what they are doing and how to adjust them properly.

4. What is the rear spring rate of the CS springs? The information I have shows them to be a lower spring rate, by about 10lbs/in, than the Swift springs I have in currently. If this is true, then I don't think it's the fact I'm not running CS springs causing the problem since my issue lies in the amount of compression. (For the record, here are the numbers I have. Swift 224F/224R and CS 235F/214R)

I appreciate any help you can give a still learning suspension n00b.

[I am a banana]

I'm having the opposite reaction. My fronts seem to be a little softer than the rears. I followed your other post and had it at 11/15, now I'm at 13/15 and will probably up it to full stiff F/R. But, I think the struts might be little soft, in general. I'm also mated to swift springs and if I've got passengers, my rear mudflaps will scrape on turns coming off stop signs, etc.

[specvspeedfreak]

@iammike; Spring rate for Swift is 250

Which bump stops do the CS utilize for the fronts?

Swift obviously designed the springs with oem struts/shocks and oem bump stops and not something like the CS rear shocks... But If oem bump stops fit I would try it out and see how you like them. I would not add packers. It seems like the 2 upper rubber bushings are just spacers to allow the adjustment part be visible and actually be adjustable. It being rubber, it would add a hint of cushion as well (if it ever fully compressed).

I wonder how much useable travel is lost with the CS rear shocks having the adjustment part.

edit: honestly I don't know why you ditched the koni's.

[jack_hammer]

Originally Posted by iammike I'm sorry, suspension, to some degree, is still a black art to me thus I'm having a hard time putting all this into words. To put it as simple as I can, the rear seems to be really weak on compression damping causing the rear to compress quite a lot compared to the front causing an unbalanced feeling in many cases. While changing the rear bump stop or adding packers would reduce travel, I fear the other impacts might make it an undesirable path to take especially if the rubber bumpers on the CS shock are designed as stops and not a progressive spring assist. Impacting the rear jounce bumper (spring assist) on the OEM setup was akin to adding spring rate to the rear spring. The real bump stop is on the LCA. Some things I'd love to know from you guys if you can release such info would be the following. 1. Is the rubber bumpers on the CS rear shock designed to act as a bump stop or a jounce bumper (spring assist)? 2. There are two rubber bumpers on the CS rear shock. One above the adjustment knob and one below. The one below is obviously impacted by the shock body if it compresses enough, does the top one also compress with impact from the shock body? Not sure if it does or not considering the adjustment knob and housing rest between these bumpers. 3. Has CS ever released shock dyno's for these dampers? Would go a looooong way to understand what they are doing and how to adjust them properly. 4. What is the rear spring rate of the CS springs? The information I have shows them to be a lower spring rate, by about 10lbs/in, than the Swift springs I have in currently. If this is true, then I don't think it's the fact I'm not running CS springs causing the problem since my issue lies in the amount of compression. (For the record, here are the numbers I have. Swift 224F/224R and CS 235F/214R) I appreciate any help you can give a still learning suspension n00b.

i think you're over thinking it. it sounds like the rear shocks are just too soft for those springs.

Originally Posted by specvspeedfreak edit: honestly I don't know why you ditched the koni's.

mad adjustability, yo!

[iammike]

OEM rear bump stops will not go on the CS shocks because of the accessible adjustment knob thus the bump stops CS puts on. As far as the front, I have a set of Fat Cat bumpstops (yeah yeah, I know, but I got them a long time ago and didn't know about the GC ones).

As far as the Koni's, my rears are leaking so even if I end up back with the Koni, something had to go in it's place for awhile. I decided, might as well try something new while I was at it.

Jack Hammer, while I agree that it sounds like the shock is too soft, it's not in the way I expected. These shocks having been designed and tested with the CS springs would make me think the compression would be stronger than I needed on these shocks since the Swift have a higher spring rate resisting compression. If I was worried about anything, it was the rebound.

The reality is, the rebound seems to be enough but the compression seems weak.

All in all, I have things pretty balanced now that I tightened the rear adjustment knob until it wouldn't move any further instead of only moving to the last click. That seems to have made a bigger difference than just a click in adjustment if that makes sense. I worry that running all 4 dampers at their highest setting will cause problems in the long run but anything less and I start getting bounce.

Originally Posted by jack_hammer mad adjustability, yo!

For the record, nothing in my price range has "mad adjustability". lol

[SpencerC]

Thanks for keeping us in the loop. Curious that @I am a banana; is having the opposite reaction.

Let us know how trying different bumpstops work.