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      09-18-2019, 11:22 AM   #23
bravehart38
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Well...its definitely a valving issue. After a short track day (3 20 min. sessions) and so street driving i'd say 90%-95% of the bounce is gone. It doesn't matter if its sport or touring valving for what we are paying it sux. It finally rides like an M should in my opinion. That being said if i could do it all over i would have just purchased a used set of coil-overs and had them dynoed and rebuilt before installing since that's what i ended up doing except my set was new. Shout out to Inertia Labs http://www.inertialaboratory.com/
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      09-18-2019, 11:03 PM   #24
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Quote:
Originally Posted by bravehart38 View Post
Well...its definitely a valving issue. After a short track day (3 20 min. sessions) and so street driving i'd say 90%-95% of the bounce is gone. It doesn't matter if its sport or touring valving for what we are paying it sux. It finally rides like an M should in my opinion. That being said if i could do it all over i would have just purchased a used set of coil-overs and had them dynoed and rebuilt before installing since that's what i ended up doing except my set was new. Shout out to Inertia Labs http://www.inertialaboratory.com/
Hello,

What spring rates are you running? Also only the fronts were done?
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      09-19-2019, 07:26 AM   #25
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Quote:
Originally Posted by 991dc5 View Post
Hello,

What spring rates are you running? Also only the fronts were done?
600 front 800 rear. Rears were ok. Just the fronts were revalved. Softer springs won’t fix the bounce I almost went down that road.
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      10-06-2019, 08:16 AM   #26
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So anyone with rs2 touring kit can give me their dampening to at least reduce the low speed bounce? I have tried tinkering on my own with no avail. I think I will get a set of ast or kwcs if I can't get a balance.
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      10-06-2019, 10:42 PM   #27
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Don't get AST. They're absolute garbage. They're tech sucks also. I had a set on an Evo 9 and a set that came with another and chucked them as soon as I could. I'd rebuilt the Evo set twice and they never stayed together
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      10-08-2019, 04:45 AM   #28
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Quote:
Originally Posted by RMDZidane View Post
Don't get AST. They're absolute garbage. They're tech sucks also. I had a set on an Evo 9 and a set that came with another and chucked them as soon as I could. I'd rebuilt the Evo set twice and they never stayed together
Was this before or after AST purchased Moton? Prior to the purchase, AST did have major quality control issues and even stopped selling dampers in the US for a few years while they redesigned their dampers. Their redesigned 5xxx series dampers now use Moton technology and they have addressed quality control issues. I know several people running their 5200 and 5300 damper setups on the track with zero issues.
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      10-08-2019, 07:59 PM   #29
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Not me. Lots of issues. Especially because of my track use.. This was just a couple of years ago. Seriously they aren't any good. Even the people I sold both sets to had so many blown units they punted them off to someone else.
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      10-08-2019, 10:10 PM   #30
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Quote:
Originally Posted by blackey View Post
You could feel the car continue to bounce at stop signs. Not nearly enough rebound.

.
That's not at all what we're talking about in this thread.

You are describing blown shocks with too little rebound valving that lets the chassis bounce at rest.

What the OP (and others) are describing are shocks with too much low speed valving (and too much gas pressure/stiction), which requires more force to initiate damper movement than the road is imparting on the suspension at very slow vehicle speeds. In other words, the forces entering the suspension are too low to get the suspension to compress/extend and thus the chassis follows every little undulation in the road, springing back to neutral very rapidly.... aka: bouncy or busy.

This, as stated, is due to two things:

1 - too much low (shaft) speed valving force (this prevents the suspension from breathing with the road whilst keeping the chassis relatively stable)
2 - too much internal gas pressure which acts as a spring and resists compression/creates stiction

Very common on track-based coil-overs with very aggressive low speed valving curves. If you look at a shock dyno and see a tall, near vertical ramp up just off of zero.... that's a clue.
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      10-09-2019, 09:16 AM   #31
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That could be true in some cases at full closed jetting but I’ve seen dyno plots for these dampers and they don’t have much low speed valving basically linear valving with not much damping force at all imo fwiw...besides even the most digressive race valved dampers when opened all the way up should lose enough low speed force to be comfortable and/or allow more yaw in low grip conditions
In other words pair them with softer springs or have them revalved

Last edited by whitstap; 10-09-2019 at 09:16 AM.. Reason: typos
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      10-09-2019, 09:31 AM   #32
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Quote:
Originally Posted by whitstap View Post
That could be true in some cases at full closed jetting but I've seen dyno plots for these dampers and they don't have much low speed valving basically linear valving with not much damping force at all imo fwiw...besides even the most digressive race valved dampers when opened all the way up should lose enough low speed force to be comfortable and/or allow more yaw in low grip conditions
In other words pair them with softer springs or have them revalved
In this case would I even benefit from increasing the rebound dampening to lessen this effect? I've been trying to adjust it according to the call I made to JRZ by leaving their recommended compression setting (6F and 4R), and increasing the rebound in increments. However the issue persists. The bouncing is evident even at freeway speeds, I've rode on spring equipped m3's and even they do not have my issue.

I am on the touring kit which is supposed to be more daily oriented already.
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      10-09-2019, 11:31 AM   #33
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Quote:
Originally Posted by whitstap View Post
That could be true in some cases at full closed jetting but I’ve seen dyno plots for these dampers and they don’t have much low speed valving basically linear valving with not much damping force at all imo fwiw...besides even the most digressive race valved dampers when opened all the way up should lose enough low speed force to be comfortable and/or allow more yaw in low grip conditions
In other words pair them with softer springs or have them revalved
What's the gas force? A lot of times they "zero" it out on the dyno plots, but in actuality it shifts the whole curve up.


Quote:
Originally Posted by 991dc5 View Post
In this case would I even benefit from increasing the rebound dampening to lessen this effect? I've been trying to adjust it according to the call I made to JRZ by leaving their recommended compression setting (6F and 4R), and increasing the rebound in increments. However the issue persists. The bouncing is evident even at freeway speeds, I've rode on spring equipped m3's and even they do not have my issue.

I am on the touring kit which is supposed to be more daily oriented already.
What are the F:R ride frequencies? The "bouncing" could be pitching. I had pitching F:R frequencies once. The car felt like it was ALWAYS moving and you felt every undulation in the road surface. It sucked.
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      10-09-2019, 04:31 PM   #34
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Quote:
Originally Posted by FaRKle! View Post
Quote:
Originally Posted by whitstap View Post
That could be true in some cases at full closed jetting but I've seen dyno plots for these dampers and they don't have much low speed valving basically linear valving with not much damping force at all imo fwiw...besides even the most digressive race valved dampers when opened all the way up should lose enough low speed force to be comfortable and/or allow more yaw in low grip conditions
In other words pair them with softer springs or have them revalved
What's the gas force? A lot of times they "zero" it out on the dyno plots, but in actuality it shifts the whole curve up.


Quote:
Originally Posted by 991dc5 View Post
In this case would I even benefit from increasing the rebound dampening to lessen this effect? I've been trying to adjust it according to the call I made to JRZ by leaving their recommended compression setting (6F and 4R), and increasing the rebound in increments. However the issue persists. The bouncing is evident even at freeway speeds, I've rode on spring equipped m3's and even they do not have my issue.

I am on the touring kit which is supposed to be more daily oriented already.
What are the F:R ride frequencies? The "bouncing" could be pitching. I had pitching F:R frequencies once. The car felt like it was ALWAYS moving and you felt every undulation in the road surface. It sucked.
unfortunately I do not have that information.
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      10-09-2019, 08:28 PM   #35
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I’m not sure of the gas force but Brian at JRZ would know, that can increase the initial comp and rebound feel if the pressure is high... the stock edc dampers have quite a bit of damping force built into them, not a lot at slow shaft speeds but digressive at mid speeds and a lot of high speed at full closed... I’ve seen the dyno plots for them and I was suprised as even the sport plus settings for the civic and ZCP setups are nowhere near full closed, haven’t ridden in or driven a cs but apparently they use more... for fun if you want to feel full stiff on the edc shocks just unplug one of the sensors and they stay at full closed https://f87.bimmerpost.com/forums/sh....php?t=1603360 awesome thread by jetbill if your interested ... anyway sorry for getting off topic... to answer the question about getting the most out of your current setup I would try going full closed with the rebound and unless you feel like it’s getting onto the bumpstops or bottoming out too easily and quickly I would open up the compression all the way and see how it feels... if it’s too soft and bottoms out too easily start adding compression, and if it improved the slow speed rebound oscillations but is too rough over big bumps reduce the rebound a bit but I doubt there will be too much rebound available... ride height and rake can effect weight transfer as well without changing spring rates... of course I could be wrong and there are a lot of factors that I don’t know just making an educated guess... good luck

Last edited by whitstap; 10-09-2019 at 09:00 PM..
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      06-16-2020, 02:09 AM   #36
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my bad guys, haven't been back on the forum for awhile. forgot my password lol. i ended switching over to airlift performance, rides like a dream. But if you're in the market for coilovers around the 2-3k price point, go with kw's. I had the rs2 with spring rates out of the box. i tried adjusting compression and rebound every way possible. i hate that little bounce you get at slow speeds over a crack in the road. If im spending 3k+ on coilovers i shouldn't have to worry about gas force or none of that. we installed a bunch of kw's on mercedes and bmw's at my shop, never had this problem, even the low end coilovers like k sport and br racing dont have that bounce. just wanted to try out jrz since it was the popular brand on this forum. I always like to try different brands for the experience. if jrz's valving cant even handle little cracks in the road, they wont be able to handle the track for sure lol. jrz definitely should spend a little more on r+d. These are not cheap suspension on cheap cars that people are purchasing!

Last edited by d00bies; 06-16-2020 at 02:34 AM..
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      06-16-2020, 02:50 AM   #37
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Quote:
Originally Posted by F3IGHTY View Post
Bouncy huh...

First let's confirm that you're adjusting the dampers in the correct direction. Full soft is clockwise, and full stiff is counter clockwise. JRZ is backwards compared to most manufacturers.

Next, as a test, set the compression to full soft and set the rebound to 50% aka 12 clicks out / counter clockwise.

Lastly, make sure your tires are set to an appropriate pressure, likely in the low to mid 30's.

This setup should feel 'soft' during bump soak up, without post-bump oscillation.

What's difficult to articulate is how you define 'bouncy'. For some people that could be excessive damping in the chassis while for others it could be too little damping. Try to really describe what's not working the way you expect. The RS twos have a lot of damping range so I'd be very surprised if you're looking for something with even more rebound damping force.

good coilovers are suppose to absorb bumps and cracks. not bounce like a pogo stick imo.
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      06-16-2020, 02:59 AM   #38
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Quote:
Originally Posted by 991dc5 View Post
Hello, hate to revive an old thread but better than starting a new one right? Anyways, I recently installed the jrz RS two touring with GC plates. I'm also experiencing alot of bounce at low speeds. The high speed rebound seems fine but the high-speed compression can also be felt over small shallow bumps on the highway.

My kit has no helper springs, so only the stock jrz rates. My stripped dc5 track car on inferior fortune autos feel less bouncy without too much bump.
had custom built fortune autos on my e46 m3. they were aite. valving on their shocks aren't that great either, if you're gonna use the same valving on every shock, whats the point of letting people do custom spring rates? honestly to me, kw's are far more superior than jrz and fortune autos. I'd go with moton coilovers if you want the high end stuff.

Last edited by d00bies; 06-16-2020 at 03:18 AM..
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      06-17-2020, 02:44 PM   #39
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Quote:
Originally Posted by d00bies View Post
good coilovers are suppose to absorb bumps and cracks. not bounce like a pogo stick imo.
I think this is where problem begins. If yo don't want pogo stick it means that you want chassis to absorb impact, shock don't do much, but if you want shocks do the work there are some occassions where pogo stick begings. Please someone correct me if above statement is wrong.

While good coilovers completely absorb bumps and handle them extremely well it takes some time to settle. So meantime if you hit another bumps or cracks before suspension fully recovers that is when multiple bounces/pogo sticks begin. I have been trying to find a good balance between them but haven't found a solution yet.

Low speed bounce mostly happens in some uneven roads where the road have some soft ups and downs where suspension reacts to much and it gets worse when fronts trigger rears or the vice versa.

I also still believe we need some terminology here in suspension forum to have a consistent chat. I noticed sometimes people talk about completely different things by using same words.
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      10-22-2020, 09:03 AM   #40
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JRZ RS2

Waking up an old thread here
What you guys might be feeling is that all the RS1 and RS2 are a twin tube designs and react differently to the Pro series or something similar which are monotube. The twin tube if I understand correctly has the gas and fluid mixed and less oil so heat soak and aeration might cause some of the problems you are seeing.
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