Suspension spec thread

[Slave IV]

motrrrpsycho, was your suspension stock before you switched to FSD with stock springs? If so, did the fronts also feel like "mush" before the switch?

[motrrrpsycho]

My mod progression (chasis related) listing in "stages" of stuff I installed at close to the same time:

0) Started with a bone stock .:R
1) Haldex + switch, Neuspeed RSB, Autotech dogbone insert, 21 lb 18x8 wheels
2) Passat aluminium LCAs + spindles, Koni FSDs
3) RB 330 brake kit (also slightly lighter than stock Centric rear rotors)
4) 17 lb 17x8 wheels, HPA dogbone, Tyrol subframe collar kit
5) 034 trailing arm spherical bushings, GC coilover conversion kit at 450lb 7" front, 350lb 10" rear

That's where I am right now, with a front ride height of 26.75 and rear at 25.75 both dialed full down.

Question on front end mush - yes - definitely still an issue with the FSDs. The Konis were a great overall improvement and perform as advertised with tighter damping under steady corner load and much better than stock small bump absorption. I think my confidence level with the car, how hard I drive it, plus other mods make it hard to compare from memory now with / without FSDs, but the main problems (for me) are still front end dive under braking, front body roll and lack of ability to take big bumps - mainly mid corner. I will be putting on a new front air dam as soon as I get my springs sorted coz my original one is ground down to a little nub from dragging on the ground so much. The FSDs may have helped with those issues to a point but can not fix them by themselves - at least not on this particular car (given its front end weight and wimpy stock front springs). So I'm pretty sure stiffer springs will help. It's just turning out to be a bit of trial and error to get the right ones. Live and learn...

[Slave IV]

A GB just started for the Ohlin TTX's that I mentioned I was going to get for my S4...how does that relate here? I mentioned some spring rates that PSi recommended and I immediately got a response from the distributor (034 in this case) about the rates they use on their Time Attack car and that all orders would be discussed with each specific buyer to determine the appropriate rates for them.

Just a comparison with the headache some of us are dealing with here to even get the rates for an off the shelf system for this car.

Basically, we need to let manufacturers and retailers of products for this car know that we actually care about the parts we put on our cars too and they can't just drop some marketing piece with a bunch of fluff and expect us to buy. Part of what I've been trying to do with threads like this since I showed up here. [/rant]

Now, back to your regularly scheduled programming...

[motrrrpsycho]

I called performance shock yesterday to ask about potentially grinding perches off and / or re-valving my FSDs. They gave me some helpful feedback and info that I thought I'd pass along in case it help anyone else considering FSDs and / or Ohlins R&T.

They said with regard to the Ohlins, that they are basically way overpriced and really not all they are cracked up to be

Just kidding - just kidding - just kidding - hehe... Just messin with Slave

Back on a serious note, they said that they think very highly of the FSDs, that they are really the only thing out there that can come close to the Ohlins in terms of giving you both improved performance AND improved ride. Basically the only 2 options out there for dampers that can actually deliver on that promise - the Ohlins being better at it but (obviously) also cost a lot more, so for the money - the FSDs are pretty dang good.

However, they also told me that they don't think the FSDs will be able to handle as heavy of spring weights as the Ohlins, and they do not rebuild or re-valve FSDs (would have to send them to Koni for that). They also said that while the FSDs compare well to the Ohlins (especially for the money) on the street, the difference is bigger on the track. They didn't actually say it this way - I'm just making up these numbers - but I got the impression they were saying FSDs might be 80% as good for the street but only 60% as good for track (something along those lines).

[BlixaBargeld]

Wonder what a good street spring rate for the FSD would be. Long time I looked into spring rates etc how big does the diff front rear need to be? There was something that otherwise you can get harmonic frequencies build up ( or so).

[SilverSquirrel]

Wonder what a good street spring rate for the FSD would be. Long time I looked into spring rates etc how big does the diff front rear need to be? There was something that otherwise you can get harmonic frequencies build up ( or so).

FSD knowledge:

http://www.golfmk6.com/forums/showth...t=32323&page=2

[BlixaBargeld]

FSD knowledge:

http://www.golfmk6.com/forums/showth...t=32323&page=2

But not applicable to my question

[SilverSquirrel]

But not applicable to my question

bottom line, FSD shocks are designed to work with stock spring rates at stock ride heights.

[motrrrpsycho]

SilverSquirrel - thanks for that link. The info re bump stop interactions with the FSDs (from someone at Koni no less) is really helpful.

Yes, FSDs are designed to work with stock springs, but the Koni guy does not say to stay away from any other springs or ride heights. He says they work well with Eibach pro kit springs and others with "moderate" lowering.

I'm staying close to stock ride height and will be looking at rather I need to cut bump stops now, but what the Koni guy said about how the FSDs cut rebound damping when they hit bump stops (when you would actually not want them to) makes me wonder if they will do the same thing with linear springs. Hm.....

[SilverSquirrel]

Well, since a dyno plot shows us that damping force varies with frequency, and since frequency is a function of spring rate and vehicle mass, (not talking about how fast the car goes, but how fast the shock goes up and down), I would think a FREQUENCY SELECTIVE DAMPER aka FSD,would be even more sensitive to changes in spring rate and /or vehicle mass than a stock or other non FSD damper.

The "sweet spot" where the FSD changes from soft to firm, on a given car, with a given spring rate, will change. better? worse? who knows. not me.



What happens when you put a shock designed for a 3000 lb car, with a 180 lb/in spring, on to a 4000 lb car with a 300 lb/in spring?

[BlixaBargeld]

Well, since a dyno plot shows us that damping force varies with frequency, and since frequency is a function of spring rate and vehicle mass, (not talking about how fast the car goes, but how fast the shock goes up and down), I would think a FREQUENCY SELECTIVE DAMPER aka FSD,would be even more sensitive to changes in spring rate and /or vehicle mass than a stock or other non FSD damper.

The "sweet spot" where the FSD changes from soft to firm, on a given car, with a given spring rate, will change. better? worse? who knows. not me.



What happens when you put a shock designed for a 3000 lb car, with a 180 lb/in spring, on to a 4000 lb car with a 300 lb/in spring?

Hmmm not sure if you understand the " sweet" spot is different from what you think it is. Short bumps will always the same. And the " designed for xxx" is to a certain degree just legal blabla
For the GTI they were reviewed favorably with DG springs ( yes I know diff weight of car, dampers, ....).
Ok what would be a good guesstimate for FSD and street? 350/250? As my car didn't gain 1000lbs overnight

[SilverSquirrel]

Sorry BLix... I was directing that last at Motorpsycho.

Interesting to learn from a previous post a page back that
Koni makes different FSD for regular mkv vs r32.
Why would they do a crazy thing like that?

compared to a mkv gti, the r32 is 400+ lbs heavier, about 13% fatter! So FSD for say, GTI, will be 13% less damped (bouncier)
Also, stock r32 springs are 20 to 35% stiffer than GTI, meaning the damping force of the FSD will be that much more inadequate, making the suspension even further underdamped COMPARED TO THE GTI, WHICH THE FSD WAS DESIGNED FOR. This will make the ride soft and bouncy, and not as smooth.

About the sweet spot comment:
Think about this: Stiffer springs will make the suspension travel less given the same bump at the same speed for the same car. right? But the bump takes the same time to go over in either case. velocity=distance/time, Therefore the velocity seen by the FSD could be seen as "low speed" where as before you changed springs, the shock thought it was getting a "high speed" bump, and opening the FSD valve to soften up. Now, it keeps the valve closed, and you experience a hard hit, and then the car pogos up and down because the damping is inadequate, where if you kept stock springs, it would have soaked the bump up and kept rollin down the road.

My point is, much like the bump stop issue (see link to MKVI forum above) with regard to FSD's working correctly, I think they would be sensitive to changes in spring rate, and car weight, MORE SO than other "normal" shocks. And this is on top of the problem of a shock not being valved correctly for a specific spring, car weight, and intended use!


Im just puzzle piecing this stuff together from reading this thread, and others, and some googling on suspension math.

[motrrrpsycho]

Good stuff, guys. Coincidentally I just discovered today while looking at shocks on tirerack.com that several PN's are the same between MKV GTI & MKV R32. I thought this seemed odd, so looked them up on Koni's web site. While TR lists same PNs between GTI and R32, both Koni sports (yellows) and FSDs show different PNs on the Koni site. I dug up my paperwork from when I got FSDs installed and guess which ones I have... The GTI PN. F**King awesome.

SilverSquirrel - your thoughts do seem to make a lot of sense. I'll be calling Koni first thing in the AM.

I'm supposed to be dropping my car off @ 9 AM to get my 2nd set of GC springs installed. Same shop that ordered the FSDs and installed the for me. If they bought them from TR or somewhere else that listed the GTI PN for the R32, then its not the shops fault, but hopefully they can get whoever they ordered from to take some responsibility for sending the wrong ones. Makes me wonder now what the CORRECT FSDs for the .:R would feel like - even with stock springs.

[BlixaBargeld]

That the FSD and other Konis were sold as " for R32" isn't good business practice. Someone ordered the STR ( or what the basic line is called). And that the GTI shocks were sold to R32 owners it even tougher to understand ( as here there are two part numbers).

Koni step up!

[JRutter]

Got results from Mike at TyrolSport today on spring rates for the VR6 A3. The only other bit of data beyond the measurements from this and my previous post is that the Euro springs lowered the front of my car by about 5/8" and kept the rear at the same ride height.

In round numbers:

S-Line F = 180 lb/in
Euro F = 280 lb/in

S-Line R = 250 lb/in
Euro R = 330 lb/in

[BlixaBargeld]

Hmm and as the FSD are probably designed for the Euro springs .....

Too much guesswork for me as I have little real knowledge on this issue and if I would try couldn't expect to improve it ( no track no experience to translate driving feel into technical changes).

[motrrrpsycho]

Got some more info and news to share. I talked with Lee G. @ Koni and he tells me that the different PN for the FSDs for R32 only came out about a year ago and is only very slightly different. He said the fronts are still the exact same PN, only the rears are different. For the rears, the body is 10mm different (I think he said longer, but can't remember for sure now) and that it had slightly different dampening. He said if you already have the older PN to not worry about it - it was not a significant difference and certainly not worth the cost / effort to replace.

As for ride height and spring questions, he basically re-iterated what he was quoted as saying in that other thread - stay off the bump stops and you should be fine. I asked if he thought linear springs that are stiffer rates than stock should be OK. He said linear vs progressive does not matter, and somewhat stiffer and/or lower is fine. He said that because they are not manually rebound adjustable, you should not go -too- much stiffer than stock - if so, get yellows. Or if you are lowering to the point where you can't avoid some bump stop contact - get yellows. Otherwise FSDs are fine.

A note on yellows: Lee mentioned that while the different PNs between GTI and R32 are not significantly different for the FSDs, he said the difference for yellows IS significant, so if anyone is thinking of getting yellows, make sure you get the R32 PN from the Koni site before you order. A lot of the sites out there may still list the same PN for both GTI and R32.

As for my set up with the Ground Control kit - GC insisted that the 5" long front springs would work for me and that I would not have an issue with travel. Maybe they work for the GTI, I don't know, but for me - first corner I took at an even semi quick pace and hit a bump - I slammed in to the bump stops hard and just as Koni described, the FSDs don't try to resist the rebound force so I bounced up and down 3 or 4 times off the bump stops from (I think) just one bump in the road. I could try cutting my bump stops, sure, but as easily and as hard as I hit them, I can't imagine I will recover enough travel unless completely removing them which can obviously kill the shocks, sooo yeah. I'm screwed. Not sure what to do next, but lesson learned - do NOT try to use a GC kit with Konis or any other shock with welded on perches UNLESS you know going in that you will have to cut / grind the perches off. Now I either have to do that, buy Ohlins or try to get GC to take the kit back and do something else all together.

[BlixaBargeld]

That blows . All this work for nothing.

But I remember the diff PN are older than 1 year. There was change to the FSD in the beginning (high pressure > low pressure or so) as the early FSD seemed to have lifted the vehicle.

[whyderp]

I asked on here before and got no reply, but what would you guys recommend for a track set up; Bilstein struts and H&R springs or Some KW v1 coilovers? I'm looking to spend around a grand, less if possible. Thanks!

[yellow bunny]

personally I would go with Bilstein Sports and Factory springs. IMO Then use the other money and go to the track and get to know your car.

Tires should be on your list for the track.

[Slave IV]

Thanks for all the recent updates! Sucks about the FSD's...sounds like those are not a great option for this car since they didn't even bother to change much between the kits for the GTi and R32. I would still try them with different springs and not use the GC coilover kit.

whyderp, between your two options, I'd go with KW V1's. But if you really want a track setup, how much track time do you have in the car so far? If not too much, I'd suggest tracking it with the stock suspension to see exactly what you want to improve and save your money in the meantime. I really think Ohlins are the way to go (even with stock springs) or maybe the KW Clubsports. It might cost more than you want to spend now but if you save up, work on your driving and be patient, I think it will be worth it to get something better than what you listed.

[ryeboy]

Got some more info and news to share. I talked with Lee G. @ Koni and he tells me that the different PN for the FSDs for R32 only came out about a year ago and is only very slightly different. He said the fronts are still the exact same PN, only the rears are different. For the rears, the body is 10mm different (I think he said longer, but can't remember for sure now) and that it had slightly different dampening. He said if you already have the older PN to not worry about it - it was not a significant difference and certainly not worth the cost / effort to replace.

As for ride height and spring questions, he basically re-iterated what he was quoted as saying in that other thread - stay off the bump stops and you should be fine. I asked if he thought linear springs that are stiffer rates than stock should be OK. He said linear vs progressive does not matter, and somewhat stiffer and/or lower is fine. He said that because they are not manually rebound adjustable, you should not go -too- much stiffer than stock - if so, get yellows. Or if you are lowering to the point where you can't avoid some bump stop contact - get yellows. Otherwise FSDs are fine.

A note on yellows: Lee mentioned that while the different PNs between GTI and R32 are not significantly different for the FSDs, he said the difference for yellows IS significant, so if anyone is thinking of getting yellows, make sure you get the R32 PN from the Koni site before you order. A lot of the sites out there may still list the same PN for both GTI and R32.

As for my set up with the Ground Control kit - GC insisted that the 5" long front springs would work for me and that I would not have an issue with travel. Maybe they work for the GTI, I don't know, but for me - first corner I took at an even semi quick pace and hit a bump - I slammed in to the bump stops hard and just as Koni described, the FSDs don't try to resist the rebound force so I bounced up and down 3 or 4 times off the bump stops from (I think) just one bump in the road. I could try cutting my bump stops, sure, but as easily and as hard as I hit them, I can't imagine I will recover enough travel unless completely removing them which can obviously kill the shocks, sooo yeah. I'm screwed. Not sure what to do next, but lesson learned - do NOT try to use a GC kit with Konis or any other shock with welded on perches UNLESS you know going in that you will have to cut / grind the perches off. Now I either have to do that, buy Ohlins or try to get GC to take the kit back and do something else all together.

Wow. Jake I somehow feel responsible for setting you on this misbegotten path. I don't understand how the Ohlins and the Koni FSDs could be that different in height with or without the perch. A real head-scratcher for me. Here are my Ohlins set up with 7" 450lb/in Eibach springs:



Here is the "stance" achieved with the 7" 450lb/in fronts and the 10" 350 lb/in rears (now about a 1/4" lower front and rear:



Looking at where the perches are placed for the linear Eibach springs, it is hard to imagine that they are much lower than what you could have achieved on your FSDs. Regarding the rears, they were high initially (~25.5") but settled to around 24.75" after a week or so. That should have been your experience as well.

"Too stiff" may be in the eye of the beholder or a function of how well the dampers work with the springs. As I mentioned in my updated post with pics:

http://forums.vwvortex.com/showthrea...content)/page2

Since the install, I have maybe hit the bump stops in the front once, but only in the most extreme conditions. Previously, I was hitting the OEM bump stops frequently on much lesser irregularities.

Moreover, by maintaining near stock ride-height, the ability of the suspension to "extend" into "dips" has been impressive--especially at higher speeds. Less so at lower speeds, but that is to be expected. Truth be told, the increased "stiffness" of the springs is really only felt at such low speeds. At 40 mph and above, the suspension seemingly does most of the work and makes the car feel "planted" and "stable", unlike the OEM suspension. Turning into corners, the front outside corner doesn't dive like before. I could go on, but I think I've made my point.

[motrrrpsycho]

Jay - no man, I don't blame you at all (maybe GC to an extent). My main reason for posting this stuff is not to whine or blame, but hopefully to get at least some value out of my pain in the arse situation by possibly helping someone else avoid the same mistakes or have a better starting point if they want to try GC + Konis. Your descriptions of results with your set up make me REALLY tempted to just splurge a bit and go for the Ohlins, though I'm trying to reserve discretionary funds for another project (SC).

BTW - what is "stock" ride height, anyway?

[Slave IV]

BTW - what is "stock" ride height, anyway?

Good question...If someone finds the answer, please post up. I can measure my car when I get a chance.

Thanks again for all the shared info here.

[abeR]

25.5 - 26 ftg

[BlixaBargeld]

Ftg can change depending on the tires. How about middle of wheel/axle to fender?

[abeR]

Ftg can change depending on the tires. How about middle of wheel/axle to fender?

this measurement was on OEM tires/wheels. I dont have the middle of the axle to fender measurements.. but im sure they are out there.

YRHMV

[ryeboy]

Got results from Mike at TyrolSport today on spring rates for the VR6 A3. The only other bit of data beyond the measurements from this and my previous post is that the Euro springs lowered the front of my car by about 5/8" and kept the rear at the same ride height.

In round numbers:

S-Line F = 180 lb/in
Euro F = 280 lb/in

S-Line R = 250 lb/in
Euro R = 330 lb/in

Good to get real numbers. Did you happen to measure the spring lengths for these?

[JRutter]

Measurements are back a couple of pages:
http://forums.vwvortex.com/showthrea...1#post79031543

Someone mentioned that the stock springs are pretty much the same as the Mk5 R32. I think that Mike has test results for them vs Mk6 R springs in his build thread on that forum, but I'm running late and can't find it right this second.

[motrrrpsycho]

Hey John, so are you planning to run the euro springs and Ohlins then? That seems like it might be a really good combo. Is there a "magic decoder ring" somewhere for those color dot abbreviations? Grn and Gry seem obvious enough but not sure about all the Ps (pink? purple?).

BTW, on the "what is stock ride height" question, I measured my friend's bone stock R the other day (MKV with about 30K miles) and it was 26" all around. (His front left corner was about a 1/4" lower tho.)

I'm in the process of following the suspension DIYs to take my GC stuff off. One thing I noticed when fiddling with adjusters before doing anything else was that I had to adjust the left vs right sides differently to get to the same height. With both sides full up, I got to 25.5 LR and about 25.75 RR. I had to drop the adjuster down about a half inch RR to even it out. Then when I put the stock rear springs back on its about the same difference, so its not an issue with the GC kit. Just curious if others who have measured all 4 corner heights have run in to this, or if those with coil-overs have had to adjust the height differently left to right to balance it. May be perfectly normal, IDK, or maybe something is a bit off with my car?

[Ryan E.]

hrrmm, last time I adjusted my rear I had pretty equal ride height in the rear and the same amount of threads showing...

[motrrrpsycho]

You also haz that rigi cola mojo working

Not asking specifically about front / rear / left / right, but just variations in general. I'm guessing that in a perfect world everything would be nice and symmetrical, but in reality, maybe its not uncommon for some asymmetry? Ryan's car is good - anyone else slightly off left to right (either front or back)?

[skaven-R32]

FTG measurements can be impacted by very minute differences in what appears to be a perfectly level parking surface. I measured my FTG daily after my coil install and would see up to .25" swings despite parking in the same place every day.

Maybe go from fender-to-hub measurements and it will be a bit more accurate for you?

[JRutter]

P=pink

Yeah - I will be starting out with the base Ohlins and the Euro springs. I also ordered used Passat swivels and new TT arms and ball joints.

I was wrong about measurements for the stock R32 springs, but the R20 springs are 185 F and 285 R.

http://forums.vwvortex.com/showthrea...1#post78806300

[Slave IV]

So, who's going to try some FSD's or Ohlins with the new VWR springs?
Might be close to a perfect combination. I've updated the OP with specs for the VWR springs but here they are:
Spring Type/Rates:
Linear
Front: 35 N/mm or ~200 lbs/in
Rear: 45 N/mm or ~257 lbs/in
Additional:
Front Lowering - 10-15mm or .4" - .6"
Rear Lowering - 8-13mm or .3" - .5"