Public Service Announcement - Re: dampers, coilovers, etc. (particularly, "budget setups")

I posted a similar thread to this one over at another forum that I'm a member of and got a pretty positive response, so I'm posting it here too as I thought there might be some people here who would appreciate it or who could perhaps learn something from it...:

I've decided to start this thread in an attempt to remind people that for the most part, you get what you pay for and that you shouldn't expect too much out of a "budget" setup.

This is a link to a 24/7 thread where Jeff from Tri-Point Engineering posted some striking shock dyno results:

Truth about K-Sports? - Mazda Forums

...and this is a link to a pretty well-known site that dissects and explains the difference between the "budget setups" and setups from the likes of Bilstein (from who I believe H&R sources their dampers), Ohlins, Penske, Koni, Dynamic, Sachs, etc. The site author takes some liberties and may go a bit overboard in his sweeping generalizations, but the major theme is a valid one:

DGs Autocross Secrets aka Autocross to Win - Shocks

In both cases, shock dyno testing reveals that at the very best, the "budget brands" (Tein, Raceland, Ksport, D2, etc.) are horribly inconsistent and at the very worst they're valved completely wrong and/or they do not at all live up to the claims of the manufacturer when it comes to their adjustability.

I'm not starting this thread to say that these products are completely worthless or that they don't have their place in the market, but I do think it needs to be pointed out that there is a reason you can buy some of these setups for substantially less than (or right around) the $1K price point. They simply aren't engineered well (and likely aren't even engineered on a platform-specific basis) and the shock dynos show it.

If this evidence isn't enough to convince you, or if you're curious to read more into it, I encourage you to do a google search for shock dynos or other evidence to the contrary. Time and time again, I think you'll find that these companies simply can't back up their claims with data, and you'll find plenty of people that toe the line of what I'm saying here.

Hopefully this will save some people who perhaps just didn't know any better from putting a product on their car that isn't what the manufacturer claims it is. I just want people to be as well-informed as possible.

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In the interest of bringing products more relevant to the MS3 market into this thread, I've searched to see what I can find regarding shock dynos for a few more brands (also, if anyone else has more data they'd like to add to the discussion, please post it up and I'll update this OP):

Here's a plot for BC damper from a "BR Type" setup for an 8th gen Civic that were posted on another forum by a BC salesperson (note that this is only for one damper in each graph - 1 front damper and 1 rear damper - and for some reason one of the graphs is in metric units and one is imperial units, so making a judement about consistency across the dampers in a set cannot be made easily from these graphs):





And here's the thread I pulled it from (the thread was initially started as a discussion about a Stance setup):

Stance Coilovers Information - 8th Generation Honda Civic Forum

And for some contrast here are the dyno plots that KW has on their website that show the shapes of the damping curves and how they change with rebound and compression adjustment (I tried for some time to find some "independently obtained" shock dyno results for a KW setup as well, but gave up after awhile. If you have some you'd like to add to the thread, please do - and I'll get them added to the OP):

Rebound:


Compression:


KW automotive North America Inc. Suspension -- Coilovers -- Shocks -- Springs

As you can see in the BC plots, there is really no compression damping adjustment to speak of, and the MINIMUM ratio of rebound:compression damping near mean velocity is roughly 2:1 (with an arguably useless 8:1 ratio at full stiff). It's no wonder people describe these things as bouncy/harsh, since the car is likely "jacked down" over sections of road/pavement with a series of small bumps and ends up riding on the bumpstops.


For anyone who'd like a very well-explained run-down of how the KW V3 valving works, you should check out this article:

Suspension Basics - Whiteline Swaybars & KW V3 Coilovers

 

If I can add to this, BC Racing (from my many phone conversations with them) is fairly open about the fact that their valving is not perfect and are willing to do shock dynos on a set of coilovers upon request. A curious man on the NASIOC forums made such a request and got some shock dynos of his whole set of BC ER coilovers.

NASIOC: BC ER Coilovers Shock Dyno'd









They're better than K-sports by far for consistency, but, not perfect. Quoting the NASIOC poster's takeaway message,

• Little to no cross talk between bump and rebound
• Rebound has a ton of adjustment range
• Bump adjustment is not as sensitive
• First 10 clicks on bump adjustment do nothing
• Bump curve looks pretty digressive
• Rebound curve starts pretty progressive then becomes linear and you stiffen it up even further it becomes slightly digressive
• Each coilover is very consistent. Data that you see is the actual raw data with no averaging. Most of the time you will see a shock dyno with only five points tested and straight lines drawn in between. We tested the shock at setting 15 then went to full stiff and back to 15 and were able to get the same plot all day long.
• There is slightly too much bump dampening
• Front and rear dampers are valved exactly the same
• There is about 2 click offset between left and right dampers

For the money ($1700-1800) you can almost get yourself into a set of Mazdaspeed (KW) coilovers that will be plusher and more consistent out of the box. 99%, handle better as well.

On the other hand, though: off-the-shelf Bilstein/KW coilovers cannot be revalved (at least that's what the reps told me!). They are designed (and TUV certified) for a certain setup "window" ideal for a stock, or lightly modified chassis. Deviate enough from that (say, 500lb weight reduction or 500lbs of downforce), and you will need to change the setup significantly to suit. When you hit this point, interestingly, budget coilover parts are plentiful and available enough that a skilled specialist can build you a perfectly valved coilover kit for not much more than the cost of a Bilstein/KW.

At the end of the day it depends on how much you know and how far you're taking your suspension setup. Good OTS products (Bilstein PSS9, KW v3) work well for a particular range of usage models (like an Apple product). Budget coils are a more flexible base to build your own system from -- if you know what you're doing (Linux).

 

Not sure where you got this information- they absolutely can be revalved.
Also "outside of the optimization window"? Where is this info coming from?
There are plenty of folks running 'brand name' coilovers with a variety of springs and rates with good results. I.E. @phate and the majority of the ground control kits which use OTS koni yellows.

This is not an accurate analogy, because quality dampers can be cheaply and easily revalved, and many of them come with adjusters!

 

@ConeKiller I'm happy to edit my post if proven incorrect, but I called both Bilstein and KW in the past and was shot down on the spot.

I and several other track-car 3's have used GC kits with OTS Koni Yellows, so that's a fair place to start the comparison. From what I know, most people are safely and effectively running 7k, 8k springs on the front Yellows -- fairly "normal" as far as suspension setups go. I decided to up that to 10k to compensate for my front splitter at one point, and killed the struts within 2000mi. That's where I'm coming from.

As far as quality dampers -- you're right, I worded that poorly. JRZ/Moton/Penske/Bilstein motorsport dampers are easily revalved, once you go into that realm. But I have not seen "consumer" OTS kits from Bilstein, H&R and KW for our Mazda3/Speed3 platform so easily serviced. Proof otherwise would be appreciated.

 

Its pretty well known in the miata community that the Koni Yellows are good with softer springs. Once you get up to stiffer springs then the Koni Race(Red) are a much better option.

I as well paused when you said Bilsteins aren't revalvable. They can definitely be rebuilt or revalved as much as needed.

 

Let me edit my post to clarify some things. Still, Bilstein Motorsports told me on the phone that the OTS PSS9 kit can't be sold with modified valving. Maybe it's just wording.

I'm not aware of Koni Race struts for the 3 platform, got a link?

@ConeKiller the "window" I'm referring to is the suspension's front and rear natural frequency, specifically, what the kit designers intended. I think we both agree that if we had the kit and suddenly dropped 300lbs off the back of the car, the car's handling and balance will change significantly. It may serve to our benefit -- not saying all deviation is bad. It's just deviation from intended use.

 

Okay, I understand that if you call the manufacturer you will get the party line- "no, we can't revalve that". However, I'm here to tell you that this is a response that they aren't interested in revalving the shocks. Coming from the dirtbike world, where nearly everything is serviceable or has been hacked to be serviceable - it can also be modified (a.k.a. revalved). Whether it means a fluid change, welding or reboring orifices, changing shim stacks or pistons. The benefit of starting with a brand name shock (KW/Bils/Koni) is that very often parts are high quality and interchangeable. For instance, Tomas on MSF (not sure if he's made it here yet) has used bilstien race shims to revalve his "non-serviceable" MS6 front bilstiens with the addition of schrader valve.

Specifically related to the KW's from here:

So it depends on you willingness to source parts and put it together, rather than which shop will do it for you.

I beg to differ, since I've run 600 inlbs springs on koni's for 10k miles without issue.

"Revalving" and "consumer grade" (or "easily serviced") and two terms that go together like oil and water- much like "Custom" and "Customer Service". Which is much of the selling point of cheap dampers, particularly BC's.

A nugget for you, a member of MSF - "MD1023" recently was quoted $40 a corner for custom valving for his MS3 bils B8 from their NC service center.

Deviation from what? It's fallacy to think that designers have the perfect setup for your particular car. Should you probably readjust your valving after a spring change- absolutely.
Should you stop racing after a 10%-15% change in spring rate? Meh.

If you change your spring rates on one axle by 300 in/lbs alone, you're going to have larger problems than valving- like roll bias.

 

The "digressive" behavior of those low end shocks is a bit of a joke. It's no wonder they ride like total shit. At low velocity they generate almost no bump force. At high velocity the rebound force is skyrocketing, which is going to cause the car to jack down over successive bumps (often into the bump stops). BC, Megan, KSport, KW, etc etc won't actually build you a shock by changing the shim stacks, they'll throw in another pre-valved damper cartridge. KW offers some high end suspension products that are truly custom, but you're into the $3k++ range at that point, and that's not even close to the budget setups in question.

Budget coils are just that. Budget. The growing room available with low end coil over kits ends with springs and drop in damper cartridges (if that's even available).

You mention design frequencies of the suspension. Ever called up one of the budget CO companies and asked them what the design frequencies are? I have, and they had no idea. And that's how I ended up building my own coil overs from Bilsteins.



Bilsteins are most definitely one of the easiest shocks to have revalved. Bilstein USA will do it for ~$100/corner, it's right on their website. Aftermarket shops that work with Bilsteins are plentiful, you can often find them around racetracks. If you want to get fancy, you can have them converted to single or dual adjustable, or even have external reservoirs added. You could even convert them to take-apart and rework them yourself.

You can absolutely build your own coil overs from Bilsteins for either the MS3 or MS6, and end up with a significantly better product than the cheap coil overs, for not much more cash.

 

See now we're talking:

Custom > OTS Good stuff > Budget coils

Which is the original point I'm making. Note how all of our examples are not talking about revalving an OTS coilover kit. You're starting from scratch with Koni Yellows, Bilstein B8's, etc. which are -- I totally agree -- a great product to build custom coils off of.

I was quoted $100/corner as well to revalve B8's. @ConeKiller please share what happened to get that hookup, that makes the whole proposition worth it. Without going into special deals or whatnot:

BC-based custom coilovers:
BR kit: $1000
Revalve: $150/corner = $600
Swift springs: $300
Total = $1900

Bilstein-based custom coilovers:
Bilstein strut/shock set: $800
Threaded perches (front): ~$100
Threaded perches (rear, BC): $85
Revalve: $100/corner = $400
Swift springs: $300
Camber plates: $350 (Ground Control or Corksport)
Total = $2035

Either way, cheaper and better than OTS, but if the Billies can actually be revalved for $40 that setup becomes an amazing deal.

 

I think you missed the section about KW's. Regardless, manufacturers rarely reinvent the wheel when they create an "coilover kit". Internally they the same or extremely similar.

I'm sure we'll all hear about it when it comes to fruition.

I'm not seeing what you're trying to say here. Your numbers support NOT buying BC, if anything.

 

They support putting together a custom setup over buying an OTS quality kit. Whether you piece the kit together from Bilstein/Koni or BC components, the numbers would suggest you do it based on your own preference (assuming you believe in the quality of a rebuilt, revalved BC). I don't side towards BC in particular, which appears to be what you think I'm doing; the best solution is the best solution.

 

I don't know why I got such a good deal on the revalve. It was never really explained to me. But I don't think my contact over there in North Carolina will be doing any more revalves for MS3's because he discovered that the rears don't fit on his dyno, so they're on their way to CA right now to be revalved over there at the usual rate (I think $100/corner). Meantime he revalved the fronts and is sending them back to me. I'll post dyno data when I have it in my thread.

As for Bilstein vs Koni...it's my understanding that there are a wide variety of shops that will revalve/rebuild both. Probably boils down to personal taste. I went with the Bils because I like the inverted design in the front (more robust for use in macpherson setups where front dampers really get trashed) and also Clint's recommendation influenced my decision. Also the price. The Bilsteins with a revalve from Bilstein even at full price are well under $1000. It's a no brainer I think for what you're getting. BTW mine are the B6, not the B8. Same damper, longer rods.

 

Still holding my breath about your gc kit with bils, @VTMongoose

More detailed response tonight.

 

@ConeKiller Are GC making pillow-ball camber plates that match the Billies? They sent me a urethane bushing version that would never torque properly. You can hold everything still and measure out 44ft-lb torque, the strut shaft will still back out causing my Konis to snap after 1000mi, and same for the guy who owned the plates after me.

@VTMongoose excited to see your dyno plots. Is the B6 rear shock too tall to go on the dyno?

 

Not to my knowledge. I warned people about those plates on the other forum.

The doesn't surprise me completely. They may use the same internals as the race shocks, but have a longer body. It's silly that they should cost so much more just for a larger machine.

Actually, there are fewer shops that handle koni's than bilstein- even fewer that handle the OEM spectrum konis. However, I've converted mine to take apart. The koni's could be easily tuned, except for the fact that they use few shims and mostly porting of the piston and the viscosity of the shock oil, whereas bils primarily rely on shim stacks. You could report the koni's by welding and redrilling the pistons and careful selection of fluid -but it would be a pain to achieve the curve you want on one damper, not to mention two identical curves for a set.

Regarding the inverted design, it's not a bad choice, but I don't it's a total game changer. It's primarily a way for bilstein to reuse universal race dampers in custom applications. Notice they didn't have to ship your fronts to Cali. I've received different information about b6 v b8, depending on who I ask. Some say the b8 uses a larger diameter piston (probably the 12mm v 8mm), some say a larger diameter shaft, but it's definitely a longer shaft. You're getting them revalved anyways, so I'm convinced it's a huge difference.

Currently I have a b6 and SZ series shock sitting disassembled on my workbench. Hopefully will get dyno'ed tomorrow and I'll have some fun findings.