Raceland Dyno Test Results
 

Speaking of dyno charts, Disaster was kind enough to volunteer his new and unused Raceland shocks for dyno testing at Stewart Development.

Bernie dynoed the shocks today, and here are the results.

There's a lot more to this story, as Bernie had a look inside while the shocks were there. What he found was a bit surprising, but I haven't seen the photos yet so I'll leave it at that.

So......good or bad? i dont do well with charts....

Could be better, could be worse.....

Keep looking and some not to difficult to see characteristics should stand out.

They aren't very consistent are they...

the only thing i noticed is that each shock put out a diff number...

one front had i higher compression and decompression numbers than the other side, same with the rear?

im curious to see these pics you speak of...

Not particularly, but I think you'd be surprised how few shocks actually are consistent from side to side.

If you know which ones are weaker than the others couldnt you put those on the pass side of the car seing how there would be more weight on the driverside more often than not? (weight from the driver)

They have a similar curve to another shock, I just can't think of it at the moment...???

Shocks aren't really handling the vehicle weight...more the unsprung weight, so you'd be better off compensating by gluing some weights onto the A-arm...but I wouldn't seriously recommend that.

The big thing that struck me was how much less rebound damping there was on the rear shocks. I'm not sure why you'd want less rebound damping on the rear suspension....especially that much less.

I'd also be curious to see how these compared to the stock OEM Koni's and a typical aftermarket shock, like the GR2's.

Looks like a decent aftermarket shock (similar to the Xida curve) in the front and a stock shaped curve in the rear (similar to Koni sports or AGX on soft).

People are saying these things are smooth on the highway?

They're reported to be comfy for those who leave some bump travel in their setups. I suspect they'd reach their limits and become quite boingy on a rough road pretty quickly; especially the back.

What struck me is that the rears have more bump damping than rebound damping. First time I've seen that in a dyno graph.

They both have a lot of bump dampening.

Mine are still doing great. Its been exactly a year now. Still no problems. Street car though, no trak.
One thing I want to change: soften up the back. Its WAYYY too stiff. The fronts are fine over bumps and potholes, the rear shudders from time to time.

who knew? :fawk:

now if Bernie would post his pic's and comments on the dissection.

I have yet to experience that

Horrible, IMO. They're just underdamped in general.

Front, Bump - Poor low speed damping for the spring rates. High speed gradient too aggressive
Rear, Bump - As above, just worse.

Front, Rebound - No low speed control for transient control. High speed rate a touch too aggressive
Rear, Rebound - As above, just worse

Classic mistake of tuning for spring rates ie a stiffer spring needs more damping. That's not the case, as you're tuning ride frequencies not spring rates.

Phil
PS Does Bernie have a F vs PV graph as that would be the raw data rather than averaging which provides another view of the data?

Could that shutter you are feeling be because there isn't enough damping and the rear isn't being controlled like it should?

We've got a 2009 Hyundai Genesis that has this exact problem. A lot of people on the forums complaining about the shocks and springs being "too stiff" but in reality, it is a bit underdamped, which can allow the suspension to get excited over surfaces that it should not. Some people say they've hit sections of highway pavement where the car starts porpoising back and forth. The spacing of the waves in the pavement overwhelms the dampers. I'm looking into buying upgraded components from the 2010, but it just occured to me that maybe someone like Bernie could tune the shocks we've got on there...though I don't think my wife would be too happy to have her car up on blocks for a couple weeks. :-D

The only obvious underdamping I see, is the rear's in rebound.

The compression doesn't look that far off from some other, highly touted shocks (Xida's for example.) However the slope is a bit steeper...particularly the front slope. Maybe it's harder to get a flatter slope with a twintube?

The front rebound curve doesn't look to dissimilar from a trace of another good shock. The rear just makes no sense to me.

The spring rate changes the frequency, doesn't it?

I imagine he has all the typical data that dyno testing would provide but he's also got customer's shocks to work on, so more data and analysis, from him, will have to wait.

the spring rates out of the box are jacked. There's just no way to work around it. an 88% F/R bias on the RL and a 92% bias on the Rokkor's just sucks.

True, so it is a combo of too much spring and not enough rebound damping. I'd have to pair these with considerably softer rear springs because the car is weighted toward oversteer as it is...or maybe I'd have to disconnect the rear sway.

275-300# rear spring with a stock rear bar if you have an LSD

Really? There's less damping than an OE damper there.

I didn't stutter :shrug:

But on the other end I'm at 425. On a shock only "rated" to 300.

The main issue, is there's very little shape to the curves. The actual stiffness is an issue on the rear rebound, but the more important element is the shape of the curves.

The rebound is pretty much a linear line, which would suggest a piston that's allowing a lot of bleed around it rather than through it. That's poor design/manufacture/components.

Bump is similar, but clearly has a knee point where the curve 'blow-off' from the initial rate. Still, there's potential for a more low speed bump to keep those stiff springs under control for traction.

If you're interested, there's some useful stuff here: http://www.optimumg.com/OptimumGWebS...Tech_Tip_4.pdf

Poor mfg qc? Never gonna happen in a $300 Chinese product.

The problem is too LITTLE rebound to handle the heavy rates. the shocks are not in control of the spring.




Now the question is. Is Bearnie going to revalve them?

Step back from race track spring rates to performance street. The current valving with a spring change in the rear works just fine. Especially for the target market of entry level street / weekend warrior.

All the further "changes" and development are going to do is run up the cost. Keep them cheap, get more people started.

I'll give you that, but I still don't like the curves.

I'm not even looking at it from a track standpoint, you need the rebound the control the spring rates. I'm also no shock expert.

But with the reports of failure and the pictures of seen of the lack of travel; I'll pass. You can easily get a budget OTS shock / OBX coilovers for just a little more and have a little better piece of mind knowing your running konis or illumnias that may or may not fail.


I was trolling over at the m.net thread, not over here. I had considered them for a while since I DD the car and was looking for something cheaper yet spirited while maintaining a more comfortable ride. I ended up pruchasing used illunimas for $250, but had to resell them cause they required me to get shorter springs than what I'm running on my konis.

we'll let Bernie pontificate on the curves and quality.

I'm still adamant the CR failures and lack of travel are due to dumbass installs. Savingtons failures....dunno??? what springs was he on?

you; troll....NFW

there's nothing wrong with adjusters over shocks...That's all we could run in IT in the late 80's early 90's. We screwed with them until they worked.
Something I want Bernie to expound on. I've long held that the shock can be successful even if the damping capabilities are 75% of the spring rate. That they don't need to match each other 1:1. Because on a rudimentary level all were trying to do is slow the energy being input or removed from the spring.

65% is the "target" for critical rebound damping. The curves look linear to me-not so good. Softening the rear springs would probably make them much better for daily usage. The raceland rears remind me of Koni STR shocks.

Hard to do; they're twin-tube shocks masquerading as mono-tube shocks.

what is the body length compared to a bilstein?

Dunno.

I know the RL's are 1.5" F / 1" R shorter than stock

Bernie tells me that what you think is the shock when you're looking at a Raceland is really just a very pretty cover for a rather nondescript twin tube shock that is slid inside the cover. Hmmm; does that make it a triple tube?

Turns out you can open the aluminum cover and remove the steel twin shock inside. The actual shock has no markings or descriptions of any kind. It could be any number of oem style daily driver shocks built in China and sent out under various labels as economical replacement shocks for grandma's decrepit AMC Hornet. It probably wouldn't be too bad if it were, say, a GR-2 or something decent; chances are, it's something quite a bit lower on the low cost bid sheet.

But you've got to hand it to Raceland for their very clever marketing. Doll up the outside with pretty powder coated springs and an anodized aluminum camouflage cover, and chuck whatever you have extra of on the shelf into the inside. Charge $300 and profit.

So is Bernie gonna throw some Penske shocks inside the Raceland shell and create the ultimate sleeper shock?

Excellent!

http://blog.jackpotcity.com/wp-conte...illandted2.jpg

Now it's just a matter of finding inserts that will fit!

Test post.

That would be Penske shocks inside a monroe body.

oh look, Bilstein yellow
http://lh5.ggpht.com/_yxCranfljAk/SH...0/IMG_2261.JPG

and Koni red
http://www.awrracing.com/images/volv...strt_kitLG.jpg

contrary to your opinion, I think this is a great revelation and opens possibilities when the shocks do go away.
Insets have been around for decades. I guess Koni, Bilsein, KYB; et al also stole the Russian nesting game. Oh, they beat Raceland to the punch because I remember them back in the early 70's
Now we get a decent set of cheap adjustable bodies we can tinker with after getting 30k miles out of them.

These shocks have yet to surprise me. I got exactly, if not more than I paid for.

Only problem with that thinking is that you can buy Ebay coilovers for $75.

what will you install them on?

Quality shocks such as Tokico or Bilstein. For NB's out of the box Bilsteins for about $400 are much higher quality than Ricelands.

that's nice....I'll be $200 richer :fawk:

Or is that $300 dumber:laugh:

My opinion isn't quite as contrary to yours as you might think.

To a degree the concept is actually growing on me....a bit. And I do like the idea of installing something decent within a protective shell of a sort. I'm just not impressed with the insert they used, though I recognize they are building to a price point.

I have to admit, though, that not being as familiar with shocks as you are, I was completely surprised that there was another little shock inside what I thought was the shock. Learn something new every day.

I was expecting it and bought a set in the hopes that the cartridge could be changed. The BMW guys have been putting inserts into racelands for a year or so now.

Any luck finding an upgraded insert?

It's a little different for the Miata guys than the BMW guys. The BMW guys have to use inserts due to the strut style suspension unless they want to spend a little more. The idea of putting a monotube inside of a tube and then mounting that instead of just mounting the original monotube would only be for when you need to "hide" a shock (cheater). This is not as uncommon as you would think. A lot of oval track series have spec twin tube shocks, so the best way to get a rebuildable shock is to hide it in the gutted twin tube body.

I will be posting all of the data on these shocks, along with pictures, later today.

For the individuals that want to get really detailed on the data, I suggest you download the Roehrig dyno software. Here is a link: http://roehrigengineering.com/Downlo...ads%20page.htm

Download the software and install in demo mode. I will post the data file and the software will allow you to see the shocks in full detail with all available graphs.

I've read that source. Have you seen the "curve" of the Xida shock? It isn't too dissimilar...on compression or rebound. After .5-1 inch/s the curves become quite linear.

http://949racing.com/images/Xida_S_Front.jpg

Please don't get too excited about this. There is still a lot that the dyno doesn't show. Remember when I told you guys that you can build two shocks that look the same on the dyno that will not react the same on the vehicle.

Not all linear graphs mean a linear piston. You can valve a digressive piston with a lot of bleed and it will look like a linear, as in the case with some Bilsteins.

It will be interesting to view the more complete data when you get it. My point though, was the linear curve shown isn't bad, as PhilMD seemed to suggest. The curve alone (other than the rebound issue) isn't a reason to denigrate them.

I read your earlier comments suggesting there are attributes that the shock dyno doesn't show. I'm still trying to get a handle on that. Perhaps when I see the raw data it will make more sense.

Just because the rebound curve appears alright, that doesn't mean it is. It depends on how they achieved the valving. If they used a linear piston, sure. If they used a digressive with a lot of bleed, then that is sort of old school and common with production units to cover flaws.

Picture a shock where the piston doesn't have any shims, only ports/holes. When the shock changes direction, there is nothing really controlling the low speed.

Even with the raw data, you can't confirm the valving for sure until you open the shock up.

When you say there is "nothing really controlling the low speed" what do you mean and why wouldn't that be shown on the dyno charts? How low speed are we talking about? At a low enough speed, it seems, you don't even need or want damping.

P.S. Here you are up at insane hours again. ;-)

And this is why I am heading to bed. Goodnight everyone.

The trick is to pass out at 10pm like I did, and then get up at 3am. :-D

Thanks for providing the data and helping us understand how these things work...or are supposed to work.

I wondered about it. When you look down the shaft, into the top nut. The seal is about 1 cm recessed. I've never seen a mono tube like that.
The revelation of the inserts will be nice for long term service. I'm doubtful we'll get a forum correct insert in there for performance. But then again....they are $300 CO's I just don't care.

ya left my best line out :(
These shocks have yet to surprise me. I got exactly, if not more than I paid for.

Funny you should say that. I still haven't decided if I'll install them when they come back from Bernie. I might....just to be able to follow up on how they "feel" in the vehicle. In the meantime, I've become more and more enamored by the Xida's 949Racing is selling. They are an additional $200 if you want them with helper springs. You know what I'm thinking...."Are these the same coil diameter? Do I already have a perfectly good pair of Raceland helpers?"

you need to do that with 275# rear spring. Drive it for 6 mos and report back to the class.

I think what Bernie's saying here is that without shims or some other way of differentiating between low and high speed damping you're stuck with a single and mostly linear damping rate. Damping still occurs as the fluid moves past the ports/holes, but you can't set up a different damping rate (the slope of the graph) for low speed.

Those shims can be tuned to open and blow off pressure by the tuner. At low speeds they can be set to stay put, forcing the shock fluid through the bleed hole. When a large hit occurs (high speed event), the pressure spike forces the shims to deflect which opens additional ports. The damping curve now follows a different slope.

More or less bleed, and how it is combined with the control provided by the shim stack and piston ports, can sometimes mean shocks will have roughly similar plots but will arrive at those plots using different components.

This is something I don't understand as to why Bilstein does this. Looking at the dyno graph I posted elsewhere for Bilstein Corvette race shocks they have what looks to be a linear rebound similar to the NA Bilstein.