Hello all. I recently had one of my shocks dyno'd and I was looking for some feedback. It's not from a Honda, but it seems like this forum is the most proficient when it comes to reading/analyzing shock dyno graphs, so that's why I'm posting here. I was hoping to get some input as to whether or not this looks good, the curves are ok etc. I do mostly track driving with this car.

Anyways, I attached the chart. It's a KSport GT Pro on the hardest setting. The guy who tested the shock said there was a little bit of slop in the fixture, which probably explains the squiggly lines at the beginning of the graph (the top one). Thanks!

Ed




Modified by ed240 at 12:25 PM 3/28/2007

 

i wish i knew how to read these

 

they look like other graphs...I wish I knew what it ment....atleast it isn't linear

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pythoner &raquo;</TD></TR><TR><TD CLASS="quote">atleast it isn't linear</TD></TR></TABLE>

The bottom graph shows that one direction is quite linear (keeps getting stiffer with increased velocity), and the other is clearly digressive (stops getting stiffer with increased velocity). I just wonder which line is compression, and which one is rebound...

 

I don't like the graph, IMO neither line should be linear and on your graph the top line looks almost progressive and the bottom line is only very slightly digressive. I prefer the feel of a highly digressive shock myself, but the people who race more will have to chime in on whether or not that is good or bad for performance.

Jon

 

considering its a ksport, i'm sure its pretty much oem/kyb gr2

 

Looking at the second graph, the top line is your rebound and it clearly shows that you have the shock at the highest setting and probably only rebound is changed. The adjustment likely adjusts rebound only which explains why it is so linear and you don't see a knee compared to the compression curve. I wouldn't think that such a linear curve is a good thing as your shock will not have a chance to extend over repeated road inputs. But you say that it is a track car, so that may not be as big of an issue on track since you would probably be more interested in controlling body movement. Ideally you would want a steeper section of the curve before the knee to primarily control body movements and let the high speed damping digress to absorb road inputs like bumps and dips.

Without knowing your wheel rates it is hard to say whether the curves look reasonable. But in the end, you don't have much adjustment to play with anyways. I would start at full soft and tune from there.

Also, if you are interested to know whether you have a quality shock or not, test all of your shocks and look for the amount of variation from shock to shock and also test at different settings and compare how consistent the adjustments are...if they're not consistent (i.e. they give different curves even at the same setting, after you've changed and gone back) how can you tune your shocks?

 

Finally a Ksport dyno, and again, most people can't read them. Thanks for helping out.

 

Haha, had to get in and defend the product eh? Explain to us why this is a good curve please........

Jon

 

Not defending the product, just stating a fact, glad to see someone posted a dyno and people are helping him. We don't sell Ksport on Honda-Tech anymore. Most of the people do not know what customers are using there product for. Why do Bilsten off linear and digressive valving rebuild kits. As well as produce all 3 types of shock absorbers. Koni as well. I just find that some people are one sided on here. Both linear and digressive valving is used for tracking. It just seems like every time someone mentions linear valving that they make it sounds like it's complete crap. It depends on the setup. They seem to be valved differently from what I have seen. They seem to be more progessive than linear on rebound. Compression looks the same. Why were you not able to test at the softest setting. Curious to see what that would have looked like.

Modified by BodyKits NW at 8:33 PM 3/29/2007


Modified by BodyKits NW at 8:35 PM 3/29/2007

 

Certainly there are merits to having a linear, digressive or progressive curve. As I said before, since we don't know the rates, or more importantly the wheel frequencies, all I can do is speculate.

So, given this graph, I would say that for a track only car, on a course that does not have alot of ruts and bumps or curbs under braking and cornering, a linear curve could work just fine. Another situation where I could see having a linear rebound is where you're running highly biased wheel frequencies, for example on the rears of our front drive hondas. Since you have such high rates in the rear but not alot of mass back there, under compression due to road inputs and body movements, the spring stores up alot of energy and there isn't alot of mass to dampen that energy when it is being released, thus having a higher damping ratio helps control by slowing the rebound to a reasonable amount...and pitching or snap-oversteer is reduced. But hey, if you drive over a pot hole is the tire just going to skim over it and leave the ground since it can't rebound fast enough?

So, for bumpy tracks or street driving, digressive means a higher damping ratio at low speed to control body movement (which occurs at a slower rate) and have a lower damping ratio to absorb those bumps and hits and keep your wheel incontact with the road.

If you're on smooth tracks, then linear can work well since you are primarily controlling body movements and are not concerned with road input response as much. Or if you are running very stiff springs, you will need the added highspeed rebound to control the energy in the spring as it extends so that you can have a stable and predictable car.

So what car is this shock on and what wheel frequencies, what's the setup??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bsclywilly &raquo;</TD></TR><TR><TD CLASS="quote">Certainly there are merits to having a linear, digressive or progressive curve. As I said before, since we don't know the rates, or more importantly the wheel frequencies, all I can do is speculate.

So, given this graph, I would say that for a track only car, on a course that does not have alot of ruts and bumps or curbs under braking and cornering, a linear curve could work just fine. Another situation where I could see having a linear rebound is where you're running highly biased wheel frequencies, for example on the rears of our front drive hondas. Since you have such high rates in the rear but not alot of mass back there, under compression due to road inputs and body movements, the spring stores up alot of energy and there isn't alot of mass to dampen that energy when it is being released, thus having a higher damping ratio helps control by slowing the rebound to a reasonable amount...and pitching or snap-oversteer is reduced. But hey, if you drive over a pot hole is the tire just going to skim over it and leave the ground since it can't rebound fast enough?

So, for bumpy tracks or street driving, digressive means a higher damping ratio at low speed to control body movement (which occurs at a slower rate) and have a lower damping ratio to absorb those bumps and hits and keep your wheel incontact with the road.

If you're on smooth tracks, then linear can work well since you are primarily controlling body movements and are not concerned with road input response as much. Or if you are running very stiff springs, you will need the added highspeed rebound to control the energy in the spring as it extends so that you can have a stable and predictable car.

So what car is this shock on and what wheel frequencies, what's the setup??</TD></TR></TABLE>

What you wrote is exactly what this forum needs. I just find many people are so one sided, and think 1 set is best. Eibach best, Koni best, Tein best, etc. Rather than giving a decent answer to the question at hand, they rather just put a thumb up and their company name and call that an answer while bad mouthing the product.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BodyKits NW &raquo;</TD></TR><TR><TD CLASS="quote">

What you wrote is exactly what this forum needs. I just find many people are so one sided, and think 1 set is best. Eibach best, Koni best, Tein best, etc. Rather than giving a decent answer to the question at hand, they rather just put a thumb up and their company name and call that an answer while bad mouthing the product. </TD></TR></TABLE>

i second that, here is kind of fill with ppl who think whatever not their setup, then it is crap, almost have to start a race every time to prove which is good or not. sometime, someone's setup is fast doesnt mean it will be fast for other driver. same reason, someone think it is good doesnt mean it is good for other. like everybody swear koni and eibach are the best, while it is not wrong, but still doesnt mean anything else is shitty. i went thru many suspension setup like koni/gc, tein, jic, k sport, d2, cusco, zeal, jrz, etc etc, and still think a full thread body is easier to adjust height for both racing and street setup, and those taiwan/india whatever offer okay product for the price. being good product or not is totally depend on the user, if the user use it wrong, then it is not a good product, is it the product's fault? it is a good question for all of us..........

 

I am pretty bais in what i like. And don't like linear valving at all.

It doesn't make logical since to me when looking at how things work, (IE low speed, and high speed). Progressive makes even less since, IMO.


This comes from the people who i have worked for and clearly reflects what they like. But the people i work for are fast, really fast in fact.

All the JRZ and Moton graphs i have seen are digressive. Penske i haven't ever seen a graph for and the same goes for high end ohlins.


Linear valving makes even LESS since for a street car. The job of a damper is to keep the spring in control and keep the tire in contact with the road surface. If the damper is exerting tons of resistance (ie force) at high speeds of the piston, (ie bumbs in the road. Now im not saying you don't want any force at high speed you do, but you IMO can get and keep it from getting out of control with digressive valving.

Now there might be a reason why pretty much everything that comes from that land is the way it is. Their car set ups are COMPLETLY different then the way we set up our cars. Also from what poeple say there tracks are silky smooth. So maybe thats why they are like they are.

I would be willing to bet that most pro teams run a diggressive valving. Unless they are on a very smooth flat surface. But im not aware of any teams that re-valve their dampers for different tracks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">I am pretty bais in what i like. And don't like linear valving at all.

It doesn't make logical since to me when looking at how things work, (IE low speed, and high speed). Progressive makes even less since, IMO.


This comes from the people who i have worked for and clearly reflects what they like. But the people i work for are fast, really fast in fact.

All the JRZ and Moton graphs i have seen are digressive. Penske i haven't ever seen a graph for and the same goes for high end ohlins.


Linear valving makes even LESS since for a street car. The job of a damper is to keep the spring in control and keep the tire in contact with the road surface. If the damper is exerting tons of resistance (ie force) at high speeds of the piston, (ie bumbs in the road. Now im not saying you don't want any force at high speed you do, but you IMO can get and keep it from getting out of control with digressive valving.

Now there might be a reason why pretty much everything that comes from that land is the way it is. Their car set ups are COMPLETLY different then the way we set up our cars. Also from what poeple say there tracks are silky smooth. So maybe thats why they are like they are.

I would be willing to bet that most pro teams run a diggressive valving. Unless they are on a very smooth flat surface. But im not aware of any teams that re-valve their dampers for different tracks.</TD></TR></TABLE>

Well you have always answered questions in a fashion where you give any answer. Which is all I am stating. Too many people on here, and some that work for some popular companies all they do is say who they work for and a thumb up and no answer or nothing nice to say. Which is what honda-tech does not need and I do not respect people or companies like that. I could care less if they work for D2, Koni, Eibach, or whoever. They have no sense of professionalism when they come on here, and what is funny is that I have dealt with the rest of there staff before in the past. It seems like the only people that act this way are the people that work for the import division LOL.

Anyways Penske makes some nice shocks, I have spoken to them before. A lot of there stuff is monotube, and they use linear as well as digressive valved shocks. There 4 way adjustable shocks are just plain sick, and all there stuff is user rebuildable. You can adjust the shim stack and valve them to how you want. It is a matter of preference, but atleast your not coming on here and stating Ksport sucks, or Tein sucks, linear sucks and just stating this popular post I see a lot Koni & GC as an example and no answer or help in the topic.

 

here's some literature on the Force vs. Displacement Graph.
looks like your's is flipped with Rebound up top perhaps. defintiely linear piston valve. isn't the rebound adjustment on these made by a needle valve? i think that would explain why the low speed isn't affected a great deal.
Low speed is controlled by the amount of bleed, the outer valvestack configurations, and the amount of preload , which determines the nose profile.
the top left of your force/displacement graph above, the needle is closed or nearly closed at the end of your adjustment range, hence such the steep line. not much oil is allowed to pass, until the bleed chokes off and the shims activate.








Modified by hybridmoments at 9:48 AM 3/30/2007


Modified by hybridmoments at 9:49 AM 3/30/2007


Modified by hybridmoments at 9:52 AM 3/30/2007

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BodyKits NW &raquo;</TD></TR><TR><TD CLASS="quote">

It is a matter of preference, but atleast your not coming on here and stating Ksport sucks, or Tein sucks, linear sucks and just stating this popular post I see a lot Koni & GC as an example and no answer or help in the topic. </TD></TR></TABLE>

Most people who have been around for a while, including myself, will simply give a quick response only because the topic has been beaten to death over the last couple years. If Members use the search function all the information they coud ever need is readily available.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybridmoments &raquo;</TD></TR><TR><TD CLASS="quote">here's some literature on the Force vs. Displacement Graph.
looks like your's is flipped with Rebound up top perhaps. defintiely linear piston valve. isn't the rebound adjustment on these made by a needle valve? i think that would explain why the low speed isn't affected a great deal.
Low speed is controlled by the amount of bleed, the outer valvestack configurations, and the amount of preload , which determines the nose profile.
the top left of your force/displacement graph above, the needle is closed or nearly closed at the end of your adjustment range, hence such the steep line. not much oil is allowed to pass, until the bleed chokes off and the shims activate.








Modified by hybridmoments at 9:48 AM 3/30/2007


Modified by hybridmoments at 9:49 AM 3/30/2007


Modified by hybridmoments at 9:52 AM 3/30/2007</TD></TR></TABLE>
That should have been posted soo long ago. That is going to help people a great deal. Breaks it down very well.

 

All these pics should be added to the first post of the "Shock Dyno" thread... Thanks!

 

the second pic is kinda cutoff. sorry

There is ALOT of good info in this manual, and is where i got the diagrams from. A very good read!
http://www.penskeshocks.co.uk/...l.pdf
Just look at the last half of that manual, as it pertains to Penske Double Adjustables and shows part #'s and diagrams for their shocks.
However the last half of the manual explains damper theory: different piston types along with sample dyno charts (linear, progressive, digressive, velocity dependent), changing shim thickness, preloading shims, etc. along with what each one effects in a dyno chart.

Penskes have many user replaceable/buildable valving combinations for all sorts of different forms off racing. so just cause you see one dyno of a penske doesn't mean that's what most of them look like. i've only seen a real life penske dyno for 8100's that had High flow pistons and where on a Chevy Tahoe! haha.
i was planning on buying them and revalving them with digressive pistons, as the lengths were pretty close to my needs. the price was right seeing these are $800 a piece usually. but the cost after revalving them ($95 alone for each digressive valve) would end up being same as i could get Koni 3012's for new.
of course the penske 8100 have the compresion adjustment on the remote resorvoir and i believe on koni 3012 the compression adjustment is made by removing the damper and turning the shaft so not quite as easily adjustable compared to the penske.



Modified by hybridmoments at 1:47 PM 3/30/2007