wow; leaking? what year did you buy these, out of curiosity?
Truth about K-Sports?
- Thread starter Jeff@Tri-Point
- Start date
wow; leaking? what year did you buy these, out of curiosity?
yeah no kidding its almost getting dangerous getting on the highway occasionally. I just need to save up for a BC suspension so i can toss this junk in the trash...k sport is junk
Rally Ninja
Member
- :
- MSP
Doesn't BC make K-sport? lol
Not that i am aware of
red95_240sx
Member
wow. so now ksport sux
a few observations. first, i have no personal experience with KSport's product. in researching their products, i learned a lot about their company and a little about their history.
first, in many cases where people have had the shocks start leaking shortly after purchase, they were clearly not installed properly. a lot of times, ride height was adjusted at the spring perch rather than the shock body. in some instances, this reduced the amount of travel to the point where the dampers would bottom out. this causes internal damage to the unit.
second, apparently KSport changed ownership about two years ago. KSport has admitted that the quality of their early products was not so good. they have since obtained a TuV approval and ISO 9001 cert; this means their manufacturing methods are sound and their quality control program is sound.
it has been admittedly difficult to separate the cases into old product versus new, improper installation vs. correct installation. in shadow's case above, his dampers are more than two years old AND he purchased them used. there's no telling how they were installed / used / abused on the previous vehicle. it would be imprudent to simply blame the manufacturer without making room for the possibility that the previous owner could shoulder some responsibility.
i am curious how these will work out. they're cheap as all hell, so i will put them on one of my cars to gain some first hand experience. i'm willing to bet they're a bargain.
as to complaints about longevity? would you say that motons sucked if they had to be rebuilt every year? guess what: THEY DO. it usually takes several weeks and one HELL of a lot more than a hundred bucks a corner to get them back. they are phenomenal, but not if your goal is longevity!
first, in many cases where people have had the shocks start leaking shortly after purchase, they were clearly not installed properly. a lot of times, ride height was adjusted at the spring perch rather than the shock body. in some instances, this reduced the amount of travel to the point where the dampers would bottom out. this causes internal damage to the unit.
second, apparently KSport changed ownership about two years ago. KSport has admitted that the quality of their early products was not so good. they have since obtained a TuV approval and ISO 9001 cert; this means their manufacturing methods are sound and their quality control program is sound.
it has been admittedly difficult to separate the cases into old product versus new, improper installation vs. correct installation. in shadow's case above, his dampers are more than two years old AND he purchased them used. there's no telling how they were installed / used / abused on the previous vehicle. it would be imprudent to simply blame the manufacturer without making room for the possibility that the previous owner could shoulder some responsibility.
i am curious how these will work out. they're cheap as all hell, so i will put them on one of my cars to gain some first hand experience. i'm willing to bet they're a bargain.
as to complaints about longevity? would you say that motons sucked if they had to be rebuilt every year? guess what: THEY DO. it usually takes several weeks and one HELL of a lot more than a hundred bucks a corner to get them back. they are phenomenal, but not if your goal is longevity!
insite, are you still in GA. If so, check out the GA section.
I was the previous owner of the Shadow's K-sports, but I, too, bought them 2nd hand. When I installed them, i used the strut body to adjust the ride height. The ride was too bouncy for me, so I sold them. I put my TEINs back on, but have since installed BC Coilovers (see sig).
As far as the graph, i think he's trying to show how different the dampers are from one strut to the other. How can you expect a smooth, consistent ride when the dampers are so different (both set to full soft, then to full stiff)?
I was the previous owner of the Shadow's K-sports, but I, too, bought them 2nd hand. When I installed them, i used the strut body to adjust the ride height. The ride was too bouncy for me, so I sold them. I put my TEINs back on, but have since installed BC Coilovers (see sig).
As far as the graph, i think he's trying to show how different the dampers are from one strut to the other. How can you expect a smooth, consistent ride when the dampers are so different (both set to full soft, then to full stiff)?
I know how they were installed on the previous owners car and i know i installed them correctly on my car. My issue is the fact that i know they went through this big change and yet they have no contingency to help the owners of their older product. Why should i pay $400 to replace all my shocks if they KNOW their is a problem with them. Each K-sport shock has a serial number on the bottom so it could be referenced. I also know they changed the design of their stupid front endlink bracket so it doesnt spin and break endlinks like the one on the old shocks (yeah have a nicely bent front endlink sitting in my tool box).
bouncy ride = underdamped or oversprung (or blown seals).
problem is that this graph does not tell us that. if this is a constant velocity plot, this tells us very little. there are certain velocity ranges outside the realm of normal operation where ALL shocks will exhibit poor behavior. choosing a CV plot rather than the conventional FV plot allows a user to 'cherry pick' his data should he choose to do so. it's like getting an engine dyno of a car at 3840 RPM. great; what does THAT tell us? nothing. we want to see performance through the RPM range. with shocks, we need to see the performance through the entire velocity range. virtually ALL shock dyno graphs show this. why would this guy do it differently?
at some point, business is business. if you were the first owner and these were six months old, that's one thing. you are the third hand owner (at least) and these are several years old. they were probably out of warranty when you bought them; certainly out of warranty now. if i buy a six year old car from a second owner and the motor blows because of a design defect, the company has NO obligation to fix it. whether they SHOULD fix it is another matter......
IMO, $400 is cheap as hell to get four shocks overhauled. if they install their new style shim stacks and seals, you basically get an upgrade from their old sh1tty shocks to their newer ones. probably you'd get a warranty, too.
i can tell you that even if you'd spent $7,500 on a set of 4-way motons, you'd still be rebuilding them now.
Jeff@Tri-Point
Member
The Force vs. Displacment graph is a general graph that we give to customers that allow them to see what there shocks output on min and max settings.
Our dyno tests CVP which is known as (continous velocity plot) This is collecting data points continously through the 360 degree of rotation that the dyno goes though at 10"/second. So it will take dyno plots of compression open - rebound close and compression close - rebound open. We feel that CVP testing is more accurate then your standard PVP (peak velocity plot) testing (which is a reason why to go to us), it gives us and the customer a piece of mind.
Here are some graphs that you requested
Ksport Fronts on Max Setting
K-Sport on Min Settings
K-Sport Rear on Max Settings
K-Sport Rear on Min Settings
Overdampened shocks can cause a harsh/bouncy ride.
You can see from above, the shocks are clearly not even remotely close to matching. I guess the quality control back then could be that bad? Who knows..
Our dyno tests CVP which is known as (continous velocity plot) This is collecting data points continously through the 360 degree of rotation that the dyno goes though at 10"/second. So it will take dyno plots of compression open - rebound close and compression close - rebound open. We feel that CVP testing is more accurate then your standard PVP (peak velocity plot) testing (which is a reason why to go to us), it gives us and the customer a piece of mind.
Here are some graphs that you requested
Ksport Fronts on Max Setting
K-Sport on Min Settings
K-Sport Rear on Max Settings
K-Sport Rear on Min Settings
Overdampened shocks can cause a harsh/bouncy ride.
You can see from above, the shocks are clearly not even remotely close to matching. I guess the quality control back then could be that bad? Who knows..
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jeff -
why does force vary with displacement at a continuous velocity? shouldn't it be more or less one constant for compression and another for rebound? i can see how a cv plot could be useful to verify performance through the entire motion range. why is 10" per second the standard rate?
thanks for posting the velocity graphs. i do have a question, though. on your velocity plots, how come your graphs show a force at zero velocity? shouldn't the graphs start at zero force / zero velocity? i think the plots i've seen start at zero force or very close to it.
what does the industry consider to be a 'good' match between dampers? 5% difference?
thanks for your input.
why does force vary with displacement at a continuous velocity? shouldn't it be more or less one constant for compression and another for rebound? i can see how a cv plot could be useful to verify performance through the entire motion range. why is 10" per second the standard rate?
thanks for posting the velocity graphs. i do have a question, though. on your velocity plots, how come your graphs show a force at zero velocity? shouldn't the graphs start at zero force / zero velocity? i think the plots i've seen start at zero force or very close to it.
what does the industry consider to be a 'good' match between dampers? 5% difference?
thanks for your input.
Jeff@Tri-Point
Member
10"/second is the peak velocity, so the ramp up to get up there is how it calculates the other displacments as the crank shaft on the dyno moves 180 degrees at a time for the full 360 revolution. If we were to run it at 10"/second then yes, it would be constant on rebound/compression.
10" per second is the standard rate for us because we feel that is about as much as a car would see on the street/track. I know Koni NA tests 10"+/second.
It's from the gas pressures from what I've heard. I'm not 100% sure myself.
I believe our standard is the same as Koni NA which is 10%.
10"/sec is considered high speed bumps. The low speed control is typically between 3 - 4"/sec.
Another paper caught while printing. Sorry
eureka! ok, so essentially this is not a CONSTANT velocity plot, but a CONTINUOUS velocity plot. the angular velocity of the crank on the dyno swings a full 360 degrees from zero to compressive 10" / sec, back to zero, up to rebound 10" / sec and back to zero again. measurements are taken continuously rather than at discrete intervals (or discrete intervals are so short as to be negligeble) is this correct?
this would mean that the velocity plots you posted are ALSO continuous velocity, right?
probably right. at the angular velocity required to accelerate through 10" / sec, there probably isn't enough time at V0 for the pressures to stabilize, so there is still a latent force in the damper.
very helpful, jeff. thanks for posting this information. to make sure i'm reading your graphs right (it's hard to tell pink from purple!), for each damper there are two sets of lines. the first compression trace is on the way TO 10" / sec. the second compression trace is on the way BACK from 10" / sec to zero. ditto for the two rebound lines. is this correct?
for comparison purposes, since i can't tell a color difference between the two lines, consider the first graph you posted. one set of lines has its origin at about 50 lbs at V0. are all four lines here for the same damper? thanks again.
