From http://www.njtuners.com/showthread.php?t=19445

I was at a shop that im not going to name and we were discussing how so many noob 240 owners buy cheap coilovers in a rush to be cool and i brought up the brand K Sport. An employee over heard this conversation and proceeded to tell me that just last week he tested a brand new set of K Sport coilovers on thier dampening test machine(awesome machine). What he told me was'nt a suprise. Each damper had a different compression and rebound rate # , meaning , not one damper matched the other.

In layman's terms , it means that its like driving your car with a different coilovers on each corner. Say a Tanabe on your front right , TEIN on your front left , JIC on your left rear , and Stance on your right rear , without the quality of each , ofcourse.


Now , dont post "my K Sports are great , i love them blah blah blah" if you only drive your car around town or back and forth to the local Burger King.








Quote, originally posted by Jeff@Tri-Point »
In case no one understands, the forces on the Bottom that are labeled is basically a Full Soft and Full Stiff Setting on the shocks.

If you were to have one shock on full stiff and the other on full soft, the rears would almost match, but the fronts are out of control and just completely wrong.

 

Yeah.... that's no suprise. What is a suprise is that just about every shock under $2500 will give you the same results. You have to go with the big guys like Penske, MOTON, ZEAL, KONI to get a well matched set of dampers.

Once the cheap shocks get hot the dampening becomes even uglier.

But for the average guy cheap coilovers are all they need to lower their car and get stiffer spring rates.

 

No surprise.

To be fair, though, a set of Tein dampers for a guy's S14 were tested here, and they were pretty crappy as well. I don't know which Tein coil-overs he had, but he was in SAE with us and CNC'd some Al heim mounts for the dyno. The dampers had a lot of bleed-over and cross talk, and were way off from critical for that chassis. Very over-damped for the spring. Now, Tein supposedly told him that the low-speed rebound and compression were supposed to adjust together, which didn't make any damn sense to us (and still doesn't to me). I have since seen that a lot of Japanese coil-overs do this, and I'm not sure why. These K-sports are no different in this regard.

As far as unequal damping rates, that's almost inevitable. We tested his two fronts and neither of the Teins were identical, although not nearly as bad as these K-sports. They were sloppy, however; if you give me any off the shelf kit for a production car they won't be the same in damping, no matter who makes it. Now, these K-sports are really bad, but unless you have your own dyno or some money, you will not have identical damping rates at all four corners. A good company will deliver within a small margin of error, but will not be identical. Even the Penske dampers used on our prototype racer went through a rebuild to get them identical; that's just the way the tail is on the cat.

Same goes for spring companies and their rates. Hypercoils and Eibach are all the motorsports department uses, and both companies have failed to ever provide two springs that were identical for a stated rate. They were extremely close, but material consistency is never perfect.

All this to say... you do get what you pay for. There are a ton of cheap companies out there, but even the good ones are not going to have an off the shelf system that will be identical between units. What you will get with a good company is a product that is close, and really, what's most important- consistent. K-sport makes crap, there is no question, but there are those who will never know the difference and have no real way (or interest) of even verifying if their set-up is even consistent with changes and tuning. They only want to look slammed and putz around town. They won't see road course time, they won't ever use track telemetry or data acquisition, and they really only need coilovers to brag about how many levels of damping they have, much less ever know what the hell they are doing when they adjust them. For those people, I guess products like K-sport serve a purpose.

Will (ends rant about cheap-*** coilovers)

 

Exactly. To get identical dampers, even from the big names, you will have to tune them yourself to get rid of any slop between production batches. The good companies, though, should be close in performance out of the box and not really an issue unless its a pro racing team with their own engineers. Most importantly, though, the good companies will make a product that is consistent. How consistent damping changes perform on lap one versus lap 300, how consistent the valving remains on lap one versus lap 300- that's what makes a professional damper so expensive. (and worth every penny for a winning race team)

Will

 

Will... you don't have to sound so angry about it.

Who cares. If it fits their needs so be it. I bought and used D2's which are the same junk, and when I was ready to get serious about tracking my car did I buy something much more appropriate.

Honestly it was hard for me to spend $3000 on coilovers but being aware of what cheap shocks were like from driving them on the track I had to make the expenditure.

But to each his own. These cheap shocks fill a demand in the market.

I have noted the same thing happening in the big brake kit market recently as well. All these new Taiwanese and Chinese companies flooding the market with cheap brakes like Megan, Alliance, D2, KSport, WP Pro etc.

 

good read:

http://farnorthracing.com/autocross_secrets6.html

 

Very good info! And it told me something I already know, my Tein's suck!

 

This is a good read. Thanks. I have a question tho, obviously not everyone can afford a set of coilover for 3k. Now, since these cheap coilovers are so bad, what would be a good set-up that won't break my bank? Sure anyone can stay with OEM set-up, but say if I want to improve the performance of the car slightly, what's a good alternative solution? Or is there one?

Note that I'm trying to argue anything, just would like to get some ideas. Thanks.

 

That sounds horrible if you combine the degree of error that you mentioned w/ a unit like the edfc on the flex's. It sounds like 16 different modes of unbalanced coils w/ respect to each other.

 

The author of that page seems to imply that Koni's are good value for the dollar, but also suggests you must have them rebuilt for good results. Unfortunately that doesn't help us at all on our coilover hunt.

I think ultimately, if you go track your car for a baseline, then install coilovers and go race at the same track under the closest possible variables (temp, weather, track surface, etc) and you improve your time by a noticeable amount, then the part is still helping regardless of if all of the shocks have been verified on a dyno has having the same compression and rebound.

On the same note, I do think it's BS that a manufacturer can't produce a shock that puts out the same numbers and sell you a set of 4 for a relatively good price and not need to rebuild a brand new shock to achieve that. Then again I'm not a shock engineer.

 

Well after reading Resolute's post and that link I think its safe to say that my Stance GR pro+ spoilovers are crap....Knowledge is powa so my next coilovers will be from on of the mfg's mentioned in that link....Thanks for the info.

 

Bilstein PSS/9/10's are less than $1,600 from most sellers. They are on the "good" list. So you don't necessarily have to pay $3,000+ for good coilovers.

After reading that Far North Racing link I'll never own anything that's not on the list mentioned.

 

I would like to do a Ground Control+Koni set up. I don't think Grouind Control makes a set up for the 350z, but I believe some one here made his own. Just bought the cheap sleeve coilovers off ebay. He just used the sleeves then bought some springs, Konis and made his own.

Not attacking anyone with the following, just posting some info(most likely useless)

To defend the "240 noobs" this has been talked to death on Zilvia.net(240sx forum) way before the op started this thread. It is also agreed by many on Zilvia that a Ground Control+Koni set up is as cheap and better then all low priced coilovers and as good if not better then the mid to high grade coilovers.

 

wow. his article was a great read. makes me think a bit about
coils i have considered purchasing on rep alone.

 

I can honestly say I'm not surprised. I heard terrible things about KSport and D2 coilovers back in my Maxima days, and also from the 240 crowd. I thought it was common knowledge that they are garbage, but then I see Z/G owners buying them. This shock dyno finally provides some solid empirical evidence to prove what many of us already knew all along.