No surprise here. I was specifically talking about the ones that cater to use with lowering springs. They ought to have added more travel. Otherwise you sit on your bumstops just like you did with your stockers. I was quite disappointed to find that the koni yellows I had purchased had the same limited travel as my stock struts (this was years back when they were rather new).

What hurdles do you foresee arising? Only ones I can think of is the header flex joint, and clearance due to tight spacing. The VW's guys have been doing it without any other required work.

 

Clearance with the bodywork, shift linkages, plumbing etc. Nothing that can't be done. (Hey, put a 5.0 into a TVR. Anything is possible with a big enough hammer)

Surprised on the yellows as they are specifically listed for lowered springs.
Truth is, modern cars don't have a lot of range to play with. It takes more than just chopping off a spring like the old days. Note that Koni will build any shock you want. All it takes is money. True Choice used to be the rep.

 

As was I. I emailed a rep asking about the specs assuming that the travel would be increased to accompany the suggested lowering springs only to find out that they are the exact specs as stock (besides the obvious damping differences and such)

That's the route I took, although I went with bilstein out of preference and the need for an inverted monotube setup.

 

I am experiencing this on my kw's def seems like cv issue. my s2000 had the same issue with the rear cvs which was fixed with spacers . Anyone have any updated remedies other than lifteing the sucker... it looks sooo good!

 

I just installed my vmaxx coilovers. i too have the same vibration 1st or 2nd gear. i dont intend on lifting the car back up. someone needs to make a solution!
http://www.flickr.com/photos/62378409@N02/5676499761/

 

the solution is changing the cv angles one way or another.


CV spacer which no one produces,

Lifting or lowering beyond the vibration threshold


I liftred min 5mm at a time on the coil until it went away and now im smooth as butter!

 

I made some 0.75 inch spacers and that seemed to fix the problem on mine. Sure it raised the car up some, but the car still handles great.

 

Where did you place the spacers? For the perch or cv's?

 

+1

 

I put the spacer on top of the strut in between it and strut tower.

 

Ok so I am reviving this thread, I'm experiencing the same vibration issue under acceleration WOT in 6th gear around 2500-3500 RPM.

So your saying you put a spacer at the top of the perch on each strut tower bolt? Sorry just not sure where the spacer went and if after installing that spacer the vibration went away?

I was thinking it was the shocks but it does seem like the CVJ/shafts is where the vibration is coming from.

Has anyone found a remedy on this yet other than going to coilovers and adjusting the ride height?

 

I put the spacers under the strut tower on top of the strut itself.

 

The spacer will do the same thing as lifting the car by adjusting the springs (If you have coilovers).

Try raising (or lowering) the car small amounts (try one round each time) until the vibration dissipates. You will want to have the car re-aligned after making your final adjustment.

 

any thoughts on how with standard struts that don't adjust? Where would I put a spacer? I was thinking between the Strut hat (part that sits on spring) and the Strut guide (the part that mounts into the strut tower of car with 3 bolts)?

Thoughts, this is really killing me, the other option would be to replace the output shaft (aka passenger side).

 

Replace the output shaft?

The best place to put a shim is between the spring and the spring perch (see diagram location #1). The bottom would be better than top.

You could place the shim between the upper strut mount and the body (see diagram location #2) however this will change how the suspension travels as well. For this reason I would not recommend location 2. You could shim at location 2 to determine the thickness the shim needs to be, then remove that shim and shim to that thickness at location 1. I would start by adding a 1/8" shim then test. Keep adding a 1/8" shim each time until the vibration dissipates. This way you will raise the car the smallest amount needed to remedy the situation. You will most likely need to fabricate the shims unless someone knows of a source (unlikely) for the required shims.

 

I have no idea where to obtain a spacer that would fit either under or above the spring. What do you think about putting it here?

The outer drive shaft, aka passenger side drive shaft as that seems to be the culpret in terms of the harmonic vibration.

 

That location would cause the same issues as location 2. If you shim there you may encounter thread engagement issues. You must maintain full engagement of all threads and the the locking ring at the top of the nut. Additionally, any time the nut at the top of the strut shaft is removed it should be replaced with a new nut. Things get really ugly if that nut comes off while driving.

As for the driveshaft, it is possible but unlikely that it is causing the issue.

 

Yes I see your point on all accounts. The driveshaft angle issue has been discussed at length and the harmonic vibration from what I've read is indeed from the driveshaft because of the angle that lowering causes, this happens on some cars and not others. I guess I could go coilovers but the NM springs only lower 1.2" and max height on a coil kit is usually 1.2" of lowering. I'm kinda of stuck....

 

Welcome to the world of "Hot Rodding".

There is something you could try, but I would not recommend it as a permanent solution. Do a google search for "spring rubbers". You could get a small (aprox 1/2") rubber and try that to see if it reduces or eliminates the issue. It's up to you if you decide to keep it long term. If you do keep them in, inspect them frequently and replace as needed.

Good luck

 

ha ha ha, yeah love it. I have lowered many cars in my years and I've never run into this issue so strange but I guess it's just very tight tolerances on these vehicles. Thanks for your help.

 

does anyone here have coilovers with adjustable front camber? megan, bc, etc... if so, have you tried messing around with different camber positions so it changes the cv angle to eliminate some of the wierd vibration? im thinking about getting bc coilovers....

 

Wanted to post a follow-up, ST Coilovers installed and vibration is gone. It entirely has to do with the angle of the CV Joint/shaft. I'm a little higher now than when I had just the springs so that seemed to solve it. I could have done the trial an error thing with spacers or rubber inserts but wanted one and done. Thanks to everyone who provided ideas and help.

 

Glad you solved the issue. Coil-overs are definitely one of the better, if not the best ways to go and a lot easier overall. Spacers and such will work on the cheap if the $$ aren't there. Did you take any measurements before and after? That info may be helpful to others in the future. How many miles do you have on your car?

 

It's a little strange because I'm almost at the point I was with the springs installed, just maybe .5" higher or even less. When I first installed the coilovers I had about a 3 finger gap between tire and fender arch, with zero vibration. Was a bit higher than I liked so I lowered it down a bit, it was two full rotations as noted from the set screw facing out. the back is a little different the measurements are not the same on both sides. The only thing is I also replaced my top strut mounts with new OEM units. The car has 84k miles so the old struts were most likely shot in my opinion. I didn't take any measurements from the center hub to the top arch but I can say that I think if I went any lower from where I am now the vibration will come back, I feel like I might even slightly (could be imagination) feel it now. I'll drive it for a week and see how it goes, if it's there I'll raise it back one full rotation of the perch.

 

Keep in mind that now that you have coilovers, theoretically you can lower the car to solve the issue as well. And I think Rallys car proves the theory quite well. Don't worry you shouldn't need to go that low to solve the issue and you need more than coilovers to get there anyway.