tiresmoker

iTrader: (1)

Yesterday I put a set of KW v3's on a friends car. The install was great and went off without a hitch other than one issue...

Got the fronts on and set, perfect, lowered the car about 1" on both sides.

The rears were the kicker...

Installed the rears as I have installed many other rx8 suspensions and then went to adjust the ride height. In adjusting the lower perch to lower the car we ran into a problem. At this point in time the passenger rear is all the way at the bottom of the threads on the damper body and the car is roughly 1/4" lower than stock height. I have about 1/2" of threads on the drivers side left to go to lower it, but both sides are sitting even right now. If I lower the drivers side to match the perch position of the passenger side then the car will be very uneven favoring a lower height on the drivers side.

I have only seen this one other time in my life with ironically a KW coilover setup. A friends Mazda 3 with a KW variant 2 had the EXACT issue, the passenger side was lowered all the way and the drivers side still had about 1/2" - 3/4" of adjustment left. She came to find out her frame was tweaked and not straight.

My issue with this is with the lower perch all the way at the bottom of the damper should provide the maximum drop on rear, yet it is only minimally lower than stock height.

Anyone have any insight as to why this may be happening? Has this happened to anyone else before with this suspension setup? I had him take the car for a test drive around the block to potentially "settle" the springs a little more and it did settle about 1/8" more but that's about it.

This one is throwing me a curveball right now. Any help would be appreciated.

J8635621

iTrader: (10)

I haven't seen the KW, but do you set the height in a manner similar to this or can you adjust them while they are on the car? https://www.rx8club.com/showpost.php...4&postcount=88

tiresmoker

iTrader: (1)

With the KW V3's you only have the adjustable lower perch that you would use to add preload, there is no dual threaded body like the GR+. By raising and lowering the perch on the damper body you adjust the ride height as well as preload.

J8635621

iTrader: (10)

Oh ok. I wasn't sure.

tiresmoker

iTrader: (1)

bump.

No one has any ideas?

Fyi, I'm going back up to the car tomorrow to fill out some paperwork for KW Automotive (spring and damper part numbers and some measurements) as they sent me a a tech sheet to make sure we have the correct parts.

The only thing that I suspect it could possibly be is the springs being the wrong ones and they are too long...

GeorgeH

iTrader: (2)

My KW V3s also did not lower the rear a ton. Mine are very near the bottom, but I think they are a little too low (into the bumpstops a bit) and I may raise it this spring. Note that most knowledgeable setup guys warn against lowering the RX-8 too far; I think the KW shock heights & spring rates reflect that philosophy.

The difference between left & right is a bit odd, however. Not sure what to make of that. Adding aftermarket suspension can expose issues - I found a bent lower front control arm when I did mine, but that was a different issue.

Please keep up updated.

[edit] - two other points - the car will settle a bit after time, so the height you are seeing now will not be the final height. Also, did you loosen all the suspension bushings and then re-tighten witht the weight of the car on the wheels?

TeamRX8

iTrader: (25)

Lowering excessively is bad for geometry and only for RX-8 wannabe look at me I'm cool play racer poseurs

everything you need to know about loading the suspension during install

https://www.rx8club.com/showpost.php...6&postcount=16



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Endless Rotaries

iTrader: (6)

What Team said, but I can understand from an aesthetic standpoint.

If KW approves it you can always have them send you shorter springs. That will resolve your problem.

Rishie

tiresmoker

iTrader: (1)

Thanks guys.

@Team..
All the suspension bushings were loosened and loaded with the car off the ground on 4 jackstands. A jack was placed under each spindle and jacked up to simulate the weight of the car almost to the point of lifting the car off the jack stand at that corner.

As for the ride height, my issue is not wanting to slam the car to the ground, he doesnot want that. My issue is that even with the adjustments made on the rears so that the car "should" be as low as it possibly could go, it is still only roughly 1/4" lower than stock ride height. At the settings they are at right now the car should be about 1 3/4" - 1 7/8" lower than stock, but it is only at 1/4". Plus, for the car to sit level on both sides the passenger side is all the way down and the drivers side still has at least 1/2" more to go...

With the adjustments all the way at the bottom of the adjusting range, the car is still basically at stock ride height. This isafter the car was aslo taken around the block (a decent sized blcok) twice, in an attempt to settle the suspension some.

TeamRX8

iTrader: (25)

You didn't do it the way I described

it will also likely settle a bit in time, most of the spring and coilover kits are way too low especially in the rear, not sure you're listening ...


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fastlaneracing

Something must be really off with the installation or the car.

I have KW V3 im as low as I want to be and still have alot of room to lower more.

tiresmoker

iTrader: (1)

I'm not really sure I'm following you then. Other then settling the suspension I did everything you linked me to.

Swaybars disconnected: Check

Car on 4 jackstands: Check

All arm bolts loosened: check

Compress suspension/tighten bolts: check

I've done 11 rx-8 suspensions to date ranging from springs, to springs and dampers, to coilover setups and this is the first one I have every ran into problems with. I know 11 may not be a huge amount, but his isn't my first tour.

Please explain what you mean by "most of the spring and coilover kits are way too low especially in the rear" We're not trying to slam the car to the ground, but with everything done as noted above the car should be lower than stock height. Especially with the lower perch at the bottom of the threads on the damper body.

That's the whole problem here... The car should be slammed on the ground right now, but it's still at stock height. We don't want it slammed on the ground, as we only want about 1" max lower than stock, but we are unable to get to that adjustment because we ran out of damper to thread the lower perch down any further.

I highly doubt the car will settle 1 1/2" over time. I've never seen that much before., maybe at most 1/4" to 1/2" max. But as it sits right now and if the theory is correct that the springs just need to settle, then this thing is gonna have to drop 1 1/2"

imput1234

iTrader: (6)

^Call KW and ask them. That's really odd.

GeorgeH

iTrader: (2)

It's not going to. With my V3s, even with the rear collars dropped to the lowest setting, the car was not slammed. KWs won't do that, by design. This is what Team was saying - most kits let you go too low for proper handling.

To that end, when I had the car setup that way (rears set to max lowering), I found it's response odd & inconsistent when autocrossing. Hard to predict. I raised the whole car one or two turns (don't remember for sure) and the response got much better. Even with that, Team has told me he thinks my car is too low.

Still, it does seem that you are getting only a small amount of lowering - less than what I got when mine was set to the lowest setting in the rear. I think I had, perhaps 1.25" of lowering in that configuration - maybe a bit more. So, you will not see 2" of drop with the KWs, for good reason. But you should see more than 0.5", even before setteling, I do agree.

dannobre

iTrader: (3)

Me thinks you have a damper problem

After 11 installs....you should have a grip, and no install errors that will account for that much of a difference

Did you check that they were mirror images before you put them on the car?

Car been bent?

Saw a Lexus the body shop had fixed...and it was out more than 3/4 inch side to side ...they thought there was something wrong with the alignment

tiresmoker

iTrader: (1)

Already put a call into KW Automotive. All they did was tell me that the maximum drop was 1.8" in the rear and email me a sheet to fill in part numbers and a few measurements so they can check that we have the right parts


I know it's not going to lower the car 2"+ but like you see, even with it at full low, it's only 1/4" from stock height. We're only looking for about 1" max on the car but can't even get there

Dampers are exact mirrors of each other. Both external reserviors are facing to the rear of the car


As for if the car body is tweaked, I cannot answer that as I don't know the previous life of it. Carfax showed nothing apparently but that doesn't mean anything now adays. I actually suggested that the frame may be crooked because this doesn't make any sense.

MilesJ

How many miles are on this car? It is possible (and very likely) that the OE rear shocks and springs were sagging that 1"-1.5" and thus you are only seeing 0.25" drop with the KW's. There is another member on here that installed the progress track springs (0.5" rear drop) and they raised the rear of his car rather than lower it. His OE rear springs were apparently sagging and caused the rear of the car to be about 1" lower than when new.

tiresmoker

iTrader: (1)

^^^Not really sure on the miles, but it's a 2004. If I were to guess I would have to say somewhere in the area of 40-50k or so.

The car is used for autocross and track duty solely. I do know the owner of the car does a lot of track days and autocrossing.


If I remember correctly, the height from the center of the rear fender to the ground was roughly 26 7/8" after the drop (this is with the stock 18" wheel and a 225 45 Direzza Star Spec tire, roughly 50% worn). I do not remember the hub center to fender dimension, but basing the fact that a 255 45 18 tire is 26" outside diameter, I could roughly say the center of hub to fender would be 13 7/8".


It's a good posibility that due to the nature of this cars usage that the springs are sagging. Never though of that till now. Right before I put my GR+ on my car I noticed I was starting to get a little *** sag on mine

Knet

I am sorry for reviving this topic, but I just found out about it. The difference in tread on the rears is something I have aswell.

And I know perfectly what happened to my car since I bought it new and no accidents. Therefor I think its a KW issue and not on the car.