SIGH - Here's my problem... I purchased Eibach Pro-Line Springs and Koni Shocks, for my 04 RX-8, and had them installed by reputable local shop. Problem is we can't seem to get the ride height that Eibach reccommends.

Eibach says the heights should be 603mm front and 610mm rear.

We're getting 593mm LF / 583mm LR & 595mm RF / 585mm RR.

FYI - 25mm, the lengh the rears are off is equal to 0.98"
10mm, the lengh the fronts are off is equal to 0.39"

My problem in short is; why is the rear end down almost an INCH lower than it should be and the front nearly half an inch lower??? Has anyone here done this setup and gotton Eibach's numbers?

Input please?

THANX, in advance!

 

I probably would have measured the height before and after the drop, with the same amount of fuel in the tank and the same amount of stuff in your trunk.

You never know what kind of conditions Eibach had their RX-8 in when they measured the height. You might be able to ask.

 

I also recently installed Eibach's.

The 'drop' for the rear was also more than 'advertised'. My drop was 1 inch for the front and 1.125 for the rear. At first, I wasn;t too happy about it....but....now that I've had a couple weeks to look at it, I think the drop is perfect. I didn't replace the shocks so I wonder if the Koni's had anything to do with your's being more (shouldn't but I seem to have read another thread where this may have been mentioned). It would be interesting to know this too as I am also toying with the idea of replacing my OE shocks with Koni's.

Also, are you having any unusual noise problems? (from the rear?). I'm struggling right now trying to determine the cause of a pretty severe banging/clunking every time I go over sharp bumps at speeds of about 5-30mph. It really sounds like bottoming out but I know its not. I will be taking everything back apart this week-end searching for the cause as I have yet to find 'anyone' else experiencing this.....and a call to Eibach also confirmed that I should not have any noise problems.

 

i've also recently installed the koni's but with RB springs, and my rear is also about an inch lower then the front. i dont know why.

 

do you guys have systems in the trunk?

also, advertised drop on the eibach springs is 1.2 all the way around.

 

Had a similar problem as you,
Turned out to be the top screw/nut was not tight enough on the spring and strut assembly.
It will make a clunking and squeaking sound...
You need to drop the spring with shock and tighten that screw...
I did mine without taking the complete shock and spring out of the car.
Your back will love you when you’re bending over in the trunk

 

I've been fighting the same thing except I got over an inch lower than front in the rear after about 10k on the Konis. I put on MS springs and had the same problem, too low in the rear. I've measured the KONIs and they are very close to stock so the reason for the drop escapes me. For now I put the OEM springs back on the rear and it's 3/4" lower than stock. I've called Koni 2x but they are not good about returning calls. Prior to putting on the Konis my RBs had dropped .5" more than advertised so Im hoping another set from another run will do better. I thought is was just my car since no one else was reporting the problem. Maybe now there is enough effected that some one will find a solution or at least identify the cause.

 

as the suspension has to be preloaded before tightening everything down, maybe the supsension is being preloaded too much and that is causing the excessive drop????

 

the back looks lower or you are measuring it lower, because the wheel in the back well is deeper them the out side, and the front does not go in as deep. So you have more room in the back then it look.

 

My measurements were taken from wheel center up to fender lip. Stock was 15.25" on all corners.

 

I did not measure mine went I put them because i did like how they look/ride on my 7. so I thought they look lower in the back but I stock my hand under the well and the distance seem find (more in bac then front) I don't have any wierd noise and the car looks level overall. i'll measure them to see if they are any different then yours (all) and post again.

ps I on stock shocks

 

2f/14mm rear 2f/30mm in front that's to the outside. I'm even all the way around same tire pressure. Also stock tires, and i have a bazooka 8" speaker in the trunk and a small tool box (u never know) hope it help

 

I brought this up with our suspension engineers and we could not find a reason for the differences in ride hieght. If any of you would like me to check into this with Eibach or Koni i would be happy to. I would need some information from you to do this.

I would need to know:
-The part number on each shock and the location it is in. The part number can be found on the lower part of the shock body just above the lower mount.

-The part number of of each spring and the location that the spring is in (front right, front left, etc). This can be found on one of the coils.

 

Thanx to everyone for your input. My 8 is in the shop now. We'll start by getting the part numbers and see if we have the right parts. I'll update this string when I have more info.

 

??? Update ???

 

I don't think the koni's will have anything to do with the drop really. They are there to dampen the oscillations while driving and basically don't exert any force. I don't know about the Koni's, but most shocks/struts you can compress with just your hands. I'd be impressed if you can make any noticeable difference if you tried to compress the spring with just your hands.

 

I spoke to Eibach again, last week, they told me that they have had more reports of the Koni and Eibach combo coming out too low.

They're expecting to get a set of the Koni's in house for testing probably this week or early next week, it seems there may be an issue with the perch height being off....

My mechanic has checked all the numbers and installation of the springs, and that's all good. So, something about the springs seems fair game.... Stay tuned is the best I can say for now.....

Feel free to give additional input....

GO ZOOM

 

Great news Go Zoom... the spring length will determine ride height, but also the distance between each mount on the shock where the spring sits at each end, also needs to be correct (preferrably same as the stock shocks if we are to keep everything consistent) If this is not correct on the shocks, the ride height can be changed. However, that should affect all springs used with the Koni shocks and not just the Eibach springs.

Please let us know what you find out !

I've got H&R springs with the stock (tokico) shocks and the ride height looks good, perhaps a little higher in the rear end by 1/4". Although H&R claim 1" drop all around, my car is the lowest rx-8 I've ever seen on the street. I measured in the same manner as TheDosDog mentions above and the front is 13.25 and the rear at 13.5 with the H&R's. That's a full 2" which looks awesome.

I've also noticed Tein springs claim to keep the rear end a little higher. The Tein S-techs claim a drop of 1.4 on the front and 0.7 on the back. I didn't go for the Teins becuase I don't like the idea of the rear being 3/4" higher, even though my H&R's turned out that way to some small degree.

I elected to go with the Tokiko D-spec instead of the Koni's, just because they are made by the same company as the stock shocks. But, I'm not putting them on until the spring. I've got my fingers crossed for you guys with Koni's becuase other cars I know with the Koni's are awesome.

 

Can't speak to the Eibachs, but I do have Konis on stock springs (for a couple of months) and have driven an auto-x and 2 track days, so the suspension has pretty much settled. I've got about 14k miles on the car. Before the Konis, I was about 15 1/8 inch all around. After the Konis and suspension settling, I measured 14 1/2 up front and 14 3/8 in the back. The drop is not subtle. I didn't have any problems hitting bumpstops on the track, but I did hit them at auto-x on a bumpy course.

 

Aren't you suppose to measure the height from the body of the car to the ground?
(where you jack up the car)

That's what we did to balance the height of the car. If the frame height is the same from left to right the installation is correct. Looks are decieving due to the design of the wheel wells.

 

Hub to fender lip measurements are less dependent on wheel / tire effects (i.e tire pressure). Also, it is the measurement most visible looking at the car. I find it somewhat comforting that moto_bruce got the same ride height as my 8 on the Konis with stock springs. That supports my suspicion this is more a Koni / installation issue and less the springs themselves. However, the springs definitely can contribute. As far a bottoming out, I was having a significant problem with springs where the ride height got below 14". Especially on the freeway with a passenger and full fuel load (even with stiffer MS springs).

 

Are you sure you are bottoming out the car over bumps? My car with a 2" drop on stock shocks (stock bump stops still in place) has not bottomed at all. Maybe if I ran rough railroad tracks at 80mph they might. I would think the Koni's allow for a lower ride height over the stock shocks with bump stops and should have less of a chance bottoming out. I'm curious who is bottoming out their car and what suspension setup they have mounted?

 

I was hitting the "trimmed" rear bump stop hard at any significant dip in the highway ( note Ca. highways are not the greatest). That was one of the reasons I switched to the Konis. But, the additional drop made it worse. I've since replace the rear springs and the problem has not returned (knock, knock)