Help: Rear height too high after shock/spring install

[Zeshin]

Hey guys,

So, I installed rear 325ix springs and brand new Bilstein HD's onto my '87 coupe. I wanted a little stiffer rates for the rear, so I wanted to try out the "ix" springs. When I compared them visually to my 325is springs, they were the same height and size. After installing the springs, with spring pads, and brand new Bilstein HD shocks, the rear of the car is not settling down to the stock ride height, but is sitting at the extremely high height of when I first let it down off of the jack stands. By comparison, the fronts initially sat just as high, however have settled down to stock height after a 15 minute drive.

My question is what could be wrong with the rear suspension to prevent it from settling in? I noticed that the bottom spring pad center opening was binding slightly between the trailing arm and the spring, but otherwise everything looked fine and installed without incident. I know new springs and shocks sometimes take a week or two to fully settle, but these are used springs and the fronts have already dropped to stock height.

Any ideas on what to check for, or should I just drive it more and wait and see if it settles?

Pics:

[SmokeE30]

IX springs are not gonna "settle" down to a stock rwd ride height, they are the reason IX's sit taller than regular e30s...

[Zeshin]

IX springs are not gonna "settle" down to a stock rwd ride height, they are the reason IX's sit taller than regular e30s...

Thanks for the reply. The "ix" springs measure the exact same dimension wise as the "is" springs do in the rear. I don't have the front "ix" pair to compare, but I think the part cross references with the 325e front springs, which are a little taller than the "is" front springs. The stock reference photos I've seen of both the "is" and "ix" look like they have the same stock ride height. Although I know general consensus is that the "ix" sit taller, however most are still using stock springs, whereas most other e30's have been modified. I know my stock 325e rode extremely high when I first got it on stock springs.

Anyways, you may be right, however the rear springs do share the same dimensions as I mentioned before, so they really shouldn't ride higher. They are only 20 lbs or so stiffer. I know the 318is Euro spec rally series runs the "ix" springs as an option against the stock 318is springs, and those cars are not nearly as high as mine is currently in the rear. So, I think something else spring pad related might be happening.

[kamotors]

is your ebrake still on? that can hold the ride height up if it was jacked up with it on

[Zeshin]

is your ebrake still on? that can hold the ride height up if it was jacked up with it on

I lowered the car back down with it on, however I've driven it maybe 20-30 mins since then with the ebrake off. I'm thinking of loading up some weight into the trunk, driving around and seeing if that does anything. Maybe the spring pads I'm using are too thick.

[kamotors]

no spring pad will hold it that high. The thing is if the IX springs were the same height as reg. E30 springs and have a stiffer spring rate they will definitely hold the car up higher.

[Zeshin]

no spring pad will hold it that high. The thing is if the IX springs were the same height as reg. E30 springs and have a stiffer spring rate they will definitely hold the car up higher.

I totally get what you are saying, but the increase in stiffness isn't a whole lot, 40 lb/in more. Whereas, the height difference is significant. The car is sitting higher than an "ix" does, so I imagine something is going on.

Stock for stock, the "ix" and "is" really don't ride at a much different height.

Here are stock 325ix's:





Here are stock 325is's:

[kamotors]

just throwing out thoughts but a 325ix is about 3010lbs and a 325is is 2865lbs. So stiffer spring + less weight will increase ride height over an ix.

[Zeshin]

just throwing out thoughts but a 325ix is about 3010lbs and a 325is is 2865lbs. So stiffer spring + less weight will increase ride height over an ix.

Interesting point. I would think most of the weight though is in the front and center with the additional differential setup - maybe not? The trunk in my car is empty though, no spare or panels even. I'm going to throw a spare or three in there, drive it around and see if the weight changes the height simply being in the trunk, or after driving around. I'll let you know what the results are.

[mr.vang]

See it this way, a 200lbs fat chick will lower your car a bit.

[Zeshin]

See it this way, a 200lbs fat chick will lower your car a bit.

Yeah, I agree that weight will lower the car, but not to the degree that is needed/missing in my case. At least, that is what I think.

So, to check out what you guys are suggesting, I placed three "15 wheels with tires into the trunk, and added 50 lbs into the interior of the car. First picture is of the car with weight added, second picture is after a 15 minute drive over bumpy roads with the weight inside, and the third picture is of the car with the weight removed after driving.

1st (weight added):


2nd (after driving with weight):


3rd (weight removed after driving):


To me, there is no discernible difference in ride height. I'm sure there is a measurable difference with the weight added, but it isn't enough to "correct" the height problem.

[15Michaeljoseph]

hahaha it's kinda neat 'lifted'

[Zeshin]

I'm going to use the car for rallyX, so I want it to ride at the stock ride height, but the rear is way too high at the moment. It is throwing positive camber onto the rear wheels.

[jeffnhiscars]

I installed h&r ix springs in our 87 4dr and it sits perfectly..slightly lower than the stock springs.

Keep in mind that at least half the extra weight of an ix is in front..probably more..so it should not be that high on any spring

[Zeshin]

I installed h&r ix springs in our 87 4dr and it sits perfectly..slightly lower than the stock springs.

Keep in mind that at least half the extra weight of an ix is in front..probably more..so it should not be that high on any spring

Thanks! That is what I wanted to hear. I think something is binding on my rear suspension, and preventing the swing arms from going up or preventing the springs from properly seating on the lower swing arm spring perch. I'm going to look into it more soon. I think I'll probably take it all apart again and see what looks suspect.