Front ride height lower than normal on stock suspension

avosough · 10-31-2015, 06:33 PM

My car has 63,000 miles, and I'm ready to replace dampers. I've been going back and forth between getting Bilstein B6 with stock springs or the Bilstein B12 kit which includes Eibach lowering springs. I would prefer about a 1/2" drop and I'm a little wary of a full 1"+ on lowering springs.

The front of my car on stock suspension seems to ride lower than a stock 135i compared to other pictures that I've seen and measurements. You can fit maybe one finger between top of tire and bottom of the fender lip. I jacked up the car and did a visual inspection of all four corners suspension today. Here's the strange part: After letting the car back down the ride height looked like a regular 135i should. But as soon as I pushed down on the front fenders (like an old school shock test), it went back down to it's usual too low position. This is happening on both fronts.

Any input? Will I be fine to just get the B6 kit and use M-Sport springs? I need to order tonight before the bavauto sale ends. Is it typical to replace front strut mounts at the same time? Mine look like the rubber has some tiny hairline cracks in it.

FactorX81 · 10-31-2015, 08:33 PM

Usually when you jack up the car the tires at full droop are a little more inward toward the center of the car and when you let the car down the tires don't let it settle fully until the car is rolled a little. That may be why your car appeared to be raised a little.
As far as the role a shock plays in ride height goes, there should be almost none. The shock is only there to control the spring movement. I believe high pressure shocks like bilstein may raise the car slightly due to the added shock pressure but again that's not really their job. With all of that said, I'm not a suspension expert as a matter of fact I'm in a similar boat as you as far as thinking about doing some work soon but haven't made up my mind yet.

avosough · 11-01-2015, 03:57 PM

Quote:

Originally Posted by FactorX81

...the tires don't let it settle fully until the car is rolled a little. That may be why your car appeared to be raised a little...

I've heard of that. In this case I didn't even roll the car, just pushed it down. After I drove the car 1/4 mile and parked on level ground it sits like this. Does the front seem low for stock M-sport springs?

I went ahead and ordered Bilstein HD (B6) shocks with new strut mounts and the Dinan rear shock mount kit last night. I'm sure it'll be a great improvement... just curious about my ride height.

swagon · 11-02-2015, 01:59 PM

Front looks a tad lower than mine did. Nothing major I'd say.

Please measure the length of B6 and stock dampers. I'm curious if the Bilsteins are longer than the standard crap. Not sure if I remember correctly, but someone's car got a wee bit higher with B6s and re-used stock springs.

MightyMouseTech · 11-02-2015, 02:09 PM

Temperature can play a part. Struts are high pressure gas charged. Because of that they offer some lifting force. The colder it is, the less this effect. My car is noticeably higher in the summer, and lower in the winter.

The amount of pressure in the tube and the diameter of the shock/strut rod determine how much force. This is also why a strut will have this effect more than a shock with a smaller rod.

tracer bullet · 11-03-2015, 08:33 PM

I haven't measured my 1-Series but I know that for my old Probe GT and Eclipse the difference between a dead strut and a new (stock equivalent force) was about 1/2" give or take ride height change. Measured by me on my car and confirmed by others on their cars through info exchanged on the forums I moderate(d).

Don't take that as a solid number but as already mentioned it is definitely a factor.

avosough · 11-27-2015, 07:19 PM

I installed the Bilstein B6 all around with original "M-Sport" springs two weeks ago. I think that the front is now back at normal height. I would estimate 1/4" to 1/2" higher than before. When I was removing the original suspension one of the front strut mounts was broken (a bit of the sleeve around the bearing was pushed through) which may have caused a problem on one side.

Quote:

Originally Posted by swagon

Please measure the length of B6 and stock dampers. I'm curious if the Bilsteins are longer than the standard crap. Not sure if I remember correctly, but someone's car got a wee bit higher with B6s and re-used stock springs.

I've also heard that Bilsteins can cause a car to sit a little higher, some say short term and some say permanently. The rear shocks were identical in length between the B6 and the OE Sachs. I could not tell for sure on the front struts because apparently the OE are not fully extended when under no load (which caused all sorts of problems disassembling the OE strut). However with the spring installed on the strut the Bilstein assembly was about 1/2" to 1" longer. I think it is safe to assume the OE is fully extended when tensioned by the spring, so conclusion is the B6 front struts are slightly longer than OE. I was still able to get the strut into the fender without difficulty.

I did run into some confusion reading about Bilstein shocks on E9x forums... Specifically for the 1 I had read that B6 is an stock replacement on all vehicles and B8 is used with any sort of aftermarket lowering spring (or BMW performance). But on some 3 series forums they are saying that B6 is a replacement for vehicles with non-sport suspension, and B8 is a replacement for sport/M-sport/lowering springs. It would be nice to know what the difference in length between the two is, but I can say for certain that I was able to install B6 on the OE m-sport springs. I have a feeling that B8 would have worked just fine as well...

dojk · 05-02-2017, 10:29 PM

The respond I received from Bilstein Germany was that the 135i which comes with M-Sport springs, we should use the B8.

DIfference between B8 and B6, BILSTEIN B8 shocks are only
in the extended length -20mm shorter.

10-31-2015, 06:33 PM	#1
avosough New Member 3 Rep 17 Posts Drives: 08 SGM 135i Join Date: Jul 2013 Location: Atlanta, GA iTrader: (0)	Front ride height lower than normal on stock suspension My car has 63,000 miles, and I'm ready to replace dampers. I've been going back and forth between getting Bilstein B6 with stock springs or the Bilstein B12 kit which includes Eibach lowering springs. I would prefer about a 1/2" drop and I'm a little wary of a full 1"+ on lowering springs. The front of my car on stock suspension seems to ride lower than a stock 135i compared to other pictures that I've seen and measurements. You can fit maybe one finger between top of tire and bottom of the fender lip. I jacked up the car and did a visual inspection of all four corners suspension today. Here's the strange part: After letting the car back down the ride height looked like a regular 135i should. But as soon as I pushed down on the front fenders (like an old school shock test), it went back down to it's usual too low position. This is happening on both fronts. Any input? Will I be fine to just get the B6 kit and use M-Sport springs? I need to order tonight before the bavauto sale ends. Is it typical to replace front strut mounts at the same time? Mine look like the rubber has some tiny hairline cracks in it.
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10-31-2015, 08:33 PM	#2
FactorX81 First Lieutenant 29 Rep 363 Posts Drives: 2010 135i, 2014 Ford Escape Ti Join Date: Nov 2009 Location: NJ iTrader: (0)	Usually when you jack up the car the tires at full droop are a little more inward toward the center of the car and when you let the car down the tires don't let it settle fully until the car is rolled a little. That may be why your car appeared to be raised a little. As far as the role a shock plays in ride height goes, there should be almost none. The shock is only there to control the spring movement. I believe high pressure shocks like bilstein may raise the car slightly due to the added shock pressure but again that's not really their job. With all of that said, I'm not a suspension expert as a matter of fact I'm in a similar boat as you as far as thinking about doing some work soon but haven't made up my mind yet.
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11-02-2015, 01:59 PM	#4
swagon Major General 13518 Rep 8,163 Posts Drives: F80 6MT Join Date: Jun 2013 Location: . iTrader: (0)	Front looks a tad lower than mine did. Nothing major I'd say. Please measure the length of B6 and stock dampers. I'm curious if the Bilsteins are longer than the standard crap. Not sure if I remember correctly, but someone's car got a wee bit higher with B6s and re-used stock springs.
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11-02-2015, 02:09 PM	#5
MightyMouseTech Major General 4338 Rep 6,196 Posts Drives: 13 135i 6MT LeMans Blue MSport Join Date: Feb 2013 Location: Ottawa, Canada iTrader: (0)	Temperature can play a part. Struts are high pressure gas charged. Because of that they offer some lifting force. The colder it is, the less this effect. My car is noticeably higher in the summer, and lower in the winter. The amount of pressure in the tube and the diameter of the shock/strut rod determine how much force. This is also why a strut will have this effect more than a shock with a smaller rod.
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11-03-2015, 08:33 PM	#6
tracer bullet Brigadier General 2406 Rep 3,536 Posts Drives: '11 135i , '15 X3 35i Join Date: May 2011 Location: Saint Paul, MN iTrader: (1)	I haven't measured my 1-Series but I know that for my old Probe GT and Eclipse the difference between a dead strut and a new (stock equivalent force) was about 1/2" give or take ride height change. Measured by me on my car and confirmed by others on their cars through info exchanged on the forums I moderate(d). Don't take that as a solid number but as already mentioned it is definitely a factor.
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05-02-2017, 10:29 PM	#8
dojk Private First Class 19 Rep 179 Posts Drives: E82 135i Join Date: Nov 2010 Location: Malaysia iTrader: (0)	The respond I received from Bilstein Germany was that the 135i which comes with M-Sport springs, we should use the B8. DIfference between B8 and B6, BILSTEIN B8 shocks are only in the extended length -20mm shorter.
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