[W37V]

UPDATE:

TL;DR: Changed blown shocks to Bilsteins B6 and I love the ride. If you have sport suspension get B8 and not B6.

A great explanation:

Originally Posted by mxchris727

B4 is Bilstein's OEM replacement for stock shocks. They come in sport and non-sport variants. I have had every Bilstein shock on my BMWs...

OEM sport/non-sport - B4
Upgrade non-sport - B6
Upgrade sport/M3 - B8

The difference between the B6 and B8 is only ride high/bump stop placement; valving is exactly the same. Spring height dictates which shock to get.

I have the sport version B4s on my sport packaged E93 and they are awesome. I feel like they are 15% or so firmer than the originals (as many websites have stated).

--------

I wish I went with B8s instead of B6 since I think B8 would be more comparable to the stock shock hight. B6s are over an inch higher than stock sport shocks as can be seen here:

View post on imgur.com

Car is 2011 e92 with 66k miles.

If I could return these and get B8s, I would definitely go with them. But whatever... next time.

Here is my experience:

Install:
The install was not that difficult, but tedious. It was my first time doing any suspension work, so I took it slowly. The whole process took about 8 hours to do. I followed the Bavarian Autosport video. The rear shock install took about an hour for both. Fronts were different story. Each strut took about 3.5 hours to complete. Compressing springs was a challenge. Having proper tools def helps.


Ride hight:
Right after the install, the car sat over an inch higher than stock. Front end was significantly higher than the rear - it looked like Carolina stance. After about 24 hours and 200 miles, car sits lower, but it is still about 1/2 higher than stock.


Ride:

Old ride:
My car handled like shit. DC roads def took a toll on the suspension. The ride was bouncy and did not inspire confidence. Changing lanes on highway was becoming an adventure due to so much body roll (lean).

Once I removed my old shocks, my suspicions were confirmed. Shock and strut on passenger side were blown (at 66k miles). Rear shock was so bad that it took it over a minute to expand after compressing it. It had no resistance at all.

New ride
I got my old car back. OMG the car hand handle once again. The car is very stable and planted. No more bounciness. It's very comfortable. I was concerned that the ride would be too harsh. That is not the case. For speeds under 40 mph, the ride is bit harsher, but on highway speeds, it buttery smooth. Car is just planted and inspires confidence. Changing lanes at any speed is nonissue. Rear end is planted and there is no wiggle at all (I also used Monroe rear upper bushings). Now I feel like I have a completely different (new) car. I wish I done it sooner.

After the change, the car does need an alignment, but it's nothing too serious (very slight pull to the right).




----------------------------------
ORIGINAL POST:

I am planning on replacing my shocks with bilstein b6 (i could be talked into b4s) since my front right shock is on it's last leg and its bounciness is driving me crazy.

1) I am considering B6s, but I am afraid that they might be too harsh. How rough B6's ride is compared to stock sport or B4s?? I would still like to drive the car on these battlefield areas we commonly refer to as "roads". Would B4s be better option?

2) Do I need to do an alignment after installing shocks?

3) I am planning on following instructions as shown in this video.

My main question is: in this video at around 12 min mark, he talked about mounting the springs on the strut. He stated that you should take the note of where the old springs were mounted and try to position the spring at the same spot as where the old one was. I am confused with this statement, especially if both sides are bing replaced. Does it really matter where the old spring rested? Why not use the divot on the strut as a starting point for both sides? How crucial is it to get it on the same spot?


Edit:
4) Pelican parts, FCP Euro, and Tire Rack list B6 shocks as not suitable for cars with sport suspension. They recommend B8s for vehicles with sport suspension. The only one who lists B6 for sport suspension is ECS. Do I need to get B8s for my e92? I do not intend to replace springs or lower the car.


Video for reference:

[MrN1ceGuy]

If you have OEM sport suspension, you want to get the B8s.

As for where the springs seat, you will see indents on both the top hat and the lower spring seats on the front struts. It will all make sense when you pull it apart.

[Spitfire007]

With OEM sport suspension, you want the B6s.

B8s are for aftermarket lowering springs.


I have B6s on my OEM sport 328, with OEM sport springs,and it's great. A little firm, yes, but solid and composed.
The car itself just rides hard. The subframe design and overall architecture is just not as smooth as the e46 chassis.

[W37V]

Originally Posted by MrN1ceGuy

As for where the springs seat, you will see indents on both the top hat and the lower spring seats on the front struts. It will all make sense when you pull it apart.

Thank you. That makes sense. Do you know if I need an alignment afterwards? I don't think I should as I wouldn't mess with anything that might throw off the alignment , but I'm not sure.

[W37V]

Originally Posted by MrN1ceGuy

If you have OEM sport suspension, you want to get the B8s.

Originally Posted by Spitfire007

With OEM sport suspension, you want the B6s.

B8s are for aftermarket lowering springs.

I've read hundreds of posts on this debate and it's never clear which one is for what. People argue both.

After further reading it seems like the b6 and b8 are the same shocks with different lengths. With b8 I would potentially lose on droop and make the ride harsher. However with b6, if they are not extended to their optimal position, I would get only partial travel and not their full potential, thus making the ride suckier.

I think I'm going crazy here.

[W37V]

So according to this image posted here B8 are about 20mm or .78inches shorter than B6s. But the image is for e60 shocks.

Per workshop manuals website, the ride hight between standard suspension and sport is about 17mm (someone please correct me if I am wrong). So I am assuming that for the best use of shocks, B8 is the way to go. Or B4s for sport suspension.

[Spitfire007]

Non-sport OEM replacement option - B4
OEM sport package replacement -B6
To pair with AFTERMARKET SPRINGS- B8

[W37V]

Fine damn it. You (+bunch of other other threads on this topic) convinced me. I guess 20 mm should not affect the operation of B6 anyways. The difference between eibach springs and sport springs is about 20-30mm, which means the difference between standard suspension and eibach would be 40-50mm. That is a significant difference and could result in shock bottoming out more frequently.

[W37V]

So, I ordered following:
MONROE 907984 (rear shock mounts) from RockAuto

B6 Shocks from TireRack:

Front Left
Part Number: 35-120377
Front Right
Part Number: 35-120384
Rear x2
Part Number: 24-120395

From BMW (part numbers):
strut support gasket W/O M3 Left
strut support gasket W/O M3 Right
upper plate pad W/O M3 Left
upper plate pad W/O M3 Right
lower seat W/O M3 Left
lower seat W/O M3 Right

I hope I got everything I will need to do the swap. I am planning on doing this over the weekend, so any confirmation would be greatly appreciated.

Thanks

[larrysing]

Originally Posted by Spitfire007

Non-sport OEM replacement option - B4
OEM sport package replacement -B6
To pair with AFTERMARKET SPRINGS- B8

Let me correct this:

Non-sport OEM replacement option - B4
OEM sport package replacement -B6 (or B8 with M sport)
To pair with AFTERMARKET SPRINGS- B8

[W37V]

Originally Posted by larrysing

Let me correct this:

Non-sport OEM replacement option - B4
OEM sport package replacement -B6 (or B8 with M sport)
To pair with AFTERMARKET SPRINGS- B8

So what is considered M Sport? The BMW performance springs?

[PichaDis11]

Top and bottom spring pad will have the groves to match where the coil ends. You can't miss it. In fact just examine the one on the car before you separate strut and spring.

Make sure to have tools to tighten the Strut nut. May not be the same size as OEM - B12 Kit I know is a 22mm Strut Nuts.

[W37V]

Originally Posted by PichaDis11

Top and bottom spring pad will have the groves to match where the coil ends. You can't miss it. In fact just examine the one on the car before you separate strut and spring.

Make sure to have tools to tighten the Strut nut. May not be the same size as OEM - B12 Kit I know is a 22mm Strut Nuts.

Thanks for the heads up. I will mentally prepare for it.

Hopefully I got all other necessary parts for the swap.

[PichaDis11]

Originally Posted by W37V

Thanks for the heads up. I will mentally prepare for it.

Hopefully I got all other necessary parts for the swap.

Welcome! Hope all goes well. A good set of long reach Metric wrenches is good for the job.

This made the removal/ install of the strut a breeze. Spindle Housing Spreader Tool

Choose the 22 MM from this Strut Nut Sockets

[Spitfire007]

Originally Posted by larrysing

Let me correct this:

Non-sport OEM replacement option - B4
OEM sport package replacement -B6 (or B8 with M sport)
To pair with AFTERMARKET SPRINGS- B8

Sport and M Sport are the same.
M Sport just incorporates additional badging. So I stand firm in what I mentioned.

B4 or B6 are to be paired with STOCK SPRINGS.

B8 is for AFTERMARKET LOWERING SPRINGS, although you could potentially use them with stock sport springs, but that's not what they're for.

[Camman]

To answer your question regarding an alignment, yes, it is recommended you get an alignment anytime you do suspension work. The front will be affected because you will have to loosen the inner control arm bolts in order to remove the strut assembly. The rear will probably not be affected since you're only changing the shock.

[W37V]

Originally Posted by Camman

To answer your question regarding an alignment, yes, it is recommended you get an alignment anytime you do suspension work. The front will be affected because you will have to loosen the inner control arm bolts in order to remove the strut assembly. The rear will probably not be affected since you're only changing the shock.

Thank you for answering! That makes sense. I have read many many threads and no one mentioned getting an alignment done. I wasn't sure as to why.

[W37V]

TL;DR: Changed blown shocks to Bilsteins B6 and I love the ride. If you have sport suspension get B8 and not B6.

--------

I wish I went with B8s instead of B6 since I think B8 would be more comparable to the stock shock hight. B6s are over an inch higher than stock sport shocks as can be seen here:

View post on imgur.com

Car is 2011 e92 with 66k miles.

If I could return these and get B8s, I would definitely go with them. But whatever... next time.

Here is my experience:

Install:
The install was not that difficult, but tedious. It was my first time doing any suspension work, so I took it slowly. The whole process took about 8 hours to do. I followed the Bavarian Autosport video. The rear shock install took about an hour for both. Fronts were different story. Each strut took about 3.5 hours to complete. Compressing springs was a challenge. Having proper tools def helps.


Ride hight:
Right after the install, the car sat over an inch higher than stock. Front end was significantly higher than the rear - it looked like Carolina stance. After about 24 hours and 200 miles, car sits lower, but it is still about 1/2 higher than stock.


Ride:

Old ride:
My car handled like shit. DC roads def took a toll on the suspension. The ride was bouncy and did not inspire confidence. Changing lanes on highway was becoming an adventure due to so much body roll (lean).

Once I removed my old shocks, my suspicions were confirmed. Shock and strut on passenger side were blown (at 66k miles). Rear shock was so bad that it took it over a minute to expand after compressing it. It had no resistance at all.

New ride
I got my old car back. OMG the car hand handle once again. The car is very stable and planted. No more bounciness. It's very comfortable. I was concerned that the ride would be too harsh. That is not the case. For speeds under 40 mph, the ride is bit harsher, but on highway speeds, it buttery smooth. Car is just planted and inspires confidence. Changing lanes at any speed is nonissue. Rear end is planted and there is no wiggle at all (I also used Monroe rear upper bushings). Now I feel like I have a completely different (new) car. I wish I done it sooner.

After the change, the car does need an alignment, but it's nothing too serious (very slight pull to the right).

[techwhiz]

Originally Posted by Spitfire007

Sport and M Sport are the same.
M Sport just incorporates additional badging. So I stand firm in what I mentioned.

B4 or B6 are to be paired with STOCK SPRINGS.

B8 is for AFTERMARKET LOWERING SPRINGS, although you could potentially use them with stock sport springs, but that's not what they're for.

That is not correct and runs counter to Bilstein's application guide. You can stand firm but you are wrong. Read the guide from the people that manufactured the parts. The M-Sport suspension has a shorter spring and a different shock than standard suspension.

From the Bilstein Application Guide Page 104.
2011-2007 B6 (HD)
Front Left 35-120377
Front Right 35-120384
Rear Suspension 24-120395
Excludes M-Technics Sport Suspension


2011-2007 B8 (SP)
Front Left 35-120407
Front Right 35-120414
Rear Suspension 24-120425
With M-Technics Sport Suspension

From the Bilstein description of the B8 - "High-performance shock absorbers and struts designed specifically for lowering springs and production sport vehicles".

Have you ever seen a sport packaged car right next to a non-sport packaged car. The ride height is almost an inch lower.

If you use the B6, the shock will be pre-loaded and have less travel than the B8. This will affect the suspension performance and ride.

The B8 is the correct replacement for Sport suspension.
Any other information is flawed because it runs counter to Bilstein - RTFM!

The B6 is a standard HD replacement.
For OE the B4 lists two separate part numbers for standard and sport suspension.

Do not put B6 shocks on a M-Technic/Sport Packaged vehicle. It is not the correct part.

[W37V]

Originally Posted by techwhiz

Do not put B6 shocks on a M-Technic/Sport Packaged vehicle. It is not the correct part.

After doing the replacement, I agree with this statement 100%.

Too late for me, but hopefully this thread directs next person to get the right part.

[techwhiz]

Originally Posted by W37V

After doing the replacement, I agree with this statement 100%.

Too late for me, but hopefully this thread directs next person to get the right part.

The dealer/company that sold you B6 shocks to go on a sport package car didn't RTFM from Bilstein where it clearly states what is what. I'd go back and scream at them. But that's me.

The reason I know the difference is from experience.
I had an E36 M3 and the suspension difference between it and a regular E36 was the M3 took B8 along with M-Sport suspension cars while the regular E36 took B6.

I don't understand the confusion people have.
The B8 is a shorter shock.
The sport suspension cars have a shorter spring.
Short shocks go with short springs, aftermarket OR factory.

The shocks on sport suspension cars is not the same shock on regular cars.
So why would the aftermarket replacement use the same shock when it is a clearly different application?

People don't believe what a sales guy on the phone tells you ->
The manufacturer knows.

[feuer]

I'm Koni user but would would like to know for what suspension B4 is built for?
B4-
B6-non sport
B8-sport & aftermarket lower