[UltraDave]

Just had the AC Schnitzer springs installed on my M50i. They dropped the car about 1.5 inches. The look is good, although the passenger rear is a bit lower than the drivers side. I could fit one more finger between the tire and fender on the right vs left rear. I went back to the BMW dealership that installed them the next day and we checked to make sure they front and rear springs were all in the correct locations and seated properly. They said it may take some time for the new springs to settle. How long should that take? They also said they were able to set the alignment to factory after the installation.

The ride quality is not as good as I expected. It is a little firmer but feels somewhat sloppy and a springy sensation. When changing to sport mode vs comfort it is a bit better. It seems like the factory shocks are not as good with the new spring rates or being lower has taken them out of the optimal range. I’m really surprised the AC Schnitzer would market springs for the M50i without new shocks/struts if the ride wouldn’t be dialed in. Maybe I’m just overly critical, one could obsess over this when you start modifying things.

[130FeetDeep]

Originally Posted by UltraDave

Just had the AC Schnitzer springs installed on my M50i. They dropped the car about 1.5 inches. The look is good, although the passenger rear is a bit lower than the drivers side. I could fit one more finger between the tire and fender on the right vs left rear. I went back to the BMW dealership that installed them the next day and we checked to make sure they front and rear springs were all in the correct locations and seated properly. They said it may take some time for the new springs to settle. How long should that take? They also said they were able to set the alignment to factory after the installation.

The ride quality is not as good as I expected. It is a little firmer but feels somewhat sloppy and a springy sensation. When changing to sport mode vs comfort it is a bit better. It seems like the factory shocks are not as good with the new spring rates or being lower has taken them out of the optimal range. I’m really surprised the AC Schnitzer would market springs for the M50i without new shocks/struts if the ride wouldn’t be dialed in. Maybe I’m just overly critical, one could obsess over this when you start modifying things.

That is discouraging to hear. Do you have the DHP?

The settling thing *could* be true or may be just garbage. I would give it 7 days then reassess so you know for sure.

[UltraDave]

Originally Posted by 130FeetDeep

That is discouraging to hear. Do you have the DHP?

The settling thing *could* be true or may be just garbage. I would give it 7 days then reassess so you know for sure.

Yeah I have the DHP. Some have said that makes the car more bouncy. Maybe true but only under turns with uneven pavement. The dealership is going to have the car for a week to fix a couple other things and hopefully any settling will be resolved by then.

[130FeetDeep]

I am confused? The DHP makes the car more bouncy than non or air? I drove all three and that definitely is not accurate. The air is floaty and not sport. The non DHP had a lot of body roll. The DHP is way flatter but still quite comfortable in comfort.

Are you saying the ride is more harsh or bouncy?

[UltraDave]

Originally Posted by 130FeetDeep

I am confused? The DHP makes the car more bouncy than non or air? I drove all three and that definitely is not accurate. The air is floaty and not sport. The non DHP had a lot of body roll. The DHP is way flatter but still quite comfortable in comfort.

Are you saying the ride is more harsh or bouncy?

It only becomes bouncy when you are on a bad road with turns and you put it in sport mode. That’s when the electronic roll bars kick in and get super stiff.

[130FeetDeep]

Originally Posted by UltraDave

It only becomes bouncy when you are on a bad road with turns and you put it in sport mode. That’s when the electronic roll bars kick in and get super stiff.

Hmmm. This disappointing. Now I am worried about lowering the truck. So you a basically relegated to driving in comfort mode now?

[UltraDave]

Originally Posted by 130FeetDeep

Hmmm. This disappointing. Now I am worried about lowering the truck. So you a basically relegated to driving in comfort mode now?

It actually drives better in sport mode when the shocks get stiffer. After lowering on ACS springs.

The bouncy discussion was about driving on a bad country road with lots of turns, having the DHP suspension. Thats not related to the lowering. I suspect any car with heavy performance anti-roll bars would have the same experience. Bigger roll bars don’t change the ride quality, if the left and right suspension are doing the same thing, only when they are doing the opposite. So wheels going over a speed bump at the same time roll bars are not engaged, but go at an angle and the car is going to bounce more while the roll bar try’s to keep the car flat.

[130FeetDeep]

Originally Posted by UltraDave

It actually drives better in sport mode when the shocks get stiffer. After lowering on ACS springs.

The bouncy discussion was about driving on a bad country road with lots of turns, having the DHP suspension. Thats not related to the lowering. I suspect any car with heavy performance anti-roll bars would have the same experience. Bigger roll bars don’t change the ride quality if the left and right suspension are doing the same thing, only when they are doing the opposite. So wheels going over a speed bump at the same time roll bars are not engaged, but go at an angle and the car is going to bounce more while the roll bar try’s to keep the car flat.

I think I understand you better now. It sounds like you are saying the bouncy and springy was there always because of the DHP and the lowering springs had nothing to do with it?

A lot of us looking to lower are watching this thread closely.

[UltraDave]

Originally Posted by 130FeetDeep

I think I understand you better now. It sounds like you are saying the bouncy and springy was there always because of the DHP and the lowering springs had nothing to do with it?

A lot of us looking to lower are watching this thread closely.

LOL not exactly. 2 totally separate discussions. Anyone who buys the car with the DHP will have a car that can take corners flatter but can feel bouncy when driving on uneven surfaces. Most wont notice this if they have good roads.

The lowering with the ACS springs gives me a sensation that the car lost some of the refinement and is a little springy and spongey. I think this is because the factory shocks are still in it. But I mentioned when in sport mode and the shocks get stiffer it’s not as noticeable. So when the new spring rate is higher but stiffer shocks are not matched then it would take longer for the shocks to stop the spring after it is compressed. That is what it feels like, and when the shocks are in sport mode it minimizes that effect. So that’s what I mean by the car not feeling like the suspension is dialed in now. It may not be that noticeable to others but I am very picky about these things.

It’s been 3 days since the installation so we will see if this changes at all with the springs settling. Hope that helps.

[Ninefourteener]

Post some pictures! Thats what this forum is for!

"Sometimes" the springs get twisted on the rubber grommets that rest between the spring and the perch. The good news, is that if you jack that wheel off the ground, often you can "re-seat" them by hand, with a simple twist.

"Sometimes" springs settle at slightly different rates too.

In either case, I wouldn't bee too worried.

Regarding the ride quality, often the "stiffness" of the aftermarket springs is FAR stronger that the ability of the factory struts to stabilize them. When you put the car in sport however, it stiffens the compression and rebound rates of the struts, which makes it fall more in-line with the stiffer springs. In "comfort" mode however, I'm not surprised that it may seem a bit bouncy.

So.... none of what you said surprises me, and I would consider it "normal", or at least "expected".

But..... the answer may be that you just need to leave it in sport mode. With any modification comes comprimise. I wouldn't worry too much.

But..... pics are definitely needed!

[UltraDave]

Originally Posted by Ninefourteener

Post some pictures! Thats what this forum is for!

"Sometimes" the springs get twisted on the rubber grommets that rest between the spring and the perch. The good news, is that if you jack that wheel off the ground, often you can "re-seat" them by hand, with a simple twist.

"Sometimes" springs settle at slightly different rates too.

In either case, I wouldn't bee too worried.

Regarding the ride quality, often the "stiffness" of the aftermarket springs is FAR stronger that the ability of the factory struts to stabilize them. When you put the car in sport however, it stiffens the compression and rebound rates of the struts, which makes it fall more in-line with the stiffer springs. In "comfort" mode however, I'm not surprised that it may seem a bit bouncy.

So.... none of what you said surprises me, and I would consider it "normal", or at least "expected".

But..... the answer may be that you just need to leave it in sport mode. With any modification comes comprimise. I wouldn't worry too much.

But..... pics are definitely needed!

I didn’t take any pictures unfortunately. The next day I took it back to the dealership to get some guidance and they still have to fix a few other issues. I’ll be sure to post them after I get it back.

We did however put it on a lift and we looked under with a flash light. Everything was exactly in place. The foreman even Showed me the painted hash marks where the factory lined them up.

On another note anyone taking their M50i to the dealer and it needs to go on a lift, make sure to inspect your rims before and after. The vehicle is so wide and with my wheel spacers it barely fit. Both my front rims were gouged in the same spot. Needless to say they are going to fix/replace them. Maybe it’s time to start researching some aftermarket wheels.

[UltraDave]

Here is a photo a couple days before.

[UltraDave]

I would say this ACS picture is a fairly accurate representation of the new ride height.

For anyone curious the new ACS spring rates are linear at max axle load of 1430 kg front and 1870 kg rear.

By contrast the BMW owner’s manual says the M50i has a max front axle of 1470 kg and rear of 1660 kg. It seems strange with ACS the front is less and back is more. I'm not entirely sure if this is an apples to apples comparison.

[BimmerVinyl]

Originally Posted by UltraDave

Here is a photo a couple days before.

Just to clarify, is this photo before or after the ACS springs were installed?

[UltraDave]

Originally Posted by JackB316

Just to clarify, is this photo before or after the ACS springs were installed?

The first photo is beforeThe installation, the second is an ACS official photo.

[atlas]

Hmmm interesting. I've got a set of the Eibach sittings sitting here waiting to be installed on my 40i. Wondering if I should go ahead and do it lol

[Ninefourteener]

Originally Posted by atlas

Hmmm interesting. I've got a set of the Eibach sittings sitting here waiting to be installed on my 40i. Wondering if I should go ahead and do it lol

Eibach Sportline? Send them back, and don't ever put that garbage on your car. Ever.

Eibach Pro-Kit? Is a much softer set of springs, more in-line with the factory struts. They will be comfortable..... but will not provide as dramatic of a drop as the Schnitzers in this thread. You also shouldn't expect any performance increases in handling. It will also feel very much like stock. Pro-Kit is a decent, moderate, aethetic upgrade ONLY. There's nothing wrong with that, so long as you don't go into it expecting massive appearance and performance improvement. If you do, you'll be disappointed in them.

[UltraDave]

I saw a website yesterday where you can custom design your own springs for any application. You really have to understand what you are doing though because there are a lot of variables including metal composition inner/other diameter, length, number of coils etc.

[atlas]

Originally Posted by Ninefourteener

Eibach Sportline? Send them back, and don't ever put that garbage on your car. Ever.

Eibach Pro-Kit? Is a much softer set of springs, more in-line with the factory struts. They will be comfortable..... but will not provide as dramatic of a drop as the Schnitzers in this thread. You also shouldn't expect any performance increases in handling. It will also feel very much like stock. Pro-Kit is a decent, moderate, aethetic upgrade ONLY. There's nothing wrong with that, so long as you don't go into it expecting massive appearance and performance improvement. If you do, you'll be disappointed in them.

Pro-kit - I read your previous advice on this and definitely avoided the sport line. All in looking for is a visual drop and to match the stock dampeners. As long as they don't handle any worse than stock I'll be happy! I'm not carving mountain roads in this - that's what the M2 is for lol

[UltraDave]

Here is an immediate before and after photo the dealership took. The springs had settled more after driving around and does look lower than this. I will send more when I get the car back.

[130FeetDeep]

Originally Posted by UltraDave

Here is an immediate before and after photo the dealership took. The springs had settled more after driving around and does look lower than this. I will send more when I get the car back.

I am sure you will settle a bit too. That looks really good!

[UltraDave]

Just got it back today and I think it looks great! I forgot how much I liked it with it being gone for a week.