Eibach on M

[vicj]

Anyone with an M on Eibach springs?
If you are...opinions?

[mhughett]

Not sure what benefit anyone would get by swapping BMW Motorsports springs for Eibach. Seems like about two steps down to me.

[vicj]

Thank you so much for your opinion about changing them, however, that wasn't what I was asking.
Sorry, not trying to be rude, but I'm not interested in opinions about whether or not to change them...only interested in opinions from those that currently use them.

[mhughett]

Originally Posted by vicj

Thanks for you opinion about changing them, however, that wasn't what I was asking. Sorry, but I'm not interested in opinions about whether or not to change them...only interest in opinions from those that currently use them.

I understand what you were asking for but for the reasons I noted, you are going to have a hard time finding anyone who has made the switch. Kind of like asking the question "for those of you who have taken off your PS2's (with plenty of tread left) and replaced them with Fusion Vri's, how do you like them? As you can probably tell, I had some bad experience with Eibach and don't think much of their product.

Good luck with your poll.

[vicj]

The factory set up on the M is NOT ideal. It sags badly in the rear under acceleration, and is generally very choppy. Many owners change to something, whether it's coilovers, or just springs. I have a Dinan Prototype suspension myself. This is for a buddy who is only looking for a very moderate drop, to offset the larger gap created by changing to 19-inch wheels and tires. The biggest complaint I've read about on different boards before is that the they don't really lower the car much at all...which would be perfect for this application.

[Nate2046]

Originally Posted by mhughett

I understand what you were asking for but for the reasons I noted, you are going to have a hard time finding anyone who has made the switch. Kind of like asking the question "for those of you who have taken off your PS2's (with plenty of tread left) and replaced them with Fusion Vri's, how do you like them? As you can probably tell, I had some bad experience with Eibach and don't think much of their product.

Good luck with your poll.

You really didn't note any reasons at all. And your first analogy was that all OEM parts are superior to all aftermarket parts. So maybe your second analogy should be that people would be stupid to replace their ContiSports with PS2s in the first place. We can see you have an axe to grind with Eibach but you're just spouting off silly sh&t. Obviously, lots of people, the world over use Eibach parts and the OEM BMW parts are not always optimized for what enthusiasts are looking to achieve. Sorry for the

[mhughett]

Originally Posted by Nate2046

You really didn't note any reasons at all. And your first analogy was that all OEM parts are superior to all aftermarket parts. So maybe your second analogy should be that people would be stupid to replace their ContiSports with PS2s in the first place. We can see you have an axe to grind with Eibach but you're just spouting off silly sh&t. Obviously, lots of people, the world over use Eibach parts and the OEM BMW parts are not always optimized for what enthusiasts are looking to achieve. Sorry for the

Nate: You are missing my point. Eibach's may have their place in some cars but I don't think the Z4M is one of them. Based on the lack of response to the OP's question, it sure seems like my position is reasonable. Secondly, I would suggest you stick to your own analogies and not try to tell me what mine are. Unlike springs, BMW selects tires based on a lot of variables that have little to do with the performance of the car--like price. Clearly there are better tires available than the Contisports so your comparison is ridiculous.

[vicj]

it's not surprising so few people have the Eibach springs. They came out well after many other companies had rushed out coilover suspensions for the car, and many people are already heavily invested.

I've had 8 different suspension set ups myself. Some better than the factory set up, some worse in different ways, none of them 'just right' so far.

I'm simply seeking INFORMED opinions by those that may have purchased Eibach springs for their M. I am not seeking opinions about whether or not the suspension needs to be changed at all, particularly by those that admit they have an ax to grind, and are therefore incapable of being objective.

I've gotten a few responses on some forums, and none on some others. I don't think it's indicative of how good or bad the factory set up is, just a case of Eibach developing the product a couple years after everyone else jumped in.

[nlink720]

I don't have an /M, but I have a GC Coilover Conversion kit with 440F and 550 Rear Eibach springs with Koni Sport Shocks.

The ride and handling are perfect for autocross/track daily driving in my opinion. I was previously not unhappy, but certainly wanting of improvement.

I am now 100% satisfied.

When you did coilovers, what rates were you using?

[vicj]

Impossible to compare the two. the M and the non-M Z4's have radically different suspension set ups.
I believe I ran about 400 in the front and 500 in the rear.

[S2peed]

Vicj,

I had the Eibach's in my Z4M, just upgraded to TCK Coilovers. Here's some pics w/ the eibachs and thoughts:

http://www.zpost.com/forums/showthre...ghlight=eibach

[vicj]

Thanks...
Not bad. Would you say the rear drops the full .4 inches as advertised? A tiny bit LESS would be even better, as the 19 inch wheels with a 22 offset in the rear has a real danger of rubbing.

[S2peed]

Originally Posted by vicj

Thanks...
Not bad. Would you say the rear drops the full .4 inches as advertised? A tiny bit LESS would be even better, as the 19 inch wheels with a 22 offset in the rear has a real danger of rubbing.

I'll say it drops as advertise because I was worry it would drop to low as well.

[vicj]

Ok, thanks.
Time for some very careful measurements. 22 rear offset and lowering do not play well together on this car.

[Nate2046]

Originally Posted by vicj

Ok, thanks.
Time for some very careful measurements. 22 rear offset and lowering do not play well together on this car.

I can try and take a measurement for you after I get mine on here in the next couple of weeks. They're S2peed's used Eibachs so I'm thinking they should be pretty well settled from the get-go. I'm not sure what the most meaningful measurement would be since I'll be switching to my summer wheel/tire setup at the same time. I'm thinking center of the hub to fender should be a good measure to eliminate differences in overall tire diameter. If I remember correctly my wheels are a +25 with a 9.5" width, so I'm hoping rubbing won't be a problem, we shall see.

[vicj]

Thanks Nate. Are your summer tires 19-inch, or 18? Also, are you going directly from a factory suspension set up to the Eibachs?

[Nate2046]

Originally Posted by vicj

Thanks Nate. Are your summer tires 19-inch, or 18? Also, are you going directly from a factory suspension set up to the Eibachs?

19's with a 275/30 in the rear, and yes, going from a bone stock suspension.

[vicj]

Fantastic! Same size as my buddy's, plus you should be able to give a direct comparisons on how much stiffer they are. I think you're right, a 25 offset might just make it OK. It'll be close.

[vicj]

Hey Nate...
Get these installed yet?

[Nate2046]

Originally Posted by vicj

Hey Nate...
Get these installed yet?

Ok, finished the install yesterday. It took me as a long to do the front passenger side as it did for the other 3 combined.

I wanted to get an exact measurement of the drop without any other variables so I put my winter wheel/tire setup back on for the after measurements. I used a level to go from the ground straight through the center of the hub to the fender. I also measured at the front and rear jackpoints but thats affected somewhat by the other spring.

FRONT
pax 13/16" driver 13/16"

REAR
pax 1/2" driver 5/8"

from the jack pads;
FRONT
pax 9/16" driver 3/4"

REAR
pax 1/2" driver 9/16"

So, pretty much bang on the advertised drop of .8" in the front and just slightly more than .4" on the rears.

To answer the subjective ride quality questions, I have to point out that I've only put twenty miles or so on them so take that FWIW. Overall they feel really good, definitely less harsh than the stock springs. The roads in my neighborhood have a lot of minor imprefections, washboard type surface, small potholes, etc and they feel really comfortable over those without any harshness or bouncing/undulation. Haven't been over any really large imperfections to feel them at the limits of travel so can't comment there. Car also seems to squat and dive less on accel/braking.

Vic, I'll have to get back to you on any rubbing issues at the rear when I get my summer set on in the next few days. Its a 275/30/19 tire on 9.5 wheel et+25. Obviously the 225/40/18 on there now isn't going to have a problem.

[The HACK]

Originally Posted by mhughett

Eibach's may have their place in some cars but I don't think the Z4M is one of them.

Really? I'm pretty sure Eibach supplies the springs BMW uses for the M. In fact I'm almost certain of it.

[mhughett]

Originally Posted by The HACK

Really? I'm pretty sure Eibach supplies the springs BMW uses for the M. In fact I'm almost certain of it.

If that were true, what is the point of this thread? Is the answer of the OP's question "yes, everyone that has an M"? Better question would be if they are one in the same, why would someone want to swap out their OEM springs for Eibach?