Rim size / ride height advice needed

[wjbell]

Ok, I'm seriously considering getting a set of 18" M-par replicas with tires from Lakshore. I can probably get a wheel/tire package for around $1100 shipped. And IMO m-pars on a e34 look sweet.

I've got two problems... First, my car is stock height. Even though the overall diameter of the tire is the same, and there's the same space between the tire and fender with stock 15's or 18's (in theory), it always seems to look funny when you put 18's on the car compared to the stock 15's.

Now, I like stock height. I've had my share of dropped cars and really don't want to "drop" my car. I want it as stock as possible, but I want it to look good with the m-pars if I get them. I want the ride to be as close to stock comfort as possible.

So, does anyone have any experience with putting 18's on a stock height car? Did it need to be lowered some? What are the best aftermarket springs that lower the car the least and keep the ride as close to stock as possible? I was thinking of ordering M5 springs and upper and lower spring pads and wondering if that would lower it enough for the m-pars.

And the second issue is the front end. I've heard the horror stories about switching to 18's and now you feel all the flaws in the front end. I'm guessing because you have less sidewall to cushion the imperfections. Any thoughts on this?

He'res a couple pics that show my stock ride height.

http://www.belletc.net/bmw/bmw1.jpg

http://www.belletc.net/bmw/bmw2.jpg

[Martin in Bellevue]

You're welcome to fit my tStars sometime for an idea of how it'll look & ride. I've got Eibach prokit springs on my 535. The Eibach sportlines are very short, if I remember correctly.

[Qube]

Didn't you post this a long time ago? :)

http://www.bimmerboard.com/forums/posts/228165

[wjbell]

Didn't you post this a long time ago? :)

http://www.bimmerboard.com/forums/posts/228165

Sort of, the questions are similar. Hopefully I can get some helpful answers this time though. ;)

[wjbell]

You're welcome to fit my tStars sometime for an idea of how it'll look & ride. I've got Eibach prokit springs on my 535. The Eibach sportlines are very short, if I remember correctly.

Thanks Martin! It would be nice to see what they look like on, kind of give me an idea on where I need to go suspension wise.

[E34N]

When I bought my car, it had the mpars on there on stock suspension. I rode fine, no "front end" problems.... but I really didn't like the look. so I lowered it with eibachs.

If you want the closest to stock ride.... either M5 suspension or Bavauto would do it.

[wjbell]

Does anyone know how much the bavauto springs lower front and rear? I think I remember it was 3/4 in the rear and a little over an inch in front.

Also, I've heard that the bavauto springs are softer than stock and actually bottom out.

And what about wear over time, does anyone know if they hold their initial height or do they sag over time?

Sorry for all the questions, just want to get the most info I can so I don't do something I regret later.

[E34N]

Bottoming out is not the springs.. it would be your shocks. It's possible that you've heard this from the 8cyl owners.. since the v8 engine is so much heavier. Get some quality shocks and you should be fine.

Here's (http://www.bmw4life.com/shocksSpringsGuide.htm) some good reading.

EDIT: ok.. maybe that site is where you heard the bottoming out... HERE (http://www.bmwe34.net/e34main/upgrade/suspensions.htm)

[ltflint]

Fitted staggered OEM M-Pars to my stock height touring with no issues.

[Tiger]

Don't go Bavauto spring... everyone hates them. If you do want to lower your car slightly it is M-Tech springs from your dealer... Are you sure you don't have it already? Is your car stick shift?

[wjbell]

Don't go Bavauto spring... everyone hates them. If you do want to lower your car slightly it is M-Tech springs from your dealer... Are you sure you don't have it already? Is your car stick shift?

Mines an automatic. The M5 springs would be good but I can only use M5 springs in the front... which might be good enough if the back looks fine. I think you can only use M5 rear springs if you have self-leveling suspension.

[wjbell]

Bottoming out is not the springs.. it would be your shocks. It's possible that you've heard this from the 8cyl owners.. since the v8 engine is so much heavier. Get some quality shocks and you should be fine.

Here's (http://www.bmw4life.com/shocksSpringsGuide.htm) some good reading.

EDIT: ok.. maybe that site is where you heard the bottoming out... HERE (http://www.bmwe34.net/e34main/upgrade/suspensions.htm)

Thanks. I had read that first site before and couldn't remember where I saw it. Good info.

[Tiger]

M-tech springs are available for all E34... not only M5.

[wjbell]

M-tech springs are available for all E34... not only M5.

So M-tech springs are not the M-Technic springs found on M5's? They are something totally different? It sounds like they would be performance springs for the normal BMW (not the M series). I've never heard of this.

[Tiger]

M-tech does make springs for M5... it is called sport suspension package for all BMW... you can order these for your car at BMW part counter or BMA.

[txp135]

The 540i6 have the M-technic springs from factory without the rear SLS. But I would do some research first before putting them on because of the weight difference.

[Paul in NZ]

my 535 has mtech springs,and with the narrower spring pads lowers the car just right in the rear,could do with a little more in the front(std fitment btw on the "sports" models)Here is a side shot with 17x 8 and 235 45x17 tyres
http://www.bimmer.info/bmw/kiwi535/manfeildjun05.jpg

[wjbell]

The 540i6 have the M-technic springs from factory without the rear SLS. But I would do some research first before putting them on because of the weight difference.

What I was thinking was getting the springs from a ~90 M5 3.6L. They all have the same part number and was thinking the engine weight was close to mine. (Spring (http://www.realoem.com/bmw/showparts.do?model=HD93&mospid=47412&btnr=31_0415&hg=31&fg=10) I already have the 3mm lower spring pad installed. (Number 12 (http://www.realoem.com/bmw/showparts.do?model=HD93&mospid=47412&btnr=31_0128&hg=31&fg=10) But the USA M5 come with a 9mm upper pad. Now if you go with the Euro M5 3.8 they come with both the 3mm upper and lower pads. (Euro pads (http://www.realoem.com/bmw/showparts.do?model=HC91&mospid=47387&btnr=31_0229&hg=31&fg=10) But the front springs are a different part number so I don't know if the springs are the same diameter, so in turn I don't know if the 3mm upper pad will work.

As far as the 540-6, wouldn't the rear weight of the car be similar to my 535? But I couldn't find a model without self-leveling suspension.

[wjbell]

my 535 has mtech springs,and with the narrower spring pads lowers the car just right in the rear,could do with a little more in the front(std fitment btw on the "sports" models)Here is a side shot with 17x 8 and 235 45x17 tyres


Do you have the part numbers for the front and rear springs you installed? What car were they for?

[Tiger]

Just go to dealer with your VIN number or call BMA and they will give you the right springs. It is not rocket science.

[wjbell]

Just go to dealer with your VIN number or call BMA and they will give you the right springs. It is not rocket science.


I like to know what I buying, I like to research what I putting on my car and know why I'm putting it on my car. I like to understand what I'm doing. I don't usually take one persons opinion as gospel, especially someone that comes off like a little prick with very little explanation. Can you understand that? It's not rocket science...

[Qube]

Heh. With anyone else I'd agree but Tiger hasn't been much of a prick. Anyway... as rehashed...



There are lot's of different spring manufacturers, the most popular are:

H&R: Moderately stiff ride. (1.3" front - 1" rear)

Eibach: Moderately stiff ride. (1.3" front - 1" rear)


Racing Dynamics: Slightly stiff ride. (1" front - .75" rear)

Bavarian Auto: Close to stock ride. (1.3-1.5" front - 1" rear)

Dinan: Sport spring that almost doesn't lower the car.

M5 springs: front works with any E34. Rear will not work unless you have a self-leveling suspension.

Sach "sporting" kit: bodge turbo gas/Shach spec Eibach springs, not as stiff as the bilstein/Other spring combination. (1.25" drop front). It seems that on the 540i, it created a drop of 2" front and 1.25" rear...

What shocks with what springs, form the less stiff to the stiffer ride:
Original ride: Original springs or Bavauto springs with Boge
Slightly stiffer ride: Original springs or Racing Dynamics springs with Bilsteins HD.
Moderately stiff ride: H&R or Eibach or Racing Dynamics springs with Boge.
Moderately stiffer ride: H&R or Eibach or Racing Dynamics springs with Bilsteins Sports/HD.
Adjustable stiffness: Dinan stage I (tiny drop) or use Koni shocks (expensive).

Basically if you want to lower the car and keep the OEM ride, go with the Bavauto springs.

[Tiger]

Part number for your car depends on what you standard equipments you have on the car... I attempted to do so with my ETK and shoot the part number to BMA and they come back as invalid part number...

I am not a prick... I just know what everyone is facing when they throw all the numbers to you... If you get 10 sets of numbers, you might see a pair matching... and that is because we don't know what you got in your car. BMA or BMW dealer knows what you got in the car and then match it to your car...

[wjbell]

I guess the rocket science comment rubbed me the wrong way. Typing on a messageboard makes it hard to judge the intent or tone of a persons comment.

[txp135]

For 540i6

31 33 1 138 811 Fronts

33 53 1 138 817 Rears

M-tech is just short for M-technics. I don't think these are the same parts as for the M5, these are the parts for e34 540i6. This suspension also come with sway bars.

[Paul in NZ]

for the mtech springs for a 535
front 31332226669
rear 33532226673
there is lots of info on the parts database
look up my car BF01045
the option list included option 226,sports suspension settings,i have always thought that meant m-tech

[wjbell]

Ok thanks for the replies. After I get my rims I'll see what the fender gaps looks like and probably go with m-tech springs.

[Qube]

Definitely lower first... it will look something like this...

http://www.bimmer.info/forum/showpost.php?p=80105&postcount=5

[jrobbo]

delete