Sway Bar/Suspension Inquiries

I drive a 1989 325i and would like to lessen body roll significantly and stiffen suspension all around. I just replaced all my shocks with Bilstein HD shocks, and that definitely makes a noticeable difference. In the long run I'd like to go coil over all around and lower the car a couple inches. For now my budget limits me. Is it reasonable to install piece by piece, or should I slowly acquire high performance suspension components and wait to install them all at once?

I've heard increasing the sway bar diameter without changing the spring rates (and shocks) will be likely to increase understeer and make the car harder to control, not better. Is this true?

When I had my E30 I had the Racing Dynamics adjustable sway bars installed. I don't remember the exact diameter but I'm sure you can find the specs online. Needless to saw they were fantastic! I ran them in the middle setting both front and rear and it was enough to snap the attachment points on the suspension arms on the rear about once a year. My mechanic eventually welded angle-iron to the rear arms and that did the trick. Regardless of which sway bars you choose the mounting tabs on the stock suspension arms may not be strong enough. You can also forget about the lightweight aluminum arms you might see in other catalogs. The bigger sway bars were enough for me and, I skipped lowering the car 3cm as I had originally planned.

So best to wait and put all high performance parts on at once?

Short answer, a piece at a time is the way to go.

I really think the sway-bars are going to be enough, they were for me but, I'm not sure what you're driving style is or your intentions with the car are. The other reason is that you can feel where your money is being spent when you go bit by bit. All at once and it's really tough to say what's giving the most smiles per mile.

Piece by piece isn't just my recommendation either, I was in the same boat as you, wanted to upgrade my 325is but was on a limited budget. My mechanic, and a friend of mine who was a former E30 M3 racing team tech told me the same thing. They said to go with the sway bars first, if it's still not enough, then lower. I was also told not to lower my E30 unless I planned to be cornering above 80mph. In short I'm glad I listed to their advice as it saved me a lot of money and allowed me to add other upgrades.

Here are the sway-bars I had on my E30 http://www.racdyn-usa.com/category/e30sus.html

Here's a link to BMP site, I would say go with the 3cm kit, if you decide to lower 2 inches it may be overkill and, sacrifice other handling qualities http://www.bmpdesign.com/product-exe...earch_model/34

Finally if you want to know 1st hand I see you're posting from Utah, I'm in CO. Call my mechanic, he's got a fully spec'd E30 with some of the exact upgrades you're considering. Randy is a one man operation so it's best to reach him in the mornings. If he's free he'll usually let you pick his brain a bit. If he doesn't call you back don't be offended, he's one the best, if not the best along the front range and remains very busy. http://boulderautowerks.com/

Originally Posted by LumpyJ

Short answer, a piece at a time is the way to go.

I really think the sway-bars are going to be enough, they were for me but, I'm not sure what you're driving style is or your intentions with the car are. The other reason is that you can feel where your money is being spent when you go bit by bit. All at once and it's really tough to say what's giving the most smiles per mile.

Piece by piece isn't just my recommendation either, I was in the same boat as you, wanted to upgrade my 325is but was on a limited budget. My mechanic, and a friend of mine who was a former E30 M3 racing team tech told me the same thing. They said to go with the sway bars first, if it's still not enough, then lower. I was also told not to lower my E30 unless I planned to be cornering above 80mph. In short I'm glad I listed to their advice as it saved me a lot of money and allowed me to add other upgrades.

Here are the sway-bars I had on my E30 http://www.racdyn-usa.com/category/e30sus.html

Here's a link to BMP site, I would say go with the 3cm kit, if you decide to lower 2 inches it may be overkill and, sacrifice other handling qualities http://www.bmpdesign.com/product-exe...earch_model/34

Finally if you want to know 1st hand I see you're posting from Utah, I'm in CO. Call my mechanic, he's got a fully spec'd E30 with some of the exact upgrades you're considering. Randy is a one man operation so it's best to reach him in the mornings. If he's free he'll usually let you pick his brain a bit. If he doesn't call you back don't be offended, he's one the best, if not the best along the front range and remains very busy. http://boulderautowerks.com/

Awesome man. Thanks for such a solid thorough response. I'll start saving and probably give your mechanic a call when parts are in.

Your B6 Bilstein shocks will blow if you lower your car, unless you bought the Billsteins specifically for that purpose !

Originally Posted by Nick323

Your B6 Bilstein shocks will blow if you lower your car, unless you bought the Billsteins specifically for that purpose !

Yeah, I got a great deal on them, so I got them to last me until I have the money to upgrade the suspension.

I'm seriously considering this purchase,

http://www.bmpdesign.com/product-exe...earch_model/34

However I'm not sure how a 1.3 inch drop will look. I would like a lower suspension so as to get around the track faster and more aggressively. My tires are 195-65r14, will the stock size tire look out of place with the drop?

If anybody has pictures of a 1.3 inch drop, please share. Also, please share your thoughts on this specific product and how it functions with otherwise stock suspension components.

Im running IE's sways, great improvement.,
if you like, try a convertible front 22mm and a iX or m3 rear at 14.5mm's can't beat they're low cost.