General suspension-quesion

[pihlen]

Hi all,
I am brand new to owning a car and I just bought a silver E21 '81.

I have a question about ride height lowering springs:

How do they affect the driveability? If the rest of the susp system is original but i change to springs that would lower my car 40 or 60 mm, will it make the car more stiff and bouncy? in a good or a bad way (i mean; will it give better cornering or just a more bumpy ride) ?

Or would I need more than just those springs to get a better cornering ability? i know a few things about CoG and camber/toe angle etc, but if i ONLY change the springs to lower the car, what will happen handling wise?

Thanks in advance!!

[Jeroen]

Hi, welcome and congrats on your new toy!

Some decent lowering springs will definitely both make the suspension more stiff and improve handling and cause a lot less body roll. However, if this will work properly may depend on the shocks, these may already have some wear. A budget solution is to fit just the springs, the best solution will be to replace the dampers as well. For both the front and rear strut top bearings/bushes: you may want to chec these for wear or freeplay (with compressed spring) as well as this may cause annoying suspension knocks if refitted. For more info also see the FAQ section.

[uwbuurman]

Welcome!! I would love to see some pics of your car!

[polov8]

Going from a bone stock 316, you'll certainly benefit from swapping the shocks along with the springs. Shorter stiffer springs will work the shocks much harder and give even brand new stock shocks a hard live. The shocks job is to control the oscilations of the springs, so increasing the spring rates and reducing the available travel will mean stiffer shocks are going to offer the most control.
With the age of our cars, it's very probably that the various bushes in the suspension are getting very soft. These are relatively inexpensive to buy, even genuine new from BMW, and of course can be upgraded to polyurethane for more accurate control at the expense of a bit of harshness.
Just remember the lower you go, the less travel your suspension is going to have, so when lumps and bumps are encountered, particularly when cornering when the suspension is loaded, you run the risk of hitting the bump stops which is another way of saying running out of suspension.

[pihlen]

thank u all and sorry for my super late reply!

I have another follow-up question then:

how much value would say it is with a set of coilovers compared to "just" new original stuff or even some nice bilstein shocks and maybe 40 mm lower springs? i´ve looked at some different variants and found that bilstein shocks with apex springs would cost ca 550 euros and a set of coilovers roughly 900 euros (i live in sweden so i translate from SEK). im not (yet) doing any track driving but i want some nice drivability in sunday trips along curvy no-traffic roads in the countryside



i honestly dont get the img-function so here are two instagram pics i took of my car:
https://www.instagram.com/p/BDLw16AM6dC ... schteeffoh
https://www.instagram.com/p/BDJ2nmvM6ex ... schteeffoh



thanks 1000 times again for your knowledge and help!

[ruh]

thank u all and sorry for my super late reply!

I have another follow-up question then:

how much value would say it is with a set of coilovers compared to "just" new original stuff or even some nice bilstein shocks and maybe 40 mm lower springs? i´ve looked at some different variants and found that bilstein shocks with apex springs would cost ca 550 euros and a set of coilovers roughly 900 euros (i live in sweden so i translate from SEK). im not (yet) doing any track driving but i want some nice drivability in sunday trips along curvy no-traffic roads in the countryside



i honestly dont get the img-function so here are two instagram pics i took of my car:
https://www.instagram.com/p/BDLw16AM6dC ... schteeffoh
https://www.instagram.com/p/BDJ2nmvM6ex ... schteeffoh



thanks 1000 times again for your knowledge and help!

Hello Pihlen, i´m from Denmark so you must be my friendly neighbour

If you are not going to use the car for the track (trackdays) or wants a extreme low stance, i would reccomend a set of 40 or 60mm lowering springs and some good dampers. There are alot of dampers, Bilstein is one, and is extremly good. But you can also get SPAX from Germany that can be adjustet in hardness that will also be very very good for your car.
Another thing you can do to make the car better handling is change all the rubbers for some polyurethane bushes. Superflex makes a complete kit with everything you need for the car.

I would go with the following:

http://www.fahrwerke.de/111-springkit-bmw-3er-e21

http://www.spax-deutschland.de/index.ph ... 2082_22083 (or Bilsteins)

http://www.strongflex.eu/en/bmw-e21-75- ... 19006.html (an absolute must, especially if you beef up your suspension)

This would make for a extremly well handling E21 and you will be able to enjoy your car on those twisty swedish backroads

[pihlen]

awesome! i live just by the ferry to fredrikshavn (ie gothenburg) so we could totally take a cruise this summer

thanks alot for the tips, i hadnt thought about that "change the rubbers for some polyurethane bushes". i guess i´ll have to start saving money. right now i´m working on getting a motorcycle licence and that, if anything, makes a person poor! hähä.

speaking of suspension, would u say a stiffening bar between the front susp-towers would be a good idea? i could quite easily make one myself in a metal workshop. would it make any difference for a stock power car? should i in that case also have one at the rear if i have one in front?

[Jeroen]

A front strut brace will do miracles on any E21! It's all floppy there, will make your steering and turns a lot more stable and take away all the sensitivity for deeper/worn track in the asphalt. No prob to make one yourself, as long as you make it a 1-piece (no pivot points) and rigid enough.

[ruh]

A front strut brace will do miracles on any E21! It's all floppy there, will make your steering and turns a lot more stable and take away all the sensitivity for deeper/worn track in the asphalt. No prob to make one yourself, as long as you make it a 1-piece (no pivot points) and rigid enough.

Jeroen +1
The E21 chassis is very soft, so anything to stiffen it up should be good