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Advise on upgrading suspension
Advise on upgrading suspension
Hi folks!
I’d like to upgrade my suspension a little bit. I have a 83’ 520i and the rear is sagging, not mentionning the overall suspension feeling being much too soft which is typical on our cars.
Where I live, we cannot use ajustable coilovers, unless they are soldered in one position, which kinda voids any benefit for installing them.
All kits I see available are lowering kits for the rear AND the front. I did not find à seller yet who would sell separated front and rear kits based on user preferences.
If there’s any compatibility between different models, I’m all for swapping, like installing e34 at the front and m5 at the rear for ex (this is just to illustrate, don’t take it literally). I don’t want to frankenstein my car though. It has to be compatible and safe to ride.
All I want is something a bit stiffer all around and a bit of lowering at the front, not the rear.
What would you guys suggest me to do?
I’m sorry for my average English, I’m from over the pond, from where I send you all my best wishes btw.
Thank you for your time and attention.
I’d like to upgrade my suspension a little bit. I have a 83’ 520i and the rear is sagging, not mentionning the overall suspension feeling being much too soft which is typical on our cars.
Where I live, we cannot use ajustable coilovers, unless they are soldered in one position, which kinda voids any benefit for installing them.
All kits I see available are lowering kits for the rear AND the front. I did not find à seller yet who would sell separated front and rear kits based on user preferences.
If there’s any compatibility between different models, I’m all for swapping, like installing e34 at the front and m5 at the rear for ex (this is just to illustrate, don’t take it literally). I don’t want to frankenstein my car though. It has to be compatible and safe to ride.
All I want is something a bit stiffer all around and a bit of lowering at the front, not the rear.
What would you guys suggest me to do?
I’m sorry for my average English, I’m from over the pond, from where I send you all my best wishes btw.
Thank you for your time and attention.
Re: Advise on upgrading suspension
Welcome to the group and no worries about your English writing, it's just fine and as I read it I can't tell you're not a native speaker of it.
Springs are going to be a little difficult. From what I see your car probably weighs about 1220Kg, heavier than the 4 cylinder 518s, but lighter than the other 6 cylinder cars, so shorter springs might not lower it as much as you would expect since they would be stiffer for a heavier car. Or maybe it won't make that much difference, I'm not sure, just don't be surprised if it doesn't change as much as you're hoping for.
Springs are going to be a little difficult. From what I see your car probably weighs about 1220Kg, heavier than the 4 cylinder 518s, but lighter than the other 6 cylinder cars, so shorter springs might not lower it as much as you would expect since they would be stiffer for a heavier car. Or maybe it won't make that much difference, I'm not sure, just don't be surprised if it doesn't change as much as you're hoping for.
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- Location: Chicago
Re: Advise on upgrading suspension
Remember that the reference for ride height for a set of aftermarket springs is the ride height of your original springs when they were new, not as they are now. Your rear springs are presumably sagging because they are worn. A set of performance springs will generally give you a car with a level ride height. If you have an M20B20 I doubt the weight on the front axle is meaningfully different from the same car if it had an M20B35.
Re: Advise on upgrading suspension
Got a hacksaw or torch? 

Re: Advise on upgrading suspension
Low tech but I like it. Cutting a coil off shortens the spring also which would make it stiffer. Sounds like a win-win.
Re: Advise on upgrading suspension
Mike W." wrote: Apr 25, 2025 12:33 PMLow tech but I like it. Cutting a coil off shortens the spring also which would make it stiffer. Sounds like a win-win.
Feels very slightly stiffer. Not uncomfortable at all. I had tried some spax springs and shocks and found the ride to not suit uk pot holed roads at all.
The best mod I made was to fit polyurethane bushes to the front upper and lower arms. Once you get the tracking spot on the steering is transformed.
The best mod I made was to fit polyurethane bushes to the front upper and lower arms. Once you get the tracking spot on the steering is transformed.
Re: Advise on upgrading suspension
It goes without saying that blown out old shocks will make any E28 handle like crap. Mine had its originals back when I got it in 2013, and every time a semi truck passed me the opposite way it would shake like a 2CV. New Sachs shocks completely eliminated that, and I eventually went to Bilsteins to make the car more tossable on uneven back roads, with potholes, dips/gutters and whatnot.not mentionning the overall suspension feeling being much too soft which is typical on our cars.
Re: Advise on upgrading suspension
JohnH wrote: Apr 26, 2025 9:55 AMFeels very slightly stiffer. Not uncomfortable at all. I had tried some spax springs and shocks and found the ride to not suit uk pot holed roads at all.
The best mod I made was to fit polyurethane bushes to the front upper and lower arms. Once you get the tracking spot on the steering is transformed.
i have Bilstein front inserts with spax 45mm front springs and then spax 34way adjustable rear struts with spax 35mm rear springs . car drives great on uk roads but i am running 16 inch alpina staggered rims so i have some tire profile . where abouts in the uk are you ? im in Birmingham
Re: Advise on upgrading suspension
Thank you all for your advises. Those polyurethane bushings are definitely something I’m considering. It’s true my car behaves like crap at speed (I mean you get my point right
, 90mph is already too much to handle lol). It’s kinda frustrating. I also have to admit it sits on 70’ tires (14 inches) which does not help rigidify the ride of course. I think I’m in for a rear mainframe bushings replacement as well, as I also get a mean ’floaty’ feeling from the rear, especially when crossing big trucks, or on uneven roads. I don’t like it at all, and I don’t remember any of my previous old bmw’s to ever ride like that. So it’s time overdue for a complete drive train update I guess.
As far as cutting those springs goes, though I really like the diy, cost effective and imaginative part of it, I’m not quite sure I would venture in that territory. Maybe I’m too much of a conservative guy Idk, you tell me. I’m under the impression the tightened ends of the springs are there for a reason. They probably make the spring stiffer on that portion, avoiding the car to bottom out, idk...Not sure my car deserves to be treated like that. I would prefer to use properly thought out after market parts, but hey, maybe I’m an idiot. Still considering it though, it’s just I don’t want to hurt that baby, nor putting myself at risk by going too cheap.
I really have to thank you all for each input. It gave me new ideas to consider.
I wish you all the very best,
Freundliche Grüßen!
As far as cutting those springs goes, though I really like the diy, cost effective and imaginative part of it, I’m not quite sure I would venture in that territory. Maybe I’m too much of a conservative guy Idk, you tell me. I’m under the impression the tightened ends of the springs are there for a reason. They probably make the spring stiffer on that portion, avoiding the car to bottom out, idk...Not sure my car deserves to be treated like that. I would prefer to use properly thought out after market parts, but hey, maybe I’m an idiot. Still considering it though, it’s just I don’t want to hurt that baby, nor putting myself at risk by going too cheap.
I really have to thank you all for each input. It gave me new ideas to consider.
I wish you all the very best,
Freundliche Grüßen!
Re: Advise on upgrading suspension
Since you are in Europe, my best advice would be to find a local E28 meeting and get a ride in a couple cars. A well sorted stock one at least to see what they really feel like.
Suspension discussions are like the motor oil ones: everyone has their own choice that works for them.
Suspension discussions are like the motor oil ones: everyone has their own choice that works for them.