Cutting Front Springs ... bad idea ?

[Mike Self]

Pre-73 2002s have springs that give a ride height about an inch lower than 73-76 cars. This is due to Federal bumper height requirements that began in '73; BMW met the standard in 1973 by using taller springs, and then in 74-76 by a combination of taller springs and bigger (and higher mounted) bumpers.

Easiest solution for a '73 is to get a set of springs from a '72 or earlier car. That'll preserve the ride comfort and still lower the car about an inch.

cheers

mike

[robspeed]

Pre-73 2002s have springs that give a ride height about an inch lower than 73-76 cars. This is due to Federal bumper height requirements that began in '73; BMW met the standard in 1973 by using taller springs, and then in 74-76 by a combination of taller springs and bigger (and higher mounted) bumpers.

Easiest solution for a '73 is to get a set of springs from a '72 or earlier car. That'll preserve the ride comfort and still lower the car about an inch.

cheers

mike

cept that 73 red dots are the stiffest ones. the above explains why i had to cut 1.75 off my fronts to get it close to where I wanted it!

[Bill_Riblett]

If by "red dots" you are referring to the colored striped BMW used to grade spring rates,

Red is softest

White in middle

Green are stiffest.

The second color stripe denotes front or rear, but I can't remember what they are. This stuff is in the factory shop manual.

[robspeed]

If by "red dots" you are referring to the colored striped BMW used to grade spring rates,

Red is softest

White in middle

Green are stiffest.

The second color stripe denotes front or rear, but I can't remember what they are. This stuff is in the factory shop manual.

oof. maybe thats why my car rides so nice, even tho i upped the rate by cutting em...

[Mars]

Perhaps my post did not come across properly as it should have.

1. Whoever posted that springs do not handle load and shocks do that is 100% correct. Springs do NOT hold up a car, the shocks do.

2. Cutting springs CAN and WILL weaken them. Like Robspeed or someone else said they will weaken depending on how many coils are cut and whether or not heat is used. Most people are NOT satisfied with one coil since they want their car to drop and look 'cool' so in my experience I see people do 2-2.5 coils. I would not recommend this or do this on my car.

3. Springs after 20-30 years DO get old and tired. So yes than can (and do) flex and stretch out some. I have seen it and experienced it time and again over the years. Cars can wind up with a bowed out negative camber effect.

Your call and your car but I do believe personal opinions and experience were asked for so that is all I am giving.

The right way? Buy a lowering spring kit. Or, like Mike Self suggested get the shorter ones from a different model 02.

Happy 02'ing.

[ClayW]

ClayW, it might be just your use of words, but your opinion that cutting a spring reduces the damping force shows either poor choice or words, or something worse.

Poor choice of words.....and just my opinion.

Never seemed right to just take a torch to old stock springs. Again, call Jeff Ireland and I'm sure that he could give you a better explanation.

[robspeed]

Perhaps my post did not come across properly as it should have.

1. Whoever posted that springs do not handle load and shocks do that is 100% correct. Springs do NOT hold up a car, the shocks do.

WRONG! again... springs hold up the car, shocks dampen the movements of the car on the springs.

2. Cutting springs CAN and WILL weaken them. Like Robspeed or someone else said they will weaken depending on how many coils are cut and whether or not heat is used. Most people are NOT satisfied with one coil since they want their car to drop and look 'cool' so in my experience I see people do 2-2.5 coils. I would not recommend this or do this on my car.

no, no, no... heat will destroy any metal (see WTC), but that is not what we are talking about. cutting a coil or coil and a half makes the remaining spring a STIFFER/STRONGER spring. Weakens? NO! at some point if you cut too much you are riding on the bump stops, which is stupid for its own reason. it has nothing to do with cutting a stock spring to mimic the drop of aftermarket sport springs.

3. Springs after 20-30 years DO get old and tired. So yes than can (and do) flex and stretch out some. I have seen it and experienced it time and again over the years. Cars can wind up with a bowed out negative camber effect.

so, so wrong. springs dont affect camber on 02s. and springs dont stretch out over time! they can sag, but if thats the case you probably arent worried about lowering yer car to begin with...

Your call and your car but I do believe personal opinions and experience were asked for so that is all I am giving.

opinions are fine, everyone has them. like trees have leaves...

The right way? Buy a lowering spring kit. Or, like Mike Self suggested get the shorter ones from a different model 02.

There is no "right" way. We choose whatever mode of operation fits our circumstances. $200 H&Rs are sweet, but free cut stockers are also fine, and only suffer from the lack of progressive compression action.

Happy 02'ing.

indeed!

[peteinjp]

Don't pay attention any of this- just cut them and see how you like it. Worst case scenario you end up buying a set of springs on down the road and doing the labor again. The only negative affect I can think of is that the rates might be a little put of wack with the rears but if your not tearing up the corners you'll never notice.

[Mars]

Robspeed, you don't like me anymore?

I don't disagree with what you say but I can tell you from experience that springs can tire out. They DO take form and a car can have its camber affected some time after cutting since the ride height has changed. Maybe I'm using the wrong words??

Yes, if you cut a spring it changes its compression rate. So they become somewhat stiffer and don't allow the travel required to 'suspend' the car. So I understand what you are saying there when you say they get 'stronger' if you cut them. But, lowering a car is more than just cutting springs. Otherwise everyone could save money doing it this way. Lowering springs have a different spring rate & stiffer dampers to compensate for reduced suspension travel, and different alignment settings to compensate for the fact that the suspension is further up in it's travel. A cut spring alone will not compensate for all of that and it can give you all sorts of problems especially on the front end.

Besides the alignment and possible camber or caster problems the spring won't fit in its perch properly, especially with struts. If/when it slips out it can cause a nice 'bang' too.

Overall ride quality obviously suffers too.

No one else on here agree with me? Have I been wrong after thinking this way for several decades??

Can't speak too much about modern cars as I don't work on anything past early to mid 90's so I base all I know on old skool stuff.

[TimG]

BS! cutting a spring has no effect on the metal that remains, assiming you dont heat up the metal when cutting. the metal coil that remains actually ends up STIFFER because less spring is holding up the same weight.

i did mine about seven+ years ago and LOVE IT, with Bil HDs.

Forgive my questioning, but it seems to me that cutting the springs is essentially a bad thing.

If you cut a spring, that's less overall dampering ability. Shorter, "lowering" springs have a higher spring rate, so the shorter spring could make up the height difference with more spring (dampering) force. Cutting one of the coils in a spring would produce an overall weaker spring; less dampering force than the original spring.

Now, to the effect of it's consequences on handling on a BMW 2002, you'd have to ask people that do more racing than I do.

If you ask me, go with the scienced out lowering spring, and ask Jeff Ireland to explain why if you need more convincing evidence.

Wow, a lot of dis-information here.

First of all, damping has nothing to do with springs. Your shocks provide damping force; your springs provide spring force; your car provides mass. The equations for spring-mass-damper dynamics were established a couple hundred years ago and have not changed any.

Secondly, cutting a coil off any spring makes it stiffer, not weaker.

Thirdly, the original poster just wants to reduce his front ride height CHEAPLY and does not race. Cutting the springs is a perfectly valid approach for that situation. I'd cut HALF a coil, re-install, and see if that does it. Cut SLOWLY with a saw, using water to prevent heating the spring. Do NOT use a torch. If the spring gets hot, you are screwed.

Cutting coil springs lowers your car more than you'd expect, so go easy, starting with half a coil, then another quarter, etc. The only potential problem here is the top of the coil not matching up with the spring perch; I'm sure many 2002er's have dealt with that successfully.

[TimG]

Perhaps my post did not come across properly as it should have.

1. Whoever posted that springs do not handle load and shocks do that is 100% correct. Springs do NOT hold up a car, the shocks do.

With all due respect, this is exactly wrong. Remove the shocks completely and AT REST the car will be at the same ride height as with 'em. Springs hold up the car just fine & if you only drove your car at 5mph in your driveway, you wouldn't need shocks at all. The shocks only resist motion in the suspension & have little to no effect on ride height.

If you had only shocks, but removed the springs, then the car would settle onto either the bump stops or bottom out the shocks and the car would be very low and nearly un-drivable (unless you were a ricer, in which case it might be good).

In the case of air shocks, those do carry load per your description, but that's a special case not related to the normal shocks on most cars.

[robspeed]

sorry i never replied to you Mars...

anyway, I stand by what i said. The thing is to compare a $200 sport spring (set) to a $free set of cut stock springs. The end result is a car lowered about an inch to an inch and a half, with the spring rate raised about 20%. If you are worried about cutting the springs somehow magically doing something evil to the suspension or camber, then you have to have the exact same worries about aftermarket $prings. The fact is, on 02s, lowering them, at least in the front, does not change camber one iota. It does in the back, but its true for both paid-for-springs or cut ones. If your springs are sagging or worn out, beautiful, go ahead and buy some sport ones. But if they are fine, cutting them is a highly cost-effective way to lower your car without any negative side effects except slightly higher overall weight due to the extra cash in your wallet (probably negated by the loss of the metal coil from the springs ).

Should you also upgrade your shocks to match the new spring rate? absolutely. Do you need to? No. Again, we are not talking about a radical change, just a slight drop. If your shocks are good, and you arent racing, just the spring drop wont affect you all that much. Ideally youd upgrade to at least Bilstein HDs, but that is a good idea no matter what else you are doing.

[robspeed]

also, there is no need to even remove the springs to cut them, if you have a dremel and even a scintilla of common sense. Jack car, remove wheel, and slip the dremel between the coils. WEAR EYE PROTECTION as you know if youve ever used one how dremel cutoff wheels like to shatter without warning. Cut and when the metal of the coil finally gives way, the spring will fall into place and the loose coil piece will sit there in the bottom of the perch. Remove it with pliers or your fingers and voila! The spring is wrapped around the shock/strut so its not like its going to pop out and hit you in the forehead.

EDIT: actually what will most likely happen, now that i think about it, is the coil will collapse into the gap of the dremel cut, and you will have to use vice grips to remove the loose end piece. it depends on how you cut it though. You can make an exaggerated "V" cut and when the coil collapses, it makes it easier to wrangle the loose-ish piece out.

Also, it is perfectly fine to start with a full coil, especially in the front. On my 69 i had to cut a full 1.75 coils to get it to sit anywhere near even with the back of the car, from which i had cut 1.0 coils. ALSO, remember the top of the front "hat" is on a bearing, making it very simple to rotate it around so the end of the bottom of the coil fits into its little moulded spot on the bottom perch.

[robspeed]

FWIW i just did this with my front springs on my e30. Car looked SKYJACKERED stock, and i have the trunk full of tools and other crap for winter traction, which made the front look even more jacked up. Anyway, I had the front wheels off to put new rotors and pads on it (severe wobble under braking) and decided to cut a coil off the front springs to try to even it out a bit.

FUN part was one point on the driver's side after i got the 1-coil cut off, and was maneuvering it out of the perch, i moved the remaining spring too far and it ended up wrapped around the strut BELOW the perch. Not super disasterous as it made it super easy to remove the cut portion (which i had to cut in half to get out), and with some creative use of some ultra-huge tie straps and a floor jack, i was able to compress the spring, rotate it into place, and then cut the tie-wraps. Ghetto spring compressors if you will. Very precarious operation unless you use MANY of them, and they have to be the super big kind.

In other words, put the spring back onto the perch by rotating it around and threading it back on (but unfortunately this leaves the end of the spring in the wrong place on the perch), then jack up the strut to compress the spring, tie-wrap it (i used at least eight of them--the HUGE kind), then drop the jack and locate the spring end in its (correct) little moulded area in the perch.

Anyway, got it lowered slightly along with the new brakes. One coil on the e30 dropped it VERY VERY VERY little, i think because the end of the spring is wound into a progressive finish if you will. Next time I have it up in the air ima cut another 1/2 coil and see where that leaves me relative to the back end. (rear is destined to have some used H&Rs put in there... e30 rear springs cant be cut because they are shaped like footballs). Right now the slight drop from 1 coil being cut just barely matches the rear end's trunk-full-of-crap drop...