Cutting stock springs

[Bellicose Right Winger]

All you have to do now is mount some LR78-15's and it'll look like Jeff's.

Paul Shovestul

looks better!

[bullyd]

where are you based? as cutting the springs in the uk will make your car fail the mot as a 'cut' spring is classed as a 'broken' spring, i can supply a set of springs that will lower your car 40mm for £75 inc delivery (if in uk), they the same as i used on my e28 and they didnt hurt the ride too bad at all but made the car look the business

[93-525i]

where are you based? as cutting the springs in the uk will make your car fail the mot as a 'cut' spring is classed as a 'broken' spring, i can supply a set of springs that will lower your car 40mm for £75 inc delivery (if in uk), they the same as i used on my e28 and they didnt hurt the ride too bad at all but made the car look the business

I'm in the US. Portland, Oregon to be exact. We don't have a "MOT" here as you do, all we have to pass is the air quality test (DEQ). I wouldn't think that the MOT would be able to tell that the springs have been cut since the only way to do so would be to pull them out of their seat. Even though the mot is more thorough and anything we have in the US, it's still not going to take your car apart

[bullyd]

I'm in the US. Portland, Oregon to be exact. We don't have a "MOT" here as you do, all we have to pass is the air quality test (DEQ). I wouldn't think that the MOT would be able to tell that the springs have been cut since the only way to do so would be to pull them out of their seat. Even though the mot is more thorough and anything we have in the US, it's still not going to take your car apart

believe me they can spot it, when they raise the car off its wheels the shocks are checked for leaking and at the same time they grab the spring from a coil and give it a yank, if there is any movement they take a closer look, anymore than 3/4 of a coil cut and with no weight on the spring it will move cosiderably when pulled!!

[uscharalph]

believe me they can spot it, when they raise the car off its wheels the shocks are checked for leaking and at the same time they grab the spring from a coil and give it a yank, if there is any movement they take a closer look, anymore than 3/4 of a coil cut and with no weight on the spring it will move cosiderably when pulled!!

Boy, it must cost the government a fortune to do those inspections, or do you have to pay for it? How often do they inspect your car?

[bullyd]

Boy, it must cost the government a fortune to do those inspections, or do you have to pay for it? How often do they inspect your car?

WE have to pay! once a year and its around £35-£40

[Paul in NZ]

twice a year and 35 to 40....

[Dash01]

This is really interesting:

You (and a guy in Canada who actually have experience cutting the stock springs by one coil) say it works fine, with no apparentl ill effects.

OTOH, lots of others (who presumably have not themselves tried it) say it would not work safely, if at all.

Seems to me, if you cut off only one coil and use a hack saw or other cool cutting (i.e., not a torch) tool that does not affect the temper of the metal, this should work pretty well, and the price is right.

[Kalevera]

This is really interesting:

You (and a guy in Canada who actually have experience cutting the stock springs by one coil) say it works fine, with no apparentl ill effects.

OTOH, lots of others (who presumably have not themselves tried it) say it would not work safely, if at all.

Seems to me, if you cut off only one coil and use a hack saw or other cool cutting (i.e., not a torch) tool that does not affect the temper of the metal, this should work pretty well, and the price is right.

Just because he cut the springs and put the car back together and it still somehow manages to stay on its own four wheels doesn't make it right or "good", especially after 5 miles of driving it.

*When* the car gets in an accident, how do you think an insurance adjuster is going to consider the cut springs?

Threads such as this seem to me to indicate a lack of expertise in automotive engineering that I can only equate to the typical garbage discussed on roadfly. In fact, there's so much ******** present in this thread that I frankly thought I'd ended up on the aformentioned site instead of .info.

There are two assertions in this mess that are particularly disheartening to me:

1) "handling didn't change". That's ********. I don't care about what you think you can feel in the car, by cutting a coil out of the front springs, much changed about the suspension geometry (both "beneficial" and negative) and alignment...regardless of whether or not the springs in the car are dead. The tragedy of this is, instead of buying a tuned kit, wherein (at least some) R&D determined the specifications of the product for the given application, the cheap path was taken. Now the "tuned" kit that came with the car from the factory is compromised beyond design limits.

2) "no [apparent] ill effects". Once again, I'm beating a dead horse. The stock boge automatic strut, dead/not dead/worn or broken -- any way you take it, is designed to have a specific amount of travel. Same with the spring. Suspension dynamics 101 indicates that the spring does the suspending of the car, while the strut insert acts as a counter force on the spring action. This results in the spring action being a more controlled motion. By cutting the spring, the amount of work performed by a (likely already dead) strut insert increases dramatically, limiting its usable lifespan. This is why tuned kits come with -- yes, you guessed it -- very specific strut inserts, or "recommended" products. The more immediate concern is that by limiting the spring's potential range, there's the possibility that it could jump the perch. I can't think of a more exciting way to save a few bucks by not doing it the correct way the first time than in having to locate and replace the strut housing, in addition to the spring and strut insert that weren't serviced correctly in the first go around.

Do what you want. It's your car, but I can't respect you for these actions.


best, whit

[Dash01]

Thank you, Whit, your points are well taken and well stated.

I personally have not yet cut the stock springs or fitted aftermarket springs, because I don't yet know enough about either option to make an informed choice. So, your insight and expertise are much appreciated.

Still, a couple of individuals who have cut their stock springs (by one coil) and then reported their results on this forum, both said the car handled reasonably well afterward. Their anecdotes are the sole basis for my post yesterday.

Ideally, somebody could do a scientific before and after comparison of stock, cut-stock, and various aftermarket springs. As of now, when reading the various posts over the past year or two, one gets the impression that some aftermarket spring brands may be better (or worse) than stock or cut-stock.

At least one brand of aftermarket springs seems to have a bad reputation, meaning that particular vendor probably did not do much R & D.

What brand do you recommend for use with stock shocks on a 535i, to lower the car by ~1-1.5" and still retain essentially stock ride and handling?

Just because he cut the springs and put the car back together and it still somehow manages to stay on its own four wheels doesn't make it right or "good", especially after 5 miles of driving it.

*When* the car gets in an accident, how do you think an insurance adjuster is going to consider the cut springs?

Threads such as this seem to me to indicate a lack of expertise in automotive engineering that I can only equate to the typical garbage discussed on roadfly. In fact, there's so much ******** present in this thread that I frankly thought I'd ended up on the aformentioned site instead of .info.

There are two assertions in this mess that are particularly disheartening to me:

1) "handling didn't change". That's ********. I don't care about what you think you can feel in the car, by cutting a coil out of the front springs, much changed about the suspension geometry (both "beneficial" and negative) and alignment...regardless of whether or not the springs in the car are dead. The tragedy of this is, instead of buying a tuned kit, wherein (at least some) R&D determined the specifications of the product for the given application, the cheap path was taken. Now the "tuned" kit that came with the car from the factory is compromised beyond design limits.

2) "no [apparent] ill effects". Once again, I'm beating a dead horse. The stock boge automatic strut, dead/not dead/worn or broken -- any way you take it, is designed to have a specific amount of travel. Same with the spring. Suspension dynamics 101 indicates that the spring does the suspending of the car, while the strut insert acts as a counter force on the spring action. This results in the spring action being a more controlled motion. By cutting the spring, the amount of work performed by a (likely already dead) strut insert increases dramatically, limiting its usable lifespan. This is why tuned kits come with -- yes, you guessed it -- very specific strut inserts, or "recommended" products. The more immediate concern is that by limiting the spring's potential range, there's the possibility that it could jump the perch. I can't think of a more exciting way to save a few bucks by not doing it the correct way the first time than in having to locate and replace the strut housing, in addition to the spring and strut insert that weren't serviced correctly in the first go around.

Do what you want. It's your car, but I can't respect you for these actions.


best, whit