cut coils springs

[dcrovers]

now i know alot of people dont like the idea but for those who do.....how many coils for a 2 inch drop thanks

[wayfast]

this might help a bit

[dcrovers]

hey thanks

[bmwlover0725]

this thread should be locked for stupidity

[wayfast]

this thread should be locked for stupidity

why is that?

[bmwlover0725]

its nothing against you, perhaps you didn't know... but cutting coils is a very bad idea. just buy lowering springs. taking the cheap way out ALWAYS results in failure when it comes to bmw modding/repairing. ask me how I know

[wayfast]

its nothing against you, perhaps you didn't know... but cutting coils is a very bad idea. just buy lowering springs. taking the cheap way out ALWAYS results in failure when it comes to bmw modding/repairing. ask me how I know

lol

[kdanielson]

Hmmm... Then that would make Herb Adams-who worked at Pontiac as an engineer developing the Firebird Trans Am, later building and driving his own race cars professionally and the owner of VSE a Camaro/Firebird/Corvette/Mustang aftermarket company specializing in handling. NOT likely! Buy his book "Chassis Engineering", it's a good read and you can learn a little from the pro's. He states just the opposite-aftermarket lowering springs are a waste of $$. Done correctly cutting coil springs works just fine.

Cutting coils = bad is a myth perpetuated by people that didn't get it right and didn't understand why.

its nothing against you, perhaps you didn't know...

ken

[bmwlover0725]

hence the reason american car companies are garbage.

read bmw magazines. search the forum. search google. you'll quickly see that it is just bad

[myersport]

hence the reason american car companies are garbage.

read bmw magazines. search the forum. search google. you'll quickly see that it is just bad

While you're checking the internet, check out what respected BMW tuner Metric Mechanic says about the ill effects of cutting coil springs. Wait,...wasn't that a Metric Mechanic article that wayfast just posted? Hmmm......

An engineers opinion, or a hobbyists opinion. Who to go with?

--dennis

[bmwlover0725]

shit there was a misunderstanding as to who wrote this. Now I feel like a dick. I'll admit being wrong on this one

[bflan2001]

ken's right it's a myth brought on by people not knowing what they're doing...for some reason the people who decide to cut their springs rather than buy aftermarket tend to want the 'slammed' look (perhaps because the younger crowd is the one trying to save money?)...you can't cut 4+ coils out of a spring and expect it to work properly for the same car. but taking one or two coils out, and cutting them at the right spot, will be fine.

now, heating a spring up and compressing it down, that's not a good idea.

[Turbo 3.8L E21]

every car ive ever owned has had cut springs

bought brand new springs for my e21, they werent low enough so i cut them

nothing wrong with cut springs, it changes the load rating on them a bit, but its not even noticable when your driving

[superj]

i do it and have ran that in autocross. no using a torch though, that is asking for trouble with removing temper and fatigueing the metal. use a dremel or a sawzall for ease and no metal damage

[Turbo 3.8L E21]

i do it and have ran that in autocross. no using a torch though, that is asking for trouble with removing temper and fatigueing the metal. use a dremel or a sawzall for ease and no metal damage

thats were people go wrong, using an OXY to cut them, all that does is puts all stress fracturs and that through the spring,

use a 1mm cutoff wheel on a grinder, takes 2 seconds and puts very little heat into the spring

[superj]

yup, and you don't even need to disassemble the front end. just put a spring compressor on it, cut, and remove the spring copmressor. 15 minutes and a nice looking lowered car later and there you go

[brandon11130]

I took 2 and a half coils off the rear and 2 off the front. It looks FN sweet, and the ride quality improved. Stiffened it up nice. The shocks are holding up for now, they are not bottoming out but im probably going to go with some koni shorts or some thing of that extent when these blow.

Cutting springs is fine, Bmw springs are much higher quality than most of the aftermarket springs, so long as you cut an equal and even ammount off you are fine. As some one else allready stated aftermarket springs are still too high + you waste $200 bucks, coilovers are $400.. All that work when you could of just cut what you allready had. Cutting springs is the fiscally responsible thing to do!

[jrcook320]

yup, and you don't even need to disassemble the front end. just put a spring compressor on it, cut, and remove the spring copmressor. 15 minutes and a nice looking lowered car later and there you go

This would be one of those examples of doing it wrong. The critical part to doing it right is to close the spring by heating it up and pushing the end closed so it sits in the perch properly.

As the article states, cutting coils increases the spring rate, so you'll be stiffer and lower, for free.

[bflan2001]

As the article states, cutting coils increases the spring rate, so you'll be stiffer and lower, for free.

wait a second isn't that backwards? the weight is distributed between the coils, so removing coils would lower their total load capacity..that translates to a lower spring rate, right?


also, does anyone know if the 2nd front bar they mention in that article is the one ken makes? i still need to get one of those from him...

[jrcook320]

No, spring rate goes up the less active coils there are. A coil spring is just a torsion bar that is coiled. As it compresses, the "bar" twists. Removing coils reduces the length of the torsion bar, thus making it stiffer.

This is how the progressive springs (like the rear eibachs) work. There are 8 active coils but 4 of them are placed very, very close together. All 8 coils compress equally until the 4 that are close together bottom out on each other. After that they are no longer active, and the spring rate jumps from ~90 lbs/in to ~180 lbs/in. A rate of 180 lbs/in means that it takes 180 lbs to compress the spring by 1", 360 lbs to compress it 2", etc.

wait a second isn't that backwards? the weight is distributed between the coils, so removing coils would lower their total load capacity..that translates to a lower spring rate, right?


also, does anyone know if the 2nd front bar they mention in that article is the one ken makes? i still need to get one of those from him...

No, they're talking about an add on sway bar, not a frame rail brace.

[brandon11130]

Can I see some pics of the car? Thanks.

yep ill post up a nice pic thread when i get it all together. I still want the front lower its barely tuckin. Coming from the e30 world, e21's are friggen sweet!, the oil pan is super high compared to the m50 in my e30.

I love the setup of the e21, it seams both the front and rear arches are lower in comparison to the rockers, so you get the "slammed" look much easier, with a slammed e30 you are bouncing your midsection and rockers on every drive way even at angles.

[superj]

if you heat the spring to make the ends closer then you are going to lose temper and fatigue the metal unless you normalize everything. i don't think most people on here know enough about metal work to fix any temper loss and wouldn't know that they fatigued the metal until it was to late because they wouldn't even know what to check for. cutting and setting the new edge in the little groove where the old end went is fine and the spring will conform once the weight is applied to it. it is not going to sit up on one end. i have done this on 3 or 4 cars for people and once on my e30 until i got coil overs. there will be no trouble with just using the spring compressor and popping out the cut off piece and then just removing the spring compressor. this is a tested method with no ill results with some cars running for many years on this set up. it was not just an idea that sounded good.

[g323]

Bflan2001 -
also, does anyone know if the 2nd front bar they mention in that article is the one ken makes? i still need to get one of those from him...

What ken makes is a brace rather than a sway bar. I think Addco(adco) makes the add on sway bar(as discussed in the aboveposted spring-cutting article) or used to - http://e21.tricord.be/ has multiple threads discussing this I believe.

Originally Posted by busemans
yup, and you don't even need to disassemble the front end. just put a spring compressor on it, cut, and remove the spring copmressor. 15 minutes and a nice looking lowered car later and there you go

I would be interested to see a DIY or pictures of this.

[jrcook320]

if you heat the spring to make the ends closer then you are going to lose temper and fatigue the metal unless you normalize everything. i don't think most people on here know enough about metal work to fix any temper loss and wouldn't know that they fatigued the metal until it was to late because they wouldn't even know what to check for. cutting and setting the new edge in the little groove where the old end went is fine and the spring will conform once the weight is applied to it. it is not going to sit up on one end. i have done this on 3 or 4 cars for people and once on my e30 until i got coil overs. there will be no trouble with just using the spring compressor and popping out the cut off piece and then just removing the spring compressor. this is a tested method with no ill results with some cars running for many years on this set up. it was not just an idea that sounded good.

No, you lose the temper on the 1" spot that you've heated up, NOT on everything. That's ok since that spot doesn't move or twist as the spring compresses anyway. You are to heat the spring in one spot till it's red hot, then press it closed and let it air cool slowly. If you don't flatten the end the spring will have a lower spring rate because the perch coil will be partially active. Not flattening it will work, but it's not the proper way to do it.

By the way, I cut 1 coil off my front eibachs.

Here's what it comes down to. Everytime this comes up a bunch of uninformed people pipe up and say don't do it, but they have no data, personal experience, or good reasons to offer up to not cut factory springs, only what they've read on the internet.

Trust real engineers with years of real world experience like Herb Adams.

Cutting Springs Thread

I would be interested to see a DIY or pictures of this.

Cutting Springs Pics

[superj]

fronts: e36 m3 stocks cut one link out rears: eibach drag alunch


not on the car but springs compressors on a buddies springs he took out and we cut


we got cut happy once because a buddy wanted all the way down. then we put some stock that we cut only two loops out of


tons of springs all over.