compressing springs

[steve R 0]

What happens to springs when they are compressed/re-set? Does it ruin the spring and ride quality/handling?

What would happen if you were to compress and set of lowering springs like H&R?

Asking this more out of interest than actually thinking of doing it

[gmccormack 0]

Even if you manage to restore the temper in the spring steel, the suspension will have effectively been softened by virtue of the geometric change in the spring. If you can visualise the coils in the spring will be lying more horizontally than they were when the spring was at it's stock length so the weight of the car will have an easier time squashing the spring

Edited July 30, 2007 by Graeme

[Matthew 0]

where can you get them compressed and how much does it cost?

[Nobimmer 694]

Snells were $88 a pair last time I rang...was a few months back though.

[Matthew 0]

ohkay thanks where abouts are they does any one have a contact number for them or a site whichj i could reach them thanks

[PBOY23 0]

ohkay thanks where abouts are they does any one have a contact number for them or a site whichj i could reach them thanks

look them up in phone book i got my car done there compressing good springs like h/r is a waste get your factory springs done if your just cruising

it was about $110 for a pair - pretty sure

mines a little bouncy droped 80ml goin another 20 soon

just my 5cents

goooooodddd luck!!

Edited August 1, 2007 by PBOY

[zenetti 0]

would not recommend it as they have to heat the springs to compress them further. This obviously weakens the spring and also changes the 'compression rate' of the spring. this means very bouncy!

can also be potentially dangerous as Graeme stated as the springs themselves are weaker.

[diablo23 1]

got my rear springs compressed by snells and they did a good job 80mm is not low nuff tho

[Matthew 0]

look them up in phone book i got my car done there compressing good springs like h/r is a waste get your factory springs done if your just cruising

it was about $110 for a pair - pretty sure

mines a little bouncy droped 80ml goin another 20 soon

just my 5cents

goooooodddd luck!!

hey thanks for that so did it cost 220 all up or 110 all up. and what kind of car ddi u compress them to 80ml drop and what size alloys you have on them. thanks for that much helped

[PBOY23 0]

hey thanks for that so did it cost 220 all up or 110 all up. and what kind of car ddi u compress them to 80ml drop and what size alloys you have on them. thanks for that much helped

allow $300 then if it cost less you got change hahaha as i cant comfirm , i did a e36 coupe on 19x8.5 wheels runing 225,35,zr19

for the guy above , what you mean 80ml not enuf? algud here it is abit lower

[Matthew 0]

mate do you get much rubing with that. thats LOW!!! what did you have to do to get i like that. whats the front like

[PBOY23 0]

mate do you get much rubing with that. thats LOW!!! what did you have to do to get i like that. whats the front like

[/quote

hahaha nah it rubs a wee bit with a full car just a bit of plastic triming here an there rolled gaurds,

thats 100ml drop on 19s people would say it wrecks the car but each to there own

i cruise not race, low an slow although i have a bit of fun now an then ahahhaha

Edited August 2, 2007 by PBOY

[bravo 34]

Seeing as the original question used H&R's as anexample, and H&R's are one of the best springs for BMW, and seeing as I knew this was on their website, here's some info:

All H&R Springs are cold wound on precision Wafios CNC spring coiler. After the coiling process, the springs are heat-treated. This heat treating is very important since the spring is wound from a one ton ring of heat treated wire stock that is about three meters in diameter, and then formed into a small coil spring. This winding process creates heat and stress spikes between the molecules of the wire. The stressed molecule spikes must be realigned. If more than two hours pass prior to heat treatment, the springs lose their resilience.

Next, the springs are shot peened. Shot peening is a process that works on the thin surface layer. The spring surface is blasted with metal shot moving at very high speed. This blasting or peening action of the shot removes surface imperfections and relieves internal stresses. Shot peening technique is only useful if the blasting action is directed to the area of the highest stress, which is the inside of a coil spring. So important is the shot peening for a cold wound coil spring that service life is extended by more than 200%.

The next step in high quality manufacturing is pre-setting the spring. Pre-setting is when the spring is completely set to block. This is where the spring is compressed so all the coils are touching. This gives the spring a permanent set and will not sag during its service life. A pre-set spring can also be referred to as a block resistance spring. In production, a spring is actually made to a longer free length than required because the spring gets shorter during the setting process, thus bringing it down to the design specifications. All H&R Springs are pre-set using an exclusive Super Blok' spring setting procedure. The springs are set 4 times or to specific time duration depending upon spring design. Some manufacturers do not set their springs, or if they do, they set them only once. There are more springs on the market today that are not "block resistant," than are "block resistant."

So as you can see, there is alot to know in making a spring work as designed. Why would you f**k up what the manufacturer was trying to do UNLESS you are such a pro you can get an equally good spring with a more desirable height. Just buy a spring designed to go that low - don't f**k about with compressing them.

Also, I'm inclined to agree with 3pedals about the angle of the coils not making much difference to the rate as a spring is essentially a compact torsion bar - however it may mean you get coil bind (coils touching) and that does effect the rate dramatically.

I found out most of this the hard way buying the wrong springs because they were cheap. now I have decent springs, and my car is still low and I would never go back.

Edited August 2, 2007 by bravo

[gmccormack 0]

The angle of the spring, that is to say the spacing between the coils makes a huge difference to the spring rate, you will note how progressive rate springs are wound with varying distances between the coils. The more tightly spaced part of the coil compresses more readily than the more open part of the coil. Many lowered springs are made with a section of very closely wound coils that compress completely with only the static load of the car placed apon them, they are only there to provide adequate free height to the spring so that it remains captive during suspension extension.

Once I had a set of lowered "King" springs in a wreck that were taller (free height, that is) than the factory springs, so tall in fact that I had to resort to using spring compressors to get them out, unlike the factory springs that could be removed without compressing

Edited August 2, 2007 by Graeme

[Silver Fox 43]

The 318 race King springs are an example of what graeme's talking about. They have a section which has no performance aspect, it's just a few coils of lighter spring section which collapses when the load of the cars on them, and serves to keep the spring captive when you jack the car up. The rest of the spring's much heavier and performs when the car's under load.

[bravo 34]

Again from H&R's website:

when most spring manufacturers say that their springs are progressive they are not! Springs may be wound progressively, but that does not mean that they function progressively. Some suspension springs are wound progressively but function as a linear spring. These springs can be called "dual-stage" coils, but are generally referred to as springs with "dead" or "inactive" coils. Dead or inactive coils are coils that are in contact with adjacent coils at loaded height. Inactive coils do nothing but give the spring enough free-length to stay tight in the spring perches at full rebound (when the tires and wheels are hanging in the air like when the car is on a lift). A spring that is wound with inactive coils and no progressive coils that are active, is actually working as a linear-rate spring.

Until the adjacent coils in this fictional "compressed spring" actually touch, the rate is not affected by the gap between them. Therefore, to say the gap between the coils affects the rate is not correct unless the coils touch. But at the end of the day that's either just semantics, or difference in how I understand the theory compared to you. AFAIK none of us are experts even if we talk like we think we are.

Long story short - compressing springs is best left to the pros, and buying correct springs in the first place is even better.

Edited August 2, 2007 by bravo

[steve R 0]

thanks for all the info guys, im buyign a set of H&Rs soon...if sure they will be perfect for what i want

[diablo23 1]

allow $300 then if it cost less you got change hahaha as i cant comfirm , i did a e36 coupe on 19x8.5 wheels runing 225,35,zr19

for the guy above , what you mean 80ml not enuf? algud here it is abit lower

well 80mm just didnt bump the rear of my car that much id prolly go for 100 or 90 next time lol