How To Cut King Springs?

[coln72]

cutting I can deal with, but welding springs..........don't think so.

[flat out]

yeah saw them james, not my idea of making them captive,

[tas_ae71]

eeerrr, wolf has you driven a car with and without cut standard springs..??

 

its a basicly free way of making the handling slightly better. it should not been seen as a good set-up I personally hate standard springs for there complete lack of ability to suppress body roll. they are stupidly soft.

 

say you cut 25% off the spring and that increases the rate by the same amount. standard springs are what 1.5kg? wow that makes then 1.9ish kg huge increase, not.

 

i have managed to put some stupidly stiff springs in the front (just temporarily). i estimate they would be a minimum of 8kg's. i have cut standard springs in the back and it has made the car very unbalanced as you would expect from such radical differences. i have some TRD 6 and 4.7kg springs which should work reasonably well with some KYB (excel'g/agx) front shocks and my own (Kyouteki supplied) rear adjustable short stroke shocks.

 

one thing i do not like about having a low car is the amount of travel you end up with, its not enough imo. i know stiffer springs tend not to have a lot of movement in them but for a street set-up I think its imperative that you do.

 

the one on the left is a standard spring with 1.5-2coils cut off and the left is a king from another car that has been cut in half (currently in my car)

 

[coln72]

tried cut down V8 Kingswood springs in my 20 and the standard struts didnt like them at all. As soon as you hit a bump at speed you would start bouncing. Its a tad hard trying to get it turned in when both fronts are 3 inched off the ground!

 

Toss Holden springs, whack in cut standards back to good again :D

[love ke70]

  tas_ae71 said:

eeerrr, wolf has you driven a car with and without cut standard springs..??

 

its a basicly free way of making the handling slightly better. it should not been seen as a good set-up I personally hate standard springs for there complete lack of ability to suppress body roll. they are stupidly soft.

 

say you cut 25% off the spring and that increases the rate by the same amount. standard springs are what 1.5kg? wow that makes then 1.9ish kg huge increase, not.

 

i have managed to put some stupidly stiff springs in the front (just temporarily). i estimate they would be a minimum of 8kg's. i have cut standard springs in the back and it has made the car very unbalanced as you would expect from such radical differences. i have some TRD 6 and 4.7kg springs which should work reasonably well with some KYB (excel'g/agx) front shocks and my own (Kyouteki supplied) rear adjustable short stroke shocks.

 

one thing i do not like about having a low car is the amount of travel you end up with, its not enough imo. i know stiffer springs tend not to have a lot of movement in them but for a street set-up I think its imperative that you do.

 

the one on the left is a standard spring with 1.5-2coils cut off and the left is a king from another car that has been cut in half (currently in my car)

 

 

good shocks will limit most body roll.

[tas_ae71]

shock do not have a lot of effect on body roll. the springs do most of the work with swaybars helping a little.

 

coln72: the springs may of been a little stiff for what you want them for but your shocks wouldnt of matched the spring rate if they where just standard ones even if they are still working.

[coln72]

I know that the shocks could not of handled the springs now ;) It was just something I thought I should try as people kept saying "why not stiffen up the front, it would be so much faster" etc. I wasn't and even when it wasnt bouncing it would understeer heaps. So back the the way it was and back to winning events again :D

Edited September 17, 2007 by coln72

[tas_ae71]

  coln72 said:

I know that the shocks could not of handled the springs now :P It was just something I thought I should try as people kept saying "why not stiffen up the front, it would be so much faster" etc. I wasn't and even when it wasnt bouncing it would understeer heaps. So back the the way it was and back to winning events again ;)

 

i hear what your saying and when you where on a smooth peice of road it would grip like all hell but if it started bouning it was like shit and slower than standard cutties would be. :D

[coln72]

  tas_ae71 said:

i hear what your saying and when you where on a smooth peice of road it would grip like all hell but if it started bouning it was like shit and slower than standard cutties would be. :D

 

Dunno what they would have been like on bitumen, but on smooth dirt they would turn in ok, but the front would then wash out unter power. Guess it was because the front was mismatched to the rear blah, blah, blah. Went faster with softer suspension, ended up softening the rear as well.

[Rollaboy2608]

I have to say there seems to be alot of heresay on this topic without the sufficient research. At the end of the day the car manufacturer poors billions into development, so I disagree when people say that factory springs are soft as. they are engineered for a balannce of comfort and handling. you must remember that as car owners we are a minority, and sharp as handling isnt number one on everyones list. After saying all that, I had a vehicle once in which I chopped that springs, and several days after this, one of the springs broke in half as I was leaving a driveway, causing extensive damage to both tyre and inner guard. Is $120 really that much for peace of mind????????????

[tas_ae71]

rollaboy,

 

i don't know about hear say and the you would have to be the first person i have eaver heard to have a spring snap in half! perhaps you cut partway threw the next coil..?

 

manufactors sepcialy of these cars really didnt care too much of the handeling of the car they more cared more about comfort. being that the car would be a daliy commuter it would not be practical or safe to put 8&6kg springs made very low spring into a car that being aim for such purpouses (i also think that 8&6 is too stiff for any grip focused street car). do you think a sports car would have the same type of suspension? i don't think they would put very high (off road spec) very veyr soft springs into a fazza now would they? no they wouldnt because it would handel like a boat as ke's do with stock standard suspension. I'm betting that ferrari would make a suspension setup thats firm but not spine crushing, matching shocks and swayars tuned together to give the whole car a good overall balance. you wouldnt want to change them unless you wher into some serious track only shit.

 

i have driven with 8&6, 6.5&4.5 standard, cut standard, s13 coilovers etc...

Edited September 19, 2007 by tas_ae71

[love ke70]

  tas_ae71 said:

shock do not have a lot of effect on body roll. the springs do most of the work with swaybars helping a little.

 

coln72: the springs may of been a little stiff for what you want them for but your shocks wouldnt of matched the spring rate if they where just standard ones even if they are still working.

 

take your shocks out and do some turns then. they do alot more than you seem to think.

[tas_ae71]

  love ke70 said:

take your shocks out and do some turns then. they do alot more than you seem to think.

 

eerrr, yes shock are a very very important part in a suspension setup. they are the diffrence between a a car handeling ok and sticking like glue. shocks do not play a large effect on supressing body roll.

 

what i eman by this is with some correctly rated springs and kyb excel g shocks you should have a good handeling car, if you went to something like a beilstein or TRD ajustable shock there is a world of differance.

[Rollaboy2608]

I actually did a little bit of work on Ferraris at one stage, and if you have ever been in one you will find that they are generally a bone crunching ride. They do not accommodate for comfort(except in touring models,which is a whole other tangent) I can guarantee you that factory springs are designed with both comfort and handling in mind. A car without any handling whatsoever is an unsafe one at that. If you want to argue with a multi billion dollar industry then be my guest!! My guess is, you wont get far!!

Also I did not cut through the next coil, the heat damaged the metallurgy by cutting it ,in my opinion

Edited September 19, 2007 by Rollaboy2608

[slapper]

so ... to summarise (and maybe dispel a few misconceptions) ... without making any judgement calls about whether cutting springs is a good idea or not ...

 

cut springs exhibit two specific problems:

• the cutting activity can affect the structure of the metal the spring was made from, resulting in brittle behaviour that can lead to unexpected failure (snapping) of the spring. This can have catastrophic results for the vehicle depending on where/how it's being driven. This risk can be alleviated for the home-mechanic by minimising the heat build-up in the cutting process (make it quick) and allowing the metal to spring to cool slowly (don't quench). Don't even bother trying a hack-saw, work hardening of the spring material will probably kill the saw before you get anywhere :)
  
• you need to cut one end or the other of the spring, thereby removing the nice flat coils at that end that help locate the spring. This will exacerbate any spring locating problems as you approach the extension limit of your dampers
  

cutting springs makes them shorter and stiffer ... producing other problems that are shared with installing any shorter and/or stiffer spring - including factory and/or after-market.

• Shorter springs may no longer be captive, or may not have the same spring pressure keeping them captive at suspension full droop. Having springs fall out of their carriers is always a bad thing. There are several potential remedies - short stroke shocks, clamping the springs to the top and bottom carriers and restricting the extension of the shock with webbing attached between the top and bottom seats.
  
• stiffer springs may require uprated damping to alleviate problems with oscillation. Under-damped springs will tend to bounce.
  

Some posters have extended the conversation to include handling ... in a drastically simplified nutshell:

• stiffening the front springs will tend to induce understeer
  
• stiffening the rear springs will tend to induce oversteer
  

stiffer swaybars try to reduce roll by making the car squat as it turns ...

• stiffening the front swaybar will tend to induce understeer
  
• stiffening the rear swaybar will tend to induce oversteer
  

stiff swaybars and soft springs are better suited to smooth environments, where both sides of the vehicle are traversing an essentially flat surface.

stiff springs and soft swaybars are better suited to bumpy environments, where you need one side of the vehicle to traverse bumps without affecting the other side too much.

 

The evil of cut springs is purely and simply in the fact that it's hard to predict how the metal itself will react to the cutting, coupled with the removal of the flattened coil at the cut end. All the other problems people have talked about are not specific to cut springs ... they are a legacy of replacing a spring with another one that is horter and/or stiffer.

 

cheers,

Slapper