# Cutting The Springs ?



## dat411kid (Nov 28, 2004)

Hi i have a 94 Sentra XE and im trying to figure out what are the best ways to lower the car in a inexpensive way i was thinking coilovers but heard alot bad things about them.. Does anyone have experience with cutting the springs on thier car to lower it, or have coilovers and turned out to be good ? Feel free to post any usefull info or Links THAnks.


----------



## black_ser95 (Mar 19, 2004)

dat411kid said:


> Hi i have a 94 Sentra XE and im trying to figure out what are the best ways to lower the car in a inexpensive way i was thinking coilovers but heard alot bad things about them.. Does anyone have experience with cutting the springs on thier car to lower it, or have coilovers and turned out to be good ? Feel free to post any usefull info or Links THAnks.


no, do not cut your springs, buy aftermarket springs


----------



## chimmike (Oct 17, 2002)

please, for the love of god, don't cut the springs.

PLEASE look in the suspension forum and READ THE STICKIES!

geez. it's like the only forums that exist are the ones for your chassis designation


----------



## Twiz (Aug 24, 2004)

Why cut them ? so they fit in the dumpster ?


----------



## Slacky (May 31, 2004)

seriously, doesnt change the stiffness if u cut them, actually probebly reduces stability


----------



## ReVerm (Jan 13, 2003)

Slacky said:


> seriously, doesnt change the stiffness if u cut them, actually probebly reduces stability


That is incorrect. Cutting coils off of your springs increases the spring rate. Consult your high school physics texbook or this section of eFunda.com for details.


----------



## pete? (Jul 6, 2004)

chimmike said:


> please, for the love of god, don't cut the springs.
> 
> PLEASE look in the suspension forum and READ THE STICKIES!
> 
> geez. it's like the only forums that exist are the ones for your chassis designation


remember this one mike? 

lew you can save your breath :thumbup:



dat411kid said:


> i was thinking coilovers but heard alot bad things about them.. Does anyone have experience with cutting the springs on thier car to lower it,


where in the world did u hear coil overs were bad! thats the only true way to go if you want to lower your car and have it handle far greater than stock. if you just want it lower get some hyperco's or eibac's with kyb agx struts


----------



## ReVerm (Jan 13, 2003)

dat411kid said:


> Hi i have a 94 Sentra XE and im trying to figure out what are the best ways to lower the car in a inexpensive way i was thinking coilovers but heard alot bad things about them.. Does anyone have experience with cutting the springs on thier car to lower it, or have coilovers and turned out to be good ? Feel free to post any usefull info or Links THAnks.


It's funny you should mention this, because just yesterday I went and did a bit of measurement/calculations with a pair of stock B14 springs. According to Nissan FSMs, B13s and B14s do share some springs, although not all B13 springs made their way onto B14s (and vice versa). The stock B13 and B14 dampers are of similar dimensions.

Through the data listed in the FSMs, I found that the spring rates for the front springs for our cars are all in the neighborhood of 100~118lbs(f)/in and have five active coils. If you remove the topmost coil, the spring rate goes up to the mid-high 130's, BUT you lose over 2.5 inches of travel (given that the springs are not sagging from age). This leaves you with less than half the damper travel you started with and a spring that is way too high for the stock dampers but still way too soft to keep the car off the bump stops. The result is a car which won't feel much "sportier" than stock, will be dangerous on the track or during emergency avoidance maneuvers (see LShadoff's post in the thread 1.6pete linked to), and will fail inspection in certain states. Yes, apparently some states will now fail your car if your springs come loose from the damper during the front end "jounce" test. According to my source, NJ and NY do.

In any case, back to your main question. What "bad things" have you heard about coilovers which you deem unacceptable for your application?


----------



## Slacky (May 31, 2004)

ReVerm said:


> That is incorrect. Cutting coils off of your springs increases the spring rate. Consult your high school physics texbook or this section of eFunda.com for details.


 sorry meant handling, all springs are different


----------



## ReVerm (Jan 13, 2003)

Slacky said:


> sorry meant handling, all springs are different


It will change the handling. Significantly. Please see my post above and the posts in the other thread.


----------



## SeR.NisSUN (Sep 29, 2004)

lame go buy some real stuff... i got me some D2 full coilover suspension system... kick ass


----------



## pete? (Jul 6, 2004)

while lews posts are allways full of in site and wisdom, i found 99's to be alittle easyer to follow (well if you are thinking about cuting your springs you need the easyest one :thumbup: j/k) here you go



Ninety-Nine SE-L said:


> What are the stock spring rates? 100-120lb/in? well, when you bottom out, that spring rate goes all the way up to infinity, (aka, it cannot compress anymore). This transition from 120lbs to infinity causes unpredictable and uncontrolable response. When you cannot compress anymore, it is possible the wheels opposite to the side bottomed out can lift off the ground and flip.
> 
> Another way to put it. When you go into a corner springs transfer lateral forces into compression. Stiffer springs take more force to create the same amount of compression, but so long as compression is allowed, you will have no problem maintaining traction at all 4 wheels. When you bottom out, there is no compression allowed. Therefore, if you bottom out in a hard corner, the only way to absorb the lateral force is by you actually going up on 2 wheels.
> 
> You cut your springs ---> you bottom out more ---> you end up on the news when your car flips on I-4.


please read the other thread but thos os the meat of it :cheers:


----------



## velardejose (Sep 9, 2004)

I cut mine and handling suffered a lot...
The car feels sloppy and has no stability in a normal corner, not to say a quick one...
Save some money and grief and get aftermarket ones, or another model...
You can get some info here about what springs to get


----------



## BikerFry (Jul 31, 2003)

ReVerm said:


> That is incorrect. Cutting coils off of your springs increases the spring rate. Consult your high school physics texbook or this section of eFunda.com for details.


Nope. F=kx. You can't change k without getting a different spring. Cutting them just reduces the possible range of x, which reduces F, which explains why just cutting the springs makes your car ride and handle like crap.


----------



## lshadoff (Nov 26, 2002)

BikerFry said:


> Nope. F=kx. You can't change k without getting a different spring. Cutting them just reduces the possible range of x, which reduces F, which explains why just cutting the springs makes your car ride and handle like crap.


I guess this spring calculator is wrong.

Look at the spring rate with the default values and then put in two less coils and 3/4 the length. The spring rate rises.

Lew


----------



## ReVerm (Jan 13, 2003)

BikerFry said:


> Nope. F=kx. You can't change k without getting a different spring. Cutting them just reduces the possible range of x, which reduces F, which explains why just cutting the springs makes your car ride and handle like crap.


You need to modify that equation to consider coil springs and active coils as part of the equation. The total number of active coils do affect the spring rate, and significantly. Although this is kind of a repost, the formulae that explain it are listed here. The equation at the top of the page shows you how the number of active coils changes the spring constant.


----------



## BikerFry (Jul 31, 2003)

Sure enough, I did have that back asswards. I'd never seen that equation for calculating k based on material properties and spring dimensions before.

So cutting your springs reduces the number of active coils and spring length proportionally, so spring force stays constant. So by cutting your springs you're keeping the stock spring force with less possible spring travel, so aside from changing geometry from lowering, you'll wind up bottoming out a lot and bouncing around.

Haha I've already been to 2 engineering classes today and didn't really learn anything, but I learn a new and interesting mechanical engineering concept on NF... Thanks guys!


----------



## Slacky (May 31, 2004)

ReVerm said:


> It will change the handling. Significantly. Please see my post above and the posts in the other thread.


 of course but sometimes not for better, my buddys car sure looks nice low but his shocks bottom out everywhere and they are all bashed up and sure he can cut corners really sharp but he sways like floppy peice of french toast on the highway


----------



## pete? (Jul 6, 2004)

Slacky said:


> of course but sometimes not for better, my buddys car sure looks nice low but his shocks bottom out everywhere and they are all bashed up and sure he can cut corners really sharp but he sways like floppy peice of french toast on the highway


that means he dosent have a good setup and the shocks are too soft


----------



## NOS_PSR_NOS (Nov 9, 2004)

i know this is way off topic but can you put b14 springs on a b13.


----------



## pete? (Jul 6, 2004)

NOS_PSR_NOS said:


> i know this is way off topic but can you put b14 springs on a b13.


from page 1 of this thread


ReVerm said:


> It's funny you should mention this, because just yesterday I went and did a bit of measurement/calculations with a pair of stock B14 springs. According to Nissan FSMs, B13s and B14s do share some springs, although not all B13 springs made their way onto B14s (and vice versa). The stock B13 and B14 dampers are of similar dimensions.
> 
> 
> > there is *no* cheap way to lower your car


----------



## NOS_PSR_NOS (Nov 9, 2004)

1.6pete said:


> from page 1 of this thread
> 
> 
> ReVerm said:
> ...


----------



## NOS_PSR_NOS (Nov 9, 2004)

1.6pete said:


> from page 1 of this thread
> 
> 
> ReVerm said:
> ...


----------



## pete? (Jul 6, 2004)

so is that a yes? im looking at buying this but there for a b14 and since the price is right...........
http://www.nissanforums.com/classifieds/showproduct.php?product=857&sort=1&cat=5&page=1[/QUOTE]
sprint springs are bad. hyperco, gc, and eibac are the only good lowering springs for our cars (the spring rate much be high enuff to keep it off the bump stop) dont waste your money. but the answer to your question is yes. all b14 and b13 lowering springs are interchangable

if you will be lowering your b14 soon why dont you get these before mike never makes them again! help out the b14 comunity!!!!!!!!!!!!!!!please!!!!!


----------



## Slacky (May 31, 2004)

1.6pete said:


> that means he dosent have a good setup and the shocks are too soft


 i couldnt agree more, kid never listens to me the first time, always has to mess up his stock part before he byes the performance name brand, then he has nothin to fall back on when his performance ones break. silly hard headed italiens


----------



## sunnysentra (Jul 24, 2002)

here is a good one, I knew a guy that heated the coils with a torch and had 3 fat guys sit on the car to lower it. let me tell you, the ride was so bad it teetered down the road and bounced. this was on a 91 grand AM. Bad news, never do this either!!!!!!!!

Chris 92 classic

Look on classifieds for Used Ebach pro-kits.


----------



## pete? (Jul 6, 2004)

sunnysentra said:


> here is a good one, I knew a guy that heated the coils with a torch and had 3 fat guys sit on the car to lower it. let me tell you, the ride was so bad it teetered down the road and bounced. this was on a 91 grand AM. Bad news, never do this either!!!!!!!!
> 
> Chris 92 classic
> 
> Look on classifieds for Used Ebach pro-kits.


that is stupid! i have heard of people doing that on bikes (only have front and back) but there is no way to make all 4 springs the same length like that..........stupid


----------



## ReVerm (Jan 13, 2003)

sunnysentra said:


> here is a good one, I knew a guy that heated the coils with a torch and had 3 fat guys sit on the car to lower it. let me tell you, the ride was so bad it teetered down the road and bounced. this was on a 91 grand AM. Bad news, never do this either!!!!!!!!
> 
> Chris 92 classic
> 
> Look on classifieds for Used Ebach pro-kits.


Haha. Go ghetto heat treatment.


----------



## ReVerm (Jan 13, 2003)

ReVerm said:


> Through the data listed in the FSMs, I found that the spring rates for the front springs for our cars are all in the neighborhood of 100~118lbs(f)/in and have five active coils. If you remove the topmost coil, the spring rate goes up to the mid-high 130's, BUT you lose over 2.5 inches of travel (given that the springs are not sagging from age).


Sorry guys. It turns out I counted the number of active coils on the front springs somehow. Please check the updated spring rate approximations in the 3rd post on this thread. 

It turns out the spring rates are higher than what I originally listed (they're more like 122~140 lbs(f)/in), and if you cut the topmost coil off of any of them, your spring rate will shoot up to the 170's. Everything else that I said before doesn't change, just the numbers.

Again, sorry about the screw-up.


----------

