question about springs

stenguyen1 · Sep 4, 2009, 02:18 PM

i got a 2008 lancer gts and i was wonderin if anyone has cut their springs? i know its not good for the car but i would like to see any pics of someone who has done this.

i have an extra set of springs and struts in the garage that i got from the junk yard just in case my shocks go out when i cut them. i tried lookin all over for a topic on this and haven't found anything.

so if you could give me the positives and negatives or pics of ur ride that will be great.

thanks.

jer301 · Sep 4, 2009, 03:38 PM

My desktop just crashed so I could not scan the page, but there is a book:

Chassis Engineering by Herb Adams

http://www.amazon.com/Chassis-Engine.../dp/1557880557

On page 36 of that book it provides 5 quick steps to cutting your own springs. it is a very good book and relatively inexpensive so i recommend you get it but i will try to copy that page for you @ work tomorrow. As for your shocks, they should be fine but just to be sure you can put bump stops on them for some protection. Don't cut more than 1/2 coil off. you will have to use a torch to cut it and to heat the spring and reform the new half coil ends. As for your spring rates they will go up but it will handle better with the higher rates. I'll copy those pages and post them tomorrow.

EngRWW33 · Sep 4, 2009, 04:09 PM

Absolutely NOT!!! Spend the $200 and get spring made for your car.

KBgottaEVO · Sep 4, 2009, 04:16 PM

I agree...pay for thr springs, i was thinkning about going with the tein s-techs
would i have to do any fender rolls or where there be any kind of tire rub if i kept
the rim size 17...

ambystom01 · Sep 4, 2009, 04:30 PM

Quote:

Originally Posted by jer301

My desktop just crashed so I could not scan the page, but there is a book:

Chassis Engineering by Herb Adams

http://www.amazon.com/Chassis-Engine.../dp/1557880557

On page 36 of that book it provides 5 quick steps to cutting your own springs. it is a very good book and relatively inexpensive so i recommend you get it but i will try to copy that page for you @ work tomorrow. As for your shocks, they should be fine but just to be sure you can put bump stops on them for some protection. Don't cut more than 1 coil off. you will have to use a torch to cut it and to heat the spring and reform the new half coil ends. As for your spring rates they will go up but it will handle better with the higher rates. I'll copy those pages and post them tomorrow.

I'm sorry but this is quite possibly the dumbest thing I've read in a while, I certainly hope you didn't come up with it. I have no idea how cutting your springs would increase the spring rate. If you simply remove a coil, all it will do is lower ride height. At the same time, you'll put undo stress on the struts (since they'll be bottoming out a lot more) and ruin how the car handles. Even with standard springs, it's debatable whether it actually helps handling on stock struts (lower and stiffer does not equal better handling in absolute terms).

jer301 · Sep 4, 2009, 05:19 PM

Quote:

Originally Posted by ambystom01

I'm sorry but this is quite possibly the dumbest thing I've read in a while, I certainly hope you didn't come up with it. I have no idea how cutting your springs would increase the spring rate. If you simply remove a coil, all it will do is lower ride height. At the same time, you'll put undo stress on the struts (since they'll be bottoming out a lot more) and ruin how the car handles. Even with standard springs, it's debatable whether it actually helps handling on stock struts (lower and stiffer does not equal better handling in absolute terms).

From the spring rate equation:

Spring rate (lbs/in) = (G*d^4)/(8*N*D^3)

Where

G = Modulous of rigidity
d = Wire diameter (in)
N = number of coils
D = mean coil diameter (in)
8 = constant

I didn't make the equation. it is what it is. decreasing the number of coils increases the spring rate as you can see from the equation. Racers do this all the time to lower the car and increase the spring rate. 1/2 coil won't drop it more than an inch which is what most aftermarket kits do.

ambystom01 · Sep 4, 2009, 05:24 PM

Cutting the coils won't work, I suspect that by doing it, you affect the modulus of rigidity (it doesn't appear to be a constant). Racers don't do it, they know better. Moreover, spring rate is but one factor that contributes to handling.

jer301 · Sep 4, 2009, 05:34 PM

modulus of rigidity depends on the grade of steel or alloy generally 11,250,000 - 15,000,000. I have only heard of two racers doing this. one in a porsche 914 which i drove and one a 2002 trans am. spring kits are cheap that is why i think it is somewhat of a lost art. the rate for one coil will only increase the spring rate by a small factor but in the case of the 914, he was shooting for a frequency response of 2.25+- hz in the front. increasing from 250lb/in to 300lb/in was too much so he cut the 250lb/in spring down. The key to not affecting the modulus is to let it air cool slowly. If it cools too rapidly it will lower the modulus.

ambystom01 · Sep 4, 2009, 05:37 PM

It's not an art, people don't do it anymore because it's a silly practice, at least for the average consumer. As I said, there are other issues to consider as well. McPherson struts don't like being lowered at the best of times, let alone when the spring rates aren't sufficient enough to keep them off the bumpstops or from bottoming out altogether.

jer301 · Sep 4, 2009, 05:42 PM

Quote:

Originally Posted by ambystom01

It's not an art, people don't do it anymore because it's a silly practice, at least for the average consumer. As I said, there are other issues to consider as well. McPherson struts don't like being lowered at the best of times, let alone when the spring rates aren't sufficient enough to keep them off the bumpstops or from bottoming out altogether.

with exception to your last statement about spring rate being too low, i agree. rememember sring rate will increase not decrease. the important factor for minimizing bottoming out is active length not spring rate. spring rate is only a factor if it decreases.

ambystom01 · Sep 4, 2009, 06:29 PM

They won't increase enough to keep the now lower suspension off the bumpstops or the struts from bottoming out.

planetasia415 · Sep 4, 2009, 09:17 PM

Quote:

Originally Posted by stenguyen1

i got a 2008 lancer gts and i was wonderin if anyone has cut their springs? i know its not good for the car but i would like to see any pics of someone who has done this.

i have an extra set of springs and struts in the garage that i got from the junk yard just in case my shocks go out when i cut them. i tried lookin all over for a topic on this and haven't found anything.

so if you could give me the positives and negatives or pics of ur ride that will be great.

thanks.

Are you originally a hondUH owner?

jer301 · Sep 5, 2009, 05:37 AM

Quote:

Originally Posted by stenguyen1

i got a 2008 lancer gts and i was wonderin if anyone has cut their springs? i know its not good for the car but i would like to see any pics of someone who has done this.

i have an extra set of springs and struts in the garage that i got from the junk yard just in case my shocks go out when i cut them. i tried lookin all over for a topic on this and haven't found anything.

so if you could give me the positives and negatives or pics of ur ride that will be great.

thanks.

Okay as promised here are the pages. 1/2 coil is about all you can do on a stock spring. it says that most spring rates are 300 to 350 lb/in but that was for larger cars. small compact cars springrates are say 150 to 250 lb/in. Not sure how much drop you would get (between 1/2 to 1 inch lower ride hieght i would say). as you saw in the thread traffic, springs are very hard and you will have to cut them with a torch. Spring kits costing as little as they do, that might be a better choice for you.

jer301 · Sep 5, 2009, 06:30 AM

Quote:

Originally Posted by ambystom01

They won't increase enough to keep the now lower suspension off the bumpstops or the struts from bottoming out.

It will be slightly less than the works spring rates witch are about 15-25% higher than the stock spring rates with 1.1" drop (1/2 coil shouldn't drop the ride hieght this much). They would not give me exact spring rates over the phone b/c they were "proprietary", so they gave me % increase from stock.

ambystom01 · Sep 5, 2009, 09:26 AM

I highly doubt the spring rate would increase that much just by lopping half a coil off. You're forgetting that by heating the spring to cut it, you're likely going to weaken it.