SpeedxRacer

You sure its not as dumb as it looks? Sandals in a shop with a cutting wheel? lol looks pretty dumb to me.

RED MX5

LOL, that's why I took the picture. It looks pretty dumb to me too, but when I found out what was cookin' ...

Yea, I'm sure it's not as dumb as it looks.

RED MX5

You're right, but I can't say much, because I'm bad about not wearing gloves when I run a grinder. LOL, one of the reasons I always tell peole to do as I say, not as I do.

RED MX5

Well, I'd say the first step is having a good reason. I believe Ray (the guy Mike mentioned) cut his springs because he was tracking the car and wanted it a little lower and stiffer, at a time when there were no aftermarket options. Since he remains competative with the setup it's hard to argue that he screwed up his car. As for the guy in the pictures I posted, the situation is totally different, but his solution is going to work for his application just as well.

It's not always as simple as Alan93rsa suggests, but he's not that far off the mark. As long as you don't screw up either the static or dynamic alignment (a potential problem no matter how you lower a car) you generally want a shorter spring to be somewhat stiffer, and when you cut a stock spring, you get a shorter, stiffer spring. You can also bend, reshape, and retemper the cut end of the spring if there are any issues with it seating properly. As long as you end up with the spring rate and ride height you're targeting it really doesn't matter how you get there. A spring that is 20% stiffer and drops the car an inch doesn't know whether it was made that way or modified to work that way.

R3DS2K

is it more of a trial and error? cuz u would have to test the spring after each cut unless u can predetermine where to cut to get the specs you wanted?

tinkfist

http://www.engineersedge.com/spring_comp_calc_k.htm

RED MX5

Some people are very good at estimating (or maybe they calculate) the amount they need to cut off a spring. I've got some charts for common GM springs somewhere around here. Others guestimate, cut off less than their best guess, and keep cutting a little at a time (trial and error) until the get the target rate or drop. Spring cutting use to be extremely common in some motorsports venues, and some people have it down to an art.

I generally don't use my own cars as test beds, so if you ever see me cutting a spring you can be sure it's because someone else has already tried it and I've determined that it workd as expected. LOL, I'm a picky SOB when it comes to my cars.

The guy shown cutting the springs probably has two grand or more tied up in his cars suspension, so you can be sure that he has a good justification for what you see him doing.

RED MX5

Note that this calculator gives an ESTIMATE. He clearly states that test and measurement (or in this case, trial and error) is required to get exact rates.

A press and a scale is all you need to measure the spring rate. I use a nylon strap to tie the spring to the scale, just in case I screw up and let it get away from me. A compressed spring can be very dangerous (so don't try this at home kids ).

mikegarrison

[QUOTE=RED MX5,Sep 11 2007, 10:40 PM] Well, I'd say the first step is having a good reason.

trivium

I am not going to argue about whether or not cutting springs is a good idea (which I would actually like some factual data so that I can be educated on this) but what I cannot understand is why would the guy spend "two grand" on his suspension but cheap out on lowering springs when there are PLENTY of solutions out there ?