Nismo-san

anyone ever just cut there springs and use them, how did you cut them or heat them or whatever? sorry i'm tired and its a question and something i've never known how to do and just want some answers

NoPis10

iTrader: (29)

Cutting is something we did back in the day when springs weren't available for imports.
At this day and age, springs are reasonable cost wise so cutting isn't needed.
BUT... a die grinder with a cut off wheel will work wonders for you....if you MUST cut.. only cut one coil from the front and no more than two on the rear...


L8R

jgrewe

iTrader: (1)

You can cut them no problem, you just don't want to pick a random amount and end up ruining your spring.

Find a spring rate calculating program and measure what you have for coil dia, free coils, and wire dia. Wire dia. is the most important one to get right because a couple thousandths of an inch will make a big difference in rate.

Next figure if you will have the correct free length when you cut so you don't end up with your car on the bump stops when the spring is loaded. You may be better off with a spacer in your coils to effectively remove one from the equation. With some math you can get the rate you want and the height you need with the stock spring.

Yellow S2 Rx7 13BT

maths when cutting springs???????? huh?????????? lol

agreed cut one coil from the TOP of the front spring only!!!!
then use the rear spring height to achieve desired look,
with rears:
only cut the BOTTOM unfinished end of rear springs,
so it still locates on diff properly, the TOP finished end locates in rubber insulator against the body dont mess with that!!!!!
go 1 full coil first!!!
then reinstall spring and check the look/height u want

you only need to disconnect rear shok lower mount bolts to remove rear springs
and when checking between cuts theres no need to reattatch shocks

then if u need/want cut another half coil reinstall spring and check
and if you really really need it the final half coil.....

a little extra effort installing rears after each cut is worth it!!!!!!!
after jacking push car back and forth a few yards in each direction to properly settle the suspn and get correct ride height

whenever you cut a spring, take the bit you cut off to the other side spring and
then cut exactly the same!!!!!!!

I have cut hundreds of springs with my angle grinder fitted with a metal cutting blade

jgrewe

iTrader: (1)

This method will be fine if you don't care how the car handles. You will create mystery rate springs and it will change how the car feels in the way of oversteer/understeer.

If you only care about ride height go for it, if you want to have confidence in what your car will do in a corner, do the math first.

Yellow S2 Rx7 13BT

Im a suspension mechanic/wheel alignment tech
I bet i care more about suspn and handling than you do!!!!!!

i realise this changes the rates of the spring
it only very slightly increases the rate, which is a good thing!!!!!!

this fella is askin about GHETTO springs
It would only be a mystery if it hadnt been done before...lol
It has been done in the real world,(sings in Cartmans voice)"and in the ghetto..."
myself and others have done it, and it is an improvement on std!!!
with no cost, the results are an acceptable improvement, in both looks and handling......

Have you performed simmilar modifications, and driven the cars before and after
or are you just talking theoretically about the technical aspects of spring modification???

I have 4 complete sets of springs for my car
1 set absolutely std
1 set chopped as above
1 set aftermarket lowered heavy duty springs
1 set custom rate circuit racing springs

the chopped ones look and perform better than std ones
no mystery there!!!!!!!
The aftermarket lowered heavy duty springs same height as chopped are better than chopped ones
no mystery there either........
it is more the reduction in the centre of gravity, than different rates in springs that make the big difference in performance in this case

jgrewe

iTrader: (1)

I've just seen too many guys think that you can't get springs that are good by cutting the stock ones. I take slight offense when people call them ghetto(even sung by Cartman lol). There are a lot of guys that think you have to buy stuff from a catalog or they have to have a certain name to be, uh, un-ghetto?

I've spent a little bit of time thinking about suspensions and driving race cars. Here is an old thread of mine. https://www.rx7club.com/showthread.p...ght=eprod+born

Did you know that when you lower an FB the front roll center goes down more than the center of gravity and it starts to move around side to side a lot? Add that to the rear roll center that moves with the rear end( essentially up when you lower the car) and you end up with a roll axis that is going to lead to a push. That is of course if the rear suspension didn't bind up so bad from the upper links pointing in toward the middle of the car...

Oh yea, I love the color of your car!

Yellow S2 Rx7 13BT

yeah but to the extent described its really only an appox 30-40mm drop
and depending on the amount you chop they can even still remain captured
things only really go sour with the 1st gen suspn when lowered around 60mm+
roll centre adjusters are avail for the front!!!
and with a redesigned watts link with adj roll centre, or panhard kits(not a fan)
goes a fair way with some adj rear trailing arms......
strangely all that costs heaps of money tho.....
Ive never heard of choppin bein called ghetto springs, thought it was funny
so if it only costs ya your own time, your nice n careful n do it in baby steps for the first timer, and specially if you can keep the springs captured at the same time
your car looks and drives better for free.....
theres always the junkyard or aftermarket springs if you stuff it up.....
Williams F1 team spent well over 50 million dollars redesigning their V10 engine
with a slight increase in bank angle maybe 10deg just to lower the centre of gravity of the car by less than 5mm
30mm for free is killer in my book
thanks for the comment of the colour, I have just redone it in full widebody, should be finished for christmas, ill be waitin for santa
its sunburst yellow a LTD EDTN colour that was on JDM FDs
Oh yeah my best mate just sold his 92 Honda Civic 3door
in my time i have lowered probably 12 of those things incl CRXs DEL SOLs
i have fitted probably 6 different brands of springs incl, SPOON, TIEN s-tech, Pedders, KING, Whiteline and more
my mates honda got the chop, and not one of those other cars with aftermarket springs came close to hanling as well
In my vast experience that honda chassis is a unique case, but still it can be done properly, with good results!!!!

rotaryboy23

iTrader: (1)

I've heard old Jeep Cherokee springs will fit with a little bit of work... An old guy had them in a 1st gen with a 5.0L, so I'd assume they're a bit stiffer... better for cutting

jgrewe

iTrader: (1)

Springs get stiffer as you cut them so the Jeep ones maybe have a taller free height and a softer rate. If they are he right coil dia, they may work.

Yellow S2 Rx7 13BT

jgrewe..........you disagree with slight modification of an engineered design
because of minor changes in rates that actually benefit the car
but jump on that jeep bandwagon???????
i rekon even your WOW calculator would spin out at the change in rate Jeep springs would have
taller free height did i read correctly?????
Jeep springs would have the same free height as a 1st gen MONSTER TRUCK
I need a beer!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
DONT PUT SPRINGS FROM SOME SHITBOX IN YOUR MAZDA
IF YOU HAVE TO, AND IF YOUR HARD UP FOR CASH
either slightly modify you own or
go pay some workshop to fit aftermarket ones!!!!!!!!!!
now i need another one!!!!!!!!!!!!!!!!!!!!!!!!!!

jgrewe

iTrader: (1)

I don't disagree with a slight modification, just don't continue to call it "an engineered design" if you are just going to whack an amount off of a coil based on because its been done before and it seemed to be OK.

Why not springs from another car?
The spring doesn't know what vehicle it came off of. Its just a spring. There is nothing magical about a Mazda spring.

I didn't know there was a Jeep bandwagon, it just sounded like it could be a possible solution for somebody putting a V8 in an FB. Of course the Jeep springs will have a taller free height than the FB's stock. My point was that when they are cut you may end up with a free height and rate that works.

I was born and raised in the town that Jeeps were first invented and built, Toledo, Ohio. So I would jump on a Jeep bandwagon if there was one. I'll have a Foster's with your name on it waiting for you if care to join us on the off road wagon!

Yellow S2 Rx7 13BT

Fosters is a **** beer, tastes like cats ****!!!!
absolutely no-one drinks it in australia!!!!!!

the "engineered design" is the original spring....OK
and slight modification is the cutting of it....der

and if you or anyone else is stupid enough to put a V8 in a Rx7
you have just ruined a great handling car anyway
might as well put jeep springs into it the wildly unbalanced chassis

I thought you cared about the way a car handles?????
why not springs from another car?????
If you dont understand that whats the point????

also you seem to have a problem with me whacking a random amount off a coil
I systematically trim the spring in small increments testing the results at each step untill, the desired result is reached!!!!
and you seem to back your WOW calculator for cutting springs.......??

at first you sounded like you knew what you were talking about, but
HOW MANY DIFFERENT CARS HAVE U DRIVEN???
HOW MANY CARS HAVE YOU PERSONALLY LOWERED????
HOW MANY CARS HAVE YOU PERSONALLY MODIFIED THE SUSPN OF???
AND DO YOU HAVE SPECIFIC KNOWLEDGE OF ANY PARTICULAR CAR, AND ITS CHANGE IN PERFOMANCE OVER VARIOUS STAGES IN ITS SUSPENSION TUNE?????

jgrewe

iTrader: (1)

Since we've hijacked this thread I'll start by claiming ignorance on the Foster's. Used to drink it occasionally in college, its the only aussie beer I know of because of their eleventy-billion dollar ad budget.

Don't get ideas that I would put a V8 in an RX myself. I don't fault people for doing it though, to each his own. It can be done with certain engines and not ruin the handling.

I bet I can go to a junk yard with a dial caliper and a measuring tape and find springs that I can make work in any car you choose, for any performance level. All I need is the dimensions that are required to fit, I can get the spring rate needed a bunch of ways. I can even change the free height by shrinking a spring in a normal oven.(mom freaked out when she saw a spring compressed to coil bind with some threaded rod and two 1/2" thick plates in the oven at 500F, but that was 20 years ago) Those springs lost about 3/4" in free height after about an hour in the oven.

As for cars I've done suspension stuff to? Too many to list all of them. I've owned and raced VW Golf's, FIAT X1/9, FB and FC RX7's over the last 20+ years. I've been involved with building and racing Alfas, Porsche 911's, BMW M3, Chevy powered Spice chassis'd World SportsCar, Elva Courier, Turner Mk lV and a bunch of others I can't remember. I've worked with a few different suspension design programs like Susprog and OptimumK. I also own my own shock dyno and revalve my own shocks. I've got about 22 years of playing with suspensions, on at least that many types of cars that I have put track time in. I've been paid to show up at the track just to make a car handle better and have extensive experience with dataq interpretation of suspension info from sensors. I have over $1000 in sensors alone on my car, not including the dash/dataq unit.

From some of your statements you're sounding like a guy that just cuts springs to lower cars...
Sorry, I just had to get snippy after your last few sentences when your cap's button was stuck

I don't have a problem with random cutting of a spring, I just think there is a better way. A spring is just a long rod of high carbon steel that is wrapped up into a coil, nothing more. There are only so many spring manufacturers in the world, chances are the same company makes them for Mazda, Ford, or any number of other companies. Mazda says, "we need a spring with "x" rate, 25cm tall free height and "Y" dia. The same spring could be on a Mercedes, or one just like it but 3cm longer. So we could take that Mercedes spring, do some math , and cut it to make it work for our Mazda.

vipernicus42

iTrader: (4)

I'm going to close the thread before this gets out of hand.

There have been other threads about cutting springs before, though I'm not entirely sure how much information you'll find because the general consensus seems to be that cutting and/or heating springs is not the best idea. Reducing the height of a spring will not automagically make it stiffer. The material the spring is made out of and the design of the spring will determine that. By cutting what you end up with is a spring which is shorter but it's shortness is not compensated for in an increase in stiffness so you're not going to get better handling. It's a sketchy procedure for style and looks only at best, and a dangerous proposition resulting in greatly reduced handling and ruining your springs at worst.

As it was said before, if all you care about is the look, go ahead. If you care about the safety, predictability and performance of your ride, pay the $184 for the RB spring set.

http://www.racingbeat.com/resultset....rtNumber=14080

It's really not that expensive. Heck, I bought mine when the Canadian dollar was worth $0.65USD and had to pay more for shipping, 15% tax and brokerage when they crossed the border and I still thought it was a good deal!

Jon