Marc80

After rebuilding the front suspension, swapping my motor and losing the iron intake and heads, and smog crap I lost so much weight that the body rose substantially. The distance to the front fender was over 30". (The rear was 30 1/2" after I ditched the spare, etc. but the longer bolts from Ecklers made that easy to adjust down.) I cut off a half circle of spring and dropped it down about 1/2". I was careful to key in the top of the spring into its seat but did not gain as much drop as I wished. I am afraid of cutting to much. I don't want to have to modify the camber adjustment mechanism. How much do I dare to cut. I have studdied this issue in archives and see that some have gone as low as 26 1/2". I think I would like to get it to 27 1/2", but once again, I don't want to lose camber adjustment or run the wheel into the fender.

How low can I go?

Thanks in advance. You guys are a big help!!!

:flag

Shark Racer

Terry Rudy is at 28" with unmolested 550 springs and a rather light engine compartment.

I'm at 26 7/8" right now, all iron. (Unmolested 550s...)

-Steve

BSeery

I cut my 460's by 1 1/2 coil (very low) and that is just past being able to get the camber set.

71vettman

Youve probably heard it before but just incase you havent, you shouldnt cut coil springs to lower a car. You are also altering the spring rate to a stiffer one when you cut coils off. I would purchase an aftermarket set of springs to lower it if they make any.

Shark Racer

Well, the 550lb spring VetteBrakes sells is just a chopped 460. If you chop the 460 to the same height as the 550, you should have a pretty good idea what the spring rate is. (550 +/- a few).

You can also consider the 550 VB&P sells a "lowering spring". Or, you could take the spring, apply some kind of pneumatic force to it with a scale, until it compresses a full inch. Then the amount of force applied in lbs is the spring rate. No idea where one could do that though...

-Steve

Scooter70

Steve,
At my old college we had some mechanical testing equpiment that you could probably run that test.

My 460s are getting 3/4 of a coil cut off when I get a chance to pull them out. Anybody know the uninstalled height of a VBP 550 spring?

4DLuvOfSpeed

I do, I do!!! When I get home tonight I'll measure the new 550s that I got yesterday and then I'll make my transition from "clueless newbie" to "experienced Vette guru sharing his wealth of knowledge: :D

theandies

I heard that no matter how little or much you cut your springs you have to start hanging out with ricers and watch "The Fast and the Furious" every night. :lol: :lol: :lol:
John

norvalwilhelm

Pacin California. I do spring checks all the time. MY stock car friend has a hand unit in his shop or I do them at work on a compression tester with a digital output. And the 550 refers not to totally compressing the spring but rather for every inch compressed it takes 550 pounds. It is called a spring constant. If you compress the spring 3 inches it requires 3 times 550 or 1650 pounds.
To test a spring all I do is run the crosshead down and it prints out distanced travelled on one axis and load on another. From the slope of the line a spring constant is calculated.

Marc80

Dear PacinCalifornia:


...and with those fender heights you ran into no camber adjust or tire interference problems?

Thanks, Marc

Marc80

Dear 71Vetteman:


Why would stiffer springs be a problem?

Thanks for your input.

Marc

Shark Racer

Quoting myself...
From an older topic where I asked for measurements of 460s. Those are the measurements of my 550 springs before I installed them.

I have yet to align the car, so I will tell you how that goes.

-Steve

Shark Racer

Norval -

That machine sounds interesting. :) I would have been far less precise if I had to do it myself. Would have stood on the spring, measure how much I weighed and how much the spring compressed, take my weight over the compression to get the rate.

I did mention in my above post that the spring rate referred to compression force per inch of travel.

-Steve

Jughead

I cut 3/4 of a coil to = 26.5 inches. Didn't notice any difference in ride quality.

71vettman

Marc
I dont think stiffer springs are really a problem. The only reason I mentioned that is because it would be nice to know what the new spring rate would be. I dont know if cutting the springs will make them too stiff.
You may not have any problems cutting your springs though. I just finished Steering and Suspension class at my college and my teacher told us never to cut coil springs to lower a car. Unfortunately he didnt really go into depth on why exactly or what could happen.
Kevin

BSeery

That is why I cut coils off of a 460 and not a 550 lb spring !!

Vetterodder

Within reason, cutting a full coil spring by moderate amount shouldn't create any problems or cause a dramatic increase in spring rate. Cutting a strut spring however will have a dramatic effect (that's why all those lowered ricers go down the road bobbing up and down). Spring rate is increased in proportion to the amount of spring that's removed. In the case of our shock/spring equipped Vettes, if you cut enough coil off to make a dramatic difference in spring rate, you're not likely to notice it because the car will be resting on it's oil pan anyway :). If you do cut springs, use a saw or cut-off wheel, not a torch. The heat from a torch can turn your springs to mush.

Frank75

Cutting one coil off of the stockers will increase spring rate about 10% - there's an article on this on the faq section of tech help ("VIP - Vette Improvement Program" I think). One problem with stiffer springs is that ride quality sucks. If you have bumpy roads they can be a real bear. You should also increase rear spring rate to keep roll resistance more or less the same. I dropped my front ~1" by cutting one coil.

4DLuvOfSpeed

Damn it, someone beat me to my moment to shine :banghead: Anyway, I measured my new uninstalled 550s and confirmed those numbers.

One thing I wanted to mention is that everyone seems concerned about rate being affected if you cut your springs, but I haven't read anything about the ability of the spring to seat properly. Springs have flat coils at both ends so they are flush by at least half a coil when installed. If you cut off a coil, then the contact patch of the spring is reduced to almost nothing (just the tip of the coil). I would guess that this would throw off the balance of the spring under load and it would compress unevenly, resulting in erratic (and unknown) spring rates. This is just speculation, however.

I've also heard of some people cutting their springs and then heating the end coil and and bending it so it's flat again. I asked my mechanic about this and he told me that heating a coil can ruin it and cause premature failure of the spring.

Just my $0.02

VegasJen

i disagree that cutting a spring is an absolute no-no.
of course, the proper way to lower the car would be to buy a set of lowering spindles that keep all the factory locations, except the spindle, as designed.
problem is, nobody currently makes a 'drop spindle' for our cars(VB&P, you listening?).
the other way would be to invest in something like the VB&P front mono spring. something i would like to do myself but the cost is currently out of my budget.
leaving us with the coil cutting measure. i, along with many other forum members, have done this with no adverse affects. considering how much weight you've removed from the car, you can start cutting a greater length.
start at 1/2 a coil and work your way to where you want it. additionally, to address the seating of the spring, when i cut mine i ground a taper into the coil from the point of the cut about 2" down the coil to give it a better seat. just a flat spot starting about 2" from the cut working to the point that at the cut, the coil was about 2/3 it's original thickness. don't know how much this helped but it made me feel better about it. :)
as for the ride harshness increasing, this isn't terribly noticable unless you start out with a stiffer spring than factory. the deal is, there is nearly 8 feet between the front springs and your butt. there is only about 2' between the rear spring and your butt so the difference in stiffness will be much more noticeable with a stiffer rear spring.