Guest

The 67 big block coupe I just picked up has the front end sitting slightly higher than it should be. You know when you see a midyear and the front end is just sitting a little too high? The front end components all look new (bushings, tie rod ends, shocks, etc....).

What can you do to try and lower these components? I want it to have a nice stock, original stance.

I can try to get some pics if you need them to advise.

Thanks,
Rob

wombvette

The first thing I would do is check the springs for proper installation. Sometime people will get them in wrong which can cause problems. Make sure they are up into the towers like they should be. If this is OK, the only thing left is to change the springs. It probably has a set of aftermarket or BB springs which will cause it to be too high. Typically F-41 springs will actually make it low, or I have a bunch of worn out ones. You can make it as low as you like.

Guest

Wayne, thanks for the reply, I'll check the position of the springs. It sits up pretty high, and it's bugging me to no end. I might have to take a drive by your shop sometime and let you take a look at her too, besides its been a couple of years since I have been down there.

Thanks,
Rob Harper

toddalin

To save some money, you could also have a coil cut off of your springs. I did this on my '64 which suffered from the same problem you mention. (My springs were originally installed as part of the Dick Guldstrand Touring Suspension and even they sat high.) While they were off, I had them powder coated in black and many years later they still look like new.

Andy B

Rob,

FWIW the moog replacement springs I purchased for the front of the 65 were literally a half a coil too long. You could put the spring in the correct notch at the top and it was half a turn from the notch at the bottom and vise-versa. With the springs installed with the extra half coil the car sat way too high.

I checked out the pics you posted in the other thread, that is one great looking car you have there. Congratulations on your purchase.
Andy

Guest

toddalin,

how much did you cut off?

Andy, thanks bud. :cheers: Just trying to keep up with that beauty you have. :yesnod:

Rob

toddalin

It's been years so hard to remember, but I think it was a complete turn. Of course yours may vary depending on the height and the spring rate. (Also put the long bolts in the rear spring to drop it 2".)

I think that they make these springs (front) to serve '63-'82 so they make them to accomodate the heavy cars. The light cars then sit high.

66427-450

Just remember, chopping off coils changes the performance of the spring....... as well as the car's "parked heigth".

Springs are pretty cheap, aftermarket front sets are <100$

Mr D.

Andy B, very :cool: :cool: :cool: Web page

Dyna

Listen up, this happens a lot: When a new suspension is put into a car, like new A-arm bushings, etc., a lot of guys make the mistake of tightening the bushings up BEFORE the car is let down on its springs. This causes the bushings to act like little torsion springs, keeping the A-arms from rotating fully to the car's natural stance. In other words, the springs are being assisted by the twisted bushings, holding the car higher than it would be if the springs were (properly) supporting it all on their own. I would definitely check this out before cutting my springs up.

Hope this helps,

Dyna

Andy B

Thanks for the comments guys. :D
Andy

SWCDuke

The amount of restoring force provided by strained suspension bushings is insignificant. Try installing a control arm and tightening the bushings without a spring. You can move the control arm throught the range of travel with your hand. The reason that bushings should be tightened at normal ride height is to keep them from being continuously strained in torsion.

The problem with these aftermarket springs is that they are not built to OEM specs. I don't know why, but this is the reason why I always encourage all to use the original springs. As long as original springs have not lost a signficant amount of material due to corrosion, they are very likely serviceable.

Duke

Dyna

Hey SWCDuke:

I really saw this happen on a '69 I had years ago. I am sure the bushings were more than insgnificant. They added about 1.5 in to the car's static height until I released them, let the car drop, and re-tightened them. No lie. Direct experience.

Dyna

Vetterodder

After dropping a bunch of weight off the front of my sb `65 (aluminum, heads, water pump, etc.) it was sitting way too high. I wanted it lower than stock anyway so I chose to cut the stock springs. Like already posted, springs aren't that expensive so I wasn't afraid of screwing them up. I calculated the amount needed to get the desired height and the results were within 1/8" of my goal. In my case, I took 60% percent of a coil off and that lowered the front by 1.75". Again, my car is a sb with the base suspension so I don't know that your springs would be the same. Cutting a spring does increase it's rate in proportion to the amount removed. In my case that worked out to about 6 or 7% increase, not enough to notice. If you do decide to cut your springs, us a saw or cutoff wheel, not a torch. The heat from the torch can ruin the spring. I already had a plastic mono spring with adjustable bolts in the rear so it was only a matter of turning a wrench to lower the rear for the proper stance. You can do the same thing with the stock rear spring by using longer bolts. Lowering the car will alter it's alignment so budget for that. I'd also recommend paying the extra bucks to have the alignment done at a shop that knows Corvettes.

ghostrider20

Doesn't cutting a spring actually make it stronger???

It think its service strength remains the same, but more energy is required to compress it, so a rougher rider would be the result.

I remember reading this in ME school somewhere. If I am on crack here someone help me out.

Mark

Cmacsvette

Mark, I don't think your on crack, I think your correct. :yesnod:
I thought of this earlier on this thread too. If I remember my spring lessons
correct, you are correct.
Craig ;)

SWCDuke

Did the car have something other than the OEM type rubber bushings? I recall being able to easily move the lower control are through the normal range when I removed the knuckle from the lower control arm to change a balljoiint.

Duke

SWCDuke

Here's the formula for the rate of a conventional coil spring with equal coil spacing:

K = Gd**4/8ND**3

G = Torsional modulus - 1.25 x 10**6, pounds/square inch for steel
d = wire diameter, inch
N = number of active coils
D= mean coil diameter, inch

The stress in the wire is given by:

S = 8PD/pi d**3

P= Load, pounds

By inspection you should be able to conclude that reducing the number of active coils increases the spring rate, but does not increase the material stress for the same load.

Duke

grumpy55

Duke.
The front springs on my '64 coupe seem to have coils very close together.
Is there a "correct" coil-to-coil (center-to-center) distance to work from (compair to) ?

66427-450

Grump -

I'm sure Duke with give you all the details, but I think the springs are "variable rate"? (rate changes with the degree of deflection).... not all coils are the same distance apart, at leasts the std springs.
Right'o Duke?