I am looking to lower my car and i was wondering what springs are the best to use?

Thanks!!

 

I've heard swapping to the 550 lb springs will lower the front about 1". And I think you can lower the rear with longer spring bolts.

Soemone can probably confirm that or tell you I'm an idiot and not to listen to me.

 

Some apples and oranges here. Are you interested in keeping the same spring rate, and only dropping the ride height? Or are you thinking about changing the spring rate too?
Custom springs (or modifying the static height of your stock springs) will lower your ride height while maintaining the ride quality. And as mentioned above, some other rate springs will also allow a lower ride height, but at the cost of ride quality. (I'm using the 550# springs, and I'm comfortable with the ride quality.)

 

I would like to keep the same ride quality and just drop the ride height

 

Cut the springs. If you would like info on lowering your ride heights properly to Power Book road racing prep specs, drop me a PM.

 

ok if i was to cut the springs how much should i cut off to lower it about an inch and if i do cut them will that change the ride quality?

 

First, what springs you have? In any event, getting this right is going to require at least a couple of mock-ups, as this is a trial and error process. It's best to go a little at a time rather than to over do it and end up having to buy new coils.

If you like your current ride quality, working with the springs you already have is best, but you will experience at least a nominal change, as the more spring that's cut off to achieve lowering, the higher the spring rate will become, regardless of whether you start with soft springs or stiff ones.

 

The springs i have are stock.

 

OK. Next is to establish what your ride height is now. For the front the dimension that counts is called the Z height. Below is a link to a PDF of the Chevy Power Book Corvette Chassis Section (C3). In it you will find a description of this and the D height for the rear. Once you measure these, subtract the Power Book numbers from your numbers and you'll have the amount of lowering you're looking for to get to the recommended specs.

Then you can look at you coils at rest and get a good estimate how much to cut. If the amount of change desired happens to be the same distance as that from one coil to another, then cutting off about one coil will be necessary, but you may want to start out with a little less than your first estimate, as you can't undo cutting off too much if you miss. A carbide blade works a lot better than a typical hacksaw blade. Use caution releasing the pressure of the coils. It's best to use a compressor such as the one below from KD.

Each time you let the car back down, be sure to settle the suspension completely by rolling and bouncing the car some to get accurate measurements of your results.

While you're at it, it's a very good time to replace the ball joints and install poly control arm and anti-roll bar bushings (the stock rubber pieces allow your suspension geometry to distort all over the place), but I'd wait until after establishing the new ride height before doing the ball joints, as breaking them back down during the mock-up process is hard on them, not to mention what it does to the boots.

To get the rear down is much easier, usually accomplished with 8" spring bolts. A complement to this to replace the camber strut rods with spherical camber strut rods. I cannot recommend the poly bushed units, as this item moves in more than one plane and the poly ended pieces are reported to lossen.

Now, before you change things, make sure your ground clearance requirements will work out. With standard springs, you're going to be much more likely to bottom than you would with stiffer units, which have a bad rap for being overly harsh. Personally, I've got 860# Daytona's on mine, and with a properly tuned set of shocks have no ride quality complaints. Of course, my priorities are a bit different...

One last tip... Putting on a set of Bilsteins is one of the top 5 upgrades you can do to your C3! When you're all done, get your car re-aligned ASAP, using VBP's recommendations as a guide. Your Vette should look and handle better than ever.

http://www.corvettefaq.com/c3/ChevyPower.pdf

 

I would also recommend replacing the joints and bushings beforehand, if you haven't already. That in itself made a significant improvement in ride quality on mine.

However, you do not have to break the ball joints loose each time you remove/replace the springs. After removing the shock and disconnecting the sway bar, I use an internal spring compressor (as shown by TheSkunkWorks) to compress the spring, then I unbolt the lower control arm pivot shaft from the frame. Swing it outward, with the ball joint as a pivot, and the spring is easily removed. Reverse the procedure for installation. And when you install the modified spring, make sure you hit the coil "pockets" in the control arm.

Good luck

 

Doh! Now why haven't I ever looked at it from that direction?

 

Sometimes we just like to make it hard on ourselves, its more of a challenge that way.

By unbolting the control arm and working from the bottom, you don't have to touch the brakes, not even remove the caliper from the rotor.

 

Thanks for the input, i will let you all know how it turns out