derpernicus

I own a 1970 Cutlass S, and I'm fairly new to the car building scene... I have some ideas in mind for upgrading the stock suspension on my car, but I don't know if it'll work the way I'm planning. I plan on using an Eibach Pro 1" lowering kit, paired with a Helix 2" drop spring. Will this drop me a total of 3", or do the drop spindles need a matching 2" drop spring? Any help is appreciated. Thanks!!!

Here's the links
For the lowering kit: https://www.carid.com/eibach/1-0-x-1...l#applications

for the drop spindle: https://www.carid.com/1970-oldsmobil...266457192.html

-Alex

joe_padavano

The spindles give you 2" drop with stock springs. Lowering springs make the car that much lower. Expect ground clearance issues, especially with headers.

oddball

Drop spindles are not necessarily "upgrades". They can negatively impact handling quite a bit.

Dropping the front is easy. Drop springs can drop farther than advertised. Aftermarket arms have deep pockets that can drop another 1"-2". You quickly have issues being able to get a good alignment with stock upper arms.

So, depending on your budget and goals, there's a lot of options. The A-body suspension is nearly identical (steering linkages changed a bit depending on year and model) for 68-72, so there's lots of options. "Chevelle" parts work just fine.

If you're serious about a big drop and handling, then aftermarket lowers and adjustable uppers become necessary pretty quick. Quick and cheap is springs and drop spindles. And there's lots of options between those.

Lowering the rear is rather more difficult. There are 2" springs, but that's it. Can't cut them since they're pigtailed on both ends. So the next step is a coil over or airbag conversion.

If you drive the car, it's easy to drop to far. If you're doing it just for looks, then no worries. I destroyed a deep oil pan because my combo at the time (drop springs + tall ball joints + aftermarket arms + short tires) was really low. I've gotten it up from there, but the headers still act like skid plates on some of the big bumps around here.

There are a bunch of write ups for pro touring Chevelles. Marcus at SC&C has a good product selection and wrote a decent book on A-body handling.

anthonyP

If not already equipped, adding OEM FE-2 sport suspension parts would increase handling capabilities on all road conditions without sacrificing the ride.

Fred Kiehl

Use caution with drop spindles. You can end up with a situation where the lower arm, or shock hits the ground before the rim if you have a flat. That scenario can cause the lower arm to be ripped off of the car, and possibly damage the mounts for the arm. The body can also be damaged by the displaced wheel/tire. 2 inch drop spindle requires a 4 inch taller rim for the same clearance. You can measure the clearance with a straight edge, or taught string, by going under the car with the weight on the suspension, and stretch the straight edge from the bottom of the rim on one side to the bottom of the tire on the other side. If it is clear of all parts you are probably good.

derpernicus

Thank you all for the suggestions. I'm looking for a lower stance, and to up the handling a bit. I don't have much to work with, as I don't have a job till summer, but I'd rather do it right than do it ghetto. If I keep stock arms and spindles, and just go with the 1" lowering springs in front, would that give me much in the way of handling? Or purely cosmetic? Also, thanks for the write-ups. I'll have to look into those

Fred Kiehl

I am not familiar with the adjustments for camber and caster, but the front wheels will develop some negative camber. If it uses shims, you will probably need to remove 1/16 inch of shims from all four stacks to compensate for the negative camber. Caster should not be affected. If you are not comfortable with doing the alignment adjustment yourself, take it to a shop, and have it done. If you do not, your tires will have excessive wear on the insides. I do not know the orientation of your steering linkage, but you may require a toe-in adjustment. If it is typical GM, the toe should be the same after the camber adjustment.


The actual camber change will be in the neighborhood of .3 to .5 degrees.

derpernicus

This sounds good! Will I gain much in cornering ability? I'm looking at doings a mix of straight line and cornering speed. I know a big heavy muscle car isn't the best for corners, but this is what I've got. 😂

classicmuscle442

Could you use coil over shocks on rear to lower?

Fred Kiehl

There are many things that affect handling. Lower to the ground is always good. Heavy anti-roll bars will help as well. A lower compliance bushing set will keep the suspension from deflecting into undesirable directions. Stiffer springs and shocks will keep the suspension from moving as much in conjunction with the anti-roll bar. Front and rear bars should be "tuned" to match the needs of each end, and work together. Keeping the car body from rolling keeps the tires in even contact with the ground, and that is where you get the most traction.

Lowering the car will improve the handling to some extent, only because the center of gravity is lower, and the body will not roll as much. There are some suspension designs that will cause problems depending on the layout of the pivots for the arms. Yours should not cause any issues in that regard. If the arms are both pointing up from the inner pivot, the car will actually roll more than one that has the arms more level. The body rolling will cause the camber on the outside to go positive, and that will make you loose traction on that wheel. That is why a drop spindle will do more for handling than a drop spring in most applications. Your change is minimal. The street setting of positive camber allows most people to better control the car at higher speeds, because the car will understeer more readily, giving them warning when the enter a corner a little too fast.


For the most part, the stiffer the suspension, the better the car will handle, but your ride will suffer in the same proportion. If you use aluminum bushings, the suspension will not change it orientation, but you will feel every bump, and it will be noisy. A street car is a compromise between performance and comfort. It depends on what your tolerance level is for the performance level you want.

The camber setup is for street driving. Racing may require some negative camber, because the car body tends to roll, and the negative camber will make the outside front tire stay flatter on the tread. The other side is that when you are not cornering at high speeds, you will have less traction, and it may hunt from one front to the other for an "edge" to go straight. It will also wear the inside of the tire more rapidly.

Another consideration for handling is Ackerman affect. When driving corners at high speed, you should have anti-Ackerman, but for street driving you need Ackerman affect to keep the tires from scuffing going around corners. High speed cornering requires the tires to slip, and since all of them are slipping, and steering is mostly by throttle, you do not need Ackerman. Ackerman at high speeds (or moderate speeds where the car is in a 4 wheel drift) can cause excessive tire wear on either or both front tires. You may not get the full traction of the inside tire with Ackerman as well.


As far as coilovers, you can use them anywhere they will not cause damage to the other suspension parts. Most GM cars can not use coilovers on the front, because the lower mount can not take the spring pressure. Rears are to be approached with the same object in mind...will the mount withstand the pressure of the spring. Coilovers are nice for adjusting the height of the car, because it is easy, but if your mount breaks, you have a real problem.

oddball

To improve handling on these cars, here's a list from easiest/cheapest (but less effective) to most costly (but quite effective):
1) Good tires, may require new wheels
2) larger sway bars (adding to the rear if one isn't there, and associated mods)
3) stiffer/adjustable shocks, stiffer/lower springs
4) frame reinforcements
5) aftermarket control arms with poly, delrin and/or roto-joints
6) adjustable front upper control arms
7) tall ball joints
8) AFX spindle
9) replace the GM bind-o-matic rear with an IRS or 4 link + watts or something else

Just figure out how much you want to spend. It won't compete on a road course against modern factory muscle without significant ($5k to $20k) investment.

Coilover conversions - done correctly - require new lower arms in the front, and shock mount reinforcement in the rear.

Seriously, get the book "How to Make Your Muscle Car Handle" by Mark Savitske. It's a good place to start.

Mr Nick

Unless you know what you're doing, I suggest against piecing together suspension parts from different vendors. Go to one supplier who knows what they're doing (not CarId) and stick with them, like this for example: http://www.ridetech.com/store/streetgrip/

deejai35

Two people before me have already mentioned Marcus at SC&C or Mark Savitske. They are spot on! The guy knows his stuff! I have the SC&C stage 2 plus, with some BMR Racing Stage 1 parts I had previously ordered. The car is lowered 1.5 inches in the front and 2 inches in the rear. It rides/handles great. The alignment is close to a C6 Corvette.

Mr Nick

Ditto - I'm in the process of installing SPC LCA's and Ridetech shocks as we speak. Just nee to get the tall LBJ pressed out of the stock arms and into the SPC arms.

I think the Cutlass handles better than my G8.

69455

Cant say enough about Detroit Speed stuff.
Yes pricey however I am VERY happy with results.
(speed kit 3) front and rear
Drag strip to road coarse
2" drop / coil over


r