I’m looking into the best ways to lower the front ride height of my 1970 Nova. From what I’ve learned, it appears there are two ways. The first is with a shorter coil springs. The second is I can use dropped spindles. I’ve even heard of guys doing both.
Is there one way that’s better than the other?
R.H.
The short answer is that either will do the job—but there are some advantages and/or compromises when using higher rate/shorter front springs.
The even shorter answer is: It depends on how the car will be used.
Pros & Cons of Dropped Spindles
If, for example, you really just want to cruise the car and want the lowered stance purely for appearances then a dropped spindle is a good plan. The reason for this is that the horizontal portion of the spindle is relocated upwards on the vertical height of the spindle and this lowers the car while maintaining stock suspension travel.
This allows you to lower the car yet retain the stock suspension travel (assuming the tires don’t hit the body). Plus, installation will be easier because this will not require you to remove the coil spring, which generally requires a spring compressor. When adding a dropped spindle, once the ball joints are popped loose, the spindle can be changed without removing the coil springs.
We’ve listed several companies offering dropped spindles that also vary in price. It’s important to ask each company specific questions about the disc brake assembly you will using—assuming of course that you will in fact be running disc brakes.
A full parts list is at the bottom of this article.
Some of the spindles available through Summit Racing will not accommodate the 1970 early factory discs and others will. One other item worth noting is that a few of these spindles are 1 inch taller than the original spindles. The Heidts spindle we’ve listed, for example, is 1-1/2 inches taller than stock. These taller spindles generally require a custom upper control arm in order to take full advantage of the improve camber curve offered by the taller spindle. Not all dropped spindles are taller, so that’s something you need to check before ordering so you know what you are getting.
You may also see references to bump steer problems associated with dropped spindles. This is a rather involved subject that is beyond the limited space we have here for this discussion to fully explain. The abbreviated version is that bump steer occurs where the steering arm scribes a different arc when going through suspension movement compared to the actual spindle movement. The difference in these two arcs creates toe changes as the suspension moves. These different arcs produce either toe-in or toe-out as the suspension moves. This is referred to as bump steer.
There are stories of bad bump steer problems that often exaggerate the issue. This can be a real problem and you really won’t know how this affects your car’s steering without plotting the actual toe changes with the dropped spindle in place. We’ve measured rather poor bump steer with stock spindles and a stock suspension that cannot be detected when driving because the sidewall of the tire flexes to accommodate these changes in steering input.
Frankly, unless you are a serious autocross or road course racer, these minor bump steer problems are not that serious. However, we have also seen some really bad suspension modifications that do incur massive bump steer so it’s not something to ignore. The only way to know is to test bump steer with the spindles in place. I’ve never tested any of these dropped spindles but my guess is that the bump steer is not going to be any worse than stock.
The only spindle we know that corrects the bump steer problem is the forged aluminum, modular spindle from Global West. There may be other spindles out there that accomplish this task, but this is the only one that we’ve tested that effectively eliminated bump steer on an A-body car we tested when the spindle was properly installed.
Keep in mind that when evaluating bump steer that you not be confused by wild claims of massive bump steer at the extreme ends of suspension travel. This is a fairly common shock tactic used by people with no firm knowledge of vehicle dynamics. Stock front suspensions like your Nova tend to exhibit this, but these big changes come at either full jounce where the suspension is completely bottomed out (usually more than 2 inches of compression) or at 2 or more inches of suspension rebound where the suspension is completely unloaded and up against the limit stops.
If the suspension is at either of these points in a cornering situation you have much larger problems. The only cornering application where the suspension would be completely unloaded would be with the car off the ground! The point here is to evaluate bump steer within 1 to 1-1/2 inches of suspension travel on either side of ride height. That is where 90 percent of all handling situations occur.
Pros & Cons of Lowering Springs
Now let’s address lowering springs. The advantage to lowering springs is that when a shorter spring is used, fewer coils with a larger wire diameter also increase the spring rate. A stock front spring for a small block 1970 Nova will be generally around 300 pounds per inch (lbs./in.). A shorter installed height spring will generally raise this rate to 450 to 500 lbs./in. Most lowering springs will cut the ride height by roughly 2 inches.
This shortens the distance between the frame and the lower control arm to lower the ride height but also reduces the normal suspension travel to the bump stop limiter by the same distance. If that distance was 4 inches, it now is only 2 inches. This might be sufficient but over time, the shorter springs tend to settle and reduce the ride height even more. Now the front suspension may bottom out on the factory limiter. This will create a rather harsh ride every time the frame contacts the limiter.
The advantage to a shorter spring is that it also changes the relationship of the car’s center of gravity which generally will improve handling at the expense of a slightly stiffer ride. This is also true of the dropped spindle. You may hear claims of harsh ride quality from stiff springs but in our experience a clear majority of ride quality concerns over stiffness are the result of very stiff shock absorber settings as opposed to higher spring rates.
So the decision may come down to ride quality. If that is the case, then the dropped spindles have a decided advantage.
1970 Chevy Nova Front Suspension Drop Parts List
- SUM-CK1010-1 – Summit Racing Drop Spindles with Caliper Adapters
- ART-11009300 – RideTech Drop Spindles
- RSD-DBSP04 – Right Stuff Detailing Drop Spindles
- CLP-CP30100 – Classic Performance Drop Spindles
- BMR-SP055R – BMR Lowering Coil Springs
- HSS-1937F – Hotchkis Sport Suspension Lowering Coil Springs
- DSR-031115PDS – Detroit Speed Lowering Springs
- GLS-S-3– Global West Suspension Coil Springs
- ART-11262350 – RideTech StreetGrip Coil Springs
Comments