So I know that something must limit downward travel, and it can't be the a-arms, because they both swing freely when the spindle is not attached. Yet when the whole shebang is assembled, even without a shock, there is a limit to dowward travel. Having spent about 20 hours with this stuff in my hands, you think that I'd know the answer.

The reason why I ask is that I needed to raise the lower arm a bit with a jack to get the QA1s installed about a year ago. In an arrangement like this, the shocks definitely are the downward travel limit.

Now, because I added 2" drop control arms, I am going to be adding taller springs. If I go with the same QA1s, they will definitely be the downward travel limiter -- by three inches or so. Even as is is now, the lower arm will need to be jacked up about two inches to be able to mount the shock.

Is this improper? The wheels do become airborne/unloaded from time to time, even in normal driving. I calculated unsprung weight at about 165 lbs. That seems like an aweful lot of force to subject a shock to.

Can anyone shed any light on the topic?

Thanks.

 

Sway Bar? I know removing it helps weight transfer.

 

I am not sure if this is what you are looking for. This might help you better but like I said I am not sure. Link has a lot more stuff in it.

http://www.rqriley.com/suspensn.html

Travel is everything
Front-suspension travel is important. Here's how to get it: Though not found on very late Firebirds or Camaros, most early GM cars and several other Detroit marques feature a system of limiting the downward movement of the front control arms. In a race car, especially a low-horsepower race car, you need as much front-end travel as possible. Short of adding some ball-joint extensions, which are illegal, there is a way to increase front-end travel in these vehicles.

The manufacturers often used a rubber snubber mounted to the upper control arm or front framerail to limit A-arm travel. This snubber is very similar to a conventional slapper-bar snubber. If the snubber is trimmed, the front end of the car will exhibit a much more favorable travel arrangement. Just keep trimming the snubber until the car slows down; of course, in some cases, you'll have to remove the snubber altogether. If you trim too much of the snubber, swap the snubber for a common traction-bar component. Too much material can be cut away — watch the brake flex line. If it's stretched during full travel, you've gone way too far.

 

Tim,

It's always been my understanding that the shock limits downward travel on a coil spring suspension at least with a production based vehicle. Race cars may be different. And yep, pulling the shock out really lets the suspension drop more and without a spring it flops almost vertical! When I received my QA-1's from Stan I tried to install with just raising up the lower A-arm with a jack and it wasn't enough so I ended up stripping out the threads on the top of the shock piston. Called Stan and asked what's wrong and he told me the suspension had to have all the weight on it to install the shocks. After getting the shocks rebuilt (new pistons with good threads at the top) I set the jackstands on the lower A-arms to get full weight on the front suspension to correctly install the shocks. It is a lot of weight for the shock to stop but Stan tells me its OK once the shock is installed.

Scott

 

With no shock, it's the ball joints that limit the movement. They will only allow so much angular displacement.

Shocks are often used as the limiters of downward (rebound) travel. Only QA1 will know how much load their shock can withstand.

 

Tim-

If I may ask, what arm and spring combination are you going to use? You are installing both a lower and upper control arm right?

I have the upper and 2" lower control arm kit from DJM and I was thinking of swapping out the front 2" DJM coils for a set of Stan's 1" coils with a much better shock- QA1 perhaps to improve my ride. What do you think?

Thanks.

-Monty

 

Thanks guys for all of your responses. It makes sense to me now.

 

I just ordered some 1,100 (or was it 1,200?) springs from Stan this morning. According to alphadoggy's experience, Stan's coils actually gained 1/4" in ride height with the stock spacers (Stan's are designed to run without any spacers).

I'm hoping that this combo will net me the 17" hub-to-fender height that I'm looking for. An alternative for you if you want a lower drop might be to get some thinner spacers such as those used by Hotchkis.

Keep your eye on my Web site. I will post the results there when I'm done.