Leaf Sring Question?

[74ventura]

I have a 74 pontiac ventura with cal-tracs,monoleaf springs with monroe gas shocks on the rear.The front has ce 3-way adjustable and stock springs with no swaybar.The problem i'm having is the car bounces bad when i launch and settles when you get to higher speeds.I haven't taken it to the track yet cause i'm afraid if it hooks it and unloads i might crash.Another thing is i have lightened the car up, but when i bought the leaf springs i ordered them for a factory weight vehicle and i was wondering if that could be a problem also.I had a set of hals qa1 12 way adjustable shocks on the rear and it still bounced bad upon launch.Thanks

[supernova]

It would be better if you had a video of it.
What hole do you have the C/T bar in, in the front bracket? Put it in the hole at the top of the bracket. Put ajustable shocks on the back and set them around 2/3rd's tight. I use rancho rs 9000's and work great. I also have qa single ajust in the front. I'm haven't run my new car yet but my old car was set just like this one and it worked great.

Get a video for us.

[74ventura]

The cal-tracs are in the bottom hole in the front.I'm going to the track this coming weekend and i will get some video and post them up.Thanks for the reply.

[chupa]

How much front end travel do you have? I have had a similiar problem due to the front topping out prematurely. Increased the front end travel and the bounce went away....

A leaf spring car can almost never have too much front end travel... try to obtain 5-6 inches.

[74ventura]

Right now i have 4" of travel.I didn't have any travel at first and it was awful trying to launch the car,so i took 2 coils off my front springs and that gave me four inches.Before when the vehicle weighed 3600lbs i didn't have this problem,but when i took weight out it started.

[HAULIN' IT]

i took 2 coils off my front springs and that gave me four inches

I'm having trouble with this...Your saying you cut Two coils off of the spring & it got you to Four inches travel. I don't see how cutting coils could GAIN travel. Lorne

[John_Heard]

The lower the car sets the more overall travel it has from at rest to the front suspension topped out.

[74ventura]

When i cut the front coil springs the fenders went down over the front tires.I jacked the front end up until the tires just started to come off the ground and from the bottom of the fender to the ground is 29inches.With the tires on the ground from the bottom of the fender to the ground it is 25 11/16.Before as soon as i would jack the front end up it would start to pull the tires off the ground.

[chupa]

The problem most likely is that you don't have enough energy in your front spring. Cutting 2 coils is a significant amount of spring loss. Were these stock springs?

Have you considered using a Moroso trick spring or a 6-cylinder spring. Using a lower spring rate will allow more spring to be used.

The energy of a spring is calculated by the following equation.

E=(1/2)kx^2.

k=spring rate (lb/in) , x= the amount of the compressed spring (in)

Force is alculated as follows:

F=kx

k=spring rate (lb/in) , x= the amount of the compressed spring (in)

So for example a cars front end weight = 2500lb, using a spring with a rate of 250 lb/in the spring would compress 10 inches, E= 12500. If the spring was k=500 lb/in you would have 5 inches of compressed height, E=6250. So based on the energy calculated you can see the lighter spring w/ more compressed spring stores twice as much energy.

If this car is primarily used as a drag racing car you should really consider purchasing a set of Moroso Trick Springs.

[BILTIT]

WOW, another ventura awesome.

Pics and vids are needed, please haha.

What motor are you running?

[supernova]

Hey, I have 2 sets of BB springs new for a Nova, one set is the lightest BB moroso's and the other set is stock. They have been sitting around for a while now and I would sell both for 50.00 bucks each + shipping if anyone is interested.

[74ventura]

Update on the bouncing problem i was having.I changed my rear shocks to ranchos and started with my adjustments on 5 and stopped at 7 and the car hooked and left straight no bouncing.I appreciate all the replies and help from you guys.

Biltit,I'm Brandn74 from py my ventura used to look identical to yours till it caught fire last year.I will get some pics and send them to you.

[supernova]

Update on the bouncing problem i was having.I changed my rear shocks to ranchos and started with my adjustments on 5 and stopped at 7 and the car hooked and left straight no bouncing.I appreciate all the replies and help from you guys.

Hey, glad you got it going.

[BILTIT]

Update on the bouncing problem i was having.I changed my rear shocks to ranchos and started with my adjustments on 5 and stopped at 7 and the car hooked and left straight no bouncing.I appreciate all the replies and help from you guys.

Biltit,I'm Brandn74 from py my ventura used to look identical to yours till it caught fire last year.I will get some pics and send them to you.

Ah, right on.