[screamingchief]

The problem with most lowering springs is they all usually utillize higher spring rates and this affects the "hook factor" often,and not always in a good way either.

Those springs are more about corners,not so much about straight-line traction.

There is more to spring design than just ride height...

The best option here would be a custom made spring.

And the the spring rate would be determined by scaling the car on all four corners so you would have the front/rear and corner weights to determine what is going to be needed for each specific situation.

The ride height and other design parameters are then computed by the spring maker to fit the customers chassis needs.

This is the 100% correct way to get the right spring.

Even the moroso "trick" rear springs for these '68-'72 A-bodies list the desired rear chassis weight,that is 1450 lbs.-1510 lbs. (part no.-47500),this is done so you can confirm their fitness for your particular application.

Anything else is just a crapshoot what effect it'll have really.

Simple trial and error at that point.

And when you do it this way the the chassis tuning is done in a manner to make the car fit the spring,which is not really the way it should be,the right way is selecting the spring so it fits the cars needs.

No skilled chassis builder is gonna just throw springs into a car with no idea what the effect will be,but then we dont all have their resources either...

[Jagtec1]

Bret, no "lowering springs" going into my car! I understand the whole "scale your car" custom spring deal. Just too much $ for me.

I figure I may swap a set out just to se what happens with height and "hook".

I don't have traction problems now, but the car looks like a stinkbug to me.

[Tim Corcoran]

This seems like a pretty easy deal. Just call this place (Springs and Things) and order a new set of springs and ask them to give you a spring with a 1" lower ride height. This place has a great product and the prices are very reasonable. I did the same thing for my 67 LeMans. It had the factory springs in the rear and I didn't like the look. I ordered a new set of springs and asked them for a 1" taller ride height. That's exactly what I got, the springs are great.

http://www.espo.com/

Tim C

[Jagtec1]

Well, I swapped the springs out for a donor set off another 69 Lemans. Dropped 1 1/2". The springs I had in there were apparently progressive rate springs. They were also about 4-5 # heavier EACH. Now I'll lower the fornt of the car another 2" and see what happens. FWIW, after changing the rear springs, the front is over 1/2" taller. I'm too tired to cut the front springs tonight, but I'll post pics when it's all done.

[gearbanger]

The really dangerous thing about making your springs shorter in the back is, if you raise you car up on a rack, jack it up by the frame, go over a hill fast, or other ways, your spring can fall out of its pocket and you can tear you car all to crap. If you shorten the spring it is best to restrict the travel of the shock in some way so as to maintain some preload on the spring at full droop. Otherwise you are begging for trouble.

[screamingchief]

gearbanger:
The really dangerous thing about making your springs shorter in the back is, if you raise you car up on a rack, jack it up by the frame, go over a hill fast, or other ways, your spring can fall out of its pocket and you can tear you car all to crap. If you shorten the spring it is best to restrict the travel of the shock in some way so as to maintain some preload on the spring at full droop. Otherwise you are begging for trouble.

I beg to differ,there are other solutions to that sorta spring issue you mention if that were ever to become a concern.

But restricting the travel of the rear suspension in any way is what I would considered "begging for trouble",,,at least if you ever expect the car to hook at the track that is...

If the car hits said suspension travel "restriction" during the course of it's operation at the track it'll unload the chassis instantly and most likely loose traction completely.

Remember most OE style coil spring drag chassis are modified to encourage chassis "seperation" and not chassis "squatting",when the cars squats it's not transfering weight as effectively as it does when it seperates on launch,so potentially inhibiting that seperation is a very flawed logic IMO.

If your worried about keeping the spring in place,please take the minimal time and fabricate some basic brackets &/or clamps to hold said springs in place on the rear end housing or in the frame pocket (but not both IMO),and please dont even consider restricting the suspension travel like was suggested.

I can think of another half dozen ways to deal with that sorta issue,none of those restrict the suspension travel before the shock itself acts as that restriction.

Besides,,,Darin never said he made the spring shorter,he said he tried another spring and found that the springs he had taken off his car were "variable rate" spings (aka. cargo coils),Darin stated he put some stock springs from another OE application,so please explain what leads anybody to the conclusion that those springs are somehow significantly shorter to cause that sorta conflict,,,ask me it sounds as though the cargo coils were too tall for the application to begin with.

[Jagtec1]

The new springs are NOT modified, cut, or shorter...just not variable rate, and thinner windings. Trust me, they aren't going anywhere! I got the front down 1 1/2" and back to where it was before I put the car on the diet. It sits the way I want it now. I will be doing some aero work, and will be out to the track on the 28th for the Ram Racing event at Cecil County.