Extended Bump stops to stop bottoming out...

[09Frank65]

Originally Posted by LukeMustangMalta

What is the difference between normal springs and progressive rate springs?

I'll buy the poly top insulator just in case the new springs don't solve the situation

Progressive rate springs have a lower rate during normal driving but the rate increases as the spring compresses (i.e. while cornering, bumps etc.) If you look at one you will notice a difference in spacing between coils from bottom to top.

I had also thought of the 1" coil spring spacers. It's a cheap option to see if you can make the problem go away.

[JonK]

I would think that rolling the fender trim would be easy after rolling the fender lip, the trim is much softer. If the tire can contact the fender lip at full compression of the suspension then the tires stick out a little too far (backspace). I rolled my fender lips and got ~1/2" of extra clearance and no more sharp edge facing the tire in case i hit a pothole. I'd also try ajdusting for more neg. camber.
Jon

[ripped]

4.5 backspace is a little less than ideal. 4.75 is better for the wider tires.

Every car is different, but rolling the fender lips will help. It's tough with the chrome wheel lip trim, though. I like that trim, so it's a tough call.

There are other options, but they are costly
Change to a narrower tire, on the front.

Have a wheel (welding) shop extend the backspacing a bit (this depends a lot on your tire size and clearances)

Machine the wheel face at the hub (this depends on construction of the wheel, thickness, and recommendation of the wheel shop)

Increase the negative camber, will decrease the life of your tires, incrementally

[JohnnyK]

Originally Posted by LukeMustangMalta

What is the difference between normal springs and progressive rate springs?



I'm beginning to suspect the springs may have been cut or are worn. However, should I go for the standard 1968 302 springs, or go for the Boss /GT which are slightly stiffer?



I'll buy the poly top insulator just in case the new springs don't solve the situation



Will be buying these as well

I seem to have less room than you do! ANd all I have is the shelby drop, and 1" lowering springs.. I bought the 1" insulators, and frankly, though it's mind bending, they didn't seem to do anything!

[LukeMustangMalta]

Bumpasaurus

[blue1967]

Luke which way are you going. Im about to do the Shelby drop as well and I already suspect my springs or shocks are worn out. I have to slow down a lot before I hit any kind of bumps or my wheels rub and the whole front end just feels way to bouncy. Ill be watching to see what your fix is. post links of the parts if you have gotten that far yet.

[slim]

Suspension bouncy = shot shocks. That's the classic test.

Slim