The top spring is a BZY from GM (the stiffer of the 2 springs now offered), while the bottom is a stock BZW from my 89 WS6. As you can see there is a .75" or so difference in overal length. What are the chances of this new spring being the correct height once installed. I have been told that springs never loose their height (with no load), just their rate with age... is that true?

Can anyone shed some light on this subject?

*edit* I put in the wrong stock spring code.

Dude! Springs do settle with time and load. The "free length" changes.

I installed used "BZW" springs in the front of my '82 Z28 from and '86 IROCZ. it actually lifted the car nearly an inch. This restored the steering geometry to its correct state. And the handling and feel of the car inproved dramatically.

Thanx,ANDYZ28

I don't have an answer for you.
Could you give me the length of each spring...

My 1990 BZW springs were are 14.00 inches long upon removal
plus or minus an eighth (both springs)

BZY (new) = 14 3/8
BZW (old) = 13 7/8

I hope they do settle, or my drop spindles will be a waste!

Hey Tim, when I took out my old FE1 suspension springs they were at least an inch if not more TALLER than the stiff BZX springs that were going in yet the new springs made the car sit HIGHER. Shorter springs generally have a higher spring rate since there are less coils, less movement. But springs are manufactured differently with different lengths and springrates heated into them and what I said doesn't really mean much. On the list of springs that I have, not knowing the spring rates BZZ (14029400) is the stiffest, then BZX (14029398), then BZW (14029397), then BZY (14029399), then CDB (14029396), then BXY (14029396), and finally BXX (14029396). Yes the last three have the same PNs (no idea why). Of course, this information was gathered from another individual and I have no idea how reliable it is.

But back to what I was trying to say, my new stiffer springs were shorter than my older worn springs yet they still increased the ride height.

Luke,

I know where you are getting your info from. I talked to the dealer about the 7 or so springs being combined into 2 and he thought it was weird also. How much did the new springs raise the front? Are you still doing your thing?... I have to give you a buzz.



Well, I just realized that the spring codes I found on the build sheet do not match what the car has. The sheet says they are CDB, while I just pulled out a BZW... weird. None of the receipts I have show that the previous owner had any suspension work done. Infact only 3 items have been changed since he bought it... battery, alternator and the cat/exhaust.

I am not looking forward to putting these springs in. I had to pry this one out.. and those spring compressors make me VERY nervous.