No worries Kev,

Have left my contact number on Perthcapri for ya. I'll grab a copy of Street Machine asap

Steve thanks for the info the set I believe I will be using are 255mm as they sit on the bench are also not progressive but I have not had these springs in the car so I have no idea what ride height that will give but the spring wire is alot heavier than the other set I have of which some one has cut & was very very low.

Ok will get the dimensions tonight, do you happen to know a guy named Lew who owns a XT GT Falcon ??

g'day Kev
No I dont know anyone called Lew.

For the springs I used the manuals load of 320kg per spring and did all the calcs to text book spring theory. The books spring rate is 21.8 kg/cm so at 320 kg that gives 146mm deflection. This makes the compressed length 174mm.

For my lowered set I calculated a compressed length of 126mm.

Thats a difference of around 2 inches so my guess is that my lowered set was lowered by 2 inches.

For your set I did 2 calcs, one for each pitch to get an average. I just assumed the whole spring was constant pitch.

For a pitch of 45mm it gives a deflection of 50mm so thats a compressed length of 255-50 = 205mm.

For a pitch of 36mm it gives a deflection of 63mm so thats a compressed length of 255-63 = 192mm.

So for variable pitch the result will be somewhere between these values.

Both are higher than what I calculated for the standard springs (174mm)so my guess is that your springs will be too stiff and the car will sit higher than standard V6.

I will be putting my standard set in on the weekend to take some measurements so I will be able to get an idea of the accuracy of the calcs. Sorry its not good news.

BTW freo springs said they will reset my originals for $30 each so am going to try that (which is why I need to refit and measure)

Hi Kev
I put my longer springs in and turns out they're not standard. They gave a hub to guard height of 320mm which is around the same as the kings lowered specs.

The compressed length when installed with full car weight on it is 150mm.

I adjusted the load in the formula to get them to match and re-checked yours with the same load. Came out somehwere between 182 to 197mm.


Old Springs that are too low - notice very little travel left



New lowered Springs - more travel

No probs to have a look but might be best to leave it a couple of weeks. The struts are back out for the inserts, bushes etc and its not at home so wont be back together for a while.

Geez $460 good price