Standard 3dr HDi is about 50-70kg lighter than a GTi6, and they sit the same height too (had a GTi6 and HDi both 3dr P3's)
I had the HDi weighed and it was as good as bang on book weight at 1135kg empty.
1.8 front springs may lower a GTi6 because it's a lot lighter than a GTi6, but the 1.8 and HDi probably weigh the same, so 1.8 springs might not lower a HDi much at all.
Obviously springs alter the ride height but struts can be different too, so always check the spring seat to hub locking notch distance. The HDi might have a longer throw, or a shorter one, or the same one. In any case if it's different you need to factor it in.
Ie, my 'OEM' spec shocks from GSF to fit "xsi/s16/gti6/hdi d turbo" had a different spring seat to hub notch distance by about 15mm, ergo the car sat 15mm higher after new shocks went on! Arghhhh...
That leads me to believe that either Bilstein decided all cars should sit 15mm higher, or there is some variance between the above cars and they chose a middle ground distance to use?! Would be interesting to find out
My theoretical method
Park the car on flat ground. Chock under the front sub-frame to point you want car lowering (put weights over front struts and make sure it lowers the car to the chocks)
Once happy with the chock height, remove the wheels and chock under the end of the wishbones to load the springs up, keeping the car pre-loaded with the weight it needed to lower it. Now use an oxyacetylene torch to heat up the springs. Let them heat up and then cool. Fingers crossed when you put it all back together it sits at a new lower height
From what I've seen you can have springs made/adjusted like that. But they do them in a special machine and run an electrical current through them, altering their free-length by the amount you want to alter the ride height by. Hmmmmm...
Cheers
Dave
I had the HDi weighed and it was as good as bang on book weight at 1135kg empty.
1.8 front springs may lower a GTi6 because it's a lot lighter than a GTi6, but the 1.8 and HDi probably weigh the same, so 1.8 springs might not lower a HDi much at all.
Obviously springs alter the ride height but struts can be different too, so always check the spring seat to hub locking notch distance. The HDi might have a longer throw, or a shorter one, or the same one. In any case if it's different you need to factor it in.
Ie, my 'OEM' spec shocks from GSF to fit "xsi/s16/gti6/hdi d turbo" had a different spring seat to hub notch distance by about 15mm, ergo the car sat 15mm higher after new shocks went on! Arghhhh...
That leads me to believe that either Bilstein decided all cars should sit 15mm higher, or there is some variance between the above cars and they chose a middle ground distance to use?! Would be interesting to find out
My theoretical method
Park the car on flat ground. Chock under the front sub-frame to point you want car lowering (put weights over front struts and make sure it lowers the car to the chocks)
Once happy with the chock height, remove the wheels and chock under the end of the wishbones to load the springs up, keeping the car pre-loaded with the weight it needed to lower it. Now use an oxyacetylene torch to heat up the springs. Let them heat up and then cool. Fingers crossed when you put it all back together it sits at a new lower height
From what I've seen you can have springs made/adjusted like that. But they do them in a special machine and run an electrical current through them, altering their free-length by the amount you want to alter the ride height by. Hmmmmm...
Cheers
Dave