I love a lowered car and the piazza while quite pretty at OEM ride hight looks a bit weird to me, also with my first piazza i could never really afford to lower it so didn't do it at the time.
standard height
lowered height
I had talked to a one of other piazza's owners with lowered cars (matt who had the red car was super helpful) who had used cut springs (F) and escort springs (R) with shortened shock, it looked amazing but so low i think it wouldn't be great to drive. I got some of the rear springs from them and tried them out and the springs were not captive requiring new shocks at least and it was hitting the bump stops when it was on thr ground which meant the springs weren't actually being used.
it looked cool though.
I was not tough enough to uses these so I looked around for other options, i believe you can buy ZOOM springs from Japan and these appear to work and are good but there is very little info on rates and it would have been quite expensive to get to the UK. I tried AE86 lowered springs as well but they did not fit diameter wise on the front (also were not a high enough spring rate) and did not lower the rear at all.
so that was a fail. so i thought if i new what springs rates length and diameters i needed i could then either find some after-market generic things or get custom springs made. i did some calculation and made a spreadsheet using corner weights that i measured. to do this correctly i needed to measure the OEM suspension components and find the motion ratios etc.
i think this is the correct excel speet it was done a while ago. in short though it said that if i increased the spring rate and decreased the free length i would get to where i wanted for the front, the rear however required a different solution to stay captive and a dual rate spring with dead coils would be needed.
lowered springs target
Front
300lb spring 340mm length
rear
150lb spring 206mm length with 70mm of inactive coil
it was complex though and i wasn't sure so i then reached out to faulkners in the UK to see if they could help out and make me a set that would work. after much backwards and forwards and some confirming of measurements we cam up with the following spring design.
https://dfaulknersprings.com/special-ma ... -to-order/
front
300lb 342mm free length (87mmid 117mm od spring)
fitted load of 275mm for 875lb force
205mm total travel 142mm coil bind length
one closed & ground end and one plain
rear (dual rate)
263mm free length
120lb/225lb rate
99.5mm id 124mm od
164mm total travel 99mm coil bound length
one closed & ground end and one not closed not ground end
this in itself was quite expensive at a bit above 500punds at the time with a 4-6week lead time but i went for it and have to say that they were really really good. the install of the springs went basically exactly the same as you would expect with much difficulty and some very suspect straps to remove and fit new springs. I did need to get an adjustable panhard rod from an AE86 and some nylon bushes for the diff end mounting point the details for these were
- 1 bush nylon 18id x20od x 30long to cover the diff end connector difference is size from OEM to AE86
- 2 x nylong washer 20id 30 od x 3mm thick
- AE86 whiteline adjustable panhard rod which i got from fensport
(https://www.fensport.co.uk/products/whi ... saS-aBVIdv)
The end result was that it was about 40-50mm lower on both ends and i think looking pretty good. it didn't take long for the springs to settle and this is the result
