Re: how many millimeters is "lowered all the way" on stock bolts
It varies with each car. Usually maximum lowering with stock bolts will result in @ 15mm drop from factory OEM ride height. There must be at least 2 thread rows visable on the rear bolts. The Z Axis ride height should be measured at specific points on the chassis....consult the Service Manual.
Note that maximum performance with stock bolts can ONLY be gained with a complete T1 suspension package. This includes T1 Shocks, T1 Springs, T1 Sway Bars, T1 End links, T1 Bushings in T1 A-Arms, T1 Camber Keys. The installation of a T1 suspension actually raises the ride height slightly.
You should ONLY opt for a complete T1 suspension IF you are participating in SCCA T1 competition.
So raising your car IF it was lowered to 15mm and then raising to 12mm will not produce any decernable improvement. If maximally lowered on stock bolts, a slight improvement can be gained if you install '04 shocks, which have better rebound settings.
If you ONLY want to lower using stock bolts, there are some additional things to do to improve performance.
- Set Rake to 1/2' - 3/4".
- Corner Weigh, Corner Weight
- check Cross Corner Weight % Difference (this is the most important suspension spec.)
- set up the car with a more aggressive street alignment
- Use an even more aggressive Track or AutoX alignment if competing
IF You are competing and the rules allow, lowering more than the stock bolts will increase the performance dramatically. This lowers the CG and Roll Center which is advantageous to suspension performance. Even better than a full T1 set up.
You then will need :
- longer Hardbar Titanium rear spring perch lowering bolts
- Hardbar SS front spring bolts with shorter Delrin bushings
- Shorter shaft/body shocks. I recommend Mallett/Penske DA's
There are then mirad other options to consider.
Last edited by DJWorm; 02-25-2008 at 10:40 AM.