Ok, I have searched, read and poured over the mountain of info in the FAQs and Reviews threads... I did my homework as best I could but I think I have info overload now I really just wanted to answer the basic question, not read the spanish inquisition...

Best way a 1" drop all around and reduce understeer.

So I "think" what I want is just the Tein HIgh Tech Springs.

Afordable - $220
Streetable - Max 1.2" Drop
Performance - Increased Performance (Assume they would help with understeer)

Anyone have input on this? Is my assesment wrong? Should I be looking at a Sway Bar to reduce the understeer instead of "thinking" the springs will help?

Input greatly apreciated.

 

I dont know much about increasing performance with some springs, but you may want to put some cash into some good tires first. Which tires are you running? Have you considered sway bars?
I have an 06', with no mods, RE050A in rear, and RE050A Pole Positions in front (bridgestone). I have slight oversteer, but thats because my front tires are grippy as shiza. I love it.

 

Track Z, see my sig, I run Nitto 555 all around. Once the tires are hot that are like glue. But the rear tires heat up faster then the fronts. Hence the fronts cool off faster then the rears also. Thats where I get understeer from.

I am considering sways. But I didn't want to invest in something that can be fixed by something I "am" investing in.

 

Normally understeer is designed in as a safety feature. The front tires are overloaded [too weak and too small] in a turn and the rear are too lightly loaded [relative to the fronts] so the car plows-understeers. The front sway bars already being too stiff make the understeer worse by transferring addition load to the weakest tire.

The problem with trying to compensate for tire rubber friction changes with temperature is at what tire temperature.

Over/understeer is stated in steering wheel degrees vs G load/ body roll.............how much at what G-roll do you have and how much are you trying to change.

Adjustable sway bars are the normal common method to use since springs cannot be changed easily.

Normally spring stiffness ratios [corrected for mounting angels and offsets] are fixed so that they reflect the body weight ratios. Say 55/45 so the corrected installed spring stiffness on the front is 55% and rear 45%.

Don't confuse the unloaded/unmounted spring rates with the real spring rates as measured on the wheel..............tires vary by brand and inflation as to the sidewall stiffness [1200-1700 pounds per inch] which is placed in series with springs to arrive at the actual tire/road spring stiffness [which is the only important thing]!

 

Do people still calculate wheel/tire spring rate before taking into account the manufacturer specs of coilovers?

 

Q45tech - I understand some of what your saying but a lot of it was German :-/

So to help reduce understeer I would want to look at adjustable sways or change the tire offsets? But new/different springs will not help to resolve the problem of understeer?

 

Springs are designed to hold the body up and set the amount of body roll vs the stiffness of the ride feel.

Get a good book on performance suspension design and do some technical reading before playing around with oem suspension.

People say under/oversteer this and that and don't really know the methods of measurements or the units it is expressed in: degrees per G.

The softest spring that will do the job is always BEST.

 

Here's some of my experience with suspension tuning.

https://my350z.com/forum/showthread....highlight=sway