I have one of the first sets of Eibachs that were made. With 245's on all 4 corners on my car, I have the front bar set soft and the rear bar set medium. The car is perfectly neutral. I never noticed much body roll stock, but I don't notice any at all now. These are great bars. They are hollow for light weight, 2 position adjustable front, 3 position adjustable rear and very well finished with a very nice red powder finish. They already have the locating collars on them and I've never heard a single squeek from the bushings. Sicn ethe coups normally push (understeer) while the sedans normally oversteer, you should try setting yours a little different from mine. It really depends if you han an LSD or not. If you have a sport or the cold weather package, you will have the LSD. With LSD I would say to start hard in the front and medium in the rear. Without LSD, start hard in the front and soft in the rear.

04' G35 Coupe(finally in the garage)
6-sp Diamond Graphite/Willow w/Premium

 

It all depends on what you are trying to do with them. Everyone associates sway bars with body roll. The goal of sway bars is not to eliminate body roll; it is turn-in, balance and corner stability. Body roll is not a bad thing, excess body roll is. This question you are asking is extremely subjective depending on who you ask. Some people like a safe and stable car that is set to comfortably understeer at the limit. Some people like the back end to be lively and loose with oversteer, while others like to control both ends of the car independently. You need to know your driving style before you start choosing and tuning.

I needed a set of sway bars to set my car perfectly neutral. I have been autocrossing for several years and I know how to control my cars. I went as far as having Sanar Performance custom make a front sway bar for my stock class Miata because I could not find the right one for the balance I wanted. The stock 22mm bar make the car too loose. An aftermarket 1" bar made it too tight. I had a custom adjustable 24mm bar made to tune it exactly. With the Mustang SVO I know run, I actually run a much smaller 4-cyl 15/16" mustang front bar. With the stock 1 1/8" SVO front bar, the car would never turn-in right. I know how fast I want the turn-in and how i want the car to behave if I gas or brake mid-corner. In autocrossing have the biggest bar isn't the best thing. Too stiff of a front bar, doesn't allow enough weight transfer side-to-side and kills turn-in. Too big of a rear bar makes the back end uncontrollable beyond the limit.

I have no plans to change springs on my coupe. I like the ride/handling balance of the car. I even like the ride height. I just wanted to get rid of the front end push and get it neutral at the limit. I first swapped the front tires from 225/45's to 245/40's for more bite. Why you would put smaller tires on a car that is front end heavy makes no sense to me. This helped substantually in reducing push. From here I needed to concentrate on the rear. The front was pretty well planted. In fact, in skipadding the car with only 35 psi in the front tires; the temperatures across the tread are extremely even. This shows the stock camber and roll rates are pretty close to optimal. In the rear, the inner side of the tires are hotter showing there is a little too much negative camber. Despite this, the rear actually needs less grip(i.e. a bigger rear bar) to get the car neutral. I targeted a set of bars where the front bar wasn't much bigger than stock, but the rear was. This is why I chose the Eibachs and they did exactly what I wanted them to do. Does that mean they are the best? No. If I didn't get the balance I wanted, I would have gone to a different set and chose them based on bar diameters. It does mean that for my car there can't be a set that is better though. If I bought a set of EVO or Cusco bars and put them on the car and got the same neutral balance, then they would be just as good. If I couldn't get the same balance, then they are obviously worse. If you don't have the same driving style I do, same car setup and have the same goals; then my setup may not be what you are looking for. But, hopefully this will give you a place to start.

04' G35 Coupe(finally in the garage)
6-sp Diamond Graphite/Willow w/Premium