This has been a long time coming for a few different reasons, but alas ... a review of my suspension setup.
I'll start by giving huge props to Andrew and Myles at GTWorx for all of their help. Andrew spent a lot of time helping me learn more about the fine details of suspension tuning ... stuff like understanding bump steer and camber gain were mostly a mystery to me. Andrew took the time to listen to my plans and help me decide on a setup that would suit my needs and driving style. Thanks a ton man.
The Vehicle:'06 MR (SE) ... basic bolt-ons
The Setup:OE Bilsteins
GTWorx Springs
Whiteline 26mm front sway
Whiteline 24mm adjustable rear sway
Cusco camber plates
Whiteline bump steer kit
245/45/17 Hankook RS2s on Rota Torques
Alignment Specs:-2.4º Camber Front
-1.3º Camber Rear
0 Toe
Uses:Street
Auto-X
Twisties
The InstallI installed everything with the help of my brother and his lift. I wouldn't recommend a job like this for just anyone ... The springs, plates and rear sway for fairly straight forward to install and could be done by a competent DIYer in their garage with some rented tools.
The front sway and bump steer kit are another story though ... it's not that they are difficult to install, but time consuming and potentially quite uncooperative. A proper press is definitely required for the bump steer kit and the front sway is a multi-step process that requires some extra hands. The most difficult part is the rear engine mount as it is extremely difficult to access. Disconnecting the steering column shaft and re-connecting it isn't difficult, but there is no key spline and it's easy to misalign it when reconnecting.
If you do this yourself, prepare for a long day ...
3.5 hours - Front Sway
.5 hours - Rear Sway
2 hours - Springs and Plates
1 hour - Bump Steer Kit
It took us a little longer for a few different reasons, so consider the above estimates on the optimistic side.
The StreetI've had the springs on for about 1600 miles so far. In all honesty, it feels stock while cruising. The slightly progressive rate of the GTWorx springs make them as smooth as the stock springs, and maybe even smoother over bumps and transitions. My wife even commented that it felt better over bumps the last time she drove it.
The sways go basically unnoticed on the street. If you have a habit of attacking culdesacs in your neighborhood you might notice the difference, but under normal circumstances there is only a hint of stiffness in corners.
With the toe setting zero'd out the car does like to wander a little and follow the contour of the road while cruising. However, under throttle it's straight as an arrow.
The drop from the GTWorx springs is slight, but noticeable. I ended up about .5" lower in both the front and the rear due to the Cusco plates. There is a slight but noticeable rake toward the front. It looks aggressive, but purposeful.
Auto-XI've ran about 9 auto-x events on my stock setup. I ran the stock Advans and had a wimpy alignment ... -.6º camber front, 0º camber rear and 0 toe. This was set up before i decided to compete. As you can imagine, I ended up trashing the outside shoulders of the tires due to positive camber in corners ...
You like that body roll, don't ya? The second photo was taken after I'd added a little more negative camber up front ... I was at -1.5º or so.
Then the new goodies are installed ...
The most notable improvement is the drastic reduction in understeer. The car is very neutral in corners, even when you cross the limit of traction. With the rear bar in the middle position, you can't quite throttle steer, but the car is much more controllable once traction begins to disappear. I had planned to try the other sway positions, but it was 97º out there ...
I only noticed the expected understeer when I was way too hot at corner entry, and even then it was much easier to correct with the new setup. If oversteer is your thing, it's quite simple to initiate it with a nice flick at entry or a little extra throttle on exit. I tried it a few times and the car was steady and controllable, but not any faster. So I gave up and went with tried and true "slow in fast out" approach (which isn't nearly as fun).
Turn in is also much nicer with this setup. You get just a glimpse of the progressive rate on the springs and then it bites hard and holds. I found myself waiting and waiting for understeer ... adding more and more throttle. I think the common comparison of "on rails" really applies here.
Another noticeable difference is that I was able to run much lower tire pressures with this setup. Given, I was on different tires (245 vs 235), but I found myself lowering pressure all day practically. I'm used to running 41psi front and rear (mainly to combat the understeer) and ended up at 36 psi front and 35 psi rear with very little rollover.
I wish I could post lap times for comparison ... but it's kind of impossible with auto-x. I will say this though ... I was the only competitor in SM on street tires (as usual) and ended up ~2.2" behind first place on a 50" course. Last event I was ~4.3" behind 1st on a 60" course. I think that says something about the suspension improvements since I'm sure my horrible driving didn't improve.
The TwistiesI had a chance to go on a nice drive through the lower Appalachians with some friends about 2 weeks after the install. The car was just a blast to drive. I didn't come close to the limit since we were on public roads, but the car was precise at speed. It responds to steering input much quicker and gives a much better feel of the road in corners. The car responds more like a scalpel than a butter knife now.
I wish I had more to say here, but it's all really summed up in the auto-x impressions. The car feels great.
Final ThoughtsI'm very happy with the setup so far, but I'm not done yet. I plan to add some more bushings and stout end links in the future just to get rid of variance while cornering.
I would recommend this setup to anyone who wants a great setup for both street and track. The performance results are similar to stiff coilover setups but the ride quality is much better with the GTWorx springs. I drive my car daily and that is very important to me.
Again, thanks to GTWorx for all of the insight and help in choosing this setup and for the hours of technical discussion. I'm sure there will be more in the future ...
Also, thanks to Brad Miller for letting me use his photos. You can see more of his work
here.