I have been in the process of modifying the suspension to my liking and have been doing it in stages, I also planned to experiment with alignment settings. So the idea of having to go to an alignment shop every time I made a change seemed like it would be expensive and very inconvenient. So I investigated the idea of doing my own alignment, at least well enough that I did not have to get several alignments while I was trying to dial in the car. So there are a bunch of tutorials online about using the string method, so I gave that a try.
It works however holding up a ruler or tape measure against the wheel is tiresome and prone to error. So I got the idea to make my own jigs that would attach to the wheels and allow me to quickly and easily check measurements at a glance with a fair degree of accuracy using low cost items from the hardware store. So this is what I came up with and have found it works extremely well! Initially I figured I could use it to get close and then go to a shop with a fancy Hunter laser rig to get a "real alignment", however that seems to be unnecessary now.
I have a local shop with a Hunter rack that will throw it on there and give me a print out for $30 and I have been doing that to evaluate the accuracy of my adjustments. Turns out I have been able to achieve a level of accuracy that there is no need to have it aligned by a shop. Most shops charge at least $120 for an alignment, but if you want custom settings, the ones that will even do that usually want $200 or more. So this is what I came up with:
[IMG]20190721_201508 by Eric Michel, on Flickr[/IMG]
[IMG]20190721_201552 by Eric Michel, on Flickr[/IMG]
I started out like this:
[IMG]20190406_162802 by Eric Michel, on Flickr[/IMG]
It works but it is difficult to get accuracy and easy to make mistakes. Oh and you can reach all the alignment adjustments with the car on the ground (even with it lowered), but it is not fun to do. I found those stands used for $150 and it was well worth it. I also splurged on one of these for checking/setting camber they run about $200 new.
[IMG]Camber check by Eric Michel, on Flickr[/IMG]
So for about $50 in parts from the hardware store, $200 for the camber gauge, and some optional (but recommended) stands and you can do your own alignments and get results that are well within specification and probably better than what many shops will adjust to. So after finishing my recent suspension modifications I adjusted the suspension to what I currently think is ideal for street/track with my setup. Front: 1/8 toe out (1/16 per side), camber/caster are fixed with dead set (so check only), Rear I was going for 1/16 toe out (1/32 per side) and -2 degrees camber. So after aiming for these settings in my garage I went to my local shop to see what their fancy Hunter rig says:
[IMG]2019-08-18 19_46_35-20190818_155723 by Eric Michel, on Flickr[/IMG]
It looks like a got a little sloppy towards the end as the right rear is a bit more than I intended but still less than a 1/32 and well with tolerances. I have done several alignments and if I take my time I can get within .03 degrees or better to what the Hunter rig shows. The whole process takes 2-3 hours.
What I have found so far:
I have been running toe out up front for the last 4000-5000 miles and highly recommend it even for street use. After ruining a set of old worn tires, I have been carefully monitoring tire wear of the new sets, measuring inner, outer and middle, of each tire documenting it every 1000-1500 miles. What I found is that you can do up to and slightly over 1/8 of toe out (about .2 degrees per side) up front (even with 2.5 degrees of camber) and the tire wear seems to be just fine. So far it has been very even inside to out and even comparing front to back. This is with some limited track time, spirited driving, and a lot of highway miles.
I have found that toe out is what you want for this car up front for better turn in response and front end grip, the more the better! However, if you go much more than 1/8 toe out (total) the tire wear starts to increase at what seems like an exponential rate. So for a track only car I would possibly go 1/4 toe out maybe even a little more, but for a street car unless you have money for tires don't do it, 1/8 seems to be the sweet spot (YMMV). So the setting shown above seem to be working great for me up front.
Initially I had just added a stiffer rear sway bar and that does help to some degree but the rear of this car is very mushy (for lack of a better term) because the rear bushings and even the rear sub frame mounts are very soft. So the rear just doesn't respond well to subtle inputs, you really have to flick into a corner and or lift abruptly at high load to get it to come around and then it can be rather abrupt and take a lot of correction to catch. I tried adding toe out in the rear with the rubber mounts and at low speeds (>60-70 MPH) it did help get the rear to come around but it also made it feel really unstable at high speed (>100 MPH) so much so that I went back to some toe in for the rear.
Then I replaced all the rear bushing (and I do mean all) with Super pro bushings, spherical adjustable toe links, and 034 inserts with Tyrol dead set for the rear sub frame. I was concerned that this might cause a huge increase in NVH but surprisingly the increase was negligible, but the handling response was great! It sharpened up the rear a lot, but with toe in it was very difficult to get the rear to come around now so I increased rear tire pressure (4 PSI more than the front) and started dialing out the rear toe. Now with the rear stiffened up I find I can run a bit of toe out in the rear and it feels perfect. Now I can pitch it into a corner and depending on steering angle and throttle position I can induce mild under steer or over steer, and get a nice four wheel drift. It responds much better to corrections and the transitions are far more predictable and progressive now. Under the right conditions I can even get a little bit of tail out under power and feel the rear end pushing just before it straightens out and pulls through the corner, and I don't even have a haldex tune or anything. I am still fine tuning some settings which is partly why I was a little sloppy with the rear settings trying to see how much rear toe out I can get away with, but for the most part I am pretty happy with how this car handles now and it is light years beyond where it was stock.
Anyway this is what I have found so far with this car, perhaps this will be helpful to some and I would love to hear what others have found. I know there are several conversations out there about suspension but they are all over the place and most just seem to run close to stock toe settings (other than lowering and camber). Handling was my least favorite aspect of this car when I first got it, it was capable but boring, now it is lively, responsive, and just a lot of fun.