What do I need for this setup?

[arabbit]

Hey guys I finally decided to stop being cheap, and Im going to get an Eibach Coilover kit for my 05 GT: http://www.americanmuscle.com/eibach-prostreet-coilover-1112.html

my question is, do I need anything more to get these to work? Do I need to buy an adjustable panhard bar, LCA relocation brackets, castor/camber plates, etc like I wouldve needed if I had just bought lowering springs alone?

I searched, I just need some advice on how to make this work right.

Thanks!

 

[bumblebee06]

u could not need anything, but then you could need adj panhard rod and camber plates. I would recommend them because even if you dont need them you can use them. the rear end may step out but depending on how much you lower it it might not. generally u want to get an alignment after lowering it so the camber plates will make that very easy. i would get them if it were me.

 

[skwerl]

My rear axle was off center from the factory by about 3/4". You have a couple low cost options for the panhard bar here, SD Accessories has either steel or aluminum for $110 shipped I think and Freedom Racing also has very good prices on theirs. Both are honorable, trustworthy vendors.

 

[arabbit]

well the big feature on these is that they are adjustable on the fly, and you can make 'quick' adjustments whenever you want...so I would have to adjust the panhard bar and have it aligned every time i change? that makes it worthless to me. I live in the country on a dirt road, so I wanted to be able to have stock height on my drive to the track, then lower it for track use, and then back the same way.

 

[Norm Peterson]

What kind of track and how much ride height change are you talking about?

With camber plates and a digital angle finder, just do your own alignments (it's easier than you think).

If track = road course or autocross, lowering the car will naturally give you somewhat more negative camber and the toe should shift toward zero from whatever your daily toe-in setting is (both being what you want). For most folks, it's even OK if it goes a tiny bit into "toe-out".

If track = quarter mile and your daily setting isn't aggressive at all, you may not have to do anything since the alignment that you really want there is zero-ish camber with the nose up an inch or two like it would be under WOT.

The trick either way here is coming up with a method that's as repeatable as possible, like some means of providing hard stops for the strut shafts so that when you're hard up against either one you know exactly where you're at. And this could be a set of simple home-fabbed gage blocks. Simpler but less repeatable for any single reset would be to mark the two locations. Hint: it's easier to change camber if you jack that wheel just clear of the ground.

Unless you're really crowded for tire clearance out back and can't handle even a little axle shift, you could intentionally offset the axle by about half of the total axle shift from high ride height to low.


Norm

 

[Sky Render]

You will need an adjustable panhard bar at a minimum. Depending on how much you lower it, you may need adjustable control arms, bumpsteer correction, etc.

Of course, if you're just going for the "slammed" look and don't care about racing in autocross or road course, you don't need any of that.

 

[arabbit]

haha yeah not going for "slammed", I just want an inch and a half for road course racing. Definitely some good info, I will have to do alot of toying with it when I get it, and I will get the panhard bar as well. Hopefully the coilovers and the panhard bar arent a pain in the ass to adjust all the time. I really want to be able to do quick adjustments on the ride height, I was hoping for something like what the 2012 Boss has. Is this a good kit or is there one thats better for this?

 

[Norm Peterson]

As far as I know, the only adjustability in the 2012 Boss suspension is the shock/strut damping. And adjusting this would be the easiest part of what you're looking to do - with a little practice and knowing where to put the adjustments, it's maybe a 5 minute job including the time spent opening/closing the hood and trunk.

The next level of time spent would be the re-alignment. Again, with a little practice and some sort of hard fixture so that you don't have to actually keep measuring anything this doesn't take a whole lot longer. I got to the point where I could shim-adjust my '79 Malibu between DD and auto-X settings in about 5 minutes per side including jack time. (You're up to 15 minutes setup and 15 minutes reset time per event just in the suspension at this point.)

IMO, it'll be the raising and lowering - and making that repeatable - that'll either make or break this whole business. I'll admit that I've never envisioned getting into quite this much adjustment, but if you can't make this as repeatable as the alignment stuff you'll never have any idea at all how far off your corner weights have drifted. You won't be able to adjust one corner either up or down X amount and simply adjust the other until "it looks level" or you'll risk being worse off than stock (read: more asymmetrical, left turns vs rights). I can think of a way that would theoretically work, but I don't think I'd trust it.

Just for the ride height "adjustability" function - have you considered running somewhat shorter tires out on course? For example, there's about a 2.3" diameter difference between a 255/45-18 and a 285/30-18 (and the Hoosier 285/30 is available in the R6 line specifically for track use).

Given that not messing with ride height via the suspension means that you'd never have to touch any PHB adjustment or be concerned about how the lowering would affect anti-squat, I think this would be the better way to go. You'd set the PHB just once and the A/S at most a couple more times for tuning purposes and then forget that as well (anti-squat would drop slightly with lowering which would tend toward delaying the onset of any possible brake hop under exactly the conditions where you'd be more likely to get into it).

I think you might still be in for doing something about the roll steer, though. A little swapping of the rear LCA axle side pivot heights would probably be involved here, two more bolts and a few more minutes per rear corner.

Norm