I definitely have come across some of your threads in my reading of past topics, asking some of the same advice I am now, or similar.
How much did that lower the car, if you don't mind me asking?
About half an inch up front. None in the rear. So not much. The Koni dampers up front seem to lower it another quarter inch. But I can tell you that I can't tolerate
any more lowering than this. My splitter already scrapes the driveway unless I come in at a sharp angle.
I had considered this, but the consensus from the tuning gurus seems to be the Boss rates don't change enough from the GT to matter anyway. It does make me wonder why Ford bothered to make so many different spring variations for the NA V8 Mustangs though, if they're all just too soft in the end.
The main reason I didn't just stick with the springs I already had was that I figured that Ford had done the hard work of exactly tuning the springs versus sway bars already, in order to achieve a particular handling balance. I broke from that slightly by going with the stiffer standard fronts instead of the Laguna Seca fronts, but I did that because the balance Ford achieved was with a staggered tire setup, not a square one, so I wanted to compensate some for that.
The other reason for going this route was that it was
dirt cheap. $25 per spring. That's basically free when it comes to suspension parts, so I thought "why not?". If I didn't like the end result, I could always change it after.
But I
do like the end result, quite a lot, so I'm sticking with it for now.
Base is ~126/155; Track pack ~131/167; Boss 148/186; LS 137/191; and all with unique strut/shock part numbers (And presumably valving). That seems like a lot of engineering for subtle to nonexistent changes, but maybe that's just the way OEMs work (I'm clearly not in the industry).
It
is a lot of engineering. And it's the result of an enormous amount of testing as well. I suspect it was done because the Ford engineering guys wanted to get things "exactly right", at least as much as they could, and were dealing with things at a subtle level. How does the car feel at turn-in? How does it behave mid-corner? On exit? Around all kinds of corners (with various cambers, etc.)? How does it handle the road (remember, it's a street car)?
They wanted handling to be the shining characteristic of the Boss 302, for the car to be a track weapon as street cars go, but to still be drivable in all kinds of conditions on the street. A tall order.
Subtle changes can matter a lot. While people generally thought the GT's handling (with Brembo/track pack) was good, the general consensus seemed to be that the Boss's handling was fabulous. Of course, that's all relative, and compared with cars with the kinds of modifications people here do, it's surely no contest. But for an everyday driver street car? The least one can say is that it's not bad at all. A
1:40 lap
time around Laguna Seca is what the Boss 302 is capable of -- on street tires. To put that in perspective,
1:36 to 1:45 is what race drivers in cars ranging from the Z/28 to the BMW M3 were getting
on slicks with a proper racing setup at that same track.
So it's definitely not bad at all. The setup on my car makes it
great fun to drive. I'm not in this to set records or to win races. I'm not that good, and am under no illusion that I
can be that good. And competing would ruin the fun for me anyway. If I can't reasonably win, then it's only logical for me to shift my focus to enjoying myself when driving the car. And with the car's balance and responsiveness right now, it is great fun indeed.
Again, it's all relative. You could probably do worse than to follow the path I'm on. Try it out, see for yourself if it works for you. If you like what you get, then stick with it until it's no longer any fun. If you're in this to compete (doesn't sound like it at the moment), then it may be reasonable to go down the path I have because it's very inexpensive and gets you something that will teach you
a lot about car control, something that is an absolute must if you're to compete successfully. The difference is that if you're in this to compete, you'll be making the initial changes knowing in advance that you'll be switching over to a proper coilover setup later on. The main reason for not simply going with a proper coilover setup from the beginning is that it's only once you have a good amount of experience that you'll know what characteristics you want the coilovers to give you. Put another way, right now you don't really have a good way of knowing what coilovers, with what spring rates, you should be using. And given the mission of your car at the moment, you're probably better off keeping it more or less stock for now even if you do intend to compete with it eventually.
The main temptation is just that changing the dampers is also a natural point at which to change the springs, without having to tear everything apart twice.
That is a temptation you must avoid here. You simply cannot know what to change until you know
why it needs to change in the first place. And you can't know that until you've got enough experience with the car to identify what's wrong with it. You've already identified a couple of things of note: the suspension movement and the axle hop. The former will be taken care of by decent dampers. The latter will be taken care of by something in the rear (most likely a replacement UCA).
I'd change the dampers first, and see what effect that has on the axle hop, before changing anything in the rear end.
Koni and Bilstein seem to by far be the preferred options, with FRPPs some way behind that. I'm still debating what to do. I'd be lying to say the giant sale on Konis right now wasn't tempting me more than a bit.
You could do much worse than with the Konis. The nice thing about them is that if you feel the (rebound) damping is too little or too much, you can adjust that. It allows you to play with the car's impulse handling response if you want to.
There are people here who believe the Konis are junk. But then, most seemed to have been on springs that lowered the car a decent amount. If improvement of the ride and suspension control on stock-ish rate springs and stock-ish ride height is what you're after, the Konis
will deliver that. If you increase the spring rates substantially (by that, I mean you hit the range of 300+ lbs/in up front), then the Bilsteins might prove a better choice.
If you're new to high performance driving, then I would change the dampers and leave everything else alone for now, which means leaving the springs alone, and that implies that the Konis are what you will want. There is benefit in changing as little as possible. I learned how to respond to the rear end getting loose
before I changed my springs and rear sway bar, and it's a good thing I did it in that order, too. The car is now a lot looser in the rear than before, but it's better balanced overall and (now that I know something of what I'm doing) much easier to get the rear to do what I want -- and easier to get the car to swap ends if I mess that up. On the track, the rear does want to come out more easily, so you have to be ready for that possibility. Taking care of that is usually as simple as flicking the steering wheel in the opposite direction, but it requires training the appropriate reactions in.
Of all the mods, the driver mod is by far the most important one. As you gain experience, you'll begin to feel the limitations of the car.
That is when it's time to change things: when you discover a limitation that requires a change, or some characteristic that you don't like. And you should make sure that it really is something you're experiencing, and not just something others are saying is present in your car.
For instance, I've been told, by someone who drives a Spec Miata on the track, that my car moves around a lot. And surely, compared with a Spec Miata, it does. This is coming from someone I greatly respect, and who maintains my car, so he regularly drives my car after maintenance. His comments make it tempting for me to put coilovers on the car, to substantially increase the spring rates, etc. But here's the thing: all of that seems to disappear when I drive the car on the track. There, the car seems to be responsive and controlled. It does move some, but not in a way that seems to be detrimental to its responsiveness, and not in a way that I really
notice. That could well be the result of Ford's testing and tuning of spring rates versus sway bar rates, combined with the competence of the dampers I'm using.
On the track, the car is
great fun to drive. It's responsive and balanced. It's easy to make it do what you want. And (especially at the Evolution Driving School) it's taught me a lot. Honestly, unless competition is what you're after, what more could you possibly want? Someone at one of the Evolution Driving School events commented that if he were buying a car, he'd buy what I have, because of the sheer amount of fun I was obviously having with drifting the car around the course! That really drove home to me that it really is about the fun you have with the car, more than anything else.
How the car feels is a subjective thing. What is responsive and balanced to one person may well be an uncoordinated mess to someone else. This is why there's a lot of wisdom in the notion of changing one thing at a time, and only when you notice something that you feel needs changing. It means you're tuning your car to
your preferences, on the basis of what
you think about the car, and are doing so in such a way as to ensure that you don't change anything that, from your subjective point of view, doesn't need changing.
