Hmmm, not meaning to dog anyone but that's not the advice I would've expected. Throwing the drop spindles back on isn't the answer, it's a band aid and a great way to tell you to keep what you bought and deal with it, or maybe a way to say we don't know our product line very well or we don't have the personal experience to know how to really make a car handle well, we just sell what seems to be popular. :-s Drop spindles specifically on a g body have issues on their own, they put the steering arm in an awkward position in relation to the wheel and they don't help improve the inherent G body akerman/ bumpsteer issues, sometimes making it worse. They're kind of a waste of money unless all you want is a slammed stance at the car show. If you want your car to handle better, put 'em on ebay and sell 'em to an S10 owner, then take your wife on a nice date so she won't give you a bad time for spending more money on your car to go around corners fast. :lol:
UMI probably originally sold you the coilover 10dp550 spring, i.e. 10" free height and 550 lb rate. That's pretty typical and a very common point to start with, working fine for most vehicles. Springs aren't very expensive though, even if UMI said you're SOL because that's what comes in the kit, they could have at least offered to sell you a different set of new springs. For example, straight from the Viking catalog, there's a 9dp550, or even an 8dp550. In fact springs range from 4" to 14" free height and from 175 to 700 lb spring rate. Potentially your problem could be easily solved with different springs. Shock bodies have to be matched to springs too so they maintain the proper motion range without bottoming out. I'm not in sales at work, but if you called us they could look up what part # shock body you have and let you know what height springs work with it.
A 450 lb spring may drop a teeny bit more, but only because it's a weaker spring. It's also going to give you a softer ride and not add as much to your handling. Some may argue this, in more recent years, if I have my facts right, Nascar has leaned towards a softer spring rate so that the car sucks to the ground as brakes are applied and they head into a corner. This allows a great deal of camber change but there's a lot more engineering to it than just that. All other parts have to be set up to fit within this theory. If anybody's curious about the old vs new method of spring rate, Ron Sutton did a great write up on Lateral-g.net. I'll dig up a link if you want to learn more about that.
But, for the most part, an average street car that will see an autocross now and again usually runs 550-650 lb spring weight. 550 is the common Viking spring for an LSx or small block because it's s decent rate to notice a good increase in handling and you can use the shock valving to adjust for a softer or firmer ride from that base point. We rarely sell 450 lb springs unless it's mainly a comfy cruizer. Keep in mind besides heavier rate springs, your alignment, sway bars and getting that shock setting and tire pressure dialed in at the track also play a role in how the car handles. Spring rate is only part of the equation.
From what I've seen and in my own experience, G bodies seem to like to oversteer and kick the rear end out. Some people think it's cool that their car has "enough power" to slide the rear out and they can drift it a bit at the autocross, but realistically their suspension isn't set up right and/or they don't know how to drive. Sliding in any form means you're losing seconds on the clock and a shot at the winner's circle. It's cool in a drift competition but really nowhere else. When I first set up my car I got a a lot of oversteer accelerating out of corners. I played with shock settings but it wasn't enough. I ended up unhooking my rear sway bar and can now fine tune it a bit with shock settings and tire pressure to better manage it. This isn't the answer for every car, just seems to be what my car with it's current set up likes. To start out, you really need a decent base point, for example where you are right now, and go racing... a lot. Becoming a better driver could potentially knock 5 seconds off your time in one day. Farting around with shock settings and spring rates may only yield .5 secs over the course of a day. See what I'm getting at?
Now back to your car. If you want to really get a decent spindle on there, go for the ATS AFX spindle. It's one of the greatest things to happen to a G body because it starts at the core of the car's turning geometry. They drop the car about 1", but keep the tall height and relocate the steering arm for much better all around geometry. They also use the super duty ZR1 hub and are set up to accept C5 and C6 Corvette stock or aftermarket brake options. They aren't cheap, but anybody who really knows anything about making a G body (or F body, or X body, or A body...) handle, swears by them.
http://www.speedtechperformance.com...ct_id=221/category_id=96/mode=prod/prd221.htm
The main advantage of going with the later S10 Blazer spindle is the fact that it has a tougher sealed hub and drop off rotors. This makes it easier to adapt bigger brakes from Wilwood, Baer, etc. and Kore 3 makes brackets for stuff like that. Outside of that they don't do much for you. To keep it on the cheap side, I run my original stock spindles that have been modified to use "LS" 98-02 Camaro 12" brakes with dual piston calipers. The braking ability of the car is night and day over the stock G body junk. I can only imagine what a set of 14" 6 piston Baers would be like. I believe there are also brackets available to run the stock 13" C5 brakes on a G body spindle too.
If you want, feel free to call our Speedtech tech dept., 435-628-4300. We have a long background of pro-touring type racing and the engineering know how to intelligently answer your questions. I'm sure we can shed a little light on getting you where you want to be.
www.speedtechperformance.com
