So you've decided that going fast around corners matters? Good. Before you decide to pull out that shiny new Visa card with a chip that nobody takes, there are a few things to know.
Really good suspension is expensive
Yup, it is. As with most mechanical things, there's a definite correlation between R&D and performance. Really good suspension manufacturers will dyno test each of their shocks to ensure that there's as small a variance in dampening between them as possible. Shock and spring combinations will also be tuned to one another for the best performance possible. There are also a slew of other differences in manufacturing and design that set high-end coilovers apart from their cheaper counterparts. Expect to pay upwards of $3,000 for one of these setups.
You don't need really good suspension
From the guy who's just looking to bust oil pans to the one running an amateur race car, off-the-shelf shit works just fine. Here's why: there's a lot more overall speed to be gained from more power, better rubber, and a better driver. Taiwanese coilover suspensions have flooded the market. It's even believed that many of them are produced in the same factory.
Yet if you look hard enough, you will find these "cheap" coilovers on all sorts of competitive race cars. They generally hold up well to abuse, come somewhat properly valved for their springs, and provide plenty of nifty features, such as pillow-ball top hats and fully threaded shock bodies. Oh yea, and they're cheap. But if they're cheap, why do they work?
They work because of physics...and the free-market economy. Getting low is an essential part of improving mechanical grip. The lower your car is, the lower its center of gravity is as well. Only a tiny portion of each of a car's tire is touching the ground at any given time. During cornering the goal is to keep as much of those four tires in contact with the earth. By reducing the car's propensity to transfer weight from one side to the other, you allow its inside tires to carry more of the load.
Getting low without getting stiff is pointless. In conjunction with reducing your center of gravity, you also can reduce weight transfer by increasing spring rate. For BS (#brokeswag) purposes, this includes both springs and sway bars. By adding stiffer springs to you car, you make it more resistant to rolling during cornering. Less roll = going faster. Sway bars are also effective at reducing weight transfer, however, as with everything, more is not necessarily better.
Well this is shocking
Shocks are the core of any coilover suspension setup. Oddly enough, they are also the most sloppily produced component that you'll find in any affordable setup. It costs a lot of time and money for a company to test each of its shocks to ensure that they provide the exact same amount (less than 5% variance or something) of dampening. BUT WHO CARES? You shouldn't. Shocks get the luxury of having a very easy job. They don't hold the car up, and they don't have to fight the side-to-side BS that happens around corners. All the shock has to do is move up and down at a predictable rate.
The trick is making sure that this rate matches both the weight of the car and the rate of the springs that are holding it up. Coilover companies make up for their sloppy products by making their shock's dampening adjustable. You can use this shitty excuse of a feature to tune each shock to match its attached spring. Too soft and the car will bounce. Too stiff and the shocks will be slow to react to changes in the road's surface. Honestly, you can just set them somewhere in the middle and it will probably be fine.
The delicate balance
I know, it all sounds too easy. That's cause it is. Also, this is #brokeswag--we don't have time (or money) for complicated. But there are some things to consider before buying the stiffest, lowest suspension you can. COMPLIANCE is an important word. Compliance describes how well your tires maintain contact with the ground over rough terrain. You want as much of this as possible. Since sway bars essentially tie both sides of a given axle together, if they're too stiff, you will lose compliance. The more time a tire spends off the ground, the less time it can spend propelling, turning, or stopping the car. At some point we will talk about how to use sway bars effectively to improve your cars grip.
The same principle can be applied to springs. Springs that are too stiff will cause the car to drive like shit. You want springs that are as stiff as possible for road conditions that you'll be driving on. Go-karts can get away with having no suspensions, mostly because they are basically Power Wheels® for adults. But for real, go-karts don't drive on the street (except on YouTube) and they aren't very heavy.
Your car on the other hand has to constantly battle a variety of changing road surfaces, even on the track. Besides being extremely uncomfortable, overly-stiff springs would cause your car's tires to loose traction over bumps. Another part of improving compliance is preserving as much suspension travel as possible. Generally speaking, as you lower your car, you're also reducing suspension travel. The shorter the shock body, and the stiffer the sway bar, the less droop you'll have at each corner of the car. You want to hold on to this droop stuff as much as possible (except in some circumstances).
It's okay to max that Visa on tires
You wouldn't wear a pair of four-stripe Adidas, would you? Then why would you buy shit tires? Just don't. If you want to go fast, buy the stickiest shit that you can afford. For a street-driven car, this usually means a max-performance summer tire. There are a bunch of them out there, and the internet changes its mind every 10 minutes about which one is best. What matters is that, for the most part, they're all good. If you're really ambitious, you can even run slicks. Regardless, tires are the MOST IMPORTANT part of any suspension setup. Without good rubber, everything else you do is pointless. On top of that, people will laugh and point when you show up to the track with those used ContiProContacts you bought on Craigslist. Better rubber will provide more grip and resist high-temps better than shitty tires. Having greasy tires after a few laps at the track sucks. You're out there to drive, not ice skate.
Get a goddamn alignment
Front drive, rear drive, all-wheel drive--they all respond different to different suspension setups. The same goes for alignments. If you want to go fast, you need as much of that black rubbery shit in contact with Mother Earth as possible. A proper alignment for your vehicular platform will make a world of difference in the handling depo. To get this right on your own takes a lot of testing, testing that you can't do (else you wouldn't be on #brokeswag). But fear not, there are people with better things to do than read this blog who've done the hard work for you. That Goooogle thingy should be able to provide you with all sorts of alignment specs for your car based on your needs. There are also some general principles (which we'll cover later) that you can use to get pretty close on your own. Yes, alignments are expensive and don't make your car look any better (arguable actually) but they will make it turn better.
You're not Randy Pobst. This is a simple guide designed to get you on the right track on any track. If you're good enough a driver to need more a complex solution than the one given here, then you probably know Randy (superfan here, plz say hi 4 me!). This also shouldn't be used as a replacement for specific information pertaining to your ride. There are many people out there who've done way more with your [type of] car than you have. Find them, take note, and don't be afraid to try stuff.
Stay tuned for part two
Let's be honest, we don't really know what the fuck we're doing. We'll go talk to some scientists (or engineers...whatever) and examine some of the more complex factors that can affect your car's handling. So...stay tuned for that. In the meantime, feel free to browse #brokeswag's other array of entertaining and uplifting content.