[Thepeug]

I'm trying to piece together a decent suspension setup for Christmas, yet I'm confronted by the fact that I don't know the difference between a shock, a strut, a sway bar and a strut bar, not to mention camber, caster, toe, etc. I'm simply reading reviews and going off of other people's advice. While this works to an extent, I'd feel better if I knew what in the heck I was doing. While hands-on experience is usually the best way to learn, can anyone direct me to some websites that explain some of these terms and the concept of suspension tuning? Thanks!

-Chris

 

[stick]

I'm sure our collective knowledge can help you out a bit. I've done a ton of suspension work on one of my CRX's. Here's a few terms to get you started:

Camber: The measure of how far a wheel is tilted in or out. If the top of the wheel is further out than the bottom of the wheel, this is called positive camber. If the top of the wheel is closer in than the bottom of the wheel, this is called negative camber. For basic applications, you want zero camber. A little bit of negative camber can help with cornering, but you will experience faster tire wear as a result.

Caster: The measure of how far the axis of the suspension is tilted forward or backwards. This is generally visible as the wheel being further forward in the wheel well (towards the front of the car) or further backwards in the wheel well (towards the back of the car). You generally do not want to change this setting. With the CRX, if your caster is off, it *always* means that something is bent. (be it frame, front cross member, knuckle, or lower control arm)

Toe: The measure of how far the wheel is turned in or out. You want both sides to be at zero degrees of toe, otherwise you will get weird steering characteristics. If your car is pulling to one side or the other, this is generally the setting that is off. The tie rod ends on the front of a CRX are adjustable for this purpose. Rear toe is adjusted by the compensator arm-to-chassis slider bolt.

 

[Thepeug]

That's certainly a start. I appreciate the concise definitions. I'll make a folder in which I can store these definitions for future reference.

 

[stick]

Here's a good link about alignment terms. It's a little more indepth.

http://www.ozebiz.com.au/racetech/theory/align.html

One thing to remember about the suspension geometry is that it is designed to keep the optimum wheel position through out the suspension travel (up and down movement of the wheels). Honda designed the suspension components on the CRX for the optimum positioning throughout the suspension travel. For this reason, it is strongly recommended that you do not replace the vital suspension components with ones of a different dimension. (ie: Using DA integra knuckles on a CRX is a no no. Although you can adjust the camber to be correct at the stationary position, the camber curve will be much more aggressive than optimum when the wheels are travelling up and down...resulting in loss of traction in hard cornering).

 

[Thepeug]

Great article, thanks. Can you define, or do you have any links to sites taht define different suspension components? What's the difference between a tie rod and a sway bar, for example? Or a strut and a shock?

 

[stick]

Tie rods are part of the steering rack. They basically attach the steering rack to the tie-rod end (which attaches to the knuckle bone...which attaches to the wheel bone...you get the idea).

Sway bars are a long curvy bar that attaches to the lower control arm on both sides of the car, and it has two mount points that secure it to the chassic of the vehicle as well. The sway bar helps to minimize chassis sway by transfering some of the stress to the other side of the vehicle.

Radius rods are a straight bar that attaches the front lower control arm to the front crossmember.

The shocks and struts issue is a bit convuluted. Most people think we have struts because they have a mounting perch on them for the springs. This is not the case. We have shocks and springs. Struts are defined as a damper that is a locating member of the suspension. ie: if the strut is removed, the knuckle or axle will be able to move outside it's normal motion. Shocks are just a damper that controls motion. If removed, the axle or knuckle is still completely attached to the vehicle and can't move outside of it's normal motion.

 

[Thepeug]

How would you define a coilover? Is it just a combination of of shocks and springs?

 

[stick]

How would you define a coilover? Is it just a combination of of shocks and springs?

Yup...that's basically it. Coilovers also have adjustable spring perches so you can have control over the ride height.

 

[Thepeug]

So here's where I'm confused: looking at some Ground Control coilovers, for example, the description says, "For Koni, Tokico, Bilstein, KYB, or stock shocks". If a coilover is a shock/spring combination, why do you need to buy more shocks when you purchase a coilover kit? Are they not included in the coilovers? (Sorry, this is probably a really stupid question, but I have to toss it out there.)

 

[bobski]

I think coilover is more a description of the design. I've seen a few cars that have the spring mounted next to the shock absorber as opposed to around it. If you think of it in that respect, the CRX spring/shock combo has the spring coils over (or around) the shock.
When installed as they're designed to be, Ground Control's lowering spring-threaded collar/perch setup will still be a coilover design, but so would a regular fixed height lowering spring.
I think the terms you're looking for would be coilover spring kit verus coilover suspension kit.

 

[Thepeug]

So Tein Basics, for example, would be a coilover suspension kit, while GC's would be a coilover spring kit?

 

[bobski]

That's what I'm saying. I'm not sure those are official terms - they're more of a conclusion I've come to after reading the advertising jargon.
If you want some more in-depth reading material, it's worth looking at the "High Performance Honda Builder's Handbook" by Joe Pettitt. The first volume has alot of info on boosting power output while the second covers suspension, brakes, and aerodynamics among other things.

 

[Thepeug]

Thanks for the suggestion; I'll definitely have to check it out.