I just wrote this for another thread but wanted to put up a new one so more would see it hopefully. This is just to set a few things straight, make them a bit more clear, etc;) It is concerning a bit about Megan coilovers but the primary info is for all tC suspension settings, etc.

1) the Megan coilovers come with pillow ball mounts front and rear but only the front has adjustable camber plates and they are more than sufficient for our needs. To much front camber can reduce grip coming out of corners and getting on the brakes and induce excessive tire wear.

2) the rear coilovers are not adjustable though there is a bit of adjustability in the stock suspension design but not really enough so the Hotchkiss rear camber links are a great solution, I have them as well.

3)though you may or may not like this info, I have proven it with testing and an exact demensional plotting of the suspension geometry in full scale. Go much lower than 1" of wheel gap and your handling performance starts decreasing at an alarming rate. Most all slammed cars handle horribly but the owners are not well enough informed on the suspension dynamics and geometry to realize this and their butt dyno/handling meters are way out of calibration.

4) setting the rear camber to nearly a verticle position will greatly assist in reducing understear as well as using a rear sway bar. BUT, if you go to far and do not have a front sway bar then you can start inducing oversteer at high speeds. That is fine to a degree but if you get to hot into a corner and hit a bump, lose grip for any reason, etc, you can have what is called snap oversteer that may not be correctable in time, crashing is the result in many cases.

5) setting a rear only sway bar to full stiff can do the same as #4 in the oversteer situation. #4 and #5 need to be addressed together.
_______________________________


What should you do? There are so many variables, your actual driving skill(versus your percieved skill level), how agressive you drive, perfer cornering or drag racing, tire and wheel package, general road conditions where you live,
your preference of looking fast or being fast which are not often mutually compatible when it comes to suspension settings, carry passengers or luggage often or not, willing to make major adjustments for certain events(drags, autocross, track days, shows), etc....

_________________________

For the person that wants a great all around handling, riding, predictable, fairly neutral with just a bit of push (underteer) at higher speeds(what all race cars go for), quicker turn in at lower speeds, a car that is not scraping the ground, not tearing up the tires, etc.:

With rear sway bar only, approx -1/2 degree rear camber, if shocks are adjustable then on medium for the street, full stiff for autocross, sway bar set to medium postion, to stiff can be dangerours at high speeds.

If you have both bars then medium on the rear, soft up front, test it in a safe place, then try the siffer settings and see how it works out. But, you can lose traction up front with to stiff a setting but do not go full stiff in back and soft up front, at least without testing, again in a safe place.

Front camber, a good all around setting for most would be -1.5 degrees for decent tire wear and not losing grip in the rain, out of tight turns in autocrosses on the dry, etc. If you are a very agressive corner carver then -2 and possible -2.5 will be ok as long as you remember the loss of wet weather cornering grip and tight corner dry weather forward grip that can occur.

Ride height, I know many do not like this but I have tested it extensively and have gone to the level of having an estimate done on building me some custom CNC steering knuckles to correct the geometry if I lower the car more that it is now. At 1" wheel gap above the tires the car handles a magnitude better than just lowering it another 1/2" and if I slam it, the handling goes completely out the window, from a very well sorted out and easy to drive car to one that is just plain slippery and unpredicatble.

Terms like roll center, roll couple, center of gravity, bump steer, and about ten others all come into play and they all interact with each other a great deal. Susupension is far more critical to all forms of motor sports than most imagine, sure HP is nice and fun to talk about but if you cannot use it effectively, then it is not going to win races or keep you on the track or street for long.

For those just into drag racing, you are not being left out, you do intend to drive your cars daily, to and from events, etc, at least in most cases, there are many issues with hooking up a drag car and they all a centered around the suspension and tires, which are a part of the suspension package in all cases.

Those that just do not care and want the slammed look, go for it, just know you will easily be handed a loss in handling over another car setup properly and your tires and the entire chasses will wear out alot faster, another area I could go deeper into
but this is enough for now.



Rick

 

I'm just guessing if people really want to slam their cars, they don't care TOO much about handling and likely just deal with it for the look.

 

I agree in many cases that is the story but I have seen it far to prevelent that many just do not understand and they go racing around and crashing or just plain wearing their cars down. Just like thinking you know all about modding and driving from playing video games, they can help a bit but can lead to a false feeling of confidence in abilities and knowledge that is very limited and can be dangerous to them selves and others.

Cheap power and poorly setup cars with inexperienced drivers has lead to the media hyper ventilation which leads to a tough crack down on all things import and fun, something I have enjoyed for nearly 40 years is now getting much harder to get away with.

Rick

 

bump for an amazing thread and a wealth of knowledge everyone should know about.

Here's from another auto-X junky doing everything to properly setup the car

 

I can also agree with raamaudio about the ride height. We had the car slammed to the ground for HIN and during that timeframe of driving I had the tires squealing quite often around corners, and any road imperection made for some unpredictable driving. When I raised the car up to a more suiteable height, handling was greatly improved, and the car is dead on predictable through all the turns.

I run H&R coilovers, Progress rear sway, Hotchkis front upper strut bar, Ingalls rear shock tower brace. The combo seems to work really well and the ride quality wasn't totally thrown out the window.

 

There is some great knowledge in this thread.

Even if I fall in the slammed look. LOL

 

Sounds like sticky material.

 

^^^ +1

Thanks for posting your findings Rick.

 

as my father always said - never f**k around with a car's suspension
he might be a square headed mechanical engineer but i trust that he'd never put me in peril

 

Engineers are sometimes the worst to deal with for us that want to mod our cars;)

Now, if his advice is directed to the majority of knuckheads that ***** nilly slap crap on their cars and make them handling and riding nightmares, it is some darn good advice!

If some research is done, specific goals are set, compromises are understood and acceptable then the advice is unfounded.

For the average import owner, the advice is right on the money!!!

Probably 99% of the severly loaded cars on the road have very serious suspension issues and it is those cars that are out giving the rest of us a bad name.

Rick

 

yeah he's extremely stubborn he told me i can do almost anything else on my car except touch the suspension..he doesn't live here and that's also why he told me to not touch things i don't understand

and i've personally had a scare with them and now i just try to take my turns slower :D cheap solution no?

so im going with new rims/tires/tinting