help me find the right height for my car?

[chmercer]

i am screwing with my coilovers and am having a hard time deciding on what height to set my car at. reading about suspension has just made me all the more confused and maybe you guys could help me out?

all i have ever heard people say is stuff like "2 inch drop should be fine" or " yea 2.5" inch is OK". what i am trying to find is some kind of reasoning backed up with math for what the most beneficial height for a car would be, given various statistics. if anyone knows of a good book on suspension or tire tech, please tell me.

i am switching back to my stock exhaust because i am selling my exhaust to get somthing else, so this will give me much better ground clearance. so i can probably lower my car like 1.5 - 2 more inches and not scrape.

this would probably put it somwhere around 4+ inches lower than stock height, where stock size 205/55/16 tires start to tuck into the fender.

i have always heard that the lower your car is, the better center of gravity, and therefore better handling. but all the street mod autocross cars and the amateur road race cars and stuff arent ghetto dropped .5 inches off the ground, and im sure most of them have adjustable suspension so that they could do it if they wanted, and there must be a reason.

So i dont think some massive drop is the best for handling, based on these observations. all the circuit cars that look like they are lowered to where they touch the ground usually have this look because of the aero work, not because the chassis is almost touching the ground.

the only car that i have seen that dosent fit what i am saying is the corvette. every corvette i have ever seen, on the street or on the track, is ALWAYS ludicrously close to scraping the road.

before i ramble on for too long, can somone try to clear this up? or suggest any good books on suspension / tire tech that i could find at barnes and noble or amazon? i have the skip barber book 'going faster' but it dosent get super technical in any one area.

thanks guys!!!

[C-Kwik]

If you keep it within reasonable limits, it probably won't be a big deal. Everything has a trade-off. The best setting for one car or even one person, may not be for the next. You've brought up some of the things you have to think about. But you should also consider that the more you lower it, the less suspension travel you will have. If you drive on glass smooth roads, you can probably go pretty low. But in the real world, just make sure you consider that potholes do exist. Secondly, as far as going too low, you should also consider that while the ride-height adjustable coilovers themselves will give you more suspension travel before the shock bottoms out, the 240sx has a low inner fender and it would be very easy to bottom out the tire on it. Generally, the lower you go, the stiffer the spring you will want to use to avoid bottoming out. But stiffer will make the ride harsher and depending on the roads, may make the car have less traction and may even bring up safety issues.

As far as race cars, they would probably want to go lower if all they were thinking about is handling. But safety is an issue and so are the rules. Most race cars are required to some extent that the body not touch the ground if/when the tires blow. I know the NATCC series when it was around required that no part of the chassis touches the ground with any 2 tires flat.

Book Recommendation: High Performance Handling Handbook by Don Alexander. It's pretty comprehensive and easy to understand. And they use some modern cars as examples so some of the more modern technology is discussed as well. Grant might like this recommendation. Much of the information in the tire and wheel section of the book was provided by Tire Rack.

[Nismo_Freak]

Nah you're all wrong, you need to bag your car so that the frame rails drag the ground. THATS high performance.

[Snarlynx]

What I do is go to the towns biggest speed bump and set it for 3/4 an inch higher than that. That way I get a good drop but keep the car functional even with a passenger. then it's alignment and corner weighting time.

[whiterps13]

snarlynx has a good idea. i have speedbumps on my road so im screwed ;]

[EazyBreazy]

yeah if your in cali you could just drive the 405 if you dont bottom out or have hemroids from the rough ride or jump your car into another lane then youd be pretty well set up