Originally Posted by 91camaro372

I am going to be replacing different things in my suspension over the next couple months. I have a 91 camaro RS with a 3.1l v6. Heres what i'm planning on doing first.

Springs- Summit lowering springs

front shocks- KYB GR2

Rear shocks- KYB Gas-a-Just

Bushings- Energy suspension hyperflex kit

Panhard bar- Spohn Adjustable w/poly bushings

The shocks were the only thing I wasnt sure about but they seem to be the nicest ones I could get for around that price. I'm only 14 so I dont have a lot of cash so pretty much all my money is going into this car. Also will I need to get Rear LCA relocation brackets? If you have any suggestions can you let me know.

Thanks

Originally Posted by Me

Section 1: Lowering a F-Body The Right Way


If you are wanting to lower you car, there are several things you have to take into consideration.





The first thing that needs to be done (especially on the older cars) is to check the bushings for wear and tear and replace as needed. This includes inner and outer tie rod ends, ball joints, sway bar bushings, control arm bushings, etc. This isn't an absolute necessity, but starting to modify a car with worn components.... This is especially true if you are going to build the car to turn (as in Section 2).



When selecting bushings, sticking polyurathane everywhere isn't really the best choice. While polyurathane is great in sway bars, it looses it's shine in places like the LCAs. (See FootNote 1) Rod ends work well in the LCAs, but to some they are too harsh. I have a set of LCAs built from parts ordered from the circle track suppliers. Heavy duty rubber bushing on the body and a rod end on the axle. A-arms don't see the same twisting forces that the LCAs undergo, so polyurathane is pretty good here. but the best option (or so I've been told) are the Del-A-Lums offered by Global West. Polyurathane also works in the pan hard bar. I prefer a combo ended set up for the PHB, as well. I use NAPA parts for the steering linkage bushings (tie rods, ball joints, etc). Moog also makes quality replacement parts. A word of caution, polyurathane anywhere will squeak more than rubber, but it's not really enough to be a bother as long as your in the car.



When replacing springs, GET SHOCKS WITH YOUR SPRINGS. If you lower a car, it does more than just make it look cool. Lowering springs normally not only lower the car (causing the shocks to set at a place they are not designed to do) but are have a higher spring rate (stiffer). Both of these related occurances cause stock or replacment shocks (Auto Zone, Advance, NAPA, etc) to wear out much faster. This isn't only bad for handling, it's literally dangerous after prolonged periods; it causes the vehicle to be harder to control at speed and can increase braking distance. Shocks to consider are KONIs, Re-valved Bilsteins; these are somewhat common and more expensive names. But, if you don't want to spend that kinda money (keep the stock springs), there are other brands that will work.



In addition, when you lower a car, it affects your suspension geometry. The basic fix is LCA (lower control arm) relocation brackets. They will allow you set the angle of the LCAs back to stock after lowering. An adjustable PHB (panhard bar) is a good idea, because lowering a car without one will cause the rear alxe to set off center. It's not very noticable nor neccesary, but it is a good idea.





Section 2: Making an F-Body Handle....Better

For those of you looking to do more than just get rid of wheel gap (though, nothing wrong with that)

Best first mods (after replacing worn out bushings, etc):



1. Tires: Good ones = MONEY I've heard good things about GoodYear Eagle F1 GS-D3s, Falken RT-615 and Kumho MXs (although, MXs aren't a very good wet traction option). My advice is to get onto frrax.com or other auto-x/road race enthusiast site and do some reading. Purchase the best tire you can afford with the characteristics you want. Listen to people with experience, not what your friend (unless they really do know their stuff) tells you or what the tires salesman says.



2. Shocks: (again, money) KONIs or if you don't have the money (or want to spend it) revalved Bilsteins (to match your spring of choice). I've heard that the high end Tokicos are a decent as are the high end KYBs. But, in my opinion are budget shocks. I've read that neither has dampening qualities to handle more than spirited back roading. Also, they won't live as long as the Revavles or the KONIs unless you are using factory or factory replacement springs.



3. Springs: Lower isn't better unless you have the spring rates to back it up (why 3rdGen SportLines aren't that good). While it's true that a lower center of gravity helps your car's handling, setting low to the ground on soft springs is a bad thing. It can let you hit the bump stops (which have a much higher 'spring rate' than the springs) and this can cause snap over/under steer. The combination of the right spring rate and ride height coupled with the correct shocks makes the biggest difference in a car (other than tires).



4. Sway Bars: With sway bars, the biggest you can get isn't necessarily the best; finding a balanced set of bars is very important (for example, my rear bar is too big and causes the car to over-steer instead of under-steer, especially under throttle). But, you'll also need to take into consideration how the spring rates as well as the valving of your shocks interact with your sway bars. For example - a large rear bar may work well with the factory springs, but when you install stiffer springs you notice the car behaving differently and wanting to oversteer. This can be fixed either by softening the settings on your shocks (if adjustable) or moving to a smaller rear bar. Similar rules apply to the front.



An agressive street allignment (usually overlooked) is in there somewhere...not sure where to list it, but it is VERY important. I had my car alligned more aggressively than stock and imediatly noticed a difference in the feeling/stability of the corning of the car. I can link a listing of what is reccomended if you are interested.



Some people won't agree with that listing/order, but it's what the auto crossers and road course racers recommend when your first getting into it. All the other stuff (LCAs, PHB, relocation brackets, SFCs, etc) helps of course, but you will see the most bang for the buck with that list... just expect to lot of bucks haha. You will also need to consider stiffening the frame, especially if the car is a 3rd gen. SFCs are a good option, but don't offer the complete rigidity of a 6 or 8 point cage. However, the drawbacks to a cage are obvious.



Section 3:$$What You Can Expect to Spend$$

To give you an estimate, I have the following in my suspension:

KONIs around............................................ ... $750

Pro-Kit: .................................................. .....$245

Camber/caster plates .....................................$149

Wonder bar .................................................. $70

LCAs around .................................................$200

PHB.............................................................$160

rear sway bar ...............................................$160

front sway bar I used

from my parts car...........................................$150

brake pads were about ...................................$110-120

(Not really a part of the suspension, but if you are going to be going faster, you need to be able to stop faster and the Zone won't cut it)

SFCs + installation .........................................$340

Total ~ $2200









FootNotes

1. In the LCAs, the polyurathane can create bind in hard cornering. This bind is caused by the LCAs not being able to work as they are designed to. As the rear suspension is designed, the rear of the car moves over the rear axle (imagine the axle as fixed and the body as mobile). When the car enters the turn, the body tries to move to the outside of the turn due to momentum, while the axle tries to remain in place (you hope). Now, if taken from a helicopter view, this motion must have some affects on the suspension linkages. The most appearent is in the LCAs. As the body moves over the axle, the LCAs are put into stress. The factory bushings allowed for this by flexxing and allowing the energy of the movement to absorbed and dissapated easily. Polyurathane is stiffer than the rubber, and doesn't allow this disapation so nicely. They can cause the bind I mentioned and snap back into their original postion. I've had this happen to me on several occasions, and it's interesting to say the least