Ok folks. I made the original, but it never became a sticky. Pure shame. So here is an updated version with more information on Strut bars. I hope to be as accurate as possible.
What is a Strut tower?
Your strut towers are, for ease of explanation, are the large metal towers on each side of your engine bay, and trunk ( behind the carpeting ), which holds the upper part of your suspension in place. Usually held in by 3 bolts, nuts or some combination of.
What is a Strut Bar?
A strut bar, Or strut brace, is a metal rod that connects the strut towers together. The purpose for this is to limit the flexing of the towers as you drive. Reducing this flex, gives you a better feel, better control of your car while turning and you will feel much less bump from expansion joints on highways. Also a stiff body would enable maximum performance and handling. A stiff chassis also makes suspension tuning much more precise, resulting in a car with razor-sharp handling.
Example of Front and rear Strut bars from Gravana tuning, made by vibrant:
What is a Tri-Strut bar?
A tri strut bar, is a a bar that connects your strut towers and Firewall together. The purpose of this is to reduce the flex much more, by using your firewall as a support point. The stock GM brace for convertibles had an extra mounting point for the firewall. HOWEVER: Most J bodies donut use or have available Tri-bars for a few reasons, Including, that on 2.2L and 2200 engines, the Intake would interfere.
Example of a tri-bar from a TOYOTA:
What is a Fender Bar?
A fender bar is just another version of a strut bar. In this case, a fender bar connects the strut tower to the firewall at the point of where your door hinges are connected. The only company that has Fender bars available for J bodies is HDE, In which they may 3 different versions of it. Mounts onto the door hinge and inner fender, creating a triangular support that greatly increases rigidity over OEM. Guide inserts are included to assist for a simple bolt on installation. It is also referred to as 'Gacchiri Support' in Japan or CAWL Support by SPT. This chassis reinforcement will greatly improves the handling dynamics of your car. Confidence in steering is guaranteed while reducing flexing of the uni-body."
**Heres another thing**
"On many vehicles, especially the older S-chassis 240SX/180SX/Silvia and AE86, the frontal frame experiences a high amount of flexing and twisting due to age and structural design. Frontal chassis flex affects the handling of a vehicle by introducing unintended changes in suspension geometry during cornering, acceleration and braking. Compounding the issue, whenever the suspension is upgraded and reinforced with parts such as higher spring rates, reinforced multi-link suspension, or even pillow-ball mounts, more of the stress that is absorbed by the factory suspension gets transferred directly to the chassis, which increases flexing and chassis wear. High power output engines are also known to cause twisting of the chassis.
Example of a fender bar from a 240sx:
Another version of a fender bar:
Shock tower plates
This is a completely brand new product by Nagisa Auto that helps reduce the load on the shock towers, especially during heavy braking.
Drastic improvements are achieved without needing to modify or weld the frame with obtrusive support bars. Bolts onto factory locations, and can complements a tower brace setup. Some kits come with guide inserts to assist in installation. Some kits may require drilling.
Fender to Radiator Support Bars
Fender to radiator Support bars are just another way to to stiffen the front of the chassis. You connect the fenders to the front radiator cross member. Simple concept.
How hard is it to install a strut bar?
Its very easy to install a front strut bar. While car is on the ground, and OFF, remove the bolts / nuts ( 3 in total per side ). Slide the brace's strut plates on, and reinstall hardware. If it does not side right, and you will know when it doesn't, remove, and flip it over and reinstall. 5 mins to install.
The rear bar however is a bit annoying and takes 20mins to install, maybe longer. The rear bar is in your trunk, and a very tight place to put your hands. And the bolts you need to remove are in the wheel well itself, all the way at the top. Remove those 3 bolts, per side, slide bar into position, and reinstall the bolts. Good job.
In some cases, preloading a strut bar is needed to get proper geometry. The manufacture of the bar will tell you specifically if preloading is needed. This usually involves in jacking up the front of the car and then installing the strut bar, as if your car was on the ground.
Also Not all strut bars are adjustable. Many strut bars are however at the very ends for ease of installation, and to add or remove, or have a neutral preload. And some strut bars have a preload adjuster in the middle. Like the one shown below made by cusco. This bar is specifically designed to adjust tension positively (pushing out) or negatively (pulling in) or neutral... no pull in either direction.
Is there anything else i might need to know?
A few things:
1) You can paint your bar with just about any paint.
2) To clean it off, use mild soap and warm water, and dry to a beautiful shine.
3) You can make your own, however DO NOT use plastic of sheet metal, they are not strong enough for the job.
4) You can use all types of strut bars above, but usually 1 is enough.
5) There really is a difference in how your car handles, But is not a replacement, Just a component to a well tuned suspension, and is one of the cheapest things to do for your suspension.
LINKS
www.granatuning.com
www.ebay.com
www.vibrantperformance.com
www.carcustoms.com
If i forgot some, sorry, those are the only links i personally use.
References
www.mmsacc-stainless.com
www2.propichosting.com
www.sfu.ca/~roland
www.topendmotorsports.com
www.technotoytuning.com
www.nissanperformancemag.com
Special thanks to
C.T.S
Funky Bottoms (Event)
James Cahill