DIY strut tower brace question

[lunarhighway]

I'd like to know your oppinion on a strut tower brace, especially if you've had good/bad experiences with it. does it really have to potential to improve handeling, or won't i notice it's there?

the road i take to work every day has quite a number of turns and while i generally obay the speed limit and try to keep it safe (especially since i've totalled my previous car there by missing a turn in wet wheater)the road does give you a feeling of how well a car handles.
i'm wondering if from a handling and safety prespective a strut bar is a valid upgrade,or just a gimmic or something for real racecars.
my car's about 20 years old and the ride is already quite communicative and direct, if not a bit hard. but in steep corners there's quite a bit of body rol, though the car lets you know when you're pushing it too far so you can correct. this is rather inviting for a more sporty drivestyle. but also to coast trough some curves when going downhill without loosing controle of where you're going

so right now i'm wondering if a strut bar is something for me?
just how much will it alter the cars handling qualities at "normal" speeds (70 - 120 km/h)?
are there any safety issues involved ( i've heared it causes less understeer... would this in an extreme case to cause the car to give the driver less warning before loosing grip? ), and could it's attachement cause mechanical damage (to the strut towers themselves for example)?
finally what should i keep in mind should i choose to build one myself?

anyway a lot of questions but i hope someone here might have some personal insights on the matter to share.

[brucepick]

Rear drive Volvos offer both strut tower braces and upgraded sway bars. I'm sure things are a bit different on the Opel Kadett but I can tell you my experience anyway.

The heavy duty sway bars resist any situation where the spring on one side of car compersses or expands more than the other side of the car. I installed them on my car (front and rear) and it really helps get rid of lean on curves. Also tends to stiffen up the suspension in general. I really like them on the rear drive Volvo wagons.

I've seen strut braces but don't have them on my car. One design is a straight bar (or two parallel bars) connecting the two strut towers. Another design is a diagonal brace from each tower going to the firewall (approx to center of firewall). Of course you could install both. They can be attached to the small strut screws at the top of the tower.

Strut braces can be easy to build if there are no engine components in between. If the straight line path is not possible then you need tube bending equipment or welding to make a brace that will do the job. If you brace to the firewall then the firewall needs to be very solid. I've heard of firewall bracking causing vibration, buzzing sounds due to vibration transmission.

[lunarhighway]

i'm wondering if it will be possible to add a decent strut brace to my car.
the air filter is right on top of the engine, and i'm not sure if theres enough clearance to go above it. i was considdering making two braces to the firewall but i'm not sure if it's strong enough....although the towers are close enough to it so perhaps i could use two short braces that don't go all the way to the center and than connect these with a horisontal brace, although that might make things to complicate. i'd have to avoid the water reservoir and break pump on the right....

here's a picture of the engine bay

i really like the engine, it can take a lot, and once it's warm it's really mooth, but for a strut bar that air filter is pretty much an the way unless i could go below it... there's some fuel lines there for the carb, but there might be enough room. also i'm wondering if i could use the existing screws on the towers to attach the braces to?

[bones33]

Strut tower bars are more effective on some vehicles and less on others depending on chassis rigidity and how hard you stress the chassis during driving. The on the old VW rabbit the upper bar makes a difference, however for increased road texture feel a lower bar between the suspension a-arms makes an even greater difference. On a Nissan 240SX rear wheel drive the upper bar made little real difference, even on the racetrack and in autocross conditions. I think because the stock rubber strut bushings are so soft to begin with lending an overall soft feeling to the suspension no matter how rigid the chassis.

In building your own, (I've built three so far) make them as straight as possible between the strut towers. If there is room, going under the air cleaner is not a bad idea, just try to keep as close as possible to where the stress originates at the top of the strut tower. Triangulation with the firewall will give additional rigidity, be sure to have a strong mounting surface or distribute the firewall mount over two or three fasteners to distribute the stress.

I've used electrical conduit with good success. Use 1" or 25mm or whatever, the diameter lends good rigidity, it's reasonably light and it's cheap.

Happy tinkering!

Now if someone knows how to make a pickup have good road feel and handle like the 240SX, I'll be all ears!! Hey, hypermilers are already doing the 'unthinkable'.

[bones33]

Almost forgot. Be sure to account for engine movement under accelleration and deceleration. The engine mounts will allow the engine to rock fore and aft, the amount of clearance depends on the rigidity of the rubber in your engine mounts.

[SyntheticShield]

I will personally attest to the effectiveness of strut tower braces with a caveat. Strut towers are generally meant to improve if not prevent the twisting motion longitudinally in the car. Sway bars would be more responsible for the 'rolling' motion of a car in a turn.

That is not to say that strut tower braces wont help some, but its not what they are aimed at specifically. Also, dont forget there is a rear end to the car and depending on what the wheelbase is a strut tower brace on the rear towers may be very beneficial as well.

I have front and rear strut tower braces, larger front and rear sway bars, beefed up end links, beefed up trailing arms and urethane bushings. However, I got my stuff from GMPP (GM Performance Parts) before I learned of the DIY strut tower. However, if I should ever get another car I will be utilizing that information.

[Dynamically Aero]

Do it!

You'll love it!

Free how-to e-book.

[skewbe]

Originally Posted by beatr911

...The on the old VW rabbit the upper bar makes a difference, however for increased road texture feel a lower bar between the suspension a-arms makes an even greater difference...

I was just thinking of that. I made a lower one for my rabbit and it made a HUGE difference. It was about the simplest thing to in the world to fabricate too. Just a pice of conduit with a small bend in the right place and the ends hammered flat and drilled.