Strutbraces
I think nearly everyone who's ever peered into an engine bay at shows will have seen strutbraces in there somewhere. I often get asked if they make a difference or if they are really a cosmetic mod for shows. Having tried them for myself here's my thoughts ...
How it works
The strut brace I used cost about £50 and was nothing more than a powder coated mild steel tube, adjustable in length by a treaded section in the middle. It had a ring welded onto each end that bolted onto the 3 nuts that held the strut top in place. I'll admit that I primarily bought it for looks as i'm sure many people do but there is a serious side to it. The idea as you can probably guess is that it stiffens up the front of the car allowing the car to be pushed harder through bends with more grip and more confidence. Most touring cars or rally cars have all manner of braces fitted. As the car is pushed hard into a corner there is immense pressure on the outside front wheel as the weight of the car transfers. This can cause the top mounts on the shock absorber to move inwards as they flex. By putting a brace between the two shock absorber top mounts the amount of movement is reduced causing extra stiffness in the chassis and consequently more grip. Strut braces can also be bought for the rear shock mounts on some cars and the lower suspension anchorage points on the front. Welded in braces are far more effective but on a road car this just isn't really a viable option.
The handling
It follows from the above explanation that the stiffer the suspension setup is on the car the more flex would be experienced in the chassis due to the fact that the weight transfer is not absorbed by the shock absorber. Also if more grip is provided by way of wheel/tyre combination the same effect can be experienced. This means in real terms that the stiffer your suspension setup is or the more grip you have the more benefit you would get from a strut brace. I have tried numerous suspension and wheel/tyre configurations and found this theory to be true. I have also fitted a strut brace onto the car with standard shock absorbers and springs and noticed a small difference. To be perfectly honest there are lots of ways of far more drastically altering the handling of your car like springs/shockers and lower profile or wider tyres, if you've done all of this though a strut brace certainly wouldn't do anything other than improve the handling of the car all be it in a subtle way. They also look the business under the bonnet, the alloy or chromed ones look really special but be prepared to pay more for this finish.
Pictures