I can see it would stiffen the frame up but what els does it do? Thanks

 

From what I've heard and read, not much. The X brace makes a more noticeable difference for some. I'll probably get one anyways so I have something to rest on when working on the car.

Others have noticed a slight increase in steering precision from the addition of a STB.

 

Convince yourself!

Tie a breakable(non-stretching) string like twine across the engine to each shock tower and go for a few spirited drives. Let us know your results.

 

imo it does pretty much nothing on the s2000 except for looks

 

I'm sure that if the S2k needed it, Honda would have put one on in the factory... I mean if the Integra GSR's have one, the S2K would definately have one.

 

x-brace and strut tower brace is the best combo as far as tire bars go...
more so with x-brace because "twisting" of the car in the front end is being supported by brace, making the car stiffer, making it handle better

 

No, it's not that simple. You need to understand what every change to the suspension does to affect the car's handling. Don't just go around stiffening up everything you can.

That being said, I have both a STB and x-brace and I've concluded that they don't do much but look pretty and add weight. You can improve the handling of a stock S2000 with just an alignment.

 

a really good test is to tightly tie fishing line between two of the shock bolts. See if there is any deflection. It doesn't take a whole lot of deflection to break thin test fishing line. if it breaks you need one, if it doesn't, an STB ain't gonna help.

A MacPherson strut, due to it's design carries side loads on it, which can cause deformation of the shock towers. My old e36 M3 failed the fishing line test and a good solid stb made a difference. The s2000 passes that test no problem

 

Call King Motorsports and ask them why Mugen doesn't make a front strut(shock) tower bar for an S 2000. With all the money spent on reasearch and development by Mugen, if the S 2000 needed a bar there, they would make one.

 

Bling-bling only on the S2000.

My 2004 TL has a huge honkin one, and the rear bulkhead has huge stiffeners as well (that is why the rear seat does not fold down as in the Accords). This results int he 2004 TL being much more rigid than, say, an E46 3-series.