J-McDonald

I've been thinking about adding a strut tower brace to stiffen my '91 C2 cab. In particular, I've been looking at the Brey-Krause line (check out http://www.9xauto.com/brace.html ). I've also heard good things about Weltmeister strut braces. I'm concerned, however, that stiffening the front box area could lead to more twisting in the passenger compartment area. Anyone have any experience they would like to share? Thanks very much for all replies.

GeoC2cab

High,
I have the andial one(identical to factory one) on my cab and its been there for nine yrs now, as a matter of fact It was my first performance upgrade and it does wonders for adding stiffness to the cab,one of the main reasons it went there to begin with, I highly recommend using one, I'd use one simiilar to the factory one;it fits under the carpet! (my car is a '91 also)the ones ur looking at mine is closest to R1535 in design, but it cost twice as much as i paid,
I went w/ aluminum that one is carbon fibre,
I didnt have the choises in materials 10 yrs ago that we have today, the aluminum works fine for what i use it for.

Jim Michaels

I could be wrong, but I don't think a strut tower brace will do much to actually stiffen the chassis. My understanding is that it just holds the tops of the strut towers at their set static distance apart under hard cornering, thus helping to maintain camber setting. Thus, I don't think you need to worry about the passenger compartment flexing more with a strut brace. A full roll cage would stiffen the chassis, especially the passenger area. //Edited part: See, I could be wrong. Geo related his experience that just the strut brace did wonders to stiffen his chassis. I'm surprized, but won't argue//

Strut brace wars have gone on for years, with the promoters of each design (some of which have diagonal cross bars as well as the horizontal one) claiming their's is best. My '88 had the Weltmeister bar (easily removable so I could run stock in SCCA autox), whereas my 964 has the Brey-Krause, which I never remove. I think they do about the same thing (i.e., not a lot), but the Brey-Krause looks nicer. Too bad it's hidden under the trunk carpet.

GeoC2cab

High,
Maybe "wonders" is a little overstated, but it definatly does something for ridgitity. My freind just put one on his '85 targa and noticed it immediatly, for wonders do what Jim mentioned, the roll bar/cage.

MikeF

Just installed the AJ-USA strut brace in my 94 cab. It seems to have given the car a firmer feel over-all and a sportier feel in hard cornering. It is well made, looks great and is easy to install. Best of all, it was only $179. Check out www.ajusa.com for info. I've seen the Weltmeister bar and this one is far nicer for the money. Doesn't look like an aftermarket mod. Looks like it belongs there.

Enjoy.

Adrian

Guys,
If you stiffen the front it is also a good idea to stiffen the rear as well.
Strut braces do stiffen the front and I use a FVD Strut Brace (964 Porsche design).
I am not familiar how you could stiffen the rear of a cab suitably. I am a Coupe person,
Ciao,
Adrian
911C4

GeoC2cab

High,
besides a roll bar, is the sway/ stabilizer bar what usually stiffens up a rear?

Cupcar

I think it was Automotion who some years ago instrumented a 911 and measured the motion of the front strut tower sheetmetal and the tops of the spring/strut units during cornering. They found cornering force moved the struts laterally away from the midline of the car (more positive camber). They also found that most of this motion was in the rubber upper suspension mounts rather than the chassis sheetmetal supporting the mounts. This leads me to believe that if you want maximum effect from a strut brace, it would be best to use monobal upper shock mounts as well, at least on a track car. Anybody have other thoughts?