Originally Posted by Mike Buck

if this would be a legal mod for SP3 I might be in depending on where the price ends up. I need to check with DD and my buddy who welds. Don't want the install cost > bar cost

Originally Posted by Chads996

$250-275 seems a bit much to me for this simple solution, IMO. The materials are rather cheap. Not much fab involved either.

A bud of mine has the real deal on his 944S2 Firehawk. Very simple but VERY effective. Good solid piece.

C.

Originally Posted by ritzblitz

So how much of a difference does this actually make?

Originally Posted by Potomac-Greg

My gut tells me, though, that if they are going to do anything, the attachment point at the strut towers cannot be a hinge; otherwise you just create a parallelogram. The ones being sold here are actually rigidly mounted at the strut towers. To me, the best possible bracing would be from strut tower to fire wall.

Originally Posted by Mike Buck

if this would be a legal mod for SP3 I might be in depending on where the price ends up. I need to check with DD and my buddy who welds. Don't want the install cost > bar cost

Originally Posted by smlporsche

The problem I have with this one (besides the $, ) is that once installed there is no adjustment possible. You better have the car perfectly corner balanced and not make any changes otherwise your $crewed.

Originally Posted by Oddjob

Ive been equally skeptical of any single modification that is marketed as a “big” improvement. But here is my current thinking on Strut Tower Bars.

Stiffening up the chassis, to reduce chassis flex probably has different effects on handling characteristics than does changing spring rates and sway bar settings.

Chassis stiffening can be accomplished by several means and to several levels of severity. Installing a roll cage (various types from bolt-in to custom welded in) all the way up to seam welding the body panels will stiffen a car up. Although it can alter the handling characteristics of the car because there is less body flex to account/compensate for with other suspension settings and setups, I would not necessarily consider this tuning the suspension.

With the front shock towers, the concern is that the outside shock tower deflects outward under corner loading. So if that is the case, it will change the camber on the outside wheel to a more positive wheel angle. Depending on the initial camber setting, this could reduce grip. So in theory, if the strut tower movement is reduced/limited by adding a STB, it could keep the alignment settings from deflecting (outside of the change inherent to a McPherson strut), which could actually make the car turn-in better (…?).

Now how much does a non-supported shock tower deflect? Who knows? How much does that deflection adversely affect handling? Does a STB offer that much chassis stiffening to actually improve handling?

I don’t know. Just like I don’t know how much (quantitatively) a full cage stiffens a chassis or how much seam welding does. Some people say you can really feel the difference, others say you cannot.

Keep in mind that the frame design of these cars goes back to the 924 in the early-mid 70’s. I don’t think the tub of the car was ever really altered/reinforced since that initial design. Porsche never intended the street cars to be run with solid bushings, 500 lb/in springs, 18” 245/285 Hoosiers. In a DE/Race application, my guess is that there probably is quite of bit of body flex - e.g. Ive seen a rear quarter window shatter on a 944S2 during a race practice.

When the factory did race the cars, they installed a strut brace (in the Turbo Cups and S2 Club Sports). And take a look at Jason B’s 968TRS and see the weld-in cage that the factory installed. See the pick-up points that the factory reinforced. They ran roll bar tubing out through the firewall to the shock towers and also used a STB to reinforce them. My guess is that the factory felt there must be some movement there in racing applications.

I was forced off track at my last club race and my car hit a berm. The right front shock tower was pushed up and inward. I pulled the motor and front suspension out to have the frame straightened. Also, the heat shielding was removed from the engine bay, and the fender came off. If you take a good look at the way the front frame members and shock towers are made, how thin the sheet metal is (and where it flexed and bent on my car), that its all just spot welded together - its amazing these cars hold together as well as they do (it looks weak). So, I will be adding a STB when rebuilding the car.

Depending on your type/level of driving you may or may not notice anything with adding a STB. I would think that for street use on street tires, you will never corner hard enough to deflect the shock towers enough to feel a difference in handling. In auto-x, DE, and racing, its quite possible that a car with big, fat R-compound tires, upgraded suspension, etc may be able to corner hard enough to noticeably deflect the shock towers. If that’s the case, then the car/driver could potentially benefit from a STB.