Strut Brace which one?

[James Chimney]

I have looked and found 2 different styles/models of strut brace's, one is an adjustable round bar the other is the Race Dynamics, there is about a $100 difference in price, what are, if any benefits of one over the other?

[P944GUY]

another cost your going to have to consider is that, you must put in an early brake/clutch fluid reservoir for the clearance, is yours and 85 or an 85 1/2 , for the strut bar to fit..and I think that is mainly for the strut bar that is the flat looking one.. the early reservoir is shorter in length

[jcommin]

I have a Racing Dynamics bar. You need to get the right one for your car. I shopped around - looking for discounts and free shipping. Mine does not obstruct the reservoir.

[James Chimney]

I have an 85.5 na

[p-talk]

No differences that I'm aware of besides bling. I just bought a KLA strut brace, haven't put it on yet. It's very light, very simple and always gets good reviews. Oh, and it's only $135-ish plus shipping new.

Originally Posted by James Chimney

I have looked and found 2 different styles/models of strut brace's, one is an adjustable round bar the other is the Race Dynamics, there is about a $100 difference in price, what are, if any benefits of one over the other?

[flash968]

the KLA functions as well as the sheet metal towers will allow, and in fact exceeds the sheer limits of the sheet metal and pressed in studs, so there is no point in going any farther unless it is for aesthetics or choosing something less stiff, which could save damage to your towers, but there is not much data on that

for all intents and purposes, it's really personal preference

[Rasta Monsta]

. . .and if you are still running factory upper strut mounts, you might as well light that money on fire, because the unibody isn't flexing there. Unless it's just for show.

[v2rocket_aka944]

rasta, more info on that?

[KEV951]

if you can push down on the center of your strut bar down while it is installed and it flexes, throw it away .

The only one that I have seen on the market that is not a custom one off and is good is the racing dynamics one, no flex. kla and cambermeister flex,

[Ritzblitz]

Originally Posted by v2rocket_aka944

rasta, more info on that?

He is saying that you might as well not have a strut bar if you have the factory strut mounts. The factory mounts allow deformation and geometry changes, adding a strut bar won't have much of an effect unless the strut mounts are solid.

[chrenan]

I tend to agree with Rasta. I added solid upper mounts, tubular control arms with spherical bearings, THEN a strut brace, in that order. Get rid of any rubber in the front end before you try to do any bracing.

[pjs77]

I heard the lower control braces do way more than the strut tower braces. I think flash968 might be able to back me up on that?

[flash968]

the tops of the towers do indeed flex, in the neighborhood of .10" each in lateral movement - the upper mounts move as well, and about have as much in lateral movement, but a lot more in vertical movement

eliminating the tower flex by means of a strut tower brace is quite noticeable in the ride, even with the OEM upper mounts

solid upper mounts also reduce upper end movement, but add ride harshness at the same time

flex in the strut bar is not a bad thing - you have to do the math on how much it flexes and what that correlates to in lateral movement - for example, over that span 1/4" in vertical deflection is only .005" in lateral movement - so, you can actually have quite a bit of vertical flex in the bar and still maintain the rigidity

the lower points flex even more than the uppers - a lower brace will make a significant difference, but it isn't a sexy blingy thing under the hood, so most 944 guys don't do it

[chrenan]

Originally Posted by flash968

the lower points flex even more than the uppers - a lower brace will make a significant difference, but it isn't a sexy blingy thing under the hood, so most 944 guys don't do it

I've looked at the BK lower brace a few times, I always come away concerned about fitment on a 951.

[flash968]

that is a problem - i don't know for sure if the one i make fits a 951 or not - never tried it - i said it didn't based on somebody else saying the crossover pipe was in the way, but if it was mounted on the reverse side of the brackets, it might

one of these days i'll try it and see

[chrenan]

Let me know if you ever have a chance to test fit one. Its just so tight pretty much everywhere on a 951, not much room to breathe.

[dangerous]

Got a sparco brace on my spec car. The brace is fine but I don't care for the cast alum mount and have seen 'em break. Did use early brake reservoir but remote reservoir is also an option.

Custom brace sounds interesting. May take a crack at designing one.

[IB RearWheelin]

RACING DYNAMICS STRUT BRACE at LINDSEY RACING - Your Porsche Performance Parts Center

got this one on my car

[jkb58]

For anyone that thinks the shock towers do not move under load, just accurately measure the distance between the two towers with the car off the ground compared to on the ground. Its own weight moves the towers approx 1/8” to 3/16” - closer together.

This type of loading is putting a strut tower bar in compression, not tension. The shear loading is limited to the attachment bolts. So the flexibility of the bar is critical to its ability to stiffen the chassis. Classical Euler’s buckling calculation. The anchor points being either simple supports (pivot type) or fixed supports (rigid) make a major difference in the rigidity of the bar. Given the same tube/bar cross section, a pivot type support has half the rigidity of a fixed end bar.

A good starting point for suspension and chassis upgrades is to look at what the factory did with the suspension, bars, and cages on the Turbo Cups, 968TRS, 924 GTRs, etc.





A triangulated brace or cage members that reinforce the shock towers are obviously the best/stiffest solution. Any single bar that looks flimsy or can be deflected easily by hand will offer very questionable improvement. The loads the car and suspension are under when racing are 10 times greater than what you can apply by pushing on the bar by hand.

Originally Posted by flash968

the lower points flex even more than the uppers - a lower brace will make a significant difference

What indication is there that the frame rails significantly flex at the castor block mounts? I assume this would be primarily under heavy braking, creating dynamic toe out.

[flash968]

i actually put a tool i made in there to measure the compression under load - i measured on a car with spherical bearings front and rear too, so the bushings were not the culprit - it's likely not primarily the frame rails themselves, but rather the sheet metal "pods" to which the castor blocks attach - the brace cured it completely

you can even see the improvement in shots of your car in a corner - the camber change is dramatically reduced