Alan

Maybe everyone is right - I guess strength has different measures...

The failure mode of the stock brace seems to be that it take a permanent bend.

If the carbon fiber ones bend dynamically but return to neutral position with the load removed thats one measure of strength, if they deflect more under a given load that would be another measure of their strength...

But agreed we need to be talking apples to apples or else it doesn't mean much in this case. Anyone actually have this brace installed ?

Alan

cfc928gt

If they flex at all what good are they?

Fabio421

I have one made of mild steel if anyone is interested. I guarantee that it has superior strength to both the aliminum and CF brace. I will paint to customers taste. $75 OBO

Alan

Oh - anything will bend - just depends on load... clearly the stock ones bend under not massively atypical driving loads because so many are bent...

Same with stretch or compression or torsion - some may do different in different orientations depending on composition.

If they both bend the same amount under a high load and one returns while the other sets - I'll take the one that goes back...? As long as the shock towers are much better supported than without it - its doing some good right?

For a real high load racer some more extensive bracing & attachment would be desired than any single brace.

Agree though there is too much we don't know to decide which one works best for stiffness - even someone with one installed can't tell us much more than the hand test - a lab stress test is not likely...

Alan

ew928

So do our front fenders actually twist or is the stress bar loaded only in compression and tension? Wish I had some strain gauges to slap onto the CF bar I have to see what it actually does in the engine compartment.

If an unbraced 928 jacked up in one corner will crack the windshield, from what I've read here, then I'm guessing there is some twisting of the front fenders/frame.

With them NYC roads, I need all the shark viagra I can dump into the shark. Too bad a strut tower to strut tower full cage is so pricey. And probably overkill for street use.

cfc928gt

If there's enough stress to bend our aluminum braces I don't see how a brace that can be flexed by hand would be beneficial. It seems like it would just make the front end loose.

Alan

Well the thing is that the comment related to a different brace - so we don't know... till someone who actually has one shows up.

Otherwise I agree with you - the stock brace doesn't bend by hand - at least not with my hands & leaning over the engine bay.

Alan

Abby Normal

Anything mentioned in the thread would be an improvement over stock. Put whatever you want on your car, I'm simply saying the CF bend more than the cnc aluminum ones do. Wasn't intended to ruffle feathers.

Fabio421

I've had alot of interest in my 100% mild steel super duty cross brace but so far no takers. Still available.

fabric

Ok, here's a link right to it:

http://vertexauto.com/SQLCart/Images/Large/208544.jpg
http://vertexauto.com/ShowItem/20854...8+Schnell.aspx

Here's the Intl one:

http://www.mailordercentral.com/928i...CARBON%20FIBRE

Here's the Spec one:

https://www.928gt.com/ps-1439-193-ca...r-x-brace.aspx

Here's the Motorsports one:

http://www.928motorsports.com/parts/crossbrace.php



Not meaning to ruffle anyone's feathers, but if I were replacing mine, I'd be looking at them all anyway. They seem to all have their pluses and minuses based simply on a quick scan. None of them have anything that definitely proves what gains it has - because that would require you to test the rigidity of the car with the brace in. There's obviously anecdotal evidence that the carbon one's are going to be stiffer than the stock unit, and Carl provides some actual compelling evidence that his is damn strong, but ultimately without testing the torsional rigidity of the whole car with stock, and then with each aftermarket product, are you going to have any apples to apples comparison. While the Schnell one is definitely cheap, I have to say I'm suspect of really inexpensive carbon fiber. Which doesn't mean it's awful, and the relatively speaking expensive other carbon models doesn't mean they are awesome. The adjustable Schnell would be more intriguing if I knew what to do with that. If I'm putting my money down, it's on Carl's.

In reality, I'm probably not doing anything, because I suspect for what I do with the car, any affects are placebo. Or at least that's my rational for not buying a lot of stuff for my 928.

Lizard928

Sterling just install it upside down no more advertizing

SMTCapeCod

Seriously? THere isn't a contour to clear the intake? Oopss..nevermind, I'm OB and Sterling's is...FrankenporscheS4...and I mean that in the BEST possible way!

fabric

You take the crest off the hood and the big "PORSCHE" off the rear bumper?

Mike Frye

I'm thinking this part is something like the steering rack bushings and many other parts in our cars. The 'production' version is designed for the least common denominator. If you want racing performance, you're going to give up some of the insulation that you would want in a GT for long drives on the highway. Solid rack bushings do this when compared to the stock bushings.

I think the original part was designed to flex a bit, but over time, the part tends to stay that way, which is bad. Given the opportunity and availability the designers might have gone with CF because of it's ability to bend but not break (and not retain the deformity) which would mimic the original street application and function. For a racing application I think you would want Carl's design for strength and rigidity.

We can't compare apples to apples because they're not designed to address the same market.

cfc928gt

Don't get me wrong, I was planning on buying this Schnell brace but if in fact it's bendable it seems to me that it would be a worse brace than the factory one. It would look fantastic but it would allow your suspension to change geometery on hard cornering but then return to factory specs when no stresses are on it. Even Jim Bailey said he rarely sees a factory brace that isn't bowed and I would guess most 928s aren't driven that hard much less tracked. I would think if you can bend the carbon fiber brace by hand must have a lot of flex to it, and flex is bad in a brace. I'm hoping someone can pipe up with real world experience.