Schnell Rear Strut Brace problem
 

I bought one of these from Vertex while it was on sale last month, and it came in today. I just installed it, and thought I'd share my thoughts with you all.

Overall the brace kit looks fairly well made, but the brackets that bolt to the struts seem a little wimpy. They are flat plates with welded-in studs for the spherical joints to bolt on. The joints fit over the threaded portion, then just wedges onto the unthreaded portion. It then sits about 1/2 - 3/4 inch above the plate, which seems to give the stud a chance to exert a good bit of force on the plate, possibly flexing or ultimately cracking/breaking the weld. Maybe not, but time will tell.

Second problem is that there were no instructions. You may think it painfully obvious how they are mounted, and that's true, but with a couple of exceptions. You would think that you'd simply mount and torque down the plates, then thread the spherical ends into the rod, then place on the studs, tighten their nuts, then twist the rod and tighten its lock nuts. Well, almost. The studs on the plates, when mounted and tightened down, are not pointed straight up. They are canted in toward each other and back at an angle, which causes the rod to have to be continuously adjusted while the ends are placed onto the studs. Except, that isn't possible either, because the clips on the rear panel that hold the top drive cables are in the way until the spherical ends are completely seated! You must mount one plate, put the rod and its ends in place and on the other plate, then adjust the rod while getting the second plate into position, then torque it down and complete the setup. It's a pain. If the studs were 1/2 an inch out further and pointed straight up, that would all go away.

Third problem is the biggest. Because of the studs being at such an odd angle, when the nuts are tightened down on those studs to hold the spherical ends in place, they put pressure on the free portion of the spherical ends that thread into the rod. This makes proper adjustment of the rod impossible, so you end up guessing if you have pressure applied outward, inward, or just neutral. You're guessing anyway, since there are no INSTRUCTIONS!

To be fair, I will be calling and relaying all of this to Vertex first thing tomorrow. I will post the outcome of that call to this thread, no matter if it's good, bad, or makes me look like an idiot. Maybe it's just a new product,and they are still working out the kinks. The price was certainly right.

Jack

Hi,

Sorry to hear of your trouble. I installed the Rear Strut Brace from Racing Dynamics and had none of the issues you describe. The RD Brace uses a large Bolt through the Plate rather than a separate stud for the Heim Joint on the CrossBar.

Anyway, you're done now, and I think you'll find it a worthwhile Mod. Good Luck!...

Happy Motoring!... Jim'99

Jim, could you point me to the website that you purchased your strut brace from? I checked over the Internet for the Racing Dynamics but found out that there were some trademark disputes over the brand. I'm looking to get hopefully the original one (made in Italy).

Hi,

I got both the Front and Rear Strut Tower Braces. But, because of Pricing, I got them from two different places.

The Front I purchased from Paragon Products - www.********************************************************************.com/category_s/201.htm

The Rear Brace I got from Mid-America Motorworks - www.tweeks.com

IIRC, the Racing Dynamics Brace has no welds whatever, the Strut Tower Brackets are made from CNC'd Billet Aluminum. It is actually very well made and as I stated, none of the install issues experienced by some others. Hope this helps...

Happy Motoring!... Jim'99

I've thought about adding strut braces back and front on my car. Can you tell me what the real world difference is before and after installation?

Hi,

IMHO, the addition of the Front/Rear Strut Tower Braces is the single best MOD you can do to a Boxster. The improvement is so significant, it's hard to imagine that Porsche didn't incorporate them into the original design.

Every Convertible loses some rigidity due to the lack of a Hardtop. Even the Boxster, which is one of the more Rigid Convertibles out there, experiences more flex than you would imagine.

And, every Uni-Body Car equipped with MacPherson Struts experiences some flex as the Strut Towers move in opposition due to differing Road Planes, Bumps, etc. This flex can change the Camber, and the relationship of one side to the other.

Adding a Strut Tower Brace prevents the Strut Towers from moving out of sync and the Camber and Camber relationship is preserved. Additionally, since these Strut Towers are part of the Uni-Body system, preventing their movement adds to the overall Rigidity of the Chassis.

Significant improvements in Handling are achieved and, in my case at least, virtually all rattles were eliminated as well. The Car acts much more as a Unit, whereas before the Front and Rear Suspensions were very pronounced.

At first, I thought that only a Front Brace would be needed - that the Roll Bar System would provide sufficient Rigidity to the Rear End. I was very pleased with adding the Front Brace. Thinking this was as good as you could do, I elected to forego the Rear Brace as redundant. Then, Mid-America (Tweeks) had the Rear Brace On Sale at a significantly reduced price, so in a bit of compulsion, I bought it. Not expecting much, I installed it and WOW...!! It totally pulled the whole thing together, meaning that the Rear Strut Towers were moving waaay more than I had imagined, even with the Roll Bar. My conclusion is that to derive MAX benefit from the Front Brace, you need to add the Rear as well.

I had a friend drive my Car when I first got it and he remarked how rigid it was. Several months later, after I installed the Strut Tower Braces, but without telling my friend, he drove it again and asked what I had done, that the Car seemed much more Solid (his word), confirming what I had experienced as well. BTW, this friend owns a couple Lotus and a Westfield 11, all of which are tracked regularly, so his opinion is pretty well-founded.

For the money, I have not found a better Cost/Benefit Mod for the Car. Hope this helps...

Happy Motoring!... Jim'99

I saw pics of it on the Paragon site. Can the covers still go in over the bar in the front trunk?

I saw this at ************************************************************

The final answer from Vertex...
 

Is that I did it right, and they seem to be aware of the special "problems" with it.

They said they have been talking about doing an instruction sheet for it, but just haven't gotten around to it yet.

They guy also mentioned they were thinking about making a couple of changes to it to make it easier to install... to avoid the interference problems I encountered. Good idea.

I guess for 1/2 the price of the others (I paid $119) it wasn't a bad deal, just a little frustrating.

Looking forward to driving it after I get the CV boots done to see the difference.

Jack

John,

The Bar sits directly behind the Battery and does not interfere with the Inspection Covers at all. Easy install - remove 2 of 3 Bolts (13mm) from the Struts (keep the one tight to prevent losing the Camber Setting). Install the Brackets, retighten Strut bolts to 26 ft. lbs., and then attach and adjust the Bar. Total time - under 10 min.

Happy Motoring!... Jim'99

Fantastic!

Thanks Jim :cheers:

Thanks Jim! :cheers:

Unfortunately I've seen this sort of problem on many strut tower bars out there. Many of them are not engineered properly and will do nothing to prevent flex.

I've also kind of fallen off the strut tower brace bandwagon. There really doesn't seem to be that much bang-for-the-buck in most of the cars that I've played with this on, but perhaps the boxster is different.

Take for instance my eclipse. We removed the strut tower bar and then did some flex comparisons. We jacked up each corner of the car and measured deflection of the rear hatch area, front engine compartment and cabin. In stock form there was very little flex at all. Adding bars in did little to alleviate what little flex we had measured.

The only real way to strengthen a car's structure is to brace the chassis with a roll cage which of course, is a little invasive. Reedy little bars tacked to the strut towers just don't do as much as they're touted to do, no matter what the butt tries to tell you when you're driving.

Strut tower bars will tie the two sides together but they'll still deflect and since the bar isn't braced in a plane (in most cases--sometimes you'll see the ones that also connect to the firewall) it'll still shift front to back.

Again, I don't know--perhaps the Boxster is different, but then the age old argument for this sort of statement is the following:

If all it took to radically transform the handling of your car for the better was to connect a bar across the top of the strut towers, why didn't Porsche do it themselves?

If the improvements are repeatable and demonstrable, you'd think Porsche would take heed. At the very least I'd expect to see it as an option.

@ESLAI,

Hi, while I don't necessarily disagree with you out-of-hand on all points, I'm not really certain what your Ad Hoc test really proved. It's probably safe to assume that one would expect the Car's chassis to accept it's own weight, whereas in Real-World application the added inertia from maneuvering can increase the weight greatly, possibly in Factors of the Vehicle's actual weight. This is where a Car's Rigidity is challenged.

Preventing the Strut Towers to oppose, or move independently of, each other does have an effect toward stiffening the Chassis because the Strut Towers will move Mostly laterally and the Bar will prevent this. Admittedly there is also some Fore and Aft movement, but there are additional braces on the Car's underside to help minimize this. Assuming some still remains, at least you've eliminated some part of the equation and that is worthwhile.

Also, tying the two Towers together effectively completes a circle with the Floor (chassis for all intents and purposes on a Uni-Body Car) which can then absorb (oppose actually) the forces imposed on it by the maneuvering suspension. And the suspension on that axel acts much more in unison while still preserving independent action.

I agree there are some Cars out there which do not benefit from such bracing, but for the Boxster I consider it most complimentary. I also agree that a Full RollCage adds even further Rigidity.

My own Ad Hoc test with the Braces showed positive results. I live on a twisty road and there is a very tight HairPin turn .5 mi. from my house. I have lived here many years and know this turn like the proverbial Back of My Hand. Over that time, this HairPin has served as sort of an Acid Test for all my Cars. Prior to adding the Front Brace alone, I could take this turn at 38MPH before the Rear got skittish, Tires squealing, etc. After the Front Brace, I raised the Bar to 43MPH. After the Rear was added, I could go through this turn at 52MPH before teetering on the edge. And, virtually all the annoying creaks, groans, and rattles are gone - something good is going on here...

Happy Motoring!... Jim'99

Well, perhaps i didn't describe our (admittedly off-the-cuff) testing very well. We jacked up the extreme corner of each car--not at the jacking points on the sides. We jacked them three feet in the air in fact. Certainly the car can support its own weight, but the amount of torsional force we were applying certainly went outside of the realm of what the car was designed for.

However, this was on a coupe, and so I'll defer to you on this one. I agree that putting strut tower bars on the boxster would help give a bit of a "lid" to the "shoebox", so to speak, but i'm still hesitant to say how much it would help. Again, why no option for this sort of thing from Porsche themselves?

I've seen it time and time again where people want to believe a modification helped them when in reality it just gave them confidence to exceed their personal limits. I'm not saying that you're full of it or anything, just that without formal testing I am always very hesitant to accept any sort of car modifications.

In spite of all of this talk, I DO have front and rear strut tower bars on my Eclipse. :) I just don't put much faith in them. The fact that they cost me less than $200 together and are about as solid as they can possibly be makes me not worry about it too much. Of course, next to the $4000 or so I spent on suspension tuning and R&D, one could say that the benefits of the strut tower bars could be masked--hard to say. I haven't been all that scientific in my testing either, I suppose.

I've been considering a front stut tower bar for the 987 and that racing dynamics one seems like a valid candidate, but geez, it's $300!

I have just the right turn to test it out on too, much like you do...

I'm convinced so I'm getting the Racing Dynamic front strut and Weltmeister rear strut. Hopefully can install it next week. Will post how the car handles after installation.

Which one should I get? The front or the rear? Toolpants?
 

Toolpants - do these work?

For the greatest benefit from both Braces, you really need them both. But, I would start with the Front Brace and you'll be convinced to add the Rear. Hope this helps...

Happy Motoring!... Jim'99

Installed the front brace today. Got me 30 minutes installing the stuff because I ended up wiping the dust off of the plastics, etc :)

Absolutely an improvement in handling. Not only that , it also eliminate the squeeky sounds coming from the front. Can't wait to put the rear one :)

I think this would be a very nice mod. Do you give up much on the storage capacity in the back trunk?

Pix pls!

:cheers: