Convertible braces in a Coupe???

[bugasm99]

As I was looking through pages of threads about subframe bracing and upgraded bushings I came to this thought. Although I wouldn't think i am the first, i have yet to hear this...

I am under the impression that the new beetle convertible (and most convertibles for that matter) come with extra bracing to stiffen the chassis and help overcome the inherent flex of removing the roof from the car. So my questions is where this bracing is located on the convertible and if it can be transplanted into a coupe as a body stiffener? Is this built into the unibody of the car, or are the external braces added to the subframe and/ or bolted to the unibody?

I would really like to try and find some answers but unfortunately I do not have an etka to look up parts. So if any vert owners can help out, i would greatly appreciate it.

[Deserion]

The most obvious braces are over the trunk pan/rear floor. I know there is also one by the rear seat, ones in the door sills... but the exterior ones I mentioned first are probably the easiest to transplant to a coupe.

-Des

[73standard]

Keep in mind you are going to need some flex in the coupe. You make it too stiff and you will put undue stress on other parts of the body and it could cause damage. The engineers designed each car with all this in mind, so it's not the best idea to go in and change that.

[bugasm99]

73standard - I understand your point and I would look at each brace as an individual to find a balance between comfort and precision. The engineers design a car that drives well in everyday situations as well as have a level of comfort that the consumer would want.

I myself want a higher level of precision and control and I am willing to sacrafice some comfort in order to reach that goal. An example that comes to mind is that of the audi TT. The roadster comes with a seperate set of braces for the front lower subframe. This is also sold as a "performance" upgrade for the coupe. It does not hurt the car or add an serious vibration, yet improves the handling on the coupe. A part that was originally intended to stiffen the roadster, was found to improve the coupe as well.

below is a short list of parts to also stiffen and compensate for the bracing...

20th AE front lower control arm bushings
20th AE rear lower control arm bushings
TT rear lower subframe bushings
20th AE rear axle beam bushings
VWMS front upper strut bushings
New rear strut bushings

[73standard]

I think you missed my point. But hey, give it a shot.

[Billsbug]

I see wut 73standard is saying, but I think the only downside will be increased understeer on a tintop.

The item is what I call a 'metal skid-plate', but is referred by my service manager as the 'convertible sub-frame'. It's big, at least 3/4" thick (and probably heavy) and it looks NOTHING like the deiselgeek one. I'll post a pic by Friday.

I've had to drive around without the sub-frame for a month now cuz my dealer 'misplaced' it the last time I went in for service (getting a new one installed tomorrow) and the car feels a lot looser, which is not good. To tell you the truth I would still like a bit more crispness in the steering in tight turns and will probably add a front sway bar. BTW, I also have an upper stress bar that made a HUGE difference in handling. I also have urethane lower steering control bushings.

[bugasm99]

I see what he is saying as well. Unfortunately i honestly don't know what stresses it will make and where and would hope that the displaced stresses through the unibody would not be outside of the load levels.

As far as the increasing understeer, only time will tell. What I have found though is that most people who have braced their lower subframe and added stiffer bushings have actually since decreased understeer and a more precise feel as there is decresed engine movement and less play in the steering.

Bill - I would definately like to see a pic of this "convertible sub-frame".

[Billsbug]

Re: understeer. I definitely experienced more after the upper stress bar install, but the handling was so much better that I just adjusted to the new drving conditions, i.e. a bit more wrestling with the steering wheel.

I'll take a pic when I get the vert back on Thursday.

[Billsbug]

Finally got it back, made sure before I left service that they actually installed it but hafta figure out how to get a pic since the front end is only 4" off the ground.

It's kinda like a crossmember, with lots of open spaces, and not as heavy looking as I remembered it, probably weighs maybe 20 pounds. I'll attempt pics tonite, post a few manana.

[Billsbug]

OK, here it is. Sorry for the quality and it's covered with construction dust from a trip to one of our new properties.

[bugasm99]

awesome. Thanks for the pic. I will have to look into it and see if I can dig up some more info.

[Billsbug]

Oh yeah, I forgot to tell you. It's $750.

[BigBlockBug]

The best places to brace the car are across the front strut towers, across the rear stut towers, and most importantly across the B pillars where the seat belts mount.

I recently put in a harness bar into mine due to the new Cf racing seats and sparco harnesses, I couldnt beive the difference it made. VERY noticable difference in feel, and another added bonus was how much it cut down on some various creaks and rattles from my interior.

I'll try to get some picks up of it....

[Pelican18TQA4]

The only bracing that you could transfer from the NBC to the NB are the metal, structural belly pan and the two metal braces that cross under the rear of the car. Other than that, the structural enhancements on the NBC are integral to the unibody (such as the crossbrace behind the rear seats.

[sb_beetle]

The pic shown, while providing some structural support, is more a deflector plate for the oilpan and other under engine components that might not take well to speedbumps and parking blocks. Weighs about 6 awkward pounds.

[mgwerks]

Originally Posted by Billsbug

I see wut 73standard is saying, but I think the only downside will be increased understeer on a tintop.

My God - the last things these cars need is MORE understeer. Give me an oversteering car any day. For the general population, maybe not a good idea, but as someone who came up autocrossing VWs and Porsches, there's nothing like the feeling of throttle steering......

(just don't let off the pedal in a turn!)

[Billsbug]

Originally Posted by sb_beetle

The pic shown, while providing some structural support, is more a deflector plate for the oilpan and other under engine components that might not take well to speedbumps and parking blocks. Weighs about 6 awkward pounds.

I agree, but I disagree.

The addition of the skid-plate had a TREMENDOUS effect on the handling of the vert and it was apparent at both high and slow speeds. The entire steering feel tightened up and smoothed out. It's hard to describe, but if you doubt me, take it off and drive it, u'll see wut I mean.

Oh yeah, no increase in understeer, in fact, steering responded faster.

[Billsbug]

Originally Posted by BigBlockBug

The best places to brace the car are across the front strut towers, across the rear stut towers, and most importantly across the B pillars where the seat belts mount.

I recently put in a harness bar into mine due to the new Cf racing seats and sparco harnesses, I couldnt beive the difference it made. VERY noticable difference in feel, and another added bonus was how much it cut down on some various creaks and rattles from my interior.

I'll try to get some picks up of it....

Is it inside the cabin or under the car? My biggest complaint with NB handing is when attempting a 90 degree angle turn at speed (like when turning fast off a main road onto as side street). Is it the front wheel drive?

[BigBlockBug]

Mine is inside the car.

On your B pillar where the front seat seatbelts are bolted at about head height, the bar bolts in at both side, and curls around the back of the seats. made a HUGE diff.

[Billsbug]

Pls post a pic.