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Under brace install

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Old Aug 11, 2010 | 11:00 AM
  #1  
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From: carson
Default Under brace install

I purchased the tanabe under brace ...
http://www.tanabe-usa.com/underbrace.asp

I do not have any install manual on me... BUt I think I got an idea where it goes. It's pretty straight forward seems like it. Anyone know how much torque do I put on the bolts when I tighten them back?

Anyone have picture of this installed or any other brand? Just would like to get an idea and make sure I'm doing it right.
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Old Aug 11, 2010 | 01:18 PM
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From a structural standpoint, that brace is a joke.
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Old Aug 11, 2010 | 04:27 PM
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How so? I installed 4 point brace on my other car and it made a huge difference.
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Old Aug 11, 2010 | 08:49 PM
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Look at this bridge frame.



It's all triangles, because triangles make a structure rigid. Notice also that the bracing always goes to the corner, not to a point midway between corners.

That underbody brace has both longitudinal pieces welded to the crosspieces away from the mounting points. The frame is a trapezoid, which has no inherent rigidity. The joints aren't even gusseted to distribute the loads. Any Structures 101 student would laugh at the design.
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Old Aug 12, 2010 | 04:12 PM
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If you look at the outside frame of the bridge it's a trapeziod, get rid of the outside frame and all the inner braces fall into the water, trapezoids are not inherently unstable. There are many vertical & horizontal trapeziodal braces thoughout our cars (ie front axle , shocks, shock tower brace) Although I agree that the tanabe underbrace stiffness is not great, it does tie the steering compression rod arm geometry to the carframe. Weld 1/8 aluminum plate to the bottom & top of the underbrace frame, that will stiffen the brace alot, and it makes a great skid plate.

Last edited by BrazenZ; Aug 12, 2010 at 05:31 PM.
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Old Aug 12, 2010 | 06:26 PM
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^ That man knows his stuff.

Thanks again for those tires, Davo!
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Old Aug 13, 2010 | 07:29 AM
  #7  
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There's a basic Internet Engineering assumption that stiffer = faster regarding the chassis. In the real world that's not always true. One example is the BMW E36 chassis. Testing of two different customer autocross cars, one running in FP and one running in SM (last year's SM national champ) showed that the cars were quicker around the course without front strut tower bracing.

Without any real back to back testing, no one can say if this undercar brace (or any other) will make the car handle better enough to offset the additional weight of the brace.

This thread is just another fine example of Internet Engineering Masturbation.
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Old Aug 14, 2010 | 12:28 AM
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Dude, unless you are slapping on a helmet and tracking the SOB who cares?

Its your cash spend it how you want. It will at least look nice.
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Old Aug 14, 2010 | 03:19 AM
  #9  
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With so much give in the brace, at least you don't have to worry about the welds breaking, the tubing buckling, or the bolts shearing off.
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Old Aug 19, 2010 | 03:55 AM
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I can take a picture of my Megan racing H-brace today when I put the car on a lift.

Installation of the brace was really simple. Although my Greddy exhaust touched it after the install and I had to make a special bracket for it to clear.
IMO the H-brace didn't do much. However I was already satisfied with the rigidity of the chassis before the brace. I just got it so cheap that I couldn't resist.


EDIT:

me and my memory
I totally forgot to take the picture.

Last edited by 350z-Helsinki; Jun 3, 2013 at 02:36 AM.
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