Targa brace
 

I started this thread once before but wasnt ready to share the info at that time, so Im kinda redoing it.

Ok so some of you know Im having a targa brace made to fix that squishy shimmy feeling you get when you have the top out. I should be getting it this afternoon. I am going to try to get pics taken before I prep and paint it (future ones will be powdercoated or chromed). These should be priced under $100 even for a short run, though it really just depends on the cost of powdercoating or chroming.

Im really excited about sharing this with the community and I will try to get approval for a group buy on these, but in the meantime, Im interested to hear peoples opinions on the idea. If you own a hardtop please state that in your responce as I will dismiss your opinion entirely (ROFL, just kidding...Im still interested in hearing your opinions too)

In case you have no idea what Im talking about, the brace will bolt on to the stock locations of the Targa top and connect the front windshield to the roof portion via 1'' tube steel bars. I designed mine a little different than the so called "X-Brace" in that mine is connected via two "U-shaped" bars creating more of a t-top look and feel.

So there ya have it...all opinions on the subject are welcome, and feel free to point out any flaws in my logic. :cool:

Targa Bars
 

I have a set of Targa Bars from years back from the S.O.G.I. group buy! They work well. Post pics of yours, would luv 2 C them!

I may buy some when i get my turbo. I have a ? for targa owners tho...Is the car noticeably more flexible with the top on than the hardtop version? and does the targa top include any internal bracing or is it just a panel?

I actually cant tell your from experience, but from what I read, the targa is no more flexible as long as the top is on. The top itself doesnt have any cross corner braceing that I can tell, but the window sill portions are very stout, and there are thicker portions at the front and the back. Basically its a big rectangle with sheet metal over it from what I can tell.

I have a targa supra and I was surprised at how much flex there is in the body. I prefer driving with the top on because of the difference. Every little bump really can be felt as the chassis flexes. It is not so much the sensetivity of the car but the way the car twists. You can see it in the way the windshield shakes compared to the rest of the body.

If the stiffener really works then I would like to get one. I think the car should be driven with the top off..........and look like the top is off. Maybe a strut bar would help some, but I don't think that is where the problem lies.

Russ

Mk3s dont have struts, so your twisting doesnt lie there, And strut bars are completely useless on these cars. But yah anything connecting the windshield to the rest will def help out. Even just a little bar, In the middle, Like a t-top, as weezl suggested.

Got my bar...Im not 100% happy with it, but its nothing that cant be fixed. Im going to go with what he made me for now and see how I like it. When I picked it up from him we talked about a few options. I can definately see where we can improve it. Tomorrow I will prep it and paint it and take some pictures...should have those up around lunch time.

Just me again
 

Well I have a targa top on my 1987 Turbo, and well for all your Non-Targa people...well bow down to us...JK, naw....the targa top, when removed makes the car ENTIRELY flexible....like you take a corner and you can see it flex...well I guess at least when >I< corner you can see the flex....and that is why I only cruise with the top off.

A couple weeks back I made the mistake of taking the top off, and then racing with the car. The next time I put the top back on (Later on that night) I noticed a MAJOR marked change in how easy (Or I should say hard) it was to bolt down the targa top.

NOTE: The Supra targa top has four "bolts" that hold it down, they are more like big screws that anything else. These bolts when fastened down completely, and correctly, will make the whole targe top a "structural" peice, and MAJORLY reduces body twist, and improves handling.

I have bent/twisted my frame now because I decided to race with the top off, and now I just have to live with a hard-to-bolt-down targa top. However with that all said, I don't think that your option would work for me, not for the fact that I have body flex, and damage to the chassis, its the fact that I hate the t-top look, and honestly the FULL open roof was a selling feature for me.

I have a question to ask off of that...Are the lower mid body stabilizers able to do the same as your brace, or would a combo of both, help me the most. (I think I know the answer to this one)

Well again, I do love the fact that you have designed a part FOR the supra. I want to think up creative, and effective ways to improve the temp of the supra intake, and also ease of flow. My brother builds custom exhaust systems, and manifolds....anyways, he does all my piping needs, and he is damn good at it too. So I basically have a product engineer...and I have the ideas.

Great job to all who have created custom parts to better their supra.

If your talking about the do-luck center bar, (the one that follows the floor just in front of the rear seat) from what I read it wont do alot for twist, its just not designed for that. It does have some resistance to twist thought so long as you actually use both bolt positions (alot of people dont) because then the bar acts a little like a torsion bar. Would both work? yeah, in combination they would be great for stiffening up out Targas.

The targa bar is meant to do two things:
First of all, look at your car from a profile. Essentially its a big flat triangle. When you remove the top you are basically chopping the top off a triangle, making it no longer a strong structural shape. The front and back sides of the triangle are going to want to come together to complete the shape again and the only thing stopping them is the rigidity of the bottom side. So, Im filling that gap again.
Second, take a box with a lid on it...a nice flat rectangular one works well for this demonstration. Apply a twisting force on it from corner to corner. It should be pretty resistant to that force. Now take the lid off of it and try it again...not as resistant. Thats because a rectangle is basically just two triangles. So your lid is resisting the torsional load.
Side note: if you fabricate a bar that crosses the center line of your box...just how much do you think its going to do to resist either of these forces?

And dont be too quick to condemn the bar because it approaches T-top...give me a few hours to clean it up, prep for paint, and get a couple coats on it...I WILL have pics today sometime

Cool. I wana see it! And yes you are totally right about the flex theory, There is nothing you can do to make the car as strong as when it has a roof.