Convertible Subframe Connectors

[Convertible69 17]

Just curious who has installed subframe connectors on their convertible & what brand / style you went with? Maier? Tinman? TCP?

[Rsanter 152]

While this is not specific to convertable, I have always made my own subframe connectors.

If you are a good enough welder fabricator to install them then you are good enough to make them...IMO

I don't like the bolt in ones

 

Bob

[Convertible69 17]

Bob,

I do not weld myself, but I have a friend who has a shop & he does weld. I am looking for weld in, as I've read they are better than bolt in. I see you have a vert....did you do any modification to the floor when you installed yours?

[bryonbush 85]

i was looking at making my own tube ones. Similar to the Maier ones, just not $400. I looked at my car on the lift the other day and there would need to be a little bend in the pipe or it would hit the seat area on the floors. That is unless you dont mind them hanging down a little more.

[1969_Mach1 333]

I have a set of weld in subframe connectors from Global West.  I never installed them.  They've been on a shelf in my garage since about 2005..  I did test fit them and no floor modifications were needed.  I don't know if they also fit a convertible.

[danno 128]

I have a vert, and wondering why this is necessary?  I am not aware of any issues in mine.  Do you have Big block motors? 

[69NC 21]

I Installed Tinman's subframe connectors.

 

 

I had to trim the seat pans here is a link to my installation

 

http://www.theracg.com/wp-content/uploads/2012/12/MG_9508.jpg

 

http://www.theracg.com/2012/10/seat-pans-and-the-subframe-connector/

[KipDurran 18]

+1 Tinman connectors. I had a shop put them on for me. Seat pans do need to be cut but can be welded to the connector. They blend in and look stock.

 

I have a vert, and wondering why this is necessary?  I am not aware of any issues in mine.  Do you have Big block motors?

 

Without the fixed roof, verts have a lot of flex. Unibody construction doesn't help. My car felt noticeably stiffer after the installation.

 

Steve

[1969_Mach1 333]

Yes, convertibles, regardgless of make or model, have a much less rigid chassis.  On convertibles the mfg adds stiffener plates under the car.  But that's not near the strength a roof adds to a car.  The roof adds a lot of stiffness to the chassis of a car.

[danno 128]

I would guess a lot of rust also effects the stiffness, which most (not mine) have. 

 

It is hard for me to understand what the difference could feel like, but I will take your word for it. 

Thanks

Danno

[KipDurran 18]

I would guess a lot of rust also effects the stiffness, which most (not mine) have. 

 

It is hard for me to understand what the difference could feel like, but I will take your word for it. 

Thanks

Danno

It's very much like the difference between stiffness in a golf club shaft, skis, diving board etc. It is hard to describe but it is a noticeable difference.

[Vicfreg 771]

I got mine from Global West, they are made for convertibles.   Very heavy duty, powdercoated.   I am going to run a 393 stroker in the car, and want it to be as structurally sound as possible.   I may also use an "X" brace to tie the convertible center plate into the sub-frames.   If you watch my "1970 Convertible Restoration" forum, you will see the subframes go in as soon as Mike (Lato Racing) gets finished with the shock tower reinforcements he is doing.

 

Some of the convertible sub-frame connectors require you to modify the floor pans.  I did not want to do that, but it is up to you.

[Rsanter 152]

Bob,

I do not weld myself, but I have a friend who has a shop & he does weld. I am looking for weld in, as I've read they are better than bolt in. I see you have a vert....did you do any modification to the floor when you installed yours?

The 69 conv has no modifications to the body as it is a survivor car.

I did have an early convertable that I had made a bunch of modifications to at one point.

The issue I have with the frame connectors for convertable is that they often hang down and reduce the ground clearance. For a car that was lowered that is a bad thing.

What I did with my car was to stitch weld the body seams similar to what is specified in the trans am modifications guide.

Then I added 1/8 material to the inside on the inner rockers. I had them bent to follow the countour of the original rockers.

I also extended the torque boxes again with 1/8 material so they continued all the way to the under seat support and welded them to the under seat support. I also had them bent so that they went from the rocker seam to the mid frame rail, across the mid frame rail and then bent up the inside of it. This gave a large area for plug and stitch welds.

The car was sat very low, to the point that there was not a single speed bump in town I could get over, but the car did burn through corners very well and there was much less flex in the body.

 

In addition I braced the towers like in the trans am mod guide, added the Monte Carlo bar and export brace. Lowered the upper A arms 2" which required a custom wedge made to go under the ball joint. Cut the bump stops to half their height, 1" sway bar and shortened the links as well as shortened the sway bar end bushings.

700# front springs. Lowering springs in the back with an added leaf and the leafs were clamped

 

The car drove and handled like a go cart, including the harsh ride

 

So the question for you is, why do you want to add the frame connectors to your car?

Is the body rust compromised? Do you have a bunch of HP? Going road racing? Or did you just hear it might be a good thing to do?

 

Bob

[Vicfreg 771]

Wow, nice mods to the car, no wonder it handled so well.    I have had a convertible before, and I found it to be "twisty", so I didn't want to take any chances with this one.  So, while it was down to the stripped unibody, decided to do the subframe connectors designed for the convertible, which is an easy weld in.  Also Mike made big block shock tower wraps (the shock towers were cracked), and I got the Boss 302 "dogbone" stiffeners to weld in.   The subframe connectors will hang down, but my car will be lowered about an inch, which should not be a problem.    I will also do the Monte Carlo and Export brace.   I am using the trans am guide also, and will run an old style panhard bar rear suspension with the Shelby Drop.  Will be fun.  Thanks for the info, great stuff!!!