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10/19/2019 1:01 PM  #1


Subframe connectors

What is correct way to in install subframe connectors?

Tires on ground OR off ground?

 

10/19/2019 1:31 PM  #2


Re: Subframe connectors

I think the preponderance of thread replies favor installing them with the weight on the tires.


Bob. 69 Mach 1, 393W, SMOD Toploader, Armstrong  steering, factory AC.
 

10/19/2019 1:46 PM  #3


Re: Subframe connectors

I was going to say the same as it seems lifting the car (especially a uni-body) would distort it a bit. Hopefully someone who's installed a set will chime in, also what type you are using might come in to play too. These DSE subframe connectors recommend the vehicle being supported.

https://www.detroitspeed.com/img/product/description/1964.5-70%20Mustang/1964.5-70%20Mustang%20Subframe%20Connectors.pdf
 

Last edited by Raymond_B (10/19/2019 1:50 PM)

 

10/19/2019 2:09 PM  #4


Re: Subframe connectors

Even Detroit speed’s instructions are mixed.
Rear axle is on jack stands, front frame rail on jack stands.

If front end has Monte Carlo bar/ export brace in place and on jack stands would be ideal setup.
Then everything should always be in alignment as the body was produced in factory.
Add your suspension and drop onto tires.
At least this is my thought process.

What factory measurements can be done while car is fully assembled to check squareness?

     Thread Starter
 

10/19/2019 2:17 PM  #5


Re: Subframe connectors

With no lift I put my convertible up on very high jack stands so that the preponderance of weight was on the front end,  with considerations for door gaps, lined  everything up with lasers and welded on a set of  Global West SFC’s.


Good work ain't cheap, Cheap work ain't good!   Simple Man
 

10/19/2019 3:31 PM  #6


Re: Subframe connectors

Your a slim guy, but not that slim!! You need the elevation to be able to work on it. For me, jack stands would be set to the same height for all corners and sitting under the axle and control arms to keep weight on the suspension without any flexing on the body.

Preponderance? Really? It’s like a six dollar word I have to go look up!!


John  -- 67 Mustang Coupe 390 5 speed
 

10/19/2019 4:25 PM  #7


Re: Subframe connectors

I don't weld, so, I took mine to a body shop and had them weld the connectors up while sitting on a flat table.  Worked for me.  Mine are from Maier Racing.


Original owner - 351w,T-5, 4whl disks, power R&P
 

10/19/2019 4:30 PM  #8


Re: Subframe connectors

Slim, LOL skinny is more ike it, used to be 6'5" 210 pounds. I'm a little shorter these days but not much heavier.
 Overhead welding is bad enough without lack of wiggle room. I had four wheeled roller gizmo's I made years ago that I bolted the jack stands to and it gave me a few more inches of height.


Good work ain't cheap, Cheap work ain't good!   Simple Man
 

10/19/2019 5:30 PM  #9


Re: Subframe connectors

Bolted to Floor wrote:

Preponderance? Really? It’s like a six dollar word I have to go look up!!

Ha! And it was used twice already in this thread. If you've ever been sued in civil court, you learn the meaning, more than 50%.

I installed my Competition Engineering sfc on jack stands back circa (around) Y2K


Bob. 69 Mach 1, 393W, SMOD Toploader, Armstrong  steering, factory AC.
 

10/20/2019 12:42 PM  #10


Re: Subframe connectors

Its preferable to have the weight on the tires.  A couple years back I built a set of platforms about 4' tall from 2x4s and 3/4" plywood.  Pick the car up with my two post lift and set it perfectly level on the four stands (I actually built the stands at slightly different heights so they provide a perfectly level surface for the tires to sit on, as my garage floor was not perfectly level). 

A four post lift is an option a lot of shops use.

If neither are options I would advise jack stands under the rear axle and LCAs.  That's almost like having the car on the tires.

 

10/20/2019 6:27 PM  #11


Re: Subframe connectors

I removed my floor support beams first, then made connectors that extend from the rear frame rails all the way to where the front frame rails point upward. All welded with the weight of the car on the suspension, but verified for equal height at four corners. Then installed new floor support beams and heavily plug welded them to the new subframe connectors. This gave me frame rails heavily supported by the new connectors, and about three feet longer than simple weld-on connectors.  You cannot accomplish this without first removing the two floor support beams, due to the angle where the rear floor pan angles.

The main purpose of subframe connectors is to give a longer lever arm to the front frame rails that normally end at the front edge of the seat riser.  They eliminate the flex usually found in the floor pans and seat risers.

After all the work I put into mine, I still did not notice a huge difference in the car flexing. Of course, they were installed when I installed the 427 and TKO600, so that may have negated some of the improved stiffness.

Mine came from TinMan, but I lengthened them as described.

To me, my car still seems like it wants to twist in half when the loud pedal is applied.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

10/20/2019 6:55 PM  #12


Re: Subframe connectors

Obviously, the car needs to be lifted somehow.  The car needs to be lifted WITH THE WEIGHT ON THE TIRES.  Which means if you are using a lift, it needs to be the drive up type.  When I installed mine I jacked up the car and then placed cinder blocks 2 high underneath each tire.  Kind of a pain in the -oh no I used a word I shouldn't have- to get the car that high but I don't have access to a drive up lift anyway.

Also, I would suggest verifying your suspension first. 

 

10/21/2019 4:48 AM  #13


Re: Subframe connectors

Just make sure that if you use cinder blocks you place them with the core holes vertical.  Placing them horizontally could cause catastrophic failure.  Personally I'd also add a section of 2x material atop the top block to help spread the load evenly across the block.  This would also allow you to put some cleats front and rear to prevent the tire from rotating. 

Subframes are going to help, but at some point you have to understand that its hard to stop twisting moments using bracing only acting in one plane.  Certainly they are better than a sheetmetal floorpan between two frame stubs, but its still a unibody car, so everything else is still tied together with just sheetmetal.  The only way to stop twisting is to brace the frame members is other planes, and the only way to do that is with a roll bar/cage. 

 

10/21/2019 8:58 AM  #14


Re: Subframe connectors

Installing a roll bar isn't something I'd recommend installing on a street car. However, adding convertible inner rockers and a one piece seat riser to my 69 really stiffened up the chassis. They're welded to the front and rear torque boxes, the outer rocker panel and the floor. While it entails a bit of work, the benefits imo are worth it. 

https://streetortrack.com/Installing-convertible-rockers-into-a-65-68-p-14.htmlhttps://streetortrack.com/Installing-convertible-rockers-into-a-65-68-p-14.html

Last edited by rpm (10/21/2019 9:00 AM)


Bob. 69 Mach 1, 393W, SMOD Toploader, Armstrong  steering, factory AC.
 

10/21/2019 9:44 AM  #15


Re: Subframe connectors

TKOPerformance wrote:

Subframes are going to help, but at some point you have to understand that its hard to stop twisting moments using bracing only acting in one plane.  Certainly they are better than a sheetmetal floorpan between two frame stubs, but its still a unibody car, so everything else is still tied together with just sheetmetal.  The only way to stop twisting is to brace the frame members is other planes, and the only way to do that is with a roll bar/cage. 

I installed the full subframe kit with the bolt in cross members.  The actual subframe connectors are welded in, the cross members bolt in.  Pretty good setup.  

https://www.stang-aholics.com/i-24195624-65-70-mustang-heidts-center-chassis-stiffener-w-safety-loop.html
 

 

10/21/2019 12:19 PM  #16


Re: Subframe connectors

I've seen that setup.  It certainly helps with stiffness.  Rollbars definitely suck to live with in a street car.  I wouldn't advocate one, unless you need it to be legal at the track.  I'm just saying that there's only so much you can do to create stiffness against twisting forces in a flat plane.  A lot of people think roll bars in race cars are for safety, and they are, but they also double as adding considerable stiffness that in any application by making the chassis channel the forces coming through the driveline into the pavement instead of wasting the energy twisting metal. 

There are actually ways to do the same thing with sheetmetal, Ford just didn't do it.  My WRX for example has all of the suspension pickup points triangulated.  It also has full fame rails front to back.  It tips the scales at just over 3,000lbs, so it doesn't have to be heavy when its done right.  Hopefully that's just 50+ years of evolution, but from what I've seen in modern American cars its more that the Japanese are just building better cars.  Anyway, off topic as usual, and a huge debate for another time,

 

10/22/2019 8:48 AM  #17


Re: Subframe connectors

I got my 65 working very well as far as alignment and handling then put it on the drive on (4 post lift) to weld them in place. The biggest sin the connectors prevent is shortening of the car from all that horsepower abusing the body. You get very little improvement in torsional rigidity from most sub-frame connectors. If you want rigid, weld in a nice roll cage!

 

10/22/2019 5:17 PM  #18


Re: Subframe connectors

One of the best ways to help with twist it so take out the rear seat and make a metal sheet divider welded in.

 

10/22/2019 7:40 PM  #19


Re: Subframe connectors

MS wrote:

I removed my floor support beams first, then made connectors that extend from the rear frame rails all the way to where the front frame rails point upward. All welded with the weight of the car on the suspension, but verified for equal height at four corners. Then installed new floor support beams and heavily plug welded them to the new subframe connectors. This gave me frame rails heavily supported by the new connectors, and about three feet longer than simple weld-on connectors.  You cannot accomplish this without first removing the two floor support beams, due to the angle where the rear floor pan angles.

The main purpose of subframe connectors is to give a longer lever arm to the front frame rails that normally end at the front edge of the seat riser.  They eliminate the flex usually found in the floor pans and seat risers.

After all the work I put into mine, I still did not notice a huge difference in the car flexing. Of course, they were installed when I installed the 427 and TKO600, so that may have negated some of the improved stiffness.

Mine came from TinMan, but I lengthened them as described.

To me, my car still seems like it wants to twist in half when the loud pedal is applied.

 
I was able to follow most of your description.

Please correct me if I misunderstand.

Extended length of sub frame connectors at both ends?

I was looking at Don’s pictures for mini Bash.

Last edited by Nos681 (10/26/2019 9:04 AM)

     Thread Starter
 

Board footera


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