Author Topic: Subframe choice  (Read 200 times)

Nexus

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Subframe choice
« on: September 13, 2019, 07:17:19 PM »
Ok.

My apologies for all the questions and then having little to show for it. As I get geared up to start working on the subframe, I have 3 choices.


which to use.

Subframe 1 is out, easy starting point but may need some help with its condition. It is also out of an unknown Camaro

Subframe 2 is still in the car, is filthy, and the condition is unknown. It is a 80 trans Am though. It would need to be removed which may or may not be that big a deal.

Subframe 3 is in " The Project" and I bring it in to get straightened as there is a slight twist in it.


I don't want to waste time on something like the Camaro frame to find out later, it would have  been better to use the Trans Am frame as a starting point.

The idea is easiest path to get the car back together the fastest.

Charlie

79 Esprit but like many, it will be a T/A clone
(18 years and counting but still have her)

DeCaff2007

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Re: Subframe choice
« Reply #1 on: September 13, 2019, 08:38:40 PM »
I vote for number 2.  No matter what route you take, you'll be tearing into the T/A anyway.  Might as well use the original and not have to mess with it.
1976 T/A 400, 4-speed swap.... 

Check out my resto thread:  http://transamcountry.com/community/index.php?topic=48626.0

It's all trial and error until something lines up...

LeighP

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Re: Subframe choice
« Reply #2 on: September 13, 2019, 09:22:00 PM »
Camaro frame won’t have threaded inserts to bolt the sway bars in....you’ll have to add rivnuts or similar. Depending on the year, the Camaro frame may use smaller control arm bushing bolts and you may have to cut out new rear body mount holes. The gearbox crossmember boot holes may not be in the right place, you have to use a crossmember that matches the floor pan year, and that may require drilling other holes to mount it. All in all, if I had a Trans Am frame available, I’d use that as my first option.
Regards,
Leigh

Sydney, Australia
1968 Pontiac Firebird 428 5 speed coupe

Former Firebirds -
1969 Pontiac Firebird 400
1971 Pontiac Firebird 455
1977 Pontiac Trans Am
1976 Pontiac Trans Am
1967 Pontiac Firebird 400 convertible
1967 Pontiac Firebird 400 coupe


langss

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Re: Subframe choice
« Reply #3 on: September 14, 2019, 12:21:04 AM »
Camaro frame won’t have threaded inserts to bolt the sway bars in....you’ll have to add rivnuts or similar. Depending on the year, the Camaro frame may use smaller control arm bushing bolts and you may have to cut out new rear body mount holes. The gearbox crossmember boot holes may not be in the right place, you have to use a crossmember that matches the floor pan year, and that may require drilling other holes to mount it. All in all, if I had a Trans Am frame available, I’d use that as my first option.
When I bought my Project, I got a 76 Camaro Subframe with it. The only thing it did not have was the holes and the welded in nuts for the lower "A" frame supports. Everything else was exactly the same. Here is a thread that you may find helpful. http://transamcountry.com/community/index.php?topic=68213.0 I hope this helps.

mz-formula

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Re: Subframe choice
« Reply #4 on: September 14, 2019, 07:02:02 AM »
Starting off with the straightest most solid foundation you can is the way to go.  I would recommend #2.  Just keep in mind the transmission cross member moved and is not in the same place they were on 70 to the mid 70s.  So, if you have that cross member,  keep it too.  By 81 the motor mount locations had become Swiss cheese, which is good.  You should be able to bolt any engine in there with no issues.

Re: Subframe choice
« Reply #4 on: September 14, 2019, 07:02:02 AM »

Nexus

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Re: Subframe choice
« Reply #5 on: September 14, 2019, 06:41:31 PM »
Cool.

Thanks for the replies everyone...I'm thinking I will do just that...use the TA frame as my starting point!!

Might be the fastest route as it is still together and in one piece. Just need to make sure the components are safe to use!!
Charlie

79 Esprit but like many, it will be a T/A clone
(18 years and counting but still have her)

NOT A TA

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Re: Subframe choice
« Reply #6 on: September 14, 2019, 08:05:14 PM »
I'd also recommend starting with #2 and inspecting it well. You may be able to sell the Camaro frame by narrowing down what it will fit easily using the link to the thread posted previously. Never hurts to put some money in the budget!

Have a look here https://www.lab-14.com/  for pieces to repair & upgrade the sub frame.
John Paige
Lab-14.com

79T/Aman

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Re: Subframe choice
« Reply #7 on: September 15, 2019, 09:50:04 AM »
I would also say#2, but why worry this statement?  " It would need to be removed which may or may not be that big a deal. " ? regardless it needs to be removed if you were to build a different frame.

A little guide:

-70-74 frames need modification to fit 75-81 cars and vise versa, rear body mount location, transmission cross member bolt hole locations.
-Camaro frames don't have the heavy duty front sway bar mounting holes (just threads in the frame metal, Pontiacs have threaded inserts with much more thread engagement )
-Engine mount holes vary between years and Camaro vs  Firebird

Remove, clean, inspect and paint your frame, install new body bushings to suite end usage, rubber, poly or solid ( if you don't know I will be happy to help guide)

I want to ask about #3 what is "the project" ? and if it is "in" the project how do you know it has a "slight " twist? I ask because I hear this all too often.
www.pro-touringf-body.com  your source for making your Trans am do what it does best!......SHOW OFF!

Nexus

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Re: Subframe choice
« Reply #8 on: September 15, 2019, 05:28:17 PM »
I would also say#2, but why worry this statement?  " It would need to be removed which may or may not be that big a deal. " ? regardless it needs to be removed if you were to build a different frame.

A little guide:

-70-74 frames need modification to fit 75-81 cars and vise versa, rear body mount location, transmission cross member bolt hole locations.
-Camaro frames don't have the heavy duty front sway bar mounting holes (just threads in the frame metal, Pontiacs have threaded inserts with much more thread engagement )
-Engine mount holes vary between years and Camaro vs  Firebird

Remove, clean, inspect and paint your frame, install new body bushings to suite end usage, rubber, poly or solid ( if you don't know I will be happy to help guide)

I want to ask about #3 what is "the project" ? and if it is "in" the project how do you know it has a "slight " twist? I ask because I hear this all too often.

The Camaro frame is out, been painted years ago, stripped, and leaning against my sea can, so it's just a matter of bringing it into the garage and going from there
 
"The Project" is what I named my build years ago because it has been a project of mine for 20 years. It was in some sort of accident as I had fix a bunch of damaged sheet metal in the lower right corner where the frame bolts up. Also when you measure down to the floor off the front of the frame, it has a different number left and right side. and another clue was how the fenders were strangely aligned to get it to sit properly....a whole stack of washers in places to make things line up......I just assumed from that information.
Charlie

79 Esprit but like many, it will be a T/A clone
(18 years and counting but still have her)

pancho400cid

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Re: Subframe choice
« Reply #9 on: September 16, 2019, 11:12:55 AM »
I'll second the question - What is the actual vehicle you are working on?

I agree with 79T/Aman that figuring out if/how/to what degree a subframe is tweaked is no simple matter.  I went through it myself - here's my post about it and a couple of pics:

http://transamcountry.com/community/index.php?topic=78680.msg746575#msg746575







I will also tell you that I looked exhaustively for a body shop that would just look at / work on a bare subframe and found exactly ZERO shops that would touch it anywhere near me.

I finally bought a heavy come-a-long and then a hydraulic bodywork ram from Harbor Freight and tackled it myself.  After a lot of work, I got the alignment holes to jibe more-or-less with the data in my post linked above.

I hope I got it right but the project is stalled right now and it will be a long time before the subframe and body meet up again, much less a road test (sigh....).
« Last Edit: September 16, 2019, 11:17:16 AM by pancho400cid »
1978 Trans Am - Chesterfield Brown - current project
1978 Trans Am - Silver - SOLD!

Re: Subframe choice
« Reply #9 on: September 16, 2019, 11:12:55 AM »
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