67 Firebird project ( C4 suspension, LS, T56 )

[cobraguy65]

Hi everyone, Wanted to share a project I started a month or so ago. This is my 67 firebird I've had for a couple years now. I pulled it out of a barn in Indiana (read, alot of rust). Here is a general outline of the project.

-Fab front sub-frame to join C4 corvette front suspension to 1st gen f body.

-Fab rear section to adapt C4 D44 rear suspension.

-Repair body rust

-Repair some more body rust. lol

-Install LS1 and T56.

Here is where I'm starting.

https://static1.pt-content.com/images/pt/2010/05/firebird1-1.jpg

Thanks for lookin, Scott

[John Wright]

Love those old birds.....keep us updated with pics of your progress.

[67rstbkt]

Cool, another firebird. They're just all over the place now. What sort of rust issues do you have?

[cobraguy65]

Ok, uploaded a few pics to show progress to date.

First thing was to buy a donor car for the suspension. Scored this 86 vette off of Craigslist for $900. This turned out to be a great deal. pulled the suspension, brakes and wheel/tires. Sold the rest for $1500. So far my budget is looking pretty good. lol

https://static1.pt-content.com/images/pt/2010/05/86vette3-1.jpg

https://static1.pt-content.com/images/pt/2010/05/86vette2-1.jpg

https://static1.pt-content.com/images/pt/2010/05/vettebird3-1.jpg

https://static1.pt-content.com/images/pt/2010/05/vettesusp2-1.jpg

https://static1.pt-content.com/images/pt/2010/05/vettesusp3-1.jpg

[cobraguy65]

Cool, another firebird. They're just all over the place now. What sort of rust issues do you have?

Joe, My car has similar issues as yours did. Floors, trunk, wheel houses, doors have some issues. previous owner put camaro quarters on. I have followed your build. It was inspirational on this project. thanks for sharing. I am anxious to start on the body. Working to get past the concept stage on the suspension.

[67rstbkt]

Joe, My car has similar issues as yours did. Floors, trunk, wheel houses, doors have some issues. previous owner put camaro quarters on. I have followed your build. It was inspirational on this project. thanks for sharing. I am anxious to start on the body. Working to get past the concept stage on the suspension.

Thank you, I'm glad I could inspire someone. I'm just trying not to screw up too bad. I like the direction you're taking on this. I'm looking forward to seeing how the project progresses, especially the suspension setup. The guy I bought my subframe from did something similar, but he's not done yet. He basically shoved the entire front of the C4, including the dash, firewall, and windshield under his 67 Camaro. I'm not sure how it's going to turn out, but it's definetely an interesting way to build the car. :cheers:

[68firebird]

excellent, another firebird. I think we'll overtake the camaros soon, LOL. How the hell did you score that vette for $900, thats an outstanding deal!!

[T_Raven]

Looks like a cool project.

[cobraguy65]

Bolted the corvette wheel/tires on to get some measurments on ride height.

https://static1.pt-content.com/images/pt/2010/05/ridemockup-1.jpg

https://static1.pt-content.com/images/pt/2010/05/vettesusp-1.jpg

Started with the dis-assembly to mock up the corvette front suspension under the car. More measurements

https://static1.pt-content.com/images/pt/2010/05/shell3-1.jpg

corvette front suspension in place.

https://static1.pt-content.com/images/pt/2010/05/frontmockup3-1.jpg

https://static1.pt-content.com/images/pt/2010/05/frontmockup4-1.jpg

https://static1.pt-content.com/images/pt/2010/05/frontmockup6-1.jpg

[cobraguy65]

Started building a jig for the front sub-frame. First step was to capture the mounting points from the stock sub-rame.

https://static1.pt-content.com/images/pt/2010/05/jig1-1.jpg

https://static1.pt-content.com/images/pt/2010/05/jig2-1.jpg

Then added the corvette suspension points using the measurements from the mock up.

https://static1.pt-content.com/images/pt/2010/05/jig4-1.jpg

https://static1.pt-content.com/images/pt/2010/05/jig3-1.jpg

[cobraguy65]

excellent, another firebird. I think we'll overtake the camaros soon, LOL. How the hell did you score that vette for $900, thats an outstanding deal!!

Yah, I bought this firebird a couple years ago thinking it would be something different. Its nice that they're getting popular. The vette definately turned out to be a great deal. I was only going for the front suspension and end out buying the whole car. i think i could have gotten it cheaper. I just got tired of haggling. lol

[cobraguy65]

I also bought a set of Z06 wheel/tires off of graigslist. Got the rears only for $475. tires are 325/30/19 goodyear F1's. Will have to run spacers to clear the rear control arms. Looks like the rear quarters will need to be widened an 1" to 1.5" per side as well.

https://static1.pt-content.com/images/pt/2010/05/z06rear-1.jpg

I have a lot of the new subframe fabbed. Gonna start tacking it together tonight. I'll try to post some pics tomorrow.

[CruizinKev]

sweet project!! :twothumbs

[SamHatco]

This is going to be great! Firebirds are starting to catch up on the camaros. Of course I'm a little partial. Buuuuhahahah!


Sam

[1971CHEVELLE]

Awesome project

[srh3trinity]

This is going to be a great build. There was a local guy that was selling a Camaro recently that had C4 suspension. By the wording of his ad, I thought he had only done the drivetrain, but I saw it not too long ago and it did indeed have the C4 rear suspension.

[srh3trinity]

Here is the rendering that put first gen 'Birds on my radar. ZVT designs has a great eye for these cars. http://www.zvtdesigns.com/orders.php

[ponjohn]

Subscribed.

[LSfan70s]

Subscribed.

+1 :cheers:

[John Wright]

Quick work...good job on your jig....you'll have this done in no time, if you keep up this pace.

[cobraguy65]

Thanks for the comments everyone. I got alot of the subframe tacted together last night. I am real happy with how it is turning out so far. I'll post some pics later today.

John, I'm not quite that fast. LOL. I started a month or so ago. Just now getting around to starting a build thread. wanted to get up to date in sequence.

[cobraguy65]

quick update. Got most of the front subframe fabbed and tacked together. Still have to fab the front body mount. I was hoping to have it ready to test fit under the car before i leave for the power tour. Most likely wont make it as the heater core started leaking in my '66. gotta get that fixed driving it on the PT. here are a few pics. they are kinda busy. hard to get good pics with soo much in the back round.

https://static1.pt-content.com/images/pt/2010/06/DSC00532-1.jpg

https://static1.pt-content.com/images/pt/2010/06/DSC00531-1.jpg

https://static1.pt-content.com/images/pt/2010/06/DSC00530-1.jpg

[RS_Customs]

quick update. Got most of the front subframe fabbed and tacked together. Still have to fab the front body mount. I was hoping to have it ready to test fit under the car before i leave for the power tour. Most likely wont make it as the heater core started leaking in my '66. gotta get that fixed driving it on the PT. here are a few pics. they are kinda busy. hard to get good pics with soo much in the back round.



Looking good! I like the tubing!

Do you have plans for another tube stacked / ladder style to reduce flex in the frame under the car? or tied into a roll cage?

Robert

[John Wright]

looking good.

I gotta build me some racks like you have behind your frame jig. I'm starting to get a collection of long lengths of differnt materials laying around.....(tubing, pipe, angle...ect)

[cobraguy65]

Looking good! I like the tubing!

Do you have plans for another tube stacked / ladder style to reduce flex in the frame under the car? or tied into a roll cage?

Robert

Robert, I initially had the same concern with the cross sectional height. I decided to go with this design for a few reasons. I am planning on running bars from the firewall/cage forward to the front of the subframe. I feel this will do more to reduce flex than a beefy frame from the front body mount rearward. I questioned the rigidity of the floor area where the rear frame mount is. I thought the floor would flex prior to the subframe. I also plan to run three out riggers to the rocker (this will be a full frame car when done). As a slight benefit, the engine and trans will be solid mounted, adding to the torsional rigidity as well. hope this gives you an idea of what i was thinking. One of the reasons I wanted to post this build, was to get questions/opinions. Thanks for the questions....... Scott


Example of forward bars

https://static1.pt-content.com/images/pt/2010/06/DOWNBARS-1.jpg

[RS_Customs]

Robert, I initially had the same concern with the cross sectional height. I decided to go with this design for a few reasons. I am planning on running bars from the firewall/cage forward to the front of the subframe. I feel this will do more to reduce flex than a beefy frame from the front body mount rearward. I questioned the rigidity of the floor area where the rear frame mount is. I thought the floor would flex prior to the subframe. I also plan to run three out riggers to the rocker (this will be a full frame car when done). As a slight benefit, the engine and trans will be solid mounted, adding to the torsional rigidity as well. hope this gives you an idea of what i was thinking. One of the reasons I wanted to post this build, was to get questions/opinions. Thanks for the questions....... Scott






Cool sounds like you have thought that out. Tying into the rockers and the roll cage will defiantly help. I'm not sure I would consider the engine/trans for adding stiffness though, it is going to be trying to flex the frame and body through torque.

Looks like you have a monster press in the back of the shop, what kind of work do you do?

Robert

[cobraguy65]

looking good.

I gotta build me some racks like you have behind your frame jig. I'm starting to get a collection of long lengths of differnt materials laying around.....(tubing, pipe, angle...ect)

John, The racks are definately handy. My problem now is keeping work stuff and hot rod stuff seperate. Got to keep an eye on 'em so they dont take my tubing. LOL

[cobraguy65]

I've made a little progress. Got the subframe tacked enough for some test fitting. Pulled it out of the jig. Will start mocking up the suspension tonight. Then bolt it under the car.

https://static1.pt-content.com/images/pt/2010/07/DSC00800-1.jpg

https://static1.pt-content.com/images/pt/2010/07/DSC00799-1.jpg

[cobraguy65]

Looks like you have a monster press in the back of the shop, what kind of work do you do?

Robert

Sorry I missed your question earlier. I run a small tool & die shop. The press in the backround is only 200 ton. we use it for die tryout. I did used it to form these frame mounts.

https://static1.pt-content.com/images/pt/2010/07/DSC00793-1.jpg

[RS_Customs]

Nice! I like the ease of adjusting the height and keeping the geometry of the suspension.

Robert

[ryeguy2006a]

Cool project!! I wished I had that kind of budget.

[Smock67]

Awesome project I am loving how your making it a full frame using c4 components.

[icebird84]

nice project

[T_Raven]

That subframe looks awesome. You gonna weight it compaired to the stock one?

[cobraguy65]

That subframe looks awesome. You gonna weight it compaired to the stock one?

Weighed it last night on a cheap bathroom scale. It came in at 94 lbs. I still have a few more pieces to weld in. vertical braces for motor mounts ect. The stock one weighed 121 lbs. Looks like they will be similair in weight. The suspension components will be the weight savings and alot of it is unsprung.

[cobraguy65]

Some pics with the suspension bolted up.

https://static1.pt-content.com/images/pt/2010/07/DSC00808-1.jpg

https://static1.pt-content.com/images/pt/2010/07/DSC00805-1.jpg

[John Wright]

Alright!..now slap some tires on that thing and slip it under the car...LOL

[cobraguy65]

It fits

https://static1.pt-content.com/images/pt/2010/07/DSC00815-1.jpg

https://static1.pt-content.com/images/pt/2010/07/DSC00812-1.jpg

https://static1.pt-content.com/images/pt/2010/07/DSC00816-1.jpg

[cobraguy65]

Alright!..now slap some tires on that thing and slip it under the car...LOL

Right with ya John. LoL

[John Wright]

^^^wow, that was fast. I barely finished typing and you already posted pics of it under the car.

[cobraguy65]

Gonna set the engine in next to locate the motor mount position. then back to the jig for final welding and bracing. thanks for lookin.......Scott

[nicks67camaro]

Very cool project. How did the track width with work out? Did you have to shorten the rack?

[Sheriff]

Nice project

[cobraguy65]

Very cool project. How did the track width with work out? Did you have to shorten the rack?

Track width was the same on both cars. Didnt need to shorten the rack. Front suspension geometry was left as it was in the corvette. I have 275-40-17's bolted on at the moment. I'll take a few pics this evening..........Scott

[nicks67camaro]

Track width was the same on both cars. Didnt need to shorten the rack. Front suspension geometry was left as it was in the corvette. I have 275-40-17's bolted on at the moment. I'll take a few pics this evening..........Scott

Very cool I love the project.

[srh3trinity]

I am envious of people who can take a pile of steel and tubing and create something this cool. Looks awesome and I really like the way it is coming together.

[Jeffrotech]

Subscribed! Fellow Firebird owner here... really liking your subframe!

Here's a question: have you thought about adding one more tube just behind the rear control arm bushing - to stretch between the upper & lower tubes? It just looks like they might want to flex under a good load.

And, since it hasn't been asked yet, so... planning on making more???

[Chicken Louie]

Awesome work!!!!

[cobraguy65]

Subscribed! Fellow Firebird owner here... really liking your subframe!

Here's a question: have you thought about adding one more tube just behind the rear control arm bushing - to stretch between the upper & lower tubes? It just looks like they might want to flex under a good load.

And, since it hasn't been asked yet, so... planning on making more???

Jeff, I definately plan on adding a few more supports. I wanted to fit the engine in place and put the vertical support in-line with the motor mounts. I plan to put the sub back in the jig for final welding. Will add motor mount location to the jig at that time also. A friend of mine is building a '69 camaro the same way. Will be building his sub-frame next. After that???? If someone wanted one. I could probably accommodate.

[LSfan70s]

Subscribing!!! Nice project!!!

So you are not doing any change to the original Vette suspension pick up points?

[Jeffrotech]

Jeff, I definately plan on adding a few more supports. I wanted to fit the engine in place and put the vertical support in-line with the motor mounts. I plan to put the sub back in the jig for final welding. Will add motor mount location to the jig at that time also. A friend of mine is building a '69 camaro the same way. Will be building his sub-frame next. After that???? If someone wanted one. I could probably accommodate.

Fantastic. It's cool to see this come together. It could be a great way for some of us to perform a great upgrade on a budget!

[nicks67camaro]

A friend of mine is building a '69 camaro the same way. Will be building his sub-frame next. After that???? If someone wanted one. I could probably accommodate.

It would be cool. If the jig is built already it probably wouldn't be that hard. Heck you can probably offset other upgrades on the car. I would be interested.

[neki67]

It would be cool. If the jig is built already it probably wouldn't be that hard. Heck you can probably offset other upgrades on the car. I would be interested.

I would also be interested.

[ho428]

Now, if I can only find a way to make that frame "Class Legal" in our Vintage group without bumping me into the next higher class. Hmmm....

Nice peice of work. I don't suppose you weighed the entire stock assemble to compare against this piece have you?

[Stoned_Elvis]

I like it. its different. Is that DOM or chromoly? what size?

[LSfan70s]

Updates?

[zooboy]

I am curious as to how the weight differrence between the two cars will afect the corvette suspension. Any thoughts?

[zooboy]

I googled the weight of both cars and they are both about the same. The vette is 95 lbs. more, keep up the good work!