full frame replacement for our unibody cars

[65up2d8]

Although I got a thorough flaming (3rd degree burns essentially) the last time I brought this up, I am considering a frame upgrade. A modern, full framed car, IMHO, would be a far better platform to begin with than starting with a 40 year old unibody, at least for handling and performance purposes if not safety. Perhaps one of the things I should have brought up the first time I posted a similar idea is that my car has been through some pretty serious wrecks. I had it put on a frame machine, and supposedly its great, but how accurate could a frame machine truly be on a unibody vehicle?

Anyway, the naysayers at the time said it would be virtually impossible. My 10 year old son got me the July 2005 Hot Rod for Father's day ( :OT: I went through an extremely nasty 2 year divorce and was surprised to get anything his mother funded ), and on page 50, the Hot Rod article says that Art Morrison is now offering a full frame replacement for unibody cars. Of freakin' course, they are only offered for Chevy's at this point (what else, a Camaro), but the article says "other unibody musclecars (soon)." We can't be too far down that list given our numbers of vehicles on the road today and our support of the aftermarket.

I'm sure I'll get some good flames for going back to the well on this one, but what are some members thoughts? I believe it could be a whole new level in restomod mustangs personally, and it would almost certainly allow for the installation of mod motors in our early classics (which obviously creates a great deal of debate also based on my earlier posts) unless Art Morrison screws it up royally.

 

[rbohm]

a frame machine is only as accurate as the operator that runs it. if they follow the factory specs and guidelines, the chassis will be as straight as the day the car left the factory. anything is possible if you want to spend enough time and money. a full frame car is no better or worse than a unibody car when it comes to handling or safety. in fact since unibody cars are lighter in weight, and stiffer overall, they are usually better in regards to handling. you can stiffen the chassis for far less money and time , and without adding the extra weight, of a full frame car.

 

[RogerC62]

I'm framing my 69, and incidently, I plan on using the Art Morrison MII set up on the front. I have to replace my floors anyhow (I actually paid someone to have replacements welded in wrong ). Fixing them would mean buying new ones again to replace the botched ones. I decided I wanted to go MII on the front so it kinda snowballed into developing a frame and cage. It won't be a seperate frame but will be integral with the body.

 

[Hack]

Although I got a thorough flaming (3rd degree burns essentially) the last time I brought this up, I am considering a frame upgrade. A modern, full framed car, IMHO, would be a far better platform to begin with than starting with a 40 year old unibody, at least for handling and performance purposes if not safety. Perhaps one of the things I should have brought up the first time I posted a similar idea is that my car has been through some pretty serious wrecks. I had it put on a frame machine, and supposedly its great, but how accurate could a frame machine truly be on a unibody vehicle?
SNIP....
Anyway, the naysayers at the time said it would be virtually impossible.

Modern cars don't generally have full frames. Full frames are for pickups and race cars.

It wouldn't be impossible to make a tube frame for the car. It is done all the time. Also people who put roll cages and subframe connectors are essentially adding a full frame to their cars. Depending on the performance you want, adding at least subframe connectors is a good idea IMO.

Why wouldn't a frame machine work on a unibody car? I don't think you understand how frames are checked. There are reference points on the car's body. Markers are hung from the reference points and the relative locations are measured. Reference points for a Mustang include numerous points on both front and rear subframes, as well as the center areas of the body. If you had a competent shop check your Mustang, it's straight.

 

[1320stang]

Morrison is a great company. You should be able to get a jig welded full frame from them with just about whatever type suspension you want to run, and it'll be engineered right. All it takes is deep pockets.

 

[68rustang]

What is the desired outcome? There aren't many (any?) modern full framed cars save for any truck worth its payload. If you want a ladder style frame it won't be very rigid. If you add a cage and everything to make it more rigid you couldv'e done the same thing to the unibody and probably weigh less. It is certainly not impossible or really all that difficult but it begs the question, why?

 

[302 coupe]

subframe connectors and a 6 point cage are all the frame you'll ever need in a mustang.

I don't see any reason to sit a mustang body on a ladder frame. But, I have seen some pics of hillbilly mustangs that have been grafted onto various 4x4 truck frames. Is that what you're going for?

 

[THX 138]

camaros are barely unibody. They have a rear frame tacked to the body and the front frame is bolted in.

 

[68rustang]

camaros are barely unibody. They have a rear frame tacked to the body and the front frame is bolted in.

As opposed to a Mustang that has a front and rear subframe "tacked" to the body?

 

[CochinoFilipino]

Sounds like a good idea to me. Since you are starting with a nice new frame you can design it to accomodate a better suspension. How about double A-arms? You can use longer arms since you won't have to tie into the existing frame rails. Same goes for the back. You can set-up a four-link any way you want. You won't have to worry about building off the frame rails or ruining the structural integrity of the body when you start cutting holes in it to fit the long upper links.

Please let us know if you actually do this.

 

[65up2d8]

subframe connectors and a 6 point cage are all the frame you'll ever need in a mustang.

I don't see any reason to sit a mustang body on a ladder frame. But, I have seen some pics of hillbilly mustangs that have been grafted onto various 4x4 truck frames. Is that what you're going for?

The simple reason I find this interesting is that in being in this hobby for 17 years, all I have ever heard is how the dated unibody design of these cars limits their potential for handling. I know about subframe connectors and cages. I have a 4 point bar and subframe connectors under the car currently. Nevertheless, I simply believe that if you were to make a unibody as flex resistant as what I am talking about, you'd have to add so much bracing you'd probably end up with more weight than a full frame and still a few weak spots. Hey, feel free to disagree, but I personally think this could create a lot of options for better handling, wider wheels and tires and so on.

What I'm talking about, however, is not a horse and buggy frame, nor is it something that would be put under a 4X4. I think a link would possibly be helpful to understand why this would be an intriguing mod: http://www.artmorrison.com/maxg.htm

 

[65up2d8]

Please let us know if you actually do this.

I must admit that, at this point, I'm just doing some long range planning/brainstorming as I don't currently have the funds to take on such a project. I'm really just getting a good start on a new career at this point, and I'm trying to think ahead regarding how I'd like to build my car the next time around. But, I thought that others, who perhaps have the funds for such an undertaking, might find it interesting, and I simply wanted to see what others opinions on the subject were. It would be nice to entice someone to be a guinea pig on this project before I go out on a limb and do it!!

 

[brianj5600]

Here is a guy that framed a Chevy II. http://www.iimuchfabrication.com/ Search corner carvers or pro-touring.com for a guy named preston, he did a 68 mustang. Looks very labor and $$$$ intensive. You must begin with the end in mind. If your goal is to have a full frame daily driver, it won't be that hard, but to get state of the art handling, you better have deeeeeep pockets. What are you trying to accomplish? True race cars (not production based) use what amounts to a unibody. Monocoque chassis sounds better, but it is just another name for unibody. If you don't use the body as a stressed member it will be dead weight, and if you use it as a stressed member it will be considered a unibody.

 

[65up2d8]

Here is a guy that framed a Chevy II. http://www.iimuchfabrication.com/ Search corner carvers or pro-touring.com for a guy named preston, he did a 68 mustang. Looks very labor and $$$$ intensive. You must begin with the end in mind. If your goal is to have a full frame daily driver, it won't be that hard, but to get state of the art handling, you better have deeeeeep pockets. What are you trying to accomplish? True race cars (not production based) use what amounts to a unibody. Monocoque chassis sounds better, but it is just another name for unibody. If you don't use the body as a stressed member it will be dead weight, and if you use it as a stressed member it will be considered a unibody.

I am basically wanting to build a daily driver that would out perform virtually any factory car, within some $$$ reasoning of course, in everyday situations. I would definitely be building a car that is somewhat practical to drive daily (I don't mind a pretty harsh ride, though) and a multi-purpose car that could mix it up with a 2006 Vette through the twisties, yet have some fun in some amateur'ish autocrossing and drag racing when time permits. Does this help and does it in any way explain why I am interested in this? If you have not already checked out the link above, I think it will explain a lot.

 

[65up2d8]

Here is a guy that framed a Chevy II. http://www.iimuchfabrication.com/ Search corner carvers or pro-touring.com for a guy named preston, he did a 68 mustang. Looks very labor and $$$$ intensive. You must begin with the end in mind. If your goal is to have a full frame daily driver, it won't be that hard, but to get state of the art handling, you better have deeeeeep pockets. What are you trying to accomplish? True race cars (not production based) use what amounts to a unibody. Monocoque chassis sounds better, but it is just another name for unibody. If you don't use the body as a stressed member it will be dead weight, and if you use it as a stressed member it will be considered a unibody.

After reviewing the Chevy II site you linked above (hate to hail a Chevy, but it's a nice concept), I'd say the guy who built that car has exactly the same type of goals I'm shooting for; a car that is primarily intended to be a ridiculous street car but can do everything quite well; although it may not be the absolute best at anything other than fostering a great time and an awesome driving experience, it should be an ultimate jack of all trades that would bring a Shiite eating (Muslim, of course) grin to any of our faces.

 

[302 coupe]

http://www.artmorrison.com/maxg.htm

I just don't see that frame helping out much. It will still twist. It looks alot like the kit chassis' that are offered for street rods, which for the most part are based on the frame designs of mid 30's ford cars. Anyway, I'm sure if they were to make it, some people would buy it just for bragging rights and so they could say they spent $XXXX dollars on their chassis. Then they would take their 4000 lb mustang to a racetrack and get beat by a weekend warrior in a simple budget built car.

 

[Hack]

I am basically wanting to build a daily driver that would out perform virtually any factory car, within some $$$ reasoning of course, in everyday situations. I would definitely be building a car that is somewhat practical to drive daily (I don't mind a pretty harsh ride, though) and a multi-purpose car that could mix it up with a 2006 Vette through the twisties, yet have some fun in some amateur'ish autocrossing and drag racing when time permits. Does this help and does it in any way explain why I am interested in this? If you have not already checked out the link above, I think it will explain a lot.

Hanging with a Vette is a VERY lofty goal. I'm not going to say it's impossible, but quite difficult. New Vettes have many many hours of development behind them, and their designers get much more of a clean slate to start with. Now most other cars are not nearly as much of a problem.

Let me stand in for the experts at the Corner Carvers forums and tell you that investing in driving schools will get you far more improvement than changes to your car. Start with a couple driving schools, and then go from there.

Making a well handling car isn't that big an undertaking, though. Between the Shelby drop and Boss 302 type of mods, your car will do well. One thing to realize is that the steering will never feel as nice as a new car. Possibly a rack and pinion and bump steer kit - but I've seen many complaints on here about problems with the current offerings of rack and pinions.

 

[Travis77]

I don't know if I should butt in, but I talked to a guy at Art Morison's shop and he gave me a number that installs such projects. I am in Houston and so is this fella. So, I called him up and ask him what we would be looking at as far as price. He told me for 9k he could frame my car, mock up motor /trans, this includes 4 link or ladder setup. I know it is alot of money. I am only thinking of doing it because I was quoted $2500 to reclip the front of my car. And before my body guy wants to put his name on the paint job, I'm going have to pay for a mini tub twice. I am thinking that this full frame might be a good alternative, since I am most likely going to pay for front and back subframe replacement anyway. The only thing that sucks is that I'll have to put my GW coil over conversion with the other for sale items.

 

[THX 138]

As opposed to a Mustang that has a front and rear subframe "tacked" to the body?

ya. the camaro front subframe is on with 4-6 boltsand the rear frame is a fully boxed tube rear frame like a framed car. The mustang subframe is all sheetmetal i believe. I could be wrong, but that's what I understand.

 

[68rustang]

...the camaro front subframe...The mustang subframe...

Neither car has a full frame connecting the front and back subframes so they are both unibody cars. The details of each design don't really matter, to each manufacturer their own.

The maxG chassis you linked to doesn't look very rigid to me. Welding in a proper cage and some real subframe connectors will net you a better and cheaper end result. Now if you go the route of Preston and basically tube frame the car and just "hang" a mustang silhouette over it that's a different story.