Newbie Building a Pro-Street 83 Hatch

[2FastLX]

I am currently in the middle of a 4 year long project that started out as a head swap, and has now evolved into a complete transformation of a 1983 Mustang Hatchback. I am building my first Pro-Street car (if that's what this monster is called). It's not being built for any drag racing class, and I know this is complete overkill for a street car. But that is the whole point. Basically, I have almost cut away everything except the outer shell of the car. It has a new 4-link back half and it will soon have a completely new frame from there all the way to the radiator support. I am replacing the sheet metal strut towers with round tubing and some other bracing. Basically, from the firewall on forward the only sheet metal will be the hood and fenders. So far it all seems to be going ok, but I have never done anything remotely this drastic to a car before. And I really don't have a clue what I am doing (really). So I was wondering if anyone here has done this to a car before and maybe could toss me a few ideas or advice. Here are a few pics of what I have so far...

The car is on a rotisserie that I made for this job. My brother is helping with finishing up some welds on the bottom side. You can see there is not much Mustang left in this car.
View attachment 361485

The design for the floor bracing was something I was unsure of, so I came up with using 1"x1"x1/16" wall tubing which was used around the entire perimeter of the passenger compartment, as well as for framing in the transmission tunnel and additional bracing. Below these are some triangulated pieces I made at work to stiffen things up in the seat area, and at the front of the tranny tunnel. Each side of the tranny tunnel framing is strong enough to hold me up at 250lbs. And it's not tied in to the firewall yet.

Here is the area of the frame that ran under the firewall and up to the doghouse. I cut a piece of 2"x3" tubing and tacked it in place where the original frame was. The rest of the front frame is also being replaced with the same tubing. The strut towers are being replaced with 1-1/4" round tubing and a 1/4" piece of plate steel that will all tie into the front roll bar struts that will go through the firewall.

So what do you think so far? I have some more pics if anyone would like to see them or comment on more of the work I have done so far. Like I said, I really don't know if this is the right way to brace everything up, but it seems to be pretty strong. I've had a few gear heads over that have all said it looks great so far, but I was wondering what you guys thought.

Thanks,
Kevin

 

[bloopbloob]

how heavy is this thing gonna be when its all done!??? That just looks like a lot of steel already!

 

[NOmoreHONDA]

how heavy is this thing gonna be when its all done!??? That just looks like a lot of steel already!

x2

 

[2FastLX]

I really don't know exactly. But I have seen other cars that have had the floor replaced and they had a lot more tubing than I have in mine. The front will be a lot lighter than stock. I have a PA Racing K-member, aluminum heads, and nothing but go parts on the engine.

The roll cage weighs approximately 185lbs. The frame rails weigh approximately 130lbs. The 1"x1"x1/16" wall bracing weighs approximately 25lbs. The aluminum flooring is going to weigh about 55lbs. Additional braces and misc additions - very rough guess - 100lbs. That is roughly 500lbs. If I had to guess, I have removed a lot more than that if you count the heads, K-member, power steering, air conditioning, complete interior, and the entire floor of the car. Not to mention the weight difference of the wheels and tires, and all the other parts that will be upgraded with billet aluminum replacements.

I'll be real curious to get it weighed when I get it rolling again just to see. I wish I had weighed the chassis before I started cutting. But it's not really about weight so much as it is about redistribution of the weight to the rear of the car.

 

[93 LX]

how do you keep the body straight when you cut out all the floor? This looks like fun! LOL

 

[2FastLX]

You basically start out by getting the car level front to back and side to side by sitting it on jack stands and shimming where needed. I put the jack stands under the pinch welds under the rocker panels. I also added some stands attached to the rear bumper supports, because the back of the car gets really flimsy when you cut that much material out. Then after it's all supported don't let the car move from that spot for 3 or 4 years while you slowly cut everything out and piece it back in.

First, I cut everything out from behind the front seats to the back. Then welded in the back half. Then I cut through the floor exposing the frame rails under the front of the passenger compartment and welded in the full frame rails. Then the car was mounted onto the rotisserie and gutted.

Fun? Not really, LOL. Well, it started out to be fun. Now I am just ready to get it back together so I can see how the new engine runs. But really, it has been kinda fun. A huge learning experience too.

I would suggest you didn't start anything like this unless you had a good air compressor, a plasma cutter, and a decent wire welder with argon. I cut 90% of the floor out with a 4" Makita body grinder. The rest was done with a plasma and sawzall.

 

[Aliate X]

what kinda motor setup are you going with?

 

[samickguy15]

Newbie my a&$...Looks good though. I would hope you're going big block with this thing as it should easily handle any and all power you put to it. If you're staying small block, I would again suggest going big. You don't want to be the guy that just built a Pro-Street car and left a stock motor in it...

 

[2FastLX]

The engine I had originally planned for the car is a 306 with Canfield Stage II heads. It should have around 450hp or so at the crank. But I think that engine is actually going to go in my vert. I am still debating on either a 460 or staying with the small block platform, but going with a Dart block and stroking it to death.

Since the car has evolved into what it is I think I would rather put about 600hp to the tires, but remain streetable. I'd really like to do a 408 stroker with a twin turbo setup. Now that would be fun

 

[57fairlane]

Wow, you definetly got bored!

There are stock suspension cars that run deep into the 8s but to each their own. As long as you enjoy it . . .

Oh and the shop I work at built a ~461" windsor with a dart block that went 6.0s @ 118 on the motor the first time out.

 

[rd]

You are way past any real help I could offer, for sure. But that doesn't usually stop me from trying...

You are basicly building a mini stock or a tube frame drag car.

There are several books out there for reference. I really would follow a drag class frame spec, as it would add to the appeal of the car, and may be needed if you ever want to run it on a track.

Its more work than I ever want to do, but my hat is off to anyone who can do all that.

 

[2FastLX]

I really don't ever plan to drive it down the track. If I do, it will be when and if we rent US41 dragway again. No worries with tech. Anyway, if I built this car to any certain specs, or whatever, then I would be building a car the way somebody else wanted it built. That is the reason I am basically building it the way I am - the way I want to. I guess I would just kind of like to know if it looks like I got it close to how it should be. You know what I mean?

I probably should have done some research before I got this far, but it wouldn't have been near as much fun. And the original plan was nothing like this. We actually started out mini-tubbing it. Once I did that I basically ripped that back out and decided to do the 4-link. Once I did that I decided to do the whole floor. Now it's on to the front frame. At least there I will run into the end of the car and be forced to turn around LOL.

Oh and 57fairlane - if this one makes it to the 10's I would be thrilled. As long as I can get the front wheels up

 

[mrmustangman357]

with a car at that level, you better be running 9s on a slow day

and you will eventully want to take it to the track. you will kill yourself for thinking that originally. experience talking

 

[87foxstang]

holy project!!! lol damn that looks like alot of work

 

[2FastLX]

It will more than likely run 9's. I'm just saying that 10's would make me happy. That's plenty fast for a street car.

I've driven down the strip a few times. It's fun, but not my thing.

 

[2FastLX]

holy project!!! lol damn that looks like alot of work

Yeah, it has been. Making the roll cage was about the worst of it. I bent the tubes at work in Indy (70 miles away), then brought them home and did the test fitting. Then back to Indy for tweaking.