The unorthodox budget Firebird (-74)

Won't canvas flutter too much in higher speeds? The Loove models are made out of thin aluminum sheets and doesn't weight much at all. You can reinforce it the same way as they have done (with X in the panels).

_________________
Not very much progress since last time. I'm a house owner since two weeks back so most of my spare time has been spent renovating an remodeling that. Will hopefully start working on the car within 4-5 weeks again.

Since the engine is set back appr 8", the reinforcement in the body lined up nicely with the transmission member. I decided to make a smaller member and mount it to the body instead of the large version that attaches to the sub frame. Main argument was weight (of course), but I will also gain some space for the exhaust.
https://static1.pt-content.com/image...1600x337-1.jpg
As you can see on the picture, the car has it's own gravity field ;)
https://static1.pt-content.com/image...3300x168-1.jpg
https://static1.pt-content.com/image...4300x168-1.jpg

Some inspiration..
https://static1.pt-content.com/image...6600x400-1.jpg

Battery box has also been mocked up. Had to do some reinforcements on the other side of the floor to spread the forces in case of an accident (don't want to mount the box in the passengers back...)
https://static1.pt-content.com/image...8266x400-1.jpg
https://static1.pt-content.com/image...9266x400-1.jpg

And I have bought a Vintage Air system which turned out to be a great surprise - better quality than I expected!
https://static1.pt-content.com/image...1600x337-1.jpg

Some welding left, and then paint it inside and the under carriage. Gaaah, I can't hardly wait!

Quote:

---

Originally Posted by Ripper

Won't canvas flutter too much in higher speeds? The Loove models are made out of thin aluminum sheets and doesn't weight much at all. You can reinforce it the same way as they have done (with X in the panels)

---

I've seen a bunch of BMW Car Haulers with Canvas sides so maybe I should consider doing more of a rigid type roof.

Some progress...

I've started on the uprights for the front
https://static1.pt-content.com/image...7600x450-1.jpg
https://static1.pt-content.com/image...3600x450-1.jpg

alot of different designs were made in the CAD, mostly aluminum versions based on a 1,5" water cut aluminum block to keep costs down. However, it turned out quite expensive, appr. 1000USD.
With that in mind, I decided to try to make them out of sheet metal instead, which actually turned out very good - they are light and cheap - costed me appr. 50USD to make... Steel also has some benefits against aluminum in critical suspension parts, atleast with home made parts that don't have the R&D budget of GM.

Here's just a quick picture of a aluminum version I did. Unfortunately, you cant see the holes through the upright since it's covered by a brake cooling duct. It looks more or less like a spider web. I tend to be a Little too focused when I work so I forget to save screen dumps of all the different versions...
https://static1.pt-content.com/image...2600x398-1.jpg

But here's the final result (in steel). It actually came out lighter than the aluminum version. The steel part weights appr. 4 lbs which is l i g h t.
The upper rod (?) is mounted in an aluminum block so it can be shimmed if I wan't change SAI/Scrub in the future. Camber will be adjusted on the A-arm instead. The steering arm is also replacable for trying different geometries.
https://static1.pt-content.com/image...6600x362-1.jpg

As for Wheel bearing, a Corvette hub is used
https://static1.pt-content.com/image...1600x432-1.jpg

The caliper has also been lowered as much as possible to keep CGH down. Yes, I know it doesn't change much, but doing this on every part will help.
https://static1.pt-content.com/image...4300x220-1.jpg https://static1.pt-content.com/image...5300x220-1.jpg
It resulted in 3% lower CGH on the upright assembly.
I wish I could have mounted it below the lower A-arm, but it was impossible to get a decent suspension geometry due to that the A-arm needed to be raised too much.

The subframe has also been finished (in the computer). It was mostly finished about a year ago, but I didn't had time to build it then. Instead, I let it evovle slightly during the year and some minor changes has been done.
Due to scrutineering-problems, I will have to save most of the stock construction which equals to the part of the longitudal part of the, frame. The K-member was cut away and a new one was designed. I did some FEA to see what geometry was a good compromise between stiffnes and weight.
https://static1.pt-content.com/image...4300x214-1.jpg https://static1.pt-content.com/image...5300x213-1.jpg

And here's the final result. I'm gonna go with push rods in the front suspension, mostly because I managed to creat a almost 100% linear relation between wheel and coil over. And there's also endless possibilities in the future to experiment.
https://static1.pt-content.com/image...2600x337-1.jpg
https://static1.pt-content.com/image...8600x337-1.jpg
https://static1.pt-content.com/image...1600x337-1.jpg


That's all for now. Hoping for some real-World progress in next update. :cool:

Amazing work, as always...

Andrew

Quote:

---

Originally Posted by Ripper

Some progress...

...

That's all for now. Hoping for some real-World progress in next update. :cool:

---

Wow. Just Wow.

Seriously, awesome job ! since I'm an engineering student and i do some cad (a lot) I must say that I won't be able even the quarter of what you did. You're crazy !!! Keep it up

Thanks guys!

Elcamino94; Don't worry, you'll get there too. A couple of years after you started working you will be able to manage this type of project. I wasn't very confident during my student time either, but as time went by I gained experience.

Do you have the specs for the rotisserie you made? I've also got a 74 and I'm looking for a good rotisserie design to build. Thanks!

I'm gonna sell mine, but you seem to be a little bit far away.
I'll see if I can get you some measurements. :)

After primer, I spent 18 hours to fill all the seams with putty (?)
https://static1.pt-content.com/image...5600x398-1.jpg
https://static1.pt-content.com/image...5600x398-1.jpg
https://static1.pt-content.com/image...4600x398-1.jpg

Then a thin layer of body for exposed areas
https://static1.pt-content.com/image...5600x398-1.jpg
https://static1.pt-content.com/image...6600x398-1.jpg
https://static1.pt-content.com/image...8600x398-1.jpg


And then... then... THEN!!! The epic layer of paint! No more welding on the body!!
https://static1.pt-content.com/image...0600x398-1.jpg
https://static1.pt-content.com/image...7600x398-1.jpg
https://static1.pt-content.com/image...0600x398-1.jpg
https://static1.pt-content.com/image...1600x398-1.jpg
https://static1.pt-content.com/image...2600x398-1.jpg
https://static1.pt-content.com/image...4600x398-1.jpg

Aaaah... great feeling! I'll start assembling the rear suspension within a couple of weeks.

looking awesome

Haha! Yeah I'm a little far.You're doing a beautiful job by the way, love the cad work :headbang:

body prep on this car is fantastic and the right way to do it!

https://static1.pt-content.com/image...0600x398-1.jpg
https://static1.pt-content.com/image...8600x398-1.jpg
https://static1.pt-content.com/image...9600x398-1.jpg

Quote:

---

Originally Posted by zouk52

Haha! Yeah I'm a little far.You're doing a beautiful job by the way, love the cad work :headbang:

---

Thanks!
I'll get some measurements for you within a couple of weeks.

Quote:

---

Originally Posted by Buryingthesun

body prep on this car is fantastic and the right way to do it!

---

Thanks! It was a long journey getting to where it is now, but you tend to forget how much hard work it was. I haven't kept track of time invested in it, but a rough estimate would say probably more than 1000 hrs for the body shell including the cage. I spent more than 200hrs replacing the visible body panels (fenders and rear panel that lights and bumper sits on). Another 100 to raise the fenders 1,5", 150-200 for building and welding the cage... Hmmm, 1000 might not even be enough...

here's a before-picture from the tear down...
https://static1.pt-content.com/image...d600x450-1.jpg

Quote:

---

Originally Posted by Bryce

looking awesome

---

Thanks!

Design work with the front suspension is finished. I've started building the frame, but it's a little too early to show any work from that yet.
https://static1.pt-content.com/image...1600x337-1.jpg
It's lighter, more rigid and alot more complex than the original (last thing isn't really anything good...)
1:1 motion ratio and almost 100% linear spring rate over the entire suspension travel. It took some serious time to find the right geometry, specially since I needed to keep some of the parts from the stock frame.
I wanted pull rod suspension from the start, but it was impossible to get a good packing of the components so I had to go for push rods instead. I chose push rods instead of traditional attachment because of lower arm is 21" long. Attaching the coil over close to the upright would create a quite angled position of it which would also increase during compression. Increased angle reduces spring rate, so a push or pull-rod linkage was necessary to get the characteristics I was looking for.

https://static1.pt-content.com/image...1600x337-1.jpg
https://static1.pt-content.com/image...3600x337-1.jpg
I'm not really satisfied with the added complexity, but it's impossible to avoid when involving linkage systems for the suspension.

https://static1.pt-content.com/image...4600x337-1.jpg

Dude....just stop...you're seriously making us all look stupid and lazy...LOL

Andrew

nice work again Anders, one of my favorite builds :-)

Quote:

---

Originally Posted by andrewb70

Dude....just stop...you're seriously making us all look stupid and lazy...LOL

---

lol!

Best build thread on the whole interwebz. Glad to see it's still progressing, keep up the great work Anders!