View Full Version : 32 Roadster Scratchbuild Tube Chassis

11-13-2005, 07:28 PM
Alright, some of you have maybe seen me post earlier about the roadster i want to sctrachbuild. Well today i started the project. I've been doing alot of research and started designing the all tube chassis frame. Here a list of what the final car will have:

Chevy 350 Supercharged
Chevy 700R4 built by me
Handbuilt all steel body (no bondo hopefully!)
Tubbed out rear end (9") with 22" wide tires
4-link rear suspension
Custom Designed IFS
Sucicide Doors
Chopped Top

So here's some early renderings, these took about 2 hours. As you can see the tires are really really wide! I have seen some 32's with wide tires but I haven't seen that many with them set into the body. Since I'm making the body I can do whatever I want! I'm going to design my own IFS similar to how astroracer did. Keep checking out this thread as there's more to come.


I think the tubing is going to be 1.5" DOM steel, open for comments!

11-13-2005, 09:39 PM
Well SBDB (this would be a good place for your name) it certainly an ambitious project. This type frame should be very strong. I would like to see it when you have the basic dimensions and attachment points for suspension, brakes and steering.

Several questions come to mind like what type of tubing you are planning on using. How good of a welder are you and what kind of equipment do you currently own. Do you have a jig or a fab table large enough to clamp/bolt parts to for tack up and welding?

I suppose there will be a complete chassis design in CAD before you start?...........thanks................john

Kerry Pinkerton
11-14-2005, 04:14 AM
Looking forward to your progress. One suggestion is to downsize your images a tad so they can be viewed without scrolling on a 800x600 monitor. Also makes them smaller so the folks on dialup can manage them.

roger n cindy
11-14-2005, 04:42 AM
Brendon , yo and welcome. ambitious project , good luck. driver or trailer queen ??? as a driver you might rethink those wide rear tires. as a racer and strip only car they should hook up great. again good luck and keep asking questions, we all learn from the answers. roger

11-14-2005, 04:57 AM
I'll make the pics smaller. I am was planning on using 1.5" DOM steel tubing and I have to build a chassis jig table. I would call myself a very good welder, I don't have a TIG yet but plan on getting one before I start the project. I also have done quite a bit of tube chassis fabrication (bikes and my sandrail) and seem to enjoy it. It will definatly be a different car. I want to build it and sell it and try to see if there's a market for more of them which might lead to a business in 10 years or so.


11-14-2005, 05:00 AM
The chassis looks very cool but I think you are putting the cart before the horse. Please take this as constructive criticizm only along with some info gathering.:-)
Doing this kind of design work for a living has taught me a few things...
1). The chassis is very rarely designed before the suspension points are located. The suspension points WILL determine where the chassis rails need to be and right now your forward rails look kinda wide.
2). What is your tire/wheel design based on? Having an actual tire/wheel combo on hand (or having access to them) is requisite for an accurate design. The reason I am asking this is because I have NO knowledge of any street type tire that is 32" wide... I have a set of 21.50x33-15 M/T Pro Streets and they are about the largest street tire available at 20 to 21 inches across the sidewall...
3). Have you done any steering studies with your front tire/wheel combo? This will also have an impact on the width of the front rails if you want to steer the car. Jounce and Rebound will also impact the front rail design.
As you can see there is a lot of work involved in doing a chassis/suspension design from scratch. The biggest and most important is knowing where your suspensions are going to live. This should be your main focus and, until you get these points nailed down, you are just wasting time and energy...

11-14-2005, 05:45 AM
Thanks astroracer, I am going to start to design the suspension, right now those renderings are just to give me a basic idea of chassis shape and how it will look. I can change anything easily. the tires aren't 32" wide thats the diameter, i think they are only 22". I have to start designing the suspension before i goany further. I really liked the ifs you designed. I would like to have similar numbers and easy driveability. I plan on using somekind of chevy spindles, maybe corvette. Once i pick out a pair of spindles i can actually start designing the suspension.

11-14-2005, 06:43 AM
Have you looked at Performance trends site?
They have a 9 day demo that comes with some canned suspension designs. A Corvette is one of them.
I actually did all of the design work for Bad Ast in the demo.
This will get you off to a good start and really takes a lot of the guess work out of getting a good design.

11-15-2005, 07:54 AM
I have looked at performance trends but right no i have a mac so i can't use it yet, i'm going to get virtual pc soon so i can download it.

A few questions, i saw that you recommended a cnc bender facility, i was planning on bending the long sweeps on metal bucks and using a torch, The way it was designed is that there is no compound bends it looks like it but there isn't, i haven't ever bent dom steel in long sweeps and i hope the using a buck to bend it around and a combinatino of heat will work, i'm just wondering if it will flatten the tube where it comesin contact with the flat surface of the buck.

Using performance trends software is it easy to get the numbers that i would want ideally? How do i know what numbers i want? 0 bumpsteer? can you make it better than a corvette suspension?