Intro and General Dimensions discussion
 

Hi,
New to the Forum, from Australia and have follwed the Cobra replica industry for >25 years. I hold a sort of timeless fascination for them. However having been an Engineer now for 20 years I see things in a slightly different light in terms of design efficiency and optimisation. I got the following from ERA.

Weight [w/ iron Ford 427] ...2600 lb.
Weight distribution, f/r(%).......49/51
Wheelbase.................................90"
Track, front/rear..................55"/57"
Length, overall........................156"
Width, maximum......................70"
Torsional bending stiffness.......3500ft.lbs per degree of twist

Couple of issues I have:
1. Wheelbase per se a little short
2. Dont like the rear track being wider than front
3. Not very stiff compared with production sports cars
4. No hardtop = no safety

Has anyone considered addressing these shortcomings with a few design tweaks? Eg. Lengthen the wheelbase to about 95", Increase the track to about 63", Incorporate a full rollcage into the chassis and make the body a hardtop fastback and bond/bolt to chassis. Add some ground effects and you will have a safe 180 MPH car with less than 500hp. It is for these reasons I am considering starting the design process on the above. Would there be a market? Love to hear from you.

May look a little like this...

AC Cars Mk VI Cobra Gullwing Launched In Europe | Reviews | Prices | Australian specifications

Yes, there have been a lot of attempts to address these issues. In my opinion, it's not that hard to improve on the performance. But, then you won't have a replica. Nothing wrong with that. It's personal choice.

Shelby built a safe 180 MPH plus Cobra. It's called the Daytona, aerodynamics, that was the issue. Same chassis, same wheel base, new body. You might say it won a few races.

Tongue in cheek!:)

Also as I understand Shelby tinkered with the hardtop AC Cobra, pre-Daytona. They weren't getting good results.

http://pictures.topspeed.com/IMG/cro...e-2_460x0w.jpg


Ralphy

Hi Ralphy,
Yes I had considered the Daytona Coupe but just liked the potential for a Cobra coupe. Realistically though a Daytona project would be much more feasible. They have a less than enviable reputation here in Australia though as one of our legends of motorsport, the late Peter Brock, died crashing one a few years back.
No, I think I will go a little further down the design road before I entirely abandon this one. First step is to set about finding a useable 3D model for a 427SC which I can set about modifying. If anyone can help in this regard I would appreciate it.
cheers

I'm not an aero expert by no means. But it seems to me the big trademark hole being the the radiator intake. Makes a real hindrance to keeping air from beneath the car.

Ralphy

Tinkerer,
Try here, 3D CAD Browser - Download 3D Models and CAD Models.
You can join, pay a fee and download a 3D model. I believe they do have a Cobra.

g'day,

been there done that.
i've increased wheelbase of my scratch builds to 92.4" (+60mm) and widened +60mm starting from #6.

if you want i can send you 3d dxf mathdata of 427 bodyshell to play/modify, although i've preferred 289 body for my scratch builds.

peace,
ozgur
ozgurtan.com