Chassis design was developed  using a combination of the 14.5: 1 scale drawings in the book Porsche 917: Archiv 1968 -1974 Walter Naher, the Gunnar Racing videos of rebuilding 021, and many other photos collected from various other books and the web.

The chassis design and tube diameters reflects the original geometry accurately, with only minor changes in the lower engine bay area to package the G50 clutch slave and starter motor. And a small widening of the lower engine bay frame to help package the exhausts.

Main chassis (less all brackets and roll bar) is  made-up of 206 T45 laser cut tubes. These tubes were cut direct from the iges files generated from the intersected and trimmed Catia tube models. Welding has been a combination of TIG and MIG, dependent on joint design an access.

The chassis is designed in 5 different diameters, and is 100% circular tube as per the originals. And not like the replicas produced in Australia, South Africa, or the US which use a substantial amount of square tube to simply the design and build. Box or square also reduces torsional rigidity.IThe chassis dimensions also closely follow the original dimension, apart from the gearbox and engine mountings which are designed to accept the 964 engine and G50 box.

But if someone was to ask if I could fit an original Flat 12 and box, the answer would be "Yes I can". As I would revise the chassis Catia model to have the 3 original mounts. One engine mount at the front centreline of block, and the 2 gearbox mounts on the rear engine verticals.

It has taken approx 2500 CAD hours to design and engineer the jig and chassis. But the design time has reaped benefits regards chassis build time, as the first chassis has taken approx 200 hours to build.

Tecosim have run CAE run to check the torsional rigidity of the chassis, which is approx 28,500Nm/deg. As a comparison the GT40 monocoque is approx 17,000Nm/deg.  Low speed 20 & 30mph front impact was assessed, which resulted in a reduction in  wall stock of 5 tubes to lower the G-spike from 70 to 40.

917 Sub Sections

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From the Galleries

  • 150923-body on chassis 1
  • Rolling chassis with me for website
  • Rolling chassis 2

  • 150611-transparent body and chassis 3
  • White 9
  • Rolling chassis 3