Currently reading: Lotus spearheads titanium component project
New titanium subframe technology is able to increase stiffness and reduce weight

A titanium rear sub-frame developed for the Lotus Exige S has reduced weight of the structure by 36 per cent and improved stiffness by 19 per cent.

The development was part of a six-month project between Lotus Engineering and Caged Laser to investigate the use of titanium as part of a chassis structure. The project follows one from 12 months ago, when an Ariel Atom chassis was fashioned from titanium.

Titanium is incredibly strong – it has the highest strength-to-weight ratio of any metal being as strong as steel but only 45 per cent of its weight – but is very expensive, flexible and tricky to treat as it’s chemically neutral. 

An Exige S’s steel rear sub-frame weighs 50kg, and the project targeted a 30 per cent weight reduction. The final weight reduction was 18kg – 36 per cent – a significant figure in an already light and tightly packaged car.

The torsional stiffness of the frame was also increased by 19 per cent, reducing vibration and making the car more stable in the process. The corrosion performance of the two sub-frames was comparable, as was the joining process, which is extensively tested with a variety of different adhesives with the titanium.

“We’ve shown we can join titanium and achieve durable joints,” said Lotus’s John Sellors, who unveiled the technology alongside Caged Laser’s Phil Squance at the Niche Vehicle Symposium, an event designed to promote the work of niche vehicle makers in the UK.

Sellors added that the technology was now being fitted to a prototype, and that it would begin road trials next week. There’s no word on the technology’s application to a production car. 


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Mark Tisshaw

Title: Editor

Mark is a journalist with more than a decade of top-level experience in the automotive industry. He first joined Autocar in 2009, having previously worked in local newspapers. He has held several roles at Autocar, including news editor, deputy editor, digital editor and his current position of editor, one he has held since 2017.

From this position he oversees all of Autocar’s content across the print magazine, website, social media, video, and podcast channels, as well as our recent launch, Autocar Business. Mark regularly interviews the very top global executives in the automotive industry, telling their stories and holding them to account, meeting them at shows and events around the world.

Mark is a Car of the Year juror, a prestigious annual award that Autocar is one of the main sponsors of. He has made media appearances on the likes of the BBC, and contributed to titles including What Car?Move Electric and Pistonheads, and has written a column for The Sun.

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