Published on: Feb 23, 2018 @ 01:41 (C) Jay Auger (RGBS) - website owner & author Notice: Any form of duplication methods (including but not limited to copy/paste of text and screen capture) of the website's content is strictly forbidden. Page aussi disponible en FRANÇAIS (click)
It was quite surprising to see a duo of Peugeot 205 Turbo 16 Group B homologation road cars cross the block at the January 2018 Barrett-Jackson Scottsdale Auction in the Unites States. Even more bewildering, these cars were owned and consigned by General Motors. One of the cars was listed as having ‘active suspension’ and this of course warranted some further investigation by the Rally Group B Shrine! Initial credit going to Jonathan Grabowski for cracking this ‘egg’ open back in 2013. The Shrine has since cooked the ‘omelette’ by coming into contact with many of the former Lotus people involved in the project; engineer Patrick Peal, project head Steve Green, and research & development director Peter Wright.
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During the 1980’s General Motors was heavily involved in ‘active suspension’ systems as they built and tested several road cars at the Milford Proving Grounds in Michigan. Other such systems were also being developed across the pond by then GM-owned Lotus for use in Formula One. Lotus Engineering subsequently started to test active suspension systems on road cars, first debuting with the company’s own Esprit model, then for GM models such as the Buick Park Avenue and Chevrolet Corvettes.
The active suspension development originally conceived for the F1 team in 1981/82 became a major technical offering for Lotus Engineering which ultimately grew into a suite of active systems for vehicle dynamics control. Circa-1984, Lotus secured a massive contract from GM to develop an array of active systems which were planned to be showcased in the Corvette Indy concept car.
By this time Lotus had already built several cars with active suspension for GM while the company also worked with Volvo and had sold them an idea for creating active rear steer which worked incredibly well (it was at least +/- 5 degrees of steer or more than enough to control the steer response not just trim it). So Lotus had already gone beyond just active suspension. The particular concept that Lotus were working towards for the Corvette Indy project was ‘active everything’. The ultimate intention being to be able to control all of the forces at the tyre contact patch and achieve maximum performance.
For this special project, Lotus Engineering needed some new tech and some mule vehicles to try it out on; cars that would have lots of performance, be four-wheel drive, and ideally be quite easy to modify. While the engineers did look at building something entirely from scratch, they also analysed all of the cars around at the time, ultimately landing on the then current crop of Group B rally cars. The MG Metro 6R4 was a possibility, as was the Ford RS200, but Lotus eventually purchased the last two 205 T16’s (chassis #048 and #091) from Peugeot Talbot Sport (PTS) through André de Cortanze.
Of course when the cars were delivered to Lotus they were brand new so they first had to run them in as road cars. Patrick Peal, one of the engineers involved in the project, remembers the experience as “quite a hoot!”:
“I took one from my home to Brighton for the weekend to visit some friends… I discovered pretty early on that if I gave it full throttle for an instant and then backed off I could get a huge flame out of the exhaust. Made for a good effect in the high street at night… It still makes me smile – and there are still people around Brighton talking about the flame-spitting 205 on steroids!”
Project manager Steve Green also recalls driving one of the Pugs quite fondly:
“I know it would pull 7,500 rpm in 5th gear around 130 mph because I did that at GM’s Van Dyke test track, then got told it was a 70 mph speed limit… oh well!”
This excitement was aided by the fact that Lotus decided that the 197 BHP of the ‘standard’ car wasn’t enough, bearing in mind the power drains and added weight of the future special systems (such as hydraulics), so they had decided to purchase the ‘PTS kit’ or ‘Clubman’ upgrade from Peugeot Talbot Sport which would net a more capable 300 BHP amongst other chassis improvements. More information about the upgrade can be found with THIS LINK.
After the ‘joyride’ was over, Lotus went hard at work developing and fitting chassis #091 with fully integrated active systems. As you could expect, even such sophisticated engineering required a benchmark to make sure that it truly had improved overall performance, so the other 205 Turbo 16, chassis #048, was kept as-is for reference.
The journey of the Corvette Indy mule had begun by the fitment of Lotus’ famed technical offering: active suspension. The purpose being to keep the car’s body flat and level during braking and cornering at the limit of adhesion. To achieve this the system constantly measured pitch, yaw, and tyre slippage on all four wheels – making adjustments as needed.
The project continued by modifying the standard four-wheel drive system of the Peugeot with a second differential driven by a hydraulic motor, a sort of ‘tank drive’ system, so that the engineers could accurately control the speed of the front axle compared to the speed of the rear axle and therefore control slippage.
To do so, the engineers had to compare wheel speed versus true vehicle speed (longitudinally and laterally) which was a challenge – Lotus ended up using two Leitz Correvit optical speed sensors mounted behind the passenger seat to perform this seemingly simple yet very complicated task.
These sensors were a bit like two massive telephoto lenses and were a ‘pig’ to install, calibrate, and keep working, Peal remembers, as they often had to (re)calibrate the lateral speed sensor using a belt sander as a simulated ‘road surface’ whose belt speed could be accurately measured.
And of course rear steer could play whatever static tricks the Lotus engineering team could dream up as well; same-sense giving a crabbing motion, or opposite-sense yielding a very rapid rate of rotation within a small turning circle. In fact, one of the silly party tricks was to apply full lock and full throttle and get massive burnouts in a ridiculously small circle.
“… this left two very black and very small concentric circles on the test track, not much bigger than the wheelbase of the car. Oh, and a dizzy driver!” – Patrick Peal
The rear steer system was entirely developed by Lotus and was bespoke for both the 205 T16 and the technical demands of the project. Steve Green explains how it should not be confused with Nissan’s own offering of the time:
“HICAS was a much simpler system although it did do some similar functions to the system developed for the T16. Ours (Lotus) was a lot more sophisticated and designed to explore what was possible as an R&D exercise.”
The ‘brains’ of the whole operation was fitted under the front bonnet – featuring a fully bespoke and hand-built digital computer connected to the various active systems via an array of data and electrical cables. This effectively took away the space formerly occupied by the spare tyre.
Then Lotus technical director Peter Wright hints towards the car also being equipped with anti-locking brake and traction control systems activated via ‘pedal pushers’:
“We did very little development on these two systems, although I do remember we got them working and they were reasonably effective.”
One would be hard-pressed to find any clues of the presence of all these special systems just by looking at the car from the outside, with the exception of a single ‘canard’-looking appendage found only on the right side engine panel – it served as a ‘bodywork extension’ to allow the engineers to fit part of them around the engine.
Lotus then proceeded to test the full battery of active systems quite extensively in various venues around Europe; UK, France, and even on an ice lake in Sweden. This would tend to be confirmed by the car’s odometer sitting at 15,915 kms as it went through the Scottsdale auction block. The benchmark car in comparison had its odometer reading a pretty 2,192 kms at the time of sale.
“I remember that the torque control system was very noisy, and one could tell whether it was understeering or oversteering while sat in the office, just by hearing it out on the track!” – Peter Wright
Once Lotus had sorted it all out the main focus was for GM to build the Corvette Indy with similar systems. However, there were some major problems which left the concept car as a non-functional show piece in 1986. By then the two Peugeots were already shipped out to America for further testing at the GM Technical Center in Warren Michigan. The cars subsequently sat as part of the GM Heritage Collection for about three decades before being sold-off at auction.
After the Corvette Indy project “failure”, GM shifted their intentions to an attempt at implementing active suspension into the production Chevrolet Corvette ZR1. Again, further problems and exorbitant costs prevented this from happening. The active systems developed with the Peugeot mule were ultimately ‘rebooted’ in the 1990 Chevrolet Engineering Research Vehicle / CERV III.
Not much is known after this point at how the hard work of the Lotus engineers might have directly ended up affecting other projects at GM. However, with all of the rumours of the next C8 generation Chevrolet Corvette finally going mid-engine, possibly with active systems, it would be tempting to trace its lineage back to the Indy / CERV III and their Peugeot mule. It is safe to assume that if the future yields such a product then you’ll need be thanking the little Pug.
“…the systems were awesome. We were all very sad to say goodbye to the two Pugs when they were shipped to America at the end of the project.” – Patrick Peal
“The car in its standard form was pretty good already although it needed a certain amount of commitment from the driver to fully exploit its performance. The active version was an amazing machine and we learnt a lot about vehicle dynamics from it.” – Steve Green
“Great project, and good to know the cars live on.” – Peter Wright
2018 / 2019 – ACROSS THE AUCTION BLOCKS
The two “Detroit Lions” would seemingly collect warehouse dust somewhere in America up until 2018 when GM ultimately decided that it was time to part ways with these cars. Both were first consigned at the Barrett-Jackson Scottsdale Auction in January.
“G.H.” (anonymity requested), the buyer of the first car (the benchmark) on the Scottsdale auction block, (chassis #048 / VIN VF3741R76E5100048) found the story on the website and has since graciously accepted to share information about his 205 T16. It would seem that the Peugeot was seemingly missing some upgrades normally found in the Clubman / PTS package: a mystery that the Shrine went hard at work solving. The new owner has since restored the car to perfect running condition – a labour of love taking about a year. With luck, you may occasionally see this stunning homologation special drive up and down the scenic American west coast.
The second Peugeot (chassis #091 / VIN VF3741R76E5100091) was purchased by noted collector D. Hadjopulos as a simple curiosity – because some of his closest friends suggested “it would be cool!”. The car was however soon relisted in the Motostalgia Amelia Island Auction in March 2018 where it didn’t meet its reserve although the Shrine provided the proper backstory to the auction house. From both listings, it was quite apparent that the car still sported most if not all of the special systems implemented by Lotus back in the mid-1980’s. However, it is more than likely that they were rendered inoperable after the first GM sale, with the exception of the active suspension.
In 2019, a representative for the Hadjopulos collection, which then still included the systems car (chassis #091), contacted the Shrine to get more information on its provenance – ignoring most of the car’s Lotus background and status as GM’s initial mid-engine Corvette mule. The Shrine’s published story quickly changed the Pug’s fate as a simple “quick flip” to a project of restoring all of the active systems to working glory.
The Shrine thus immediately went hard at work by contacting the former Lotus engineers involved in the project back in the 1980’s. However, untimely delays made for a difficult time-table to set things up. The subsequent loss of the initial excitement for the project unfortunately made the owner backtrack and the car was again put up for sale a few months later as part of a “thinning out” of his vast collection. Rest assured that the Shrine will remain vigilant as to correctly help preserve this very unique part of Group B’s history.
(C) Article by Jay Auger – website owner & author
- Pictures courtesy of Motostalgia Auctions d’Elegance, “G.H.”, and Steve Green. All others are the property of their original owners.
- DISCLAIMER / LEGAL NOTICES
- Jonathan Grabowski (sons of taki), for breaking part of this story back in 2013.
- Patrick Peal, former Lotus engineer, for accepting to share more of the story.
- Steve Green, former Lotus project manager, for adding some much welcomed insights and extra info.
- Peter Wright, former Lotus R&D director, for sharing last minute details.
- “G.H.“, for sharing information, pictures, and for supporting the Shrine’s endeavour at preserving the history of Group B.
This page’s article is proudly featured in the June 2018 issue of Motor Sport Magazine (abridged / edited). It is an honour for the Shrine to have contributed to such a legendary publication!