I was infact referring to the FWD Lotus elan, im aware of what the RWD one is. Im sure JT191, if he sees this thread can clarify completely...
Anyway, the Lotus elan was produced as an entry-level model during the time Isuzu owned Lotus [hence you see Handling By Lotus badges on Impulses, Storms etc].
The lotus elan suspension arrangement IS SHARED with the Isuzu/Geo storm, impulse, stylus. Also shared is the 4XE1 1.6L DOHC Isuzu Engine, and gearbox.
Yes, the lotus elan DOES HAVE AN ISUZU ENGINE.
Some of that is very accurate, some is well intentioned but a little off target.
Isuzu never owned Lotus. The quick, short, and oversimplified explanation is that General Motors owned controlling stock in Isuzu from 1971 through 2006, and GM owned Lotus from 1986 through 1993. This is usually pointed to by the Lotus historians and English speaking auto journalists (especially the American magazine writers). With reference to the Lotus Tuned Isuzu cars, the comment is usually something like "They needed Lotus to fix the suspension so that the car would handle right...". However, some of the cars without Lotus Tuned suspensions out handled the ones with Lotus Tuning, most notably the 1987 Impulse RS out corners and slaloms the following year which introduced the Lotus Tuned suspension. And, Lotus Tuned Isuzu cars seem to predate GM's purchase of Lotus in 1986. The FWD Geminis with Lotus Tuned suspension had the trim name "ZZ/R", which was also used to name the trim level of the RWD Gemini. Maybe the Australians can verify if Lotus had anything to do with the RWD Gemini ZZ/R. But Isuzu and Lotus have some ties as far back as 1969.
And with the Japanese, introduction via a third party is very important. The Japanese motoring press points out ties between both companies through Komatsu and Tamiya. They seem to put much more importance on these ties than the relationship through GM, and also the long term friendly relationship between the two companies.
Some of the confusion might have to do with the lesser known (in the US) Irmscher Tuned cars. Irmscher is an Opel tuner and this relationship would have been totally due to both company's ties with GM. Isuzu offered sporty versions of almost all of their cars named as both Irmscher and also Lotus. Some of the more important mechanical pieces of both these packages were the same, and overall, other than selection of spring rates, damper rates, and sway bar diameter, the actual pieces were all pre existing Isuzu designs, and the "tuning" was the selection of the individual pieces in a specific combination to work the best with the springs, dampers, and sway bar diameters.
There is some confusion of styling also, and claims that Lotus or Irmscher are responsible for spoiler, air dam, or bumper styling. But the Irmscher bumper in one market is the Lotus bumper in another market, and neither seems to have had any input in the vehicle styling.
This reduces the involvement of both Lotus and Irmscher to more like what any serious racer does when preparing a production car for track use. Neither Lotus nor Irmscher had anything to do with the fundamental suspension design, possibly some input on small pieces and details, and overall simply fine tuned what was already there to provide a very mild and streetable track tuned suspension with a high reputation name behind it.
Comparing the two, Irmscher understeers and Lotus is more neutral and leans more toward easily induced oversteer, but Lotus is far too soft with excessive body roll. Lotus came much closer to a road course and autocross/gymkhana setup, but the springs are too soft for ride comfort. Balance is very good with the Lotus Tuned suspension, and when two comparable vehicles are run side by side on the track, the Lotus Tuned car edges out the Irmscher Tuned car by a little over a second on a 1 minute 20 second course.
Back to the "new" or FWD Elan. Lotus decided they were going to build a new Elan with new technology. Not a retro homage to the original Elan like the Miata (same shape with modern mechanicals), but a complete reinvention for a new generation, and this time it was going to be a reliable daily driver. In the early 80's they were tight with Toyota, and did some development toward this vehicle with Toyota engines. The Toyota enthusiasts and Lotus purists then say "GM bought Lotus, killed any relationship with Toyota, and Lotus was forced to use the Isuzu engine due to GM's ties with Isuzu." This is usually followed by a comment to the effect that Toyota followed through and built the MR2, which is what the Elan should have been.
But Lotus has always been somewhat independent. They subcontract to do tuning work for anyone who can afford their fees, and they continued to do work for Toyota after GM purchased them in 1986.
Lotus isn't going to use any parts that would tarnish their name. Lotus selected the Isuzu engine and transmission for their Elan. Both were first generation finished products when they were shown to Lotus. In 1988, Lotus set their specifications based on that first generation drivetrain, and did not make changes to the engine over the life of the car, as is common with the Japanese makers (and is the reason that the production date is needed for ordering parts for a Japanese car). That first generation engine had smaller crank journals and bearings, smaller water and oil pump, and hydraulic lifters. They selected their own transmission ratios and did their own fine tuning of the ECU. If we call that a second generation of that engine, Isuzu put in further development for a third generation for their 1989/90 models using the same engine and transmission. The Elan suffers from overheating problems when driven in traffic, the Isuzu suffers overheating only on all day track day events and endurance racing.
[And as a side note, the 1.8 liter engine appears to have been developed specifically for Lotus for a second generation FWD/AWD four seat Elan that never materialized. This accounts for the step backward in valve train, back to hydraulic lifters, and lower HP per displacement because Lotus didn't like solid lifters. It also accounts for these engines being effectively dumped into the US market in 1992 and 1993 model cars, while not used at all in the Gemini in the home market.]
But, once past the purist protests of the car being front wheel drive, the engine being from a less prestigious Japanese manufacturer, and climbing price/production cost that Lotus did not anticipate with their first transition from custom building to actual assembly line production car manufacturing, the car achieved more than its reputation belays. It was the first "front wheel drive sports car". Lotus even admitted that the Esprit is faster in a straight line, but on a twisty road, the Elan walks away. It is the first dependable Lotus car that could be driven every day, on rain, snow, whatever. It has air conditioning, power windows, power steering, leather upholstery, etc. It is a entry level exotic car that can be driven to and from the office for a daily commute.
This is very different from the Elise and the various models that are more or less track day cars or the starting point for building a race car. The Esprit was always more of a temperamental exotic requiring lots of maintenance, while the FWD Elan required only basic Japanese car maintenance and a high level of driving comfort. The closest thing Lotus has to this is the upcoming Evora.
The FWD Elan was quicker and cornered better than the Miata, but the Miata cost less and had more familiar words in the description (rear wheel drive). Currency exchange rates, production costs, and reviews written by an automotive press unwilling to accept a front wheel drive sports car, all have more to do with the success or failure and reputation, than any of the details about the vehicle itself. Nine years later, Acura would bring it's Type R to the US market, and all of the reservations about a FWD car were forgotten.