Some cars leave a paper trail; the Lotus 98T left a name and a place in Lotus's list. What follows is what can be said with a source behind it. Its designer of record is Gérard Ducarouge (Technical Director) / Martin Ogilvie (Chief Designer) / Mike Coughlan (Assistant Chief Designer) / John Davis (Head of Aerodynamics and R&D) / Bernard Dudot (Chie.
Where it came from
The Lotus 98T was a Formula One car designed by Gérard Ducarouge and Martin Ogilvie and built by Team Lotus for use in the 1986 Formula One World Championship. Development of the previous year's 97T, the car was driven by Brazilian Ayrton Senna, in his second year with the team, and Scottish newcomer Johnny Dumfries.
Under the skin
it is rated at 800-900 hp (race-spec), 1,000-1,200+ hp (qualifying-trim) @ 12,500 rpm. Kerb weight is 540 kg. Power-to-weight lands near 1481 horsepower per tonne, which is hypercar territory, where the limiting factor is the tyre, not the engine. The wheelbase is 2720 mm. These are manufacturer figures carried by Wikipedia and Wikidata, not road-test measurements.
In context
Where it sits in Lotus's history is not in doubt: the 97T came before it; the 99T followed it. Nearby in the Lotus catalogue sit the Lotus 100T and the Lotus 101.