Lotus 98T

Lotus 98T

Category	Formula One
Constructor	Lotus
Designer(s)	Gérard Ducarouge Martin Ogilvie
Predecessor	97T
Successor	99T
Technical specifications
Chassis	Carbon fibre and Kevlar Aluminium honeycomb monocoque
Suspension (front)	Double wishbones, pull-rod actuated coil springs over dampers, anti-roll bar
Suspension (rear)	Double wishbones, pull-rod actuated coil springs over dampers, anti-roll bar
Axle track	Front: 1,816 mm (71.5 in) Rear: 1,620 mm (64 in)
Wheelbase	2,720 mm (107 in)
Engine	Renault Gordini EF15B, 1,492 cc (91.0 cu in), 90° V6, turbo, mid-engine, longitudinally mounted
Transmission	Lotus / Hewland 6-speed manual
Weight	540 kg (1,200 lb)
Fuel	Elf
Tyres	Goodyear
Competition history
Notable entrants	John Player Team Lotus
Notable drivers	11. Johnny Dumfries 12. Ayrton Senna
Debut	1986 Brazilian Grand Prix
Races Wins Poles Fastest laps 16 2 8 0
Constructors' Championships	0
Drivers' Championships	0

The Lotus 98T was a development of the Lotus 97T of 1985. Of the four chassis built three were assigned to Ayrton Senna, now in his second year with Team Lotus, and one to team mate Johnny Dumfries.

Designed by Gérard Ducarouge and Martin Ogilvie the chassis featured a lower monocoque than the 97T as a result of a regulation change stipulating a reduction in fuel capacity to 195 litres. The powertrain consisted of the new Renault EF15bis turbo V6 engine driving through a Hewland gearbox.

The EF15bis was to appear in two forms, the standard engine and the "D.P." engine which featured pneumatic valve springs for the first time. At the end of the season Renault introduced the revised EF15C which in addition to the D.P. valve gear also boasted common rail fuel injection and much revised water cooling through the cylinder head reducing the likelihood of pre-ignition (detonation). Power figures for this period of F1 history are largely speculative as most engine manufactures freely admitted that their test beds would not have a sufficient power rating to measure the 1.5 litre turbos output at above 4 bar boost. It is generally accepted that the Renault EF15 produced between 1,200 bhp (890 kW) and 1,300 bhp (970 kW) at 5.5bar boost.

The gearbox came in two variants, a conventional five speed and a new six speed. The six speed was very much a development gearbox and was largely unreliable. While Senna opted to run only with the five speed, Dumfries was tasked with testing the six speed. Both gearboxes featured Hewland internals within a Lotus designed casing.

Other notable innovations of the 98T included a two stage ride height adjustment, water injection through the intercoolers, an early form of barge board (also present on the 97T) and an advanced (for the time) fuel consumption micro computer.

During the 1986 Formula One season the Formula One paddock was very much alive with speculation as to the legality of the Lotus 98T. The increasing rumours prompted Peter Warr, then Lotus team manager, to issue a press statement after qualifying for the German Grand Prix, calling for the rumours to stop or for the teams to officially protest the car. While the rumours died down, they did persist, although no protest was ever lodged.

Complete Formula One results

(key) (results in bold indicate pole position)

Year	Entrant	Engine	Tyres	Driver	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	Pts.	WCC
1986	John Player Team Lotus	Renault Gordini EF15B V6 tc	G		BRA	ESP	SMR	MON	BEL	CAN	DET	FRA	GBR	GER	HUN	AUT	ITA	POR	MEX	AUS	58	3rd
				Ayrton Senna	2	1	Ret	3	2	5	1	Ret	Ret	2	2	Ret	Ret	4	3	Ret
				Johnny Dumfries	9	Ret	Ret	DNQ	Ret	Ret	7	Ret	7	Ret	5	Ret	Ret	9	Ret	6