Lotus 79, 81, 87 & 91

[chernaudi]

I know that the never raced Lotus 88 and the McLaren MP4/1 series introduced carbon fiber tubs to F1 and auto racing. But the first Lotus carbon tubbed car to race was the Lotus 91 in 1982.

I also know that Lotus introduced ground effects on the 78 of 1977 and the 79 of '78 was a refinement of the 78's GEf package.

But what I really want to know is what relation do the Lotus 81 and 87 have to the Lotus 79, and what relation the 87 has to the 91.

By the way, here's a good Lotus F1 site(mostly 70's and 80's stuff):

http://www.jpslotus.org/lotus.htm

[tony griffiths]

lots of books available about Lotus and Williams and you might eventually get to McLarten oh then there was the first carbon fibre Indy car ...........

[chris bailey]

The 81 came about because the 80 was a complete disaster. After the 79, Lotus thought they could generate enough downforce from the underbody to dispense with external wings. It didn't work. Unfortunately, Lotus didn't understand the reason. So, the 81 was an adaption of the 79 chassis. I know, I designed bits on it. The reason the 80 didn't work was largely a consequence of low chassis stiffness. I tried to make this point at the time, but was told otherwise. The 81 was ok-ish, and gained chassis stiffness halfway through the season when they finally twigged, modifying the centre section of the tub so that it could handle the downforce. By then it was too late. I saw the outline plans for the 88 at the time. Typically misguided blind alley. Whatever?

[chernaudi]

So what I'm reading is that the 81 was an updated 79. And I assume that the 87 was an updated 81 and an attempt to improve on it using some info from the twin chassis 88 that never was offically allowed to race. The Lotus 91 thus was something of a hybrid, using experience gained from the 88(the carbon tub) and the 87(basic overall design elements).

The only reason that the 88 never raced was that the FIA considered the inner tub a movable areo device(and now it would also probably be considered an illegal form of mass damper), and the FIA and FOCA complained about it.

[Darky]

Lotus 79 had riveted aluminium alloy monocoque. Lotus 80 was next development of this chassis with some changes. Same chassis like Lotus 80 had also Lotus 81. Experimental Lotus 86 used modified Lotus 81 chassis.

Comletely new carbon fibre/kevlar monocoque had Lotus 88. Pure same chassis had Lotus 87. It was very fast rebuilded Lotus 88 into classical wingcar aerodynamic. Also Lotuses 91, 92 and 94T used same carbon fibre/kevlar monocoque with limited changes.

Different chassis had Lotus 93T - carbon fibre/kevlar nomex honeycomb sandwich monocoque.

And Lotus 95T started next new chassis line.

(all from The Lotus Book by William Taylor)

[chernaudi]

Was the Lotus 87 a carbon tubbed car? I saw a picture on Flickr of(what was labled) a Lotus 87 partilay disassembled, and I saw an aluminum tub. It could've been an 81, but without being able to see the body panels, I couldn't tell.

[Darky]

Here are some pics of lotus 87:
http://www.club-lotus.fr/index.php?id=554

On cockpit photo is good visible carbon fibre monocoque.

I remember, before one race ( maybe on Silverstrone ) was Lotus 88 rebuilded into 87 specifications over night, because Lotus 88 was banned.

[chernaudi]

Well, it should've been moderately easy to convert the 88 to a rules compliant car, as the inner tub was built like a normal tub it one looks at the diagram of the 88's construction at that site.

And thus, at the JPS Lotus site that I gave a link to, the statement that the 91 was a modified 87(longer wheelbase used on the 87B, lightened chassis, and a reversion to a Lotus 78 type air box mid-season in '82(which was also fitted to the 87 in some races, as well as the 88) is correct.

[John Turner]

Much more info here:-

http://www.oldracingcars.com/f1/marque.php?MarqueID=LOT

[GTRMagic]

For Sale, the late John Dawson-Damer's Lotus 79 Here