14 replies to this topic

[BritishV8]

I've read that the original Formula Two version of the Lotus 69 chassis was "monocoque" from engine bulkhead forward, whereas the F3 and FF variants of the 69 had tubular steel frames from stem to stern. (In the case of the F3 car, a stressed skin was riveted on, right?)

I don't suppose any of you can have a photo or drawing (or link to same) that will help me better visualize the Lotus 69 F2 design?

Am I wrong to imagine an elaborate aluminum sheetmetal fabrication, something like this G.R.D. 272 tub?

(if you're curious, more photos appear here: Michael Snowden's G.R.D. 272)

[Allen Brown]

It's not that simple. There were many different Lotuses all using the model number '69'. For example, the 1970 F2 car was a spaceframe but the 1971 F2 was a monocoque. Then there were FB cars, F/Atl cars, F3 cars and FF cars; all across at least two seasons.

[BritishV8]

It's not that simple. There were many different Lotuses all using the model number '69'. For example, the 1970 F2 car was a spaceframe but the 1971 F2 was a monocoque. Then there were FB cars, F/Atl cars, F3 cars and FF cars; all across at least two seasons.

Yes, I've found this all very confusing but I'm determined to get it sorted out. I've carefully photographed 71-69-5FB and am preparing an article about it. I believe its chassis is nearly completely similar to the F3 chassis, except perhaps for tuning differences having to do with tires. What I'm very curious about is just how different 71-69-5FB is from 71-69-5F2 which was Emerson Fittipaldi's F2 car for that year. Some people throw the term monocoque around so freely. If there's a full length steel frame underneath aluminum, I think the term is misleading... Is that what Lotus did for F2 in '71?

71-69-5FB:

[Allen Brown]

When you refer to 71-69-5F2, specifically which car are you referring to? Lotus tended to build real monocoques, not the panelled space frames sometimes described as a monocoques in the same period.

[Stephen W]

When you refer to 71-69-5F2, specifically which car are you referring to? Lotus tended to build real monocoques, not the panelled space frames sometimes described as a monocoques in the same period.

Panelled spaceframes were usually described as "semi-monocoques".

[JtP1]

Iirc from what I was told at the time. The Fittipaldi/ Moonraker car had a spaceframe with the fluids running through the tubes. This apparently was only fitted to works cars, commercial sales had seperate tubes. The Fittipaldi car still exists and was at the racing car show in 2009.

[Tim Murray]

According to Justin Haler's 1970 F2 Seasonal Survey in Autosport, the 1970 F2 69 had a monocoque centre section:

Dave Baldwin’s square-tubed space-frame 59 series had put Lotus back on the lesser formulae single-seater map in 1969, although in F2 the bulky 59B had met with an aerodynamic disadvantage on the faster circuits. Baldwin saw the new fuel tank rules [bag tanks now mandatory] as an answer to several problems on the 59B, and so he did a complete revamp to produce the very effective 69. This involved taking the 59B, cutting it in half down the middle and substituting a bulbous monocoque centre section to carry the fuel. The whole package was clothed in a very stylish and practical sharp body (without an engine cover) and the 69 was completed with a set of anti-Nürburgring beefed-up front wishbones.

[BritishV8]

Thanks guys. Helpful, but I'd really like to see photos. I've been searching everywhere...

Anyhow, I've got over sixty articles in my queue and I've got to start letting some go. Here's the newest:

Kyle Kaulback's Lotus 69 Formula B Race Car - chassis 71/69/5FB


~50 big color photos of construction and preparation details!

Let me know if you spot any inaccuracies in the article, so I can fix them.

I've also photographed a 1971-vintage Lotus 69 Formula Ford, and will be featuring it in a future article.

[Peter Morley]

There's a 69 F2 car for sale on Racecarsdirect at the moment, not many photos but one is a rear view and shows the spaceframe engine compartment which is attached to the back of an aluminium tub, in the same way as Marches etc were built. Given that Lotus invented the aluminium monocoque (at least in the way the term is now used) it is unlikely they would have built a 'faux-monocoque' (e.g. panelled spaceframe) like the early Ferrari attempts.

Might be worth asking the seller for some photos?

[asapiro]

hoping I could hijack this thread for my own purposes - questions ...

I'm interested in the Lotus 27 F Jr -which was the first lower formula moncocque Lotus

the cutaway thread has the terrific Theo Page drawing
and detailed photos of two examples are findable on the web - one on the Gurney Flap site ?
And there are the excellent photos in Taylor's Lotus bible

My question is: what is the width of the tub?
the Lotus 25 measured 27.5 inches across
the type 27 tub is described as narrower, and the two "side" structures appear narrower.
My guess is that the overall tub width was 26 inches and the side structures were close to 6 inches in width
I'm also guessing that the tub was the same length and height as the 25 - or very close

how'd I do??

Is there enough interest/knowledge to create a seperate thread??

Thanks guys. Helpful, but I'd really like to see photos. I've been searching everywhere...

Anyhow, I've got over sixty articles in my queue and I've got to start letting some go. Here's the newest:

Kyle Kaulback's Lotus 69 Formula B Race Car - chassis 71/69/5FB


~50 big color photos of construction and preparation details!

Let me know if you spot any inaccuracies in the article, so I can fix them.

I've also photographed a 1971-vintage Lotus 69 Formula Ford, and will be featuring it in a future article.

[bill p]

I hope this helps

This is the Tetsu Ikuzawa car (ch. no. 69/71-1F2), owned by me in 1984/85 - note high level brake fluid reservoirs are non-standard.



Uploaded with ImageShack.us

Edited by bill p, 13 May 2011 - 16:59.

[BritishV8]

There's a 69 F2 car for sale on Racecarsdirect at the moment...

Might be worth asking the seller for some photos?

Excellent! Thanks for the tip. I've e-mailed the seller.

Incidentally, there are a few more photos on the seller's own website. Still no close-ups though. Here are links:
http://www.racecarsd...US_F2_6903.html
http://www.espritcompetition.fr/

[BritishV8]

I hope this helps...

Thank you!

[Pullman99]

Does anyone know if any of the semi-works (?) Lotus 69s entered in 1971 by the London International Racing Association (LIRA) for Reine Wisell and Richard Scott are extant?

When I saw them in period they always looked to be excellently presented but were usually outpaced by the opposition, especially Emerson in the Moonraker car.

Edited by Pullman99, 14 May 2011 - 09:02.

[Chris Townsend]

Does anyone know if any of the semi-works (?) Lotus 69s entered in 1971 by the London International Racing Association (LIRA) for Reine Wissel and Richard Scott are extant?

When I saw them in period they always looked to be excellently presented but were usually outpaced by the opposition, especially Emerson in the Moonraker car.

I believe that the Richard Scott 71/69 car survives today as does the ex Fittipaldi 1970 F2 car used by Wisell to win at Pau in 1971.
The FB car that was used by Wisell later in the 1971 season - also used by Ikuzawa in the 1971 JAF GP - was very badly damaged in Ian Mawby's accident at Snetterton in July 1973 and probably broken up, with parts of it used in John Bicht's Swift Atlantic car in 1976.