17 replies to this topic

[Huw Jadvantich]

Lots of people deride the Lotus 30 and 40. can anyone tell me what was ACTUALLY wrong with it (them)?

[RTH]

It used a Backbone chassis in the style of the Elan . This was 1964 the Elan was new to the car market probably the idea was to prove the concept in racing.

Whilst it worked fine for a road sports car , for racing it twisted in cornering, it had very poor torsional stiffness so had frightening handling and relatively poor roadholding. It just was not possible to dial out this fundamental design flaw.

The Europa and racing version the 47 and subsequent 62 also tried it in GT racing with a touch more success , but it was not the way to go for racing cars.

Some wag said the 40 was a 30 with ten more faults !!

[Huw Jadvantich]

Was the body structure glass fibre like the Elan?

[RTH]

Yes it was . Len Terry at the time advised Colin Chapman that it was not a viable concept. The backbone was made from 20 gauge sheet steel for the first 3 , it was immediatey apparent this was way too flexible and they were redone in 16 gauge but especialy with the torque of a 4.7 Ford Fairlane V8 and 271 BHP .

To make matters even worse the body shape low drag though it was , produced front end lift at high speed and all manner of chin spoilers were tried. It overheated, it had poor brakes and much else. I believe huge amounts of effort went in to it , to make it work, but ultimately Len Terry was proved right.

[simonlewisbooks]

Originally posted by RTH
It just was not possible to dial out this fundamental design flaw...

...t the time, but latter-day owners found a carefully located roll hoop (not present on the originals) can add considerable rigidity to the structure . So those cars running in historic racing now handle a lot better than they did in their youth.

Great looking car I have to say.

[RA Historian]

Originally posted by RTH
Some wag said the 40 was a 30 with ten more faults !!

That 'wag' was Richie Ginther at the Riverside Times GP, October, 1965.

[bradbury west]

Chapman's idea/obsession at the time was that the same basic design/layout would encompass 3 or 4 different models around the same theme or design parameters. Hence his displeasure when Len Terry explained a few shortcomings, both in design and materials.

Surely the modern day roll-over bars must be unlawful if they add strength and rigidity, since they must constitute chassis modifications, by definition. Or am I just an innocent at large?
Roger Lund.

[simonlewisbooks]

Originally posted by bradbury west
Surely the modern day roll-over bars must be unlawful if they add strength and rigidity, since they must constitute chassis modifications, by definition. Or am I just an innocent at large?
Roger Lund.

It's a fact of life these days Roger, look at any historic saloon car with a multi point cage . One of the main arguments against rollover bars on historic cars was that they changed the fundamental rigidity of the chassis and set up potential componant failures at a result of the loadings being changed.
The problem is who would dare ban a safty feature from a race car now and risk being sued for making the owner risk his life more than he wished to...
I know it all should be a matter of personal choice but you have to think like a lawyer these days uif you are an organiser or a rule maker - sadly.

[doc knutsen]

Originally posted by Huw Jadvantich
Lots of people deride the Lotus 30 and 40. can anyone tell me what was ACTUALLY wrong with it (them)?

Lack of torsional stiffness (backbone a la Elan not beefy enough to handle V8 power), poor accessibility due to one-piece body shell, aerodynamic lift due to bodywork design, and underbraked due to using basically Lotus 15 brakes. Not one of Chapman's better ideas.
Now, if he'd only added a carefully located roll cage

[Paul Parker]

Not only the added rigidity of latter day roll cages etc. Period pattern tyres tend to be softer than the originals and highlight chassis design faults and promote twitchy on limit handling. They also start to go off quickly on front engined sports cars with heavy engines (Listers, D types etc.) and the handling deteriorates apace.

As for the risk of component breakage elsewhere within the chassis/frame, modern parts, metallurgy and associated bits and pieces are much better designed, stronger and durable than they used to be, not to mention probably new most of the time. 1950s/60s racing cars outside of the factory machines were frequently raced on second hand tyres, shock absorbers etc., etc., out of economic necessity.

Years ago somebody, it might have been Willie Green, pointed out that sliding a 250F around in historic racing was not as predictable as in period because the cars had more grip than originally. Paradoxically latter day 'Birdcage' Masers must benefit in every area from modern welding that reduces the amount of slop inherent in the original multiple small bore tube frame that became increasingly flexible with wear and tear and of course began to break up on rough roads like Sebring and the Targa Florio.

The real worry must be the day that the FIA and insurance companies invoke an active safety policy that demands roll cages, harnesses and all the modern paraphenalia as a necessity to go racing anywhere. This would result in the further butchering of the reasonably original cars still left and the aesthetic destruction of all 'historic' racing.

[Simon Hadfield]

I must have missed something here, on the Lotus 30 I raced the rollhoop was as the factory drawings (but higher). I cannot concieve a rollhoop structure that would add stiffness to a 30 that did not look like a naked Nascar!

[Huw Jadvantich]

I think you are right Simon, the roll hoop would have to be a cage before it gave the car as described any real torsional stiffness.
Thanks for your input guys

[bradbury west]

IIRC Motoring News had a double page cutaway drawing of the 30 in period

RL

[simonlewisbooks]

Originally posted by Simon Hadfield
I must have missed something here, on the Lotus 30 I raced the rollhoop was as the factory drawings (but higher)

Doesn't look like Jim had the benefits of one...

[Simon Hadfield]

That is Jims 64 Series one car -13" wheels etc. Not visible but behind his head is a very small single hoop. The Series two cars came with an American legal full width hoop and most early cars were retro-fitted.

[sterling49]

Originally posted by simonlewisbooks


Doesn't look like Jim had the benefits of one...

Jim's car looks great! Such a pity it never performed well, not even at the Guards Trophy Meetings! If I rummage around my garage, I might just find my copy of this programme (along with the other 10 plus years worth!)

[Ted Walker]

The very first car supplied to Ian Walker Racing raced at Mallory Park in June 64 with NO hoop at all

[Doug Nye]

Originally posted by RTH
Yes it was . Len Terry at the time advised Colin Chapman that it was not a viable concept. The backbone was made from 20 gauge sheet steel for the first 3 , it was immediately apparent this was way too flexible

Len told me those original backbone chassis "were like old Duckhams oil cans - you know, they went 'boing' if you squeezed them"...

DCN