34 replies to this topic

[StanBarrett2]

I posted Tony Matthews’  drawing of the Lotus 77,  a.k.a  John Player Special 11 on the cutaway thread realizing it was what I would call 77B. 

Not at all the ‘adjustacar’  77  with the suspensions carried from the inboard brake calipers. Those special calipers must have cost Chapman a pretty penny !!.

Seems that the original 77s only were raced in that form for two or three events, before ‘normal’ suspension was bolted onto the front with rockers/ wishbones and outboard brakes.

A pity there was actually very little media exposure of this ‘adjustacar’  at the time, and little can be found now.

Anybody have some clippings or magazines lying around with some good images or sketches ?

 

 

macoran

[Allen Brown]

I cannot directly answer your question, but I was similarly intrigued when I saw that suspension in the launch photos.

 

I cannot miss the opportunity to 'plug' my own rude comments on this subject:

http://www.oldracingcars.com/lotus/77/

[StanBarrett2]

oldracingcars.com    is always a starting point for me whenever I research F1 cars. 

This is a piece out of MotorSports #10 - 1975

 

macoran

 

Edit....out of MotorSport archives 

Edited by StanBarrett2, 10 August 2018 - 20:58.

[FLB]

Dammit, i just saw JPS14 (77 R3) completely naked at Mont-Tremblant and didn't take pictures...

[StanBarrett2]

You don't take pics of  'nudes' ?   tssk

 

macoran

 

Looks like this

Edited by StanBarrett2, 10 August 2018 - 21:08.

[StanBarrett2]

Both 77s tangle in their first race in Brazil 1976

But I don't understand MotorSport's take on the incident.

Either Ronnie really chopped Mario severely.............Mario looks like he has a trajectory of understeering to Sao Paolo town centre

 

macoran

[Myhinpaa]

 

The oil (?) cooler fitted and especially the hose runs intrigues me....... Anyone who knows when this was added?

 

Doesn't seem to have Hethel written all over it exactly. Unless this was a desperate mod done during an all nighter before a particularly "hot" race ?

[StanBarrett2]

The early 77'B's  still had oil radiators in the back, not in the nose, see here G Nilsson at Monaco

 

Doug Nye in his book 'Theme Lotus'  has this to say on the 77'B'  front oil radiator

 

apparantly done for weight distribution, not a hot race, and seemingly a permanent modification - nothing desperate or hasty.

 

Later photos of 77-14 still show the hoses running through the suspension, so probably they couldn't plumb them through the monocoque.

 

macoran

[Myhinpaa]

The early 77'B's  still had oil radiators in the back, not in the nose, see here G Nilsson at Monaco

 

Doug Nye in his book 'Theme Lotus'  has this to say on the 77'B'  front oil radiator

Apparantly done for weight distribution, not a hot race, and seemingly a permanent modification - nothing desperate or hasty.

 

Later photos of 77-14 still show the hoses running through the suspension, so probably they couldn't plumb them through the monocoque.

 

macoran

 

Thanks for extra information Macoran. DCN mentions that the car which first had this feature first became a development chassis,

after the the engine mount/sagging incident at Paul Ricard.

 

Did this become a feature on all chassis or just on this car and the one in the photo above?

 

Found a photo of Jarier in a DN5 which shows the oil cooler from above and like it was planned to be there from the beginning.....

 

Still wonder what Chapman's comment would have been? But then again he was probably 100% focused on the 78 and had lost interest in the stop-gap 77??

If Tony Southgate's various modifications made the car faster Chapman would tolerated it, especially if it made Mario complain less or stop asking for when the 78 would be ready.

Edited by Myhinpaa, 12 August 2018 - 21:32.

[StanBarrett2]

 

Did this become a feature on all chassis or just on this car and the one in the photo above?

 

Various modifications were made to 77 - 14.

 

Doug Nye mentions later in his article that all the modifications were then carried over to the race cars, so that should include the nose mounted oil cooler.

 

And yes, it seems Tony Soutgate planned the nose cooler on the Shadow from the start on the DN5 model.

DN1 had twin rear coolers, and I think DN2 and DN3 started off witht the nose mounted oil coolers.

 

Your thought about Chapman already having his concentration focused on the 78 is probably correct.

 

macoran

[chr1s]

The front mounted oil radiator was carried over onto the 78, but was the installation neater?

[StanBarrett2]

The front mounted oil radiator was carried over onto the 78, but was the installation neater?

The location was carried over, the integration into the 78 design better..........not an afterthought or modification

 

macoran

[blackmme]

Just slightly off-topic but Scalextric modelled the 77 in its original launch form.
Rather an accurate and well performing car for that period and I often beat my mate with his Shadow 😃

Regards Mike

[StanBarrett2]

Really cool stuff that original suspension, probabaly too complicated for anyone to fathom.

Was it Doug Nye who dubbed it the 'Confusacar' ?

 

macoran

[mariner]

Whether it was an " adjustacar" or "confusacar" is an interesting discussion but the original design was one of those Chapman things that was very elegant  in conception as the track and wheelbase could be altered quickly without dismantling or re - setting the suspension. Just swap some little sub frames at  the front - much more work at the rear though.

 

This was in the period where Chapman was going back to basics as he tried to regain competitiveness after wearing out the 72 approach. Didn't work on the 77 but it certainly did when a bit more thinking got Lotus the 78/79!

 

I suppose all the vehicle dynamics which can now be learnt by motor sport Bsc students from books and modelled on Excel was locked up in the brains of a few engineers like Chapman in those days.  At the launch of the 77 he remarked " all that matters is how long it is, how wide it is and where the weight is" That is a profoundly accurate description of the basis of today's vehicle dynamics understanding and quantification.

[doc knutsen]

Really cool stuff that original suspension, probabaly too complicated for anyone to fathom.
Was it Doug Nye who dubbed it the 'Confusacar' ?


macoran

Most un-Chapman-like with that horrid arrangement poking out in the air stream. Remember the beautiful simplicity (and clean airflow) of the Type 24 and type 25 front suspension, utilizing the rocker arm upper w/b with the spring/damper unit tucked away, inside the bodywork.

[mariner]

With respect to things sticking into the airstream that was period when people wondered about what drag that saved as they realised how much drag the front tyres produced. That was less true on the 25 as it ran such skinny tyres inboard springs probably helped a lot.

 

I wonder if Chapman was still assuming the front tyres were prone to overheating with outboard brakes which turned out to be less true with the bigger tyres. Certainly  the original layout had massive braking capacity, twin calipers on vented brakes fully out in the airstream. Also if you look closely you can see it had rising rate pullrod spring set up.

 

Also the 77 tub was , according to Tony Southgate who worked on it, extermely light ( and fragile). Getting rid of all the inboard rocker bulkheads saved weight.

Edited by mariner, 25 August 2018 - 09:22.

[doc knutsen]

With respect to things sticking into the airstream that was period when people wondered about what drag that saved as they realised how much drag the front tyres produced. That was less true on the 25 as it ran such skinny tyres inboard springs probably helped a lot.

 

I wonder if Chapman was still assuming the front tyres were prone to overheating with outboard brakes which turned out to be less true with the bigger tyres. Certainly  the original layout had massive braking capacity, twin calipers on vented brakes fully out in the airstream. Also if you look closely you can see it had rising rate pullrod spring set up.

 

Also the 77 tub was , according to Tony Southgate who worked on it, extermely light ( and fragile). Getting rid of all the inboard rocker bulkheads saved weight.

And the inboard mounting of the lower wishbone...a big rod end mounted in single shear, ugh! And as for using the calliper casing as a load bearing structure...

[Henri Greuter]

Saw one of them at Monterey last weekend, specially the front part is beyond belief.

Chapman must have been pretty desperate to put something like that car out. It goes against everything he believed in aero-wise....

[StanBarrett2]

Good thing you didn't see the original, your eyes would still be rolling in your head 

macoran

[ibsenop]

The original front suspension:

 

The modified front suspension:

Edited by ibsenop, 02 September 2018 - 21:34.

[Charlieman]

Saw one of them at Monterey last weekend, specially the front part is beyond belief.

Chapman must have been pretty desperate to put something like that car out. It goes against everything he believed in aero-wise....

Lucky you, Henri. I'm thinking that Chapman no longer cared much about aerodynamics of the early Lotus 77. Following the change to Goodyear tyres, the decline of the 72 and the failure of the 76, Chapman was trying to re-understand the fundamentals of weight transfer. He was trying to understand how Goodyear tyres behaved after changes which were outside the limits of a conventional suspension setup. When the Lotus 77 started to work, it was tidied up. The car which won the 1976 Japanese GP was a good looker.

 

It was brave to experiment in public with a car which initially looked so crude. I'd like to know more about how the Lotus 77 contributed to the Lotus 78.

[StanBarrett2]

I'd like to know more about how the Lotus 77 contributed to the Lotus 78.

I've had a quick look at my scanned files on the 78.  Most magazines of the day which published articles when the 78 came out mention that the main dimensions (wheelbase/track)

and weight distribution .........lessons learned with the 77 were carried over as were some suspension components.

I'll have a read through some other literature to see if I can find out more.  You've got me inquisitive as well now............memory does let one down after so many years.

 

macoran

[arttidesco]

 I'd like to know more about how the Lotus 77 contributed to the Lotus 78.

 

I was recently discussing this elsewhere, I have found evidence that nylon brush type skirts were tired on the 1977 Lotus 78, but my little grey cells, damaged or otherwise by many orbits of the sun, have a memory of reading an article or race report in Motor Sport which clearly said Gunnar Nilsson tried, perhaps only during practice, this nylon brush type of skirt while driving a Lotus 77 at one, or perhaps both of the North American race meetings in 1976. Sadly my copies of Motor Sport have long since been recycled. Can anyone confirm this as fact.... or have I got my years and model types mixed up ? TIA

[smbrm]

The brush skirts appeared on the 77 at Mosport for sure, on Andretti’s car. But I also have a vague recollection seeing hard plastic skirts at some point, maybe earlier in practice. Theme Lotus by Doug Nye suggests the the 77’s used brush-skirts at the. North American races.

Edited by smbrm, 15 September 2024 - 02:10.

[Nick Planas]

The brush skirts appeared on the 77 at Mosport for sure, on Andretti’s car. But I also have a vague recollection seeing hard plastic skirts at some point, maybe earlier in practice. Theme Lotus by Doug Nye suggests the the 77’s used brush-skirts at the. North American races.

I know I have definitely seen* a side view pic of either Gunnar or Mario in the 77, taken low down and clearly showing skirts / brushes of some sort - it sort of got my teenage brain thinking about the complexities of aerodynamics in great detail.

 

*For "I know I have definitely seen" you may wish to add "unless I'm very much mistaken" 

[B Squared]

Sorry about that, that was regarding the Lotus 78 my apologies

[2F-001]

In Peter Wright’s book, he describes three iterations of skirt used on the Lotus 78 - but it’s not clear at which point of the season each was first raced:

 

1) the brush skirt (soon deemed to be hopelessly inadequate with venturis).

2) the somewhat flexible hinged-inwards polyethylene sheet skirt, sprung to keep it down, but then sucked in - and thus up slightly - at high speed to keep the wear rate down, and then PTFE rubbing strip added to combat that.

3) the rigid and hinged-outwards aluminium sheet skirt, with the much harder ceramic rubbing strip which could then be sprung down strongly without such worries about wear.

 

Then came the fully rigid, sprung, ceramic-edged and sliding “board-in-a-box skirt” (Wright’s words) for the Lotus 79. He writes that the Wolf appeared first (at Monaco) with sliding board skirts - Lotus having “not considered they would be legal”.

 

re. the 77: as the car eventually settled on a rather more conventional front end arrangement (and became a winner) can the ‘adjustacar’ concept be considered to have delivered on its purpose, rather than being a mistake or a dead-end?

[Doug Nye]

My understanding was that extensive experience with season-long development of the 77 put Team's engineers on a profitable track in producing the 78.  So experience with the confusacar served to confirm rather than confuse further....

 

DCN

[amerikalei]

Didn't McLaren start experimenting with undercar skirts in 1976?  Was this something that made its way around the paddock prior to Chapman's developments with the 78?

 

The Chaparral 2J had its skirts of course, but I don't recall hearing who in F1 started trying to control undercar airflow prior to ground effect venturis.  The first time I saw that noted was back when a lot of the Hunt-Lauda 1976 retro books were coming out.  Sadly I never got to witness that era of F1 firsthand.

[Charlieman]

Both Brabham and McLaren experimented with rigid skirts underneath the cockpit area in 1976.

[ReWind]

But not to get ground effect but to prevent air flowing under the car. It was a means to act against tendencies of a car to lift.

 

The skirts of the ground effect cars were means to prevent the air under the car to leave at the sides.

 

At least that is how I understood it at the time.

[Doug Nye]

Correct so far as I recall, although those 'skirts' were initiated by a search for something reasonably flexible to act as an air dam, originally mounted laterally just inboard of the extreme nose with the notion being to restrict airflow (causing nose-lift) beneath the car.  Experimentally the prototype flexible dams were angled variously relative to the car's centreline - one might end up transverse beneath the rear of the tub, others angled or peripherally ahead of it - closing upon the notion of peripheral skirting with airflow allowed between them.  The problem was that any airflow control tended to be only temporary since the various plastic materials employed usually abraded very quickly against the track surface.

 

DCN

[ReWind]

In brief:

Before ground effect cars the credo was: Air beneath the car is bad.

With ground effect cars the credo was: Air beneath the car is good.

[Catalina Park]

McLaren was already experimenting with under car airflow from the M6 Can Am days. Running around Goodwood with Wally in the passenger seat plugging a manometer into various holes in the floor pan measuring suction and then changing the ride height and rake, then measuring again. 
Wings sidetracked things, then Bruce died...