49 replies to this topic

[Victor_RO]

It is about an old F1 car, so it might be better off in the Nostalgia section, but I thought I'd post it here because I'm looking for some technicalities about it.

First of all, how was the twin-chassis working as a ride height adjustment mechanism, in order to circumvent the 60mm ride height regulation of 1981? Did the ground-effect generating chassis simply get sucked by the aerodynamic forces towards the ground at speed?

Second, from what I could tell in the photos I could find of the car, the engine was in the softly-sprung chassis that also held the driver. Was the transmission in the same chassis? And how did they actually put the engine power to the differential and then to the wheels if the main drivetrain is on a different chassis to the rear suspension and wheel assembly? Or what was the actual drivetrain layout in terms of utilising the two chassis?

Thirdly, some experts put forward a claim that the car was actually grossly overweight and would never have been competitive. What weight figures were quoted by Team Lotus and what was quoted by others?


Finally, if anyone knows, what was the actual modification between the 88 that was black-flagged in the practice sessions in the first 2 or 3 races and the 88B which was approved by the RAC scrutineers at Silverstone?

Thanks in advance.

[phantom II]

What I know about the 88, is that the battles it caused with what was to become the FIA and Lotus led to one of the most perfect technical partnerships in history. Chapman’s huge battle with Jean-Marie Balestre, President of FISA (who sought to ban the cars for 1981 by imposing a minimum ground clearance rule) caused Chapman to abandon F1 and apply himself to aviation which was his first love. He designed an ultru light aircraft and sort the help of Burt Rutan at Scaled Composites. These two free thinkers immediately hit it off and became soul mates. Chapman’s knowledge of composites and engine design culminated into the planned design and production of an ultru light aircraft that Chapman had been developing and flying for years. Chapman designed an ultru light engine for the joint effort that took place in the Moab Desert in California. Chapman died of a heart attack two weeks before the ‘Elisie’ was due to fly. Rutan owns a Lotus Elise. Imagine if Chapman had lived what could have been achieved?
Back to the 88. The big deal about the two chassis Lotus was simply a separately suspended compartment for the driver to keep his brains from scrambling. Everything else was on the main chassis including the body which housed the skirted ground effect aero package. This car still make appearances at F1 vintage meets.

Originally posted by Victor_RO
It is about an old F1 car, so it might be better off in the Nostalgia section, but I thought I'd post it here because I'm looking for some technicalities about it.

First of all, how was the twin-chassis working as a ride height adjustment mechanism, in order to circumvent the 60mm ride height regulation of 1981? Did the ground-effect generating chassis simply get sucked by the aerodynamic forces towards the ground at speed?

Second, from what I could tell in the photos I could find of the car, the engine was in the softly-sprung chassis that also held the driver. Was the transmission in the same chassis? And how did they actually put the engine power to the differential and then to the wheels if the main drivetrain is on a different chassis to the rear suspension and wheel assembly? Or what was the actual drivetrain layout in terms of utilising the two chassis?

Thirdly, some experts put forward a claim that the car was actually grossly overweight and would never have been competitive. What weight figures were quoted by Team Lotus and what was quoted by others?


Finally, if anyone knows, what was the actual modification between the 88 that was black-flagged in the practice sessions in the first 2 or 3 races and the 88B which was approved by the RAC scrutineers at Silverstone?

Thanks in advance.

[Tony Matthews]

Originally posted by phantom II
. The big deal about the two chassis Lotus was simply a separately suspended compartment for the driver to keep his brains from scrambling. Everything else was on the main chassis including the body which housed the skirted ground effect aero package.

Not so I'm afraid PII, the driver sat in a more or less conventional chassis with engine, transaxle, front and rear suspension all attached, but no aero. All the aerodynamics came from a seperate body/sideplate/wing assembly that influenced the inner chassis through small coil springs acting on the suspension. I have a drawing which may help if I can find it! Bear with me.

[Tony Matthews]

[DaveW]

Tony Matthews is correct - except the small coil springs (& dampers) connected the "aero" chassis directly to the uprights. I'm sure that Peter Wright described the layout in his "Formula 1 Technology" book.

The concept was developed as a solution to a severe porpoising problem experienced by the (skirted) Lotus 80. Skirts were banned whilst it was being developed & (as it happened) it was the perfect solution for the "no skirts" era. It used a "secondary" suspension because aero devices were not allowed to be attached to the uprights (a rule introduced after several wing failures scattered debris in the paths of other vehicles), but it was intended that the secondary suspension should be coil-bound when the vehicle on-track. It might be argued that the design violated the spirit of the rule - or not - because the aero bodywork could not become completely detached from the vehicle even if all the secondary suspension elements failed. Arguably, the most probable reason it was banned was a fear that Lotus might have (yet another) dominant year, or at least until other teams had time to redesign their vehicles.

[Victor_RO]

If the engine and gearbox were on the softly-sprung chassis, as I can tell from the sketch, then a bumpy circuit would have overstressed the driveshafts even more than on a regular ground-effect car. And the rule about wings not attached to uprights dates from 1969, doesn't it? After the high wing contraptions kept failing and causing severe accidents.

And Chapman's design team seemed, at the time, to have failed to grasp the entire potential of ground effects; Brabham and Williams were miles ahead in that department by the time the 88 was rolled out.

And what is actually "porpoising"? Simply a continuous variation of the location of the center of low pressure in the venturis under the car, upsetting the balance of the car by modifying the balance of grip?

[phantom II]

OK. Thanks.

Originally posted by Tony Matthews


Not so I'm afraid PII, the driver sat in a more or less conventional chassis with engine, transaxle, front and rear suspension all attached, but no aero. All the aerodynamics came from a seperate body/sideplate/wing assembly that influenced the inner chassis through small coil springs acting on the suspension. I have a drawing which may help if I can find it! Bear with me.

[phantom II]

How would the 'soft'suspension over stress the driveshafts?
To make GE work, the ground clearance had to be constant from front to back and very low. Brabham had an elaborate suspension mechanism that other teams tried to copy to meet this objective. Chapman looked at the rule book the same way Smokey Yunick would have done and came up with a smarter solution. Everyone new the advantage to GE and to say Chapman didn’t grasp it‘s value is absurd. Chapman’s active suspension was designed to address this problem later. This car never raced because the authorities figured that the body was an aerodynamic device which was not allowed to be attached to the suspension.

Originally posted by Victor_RO
If the engine and gearbox were on the softly-sprung chassis, as I can tell from the sketch, then a bumpy circuit would have overstressed the driveshafts even more than on a regular ground-effect car. And the rule about wings not attached to uprights dates from 1969, doesn't it? After the high wing contraptions kept failing and causing severe accidents.

And Chapman's design team seemed, at the time, to have failed to grasp the entire potential of ground effects; Brabham and Williams were miles ahead in that department by the time the 88 was rolled out.

And what is actually "porpoising"? Simply a continuous variation of the location of the center of low pressure in the venturis under the car, upsetting the balance of the car by modifying the balance of grip?

[Victor_RO]

I was thinking about the movement of the softly-sprung chassis when it came to the driveshafts. Apart from the rotation, there would have been a lot of oscilatiory movement over the bumps.

As for the comment about Chapman, I didn't mean to put it as harshly as that. I actually wanted to say that Lotus had fallen quite badly behind in the ground effect race, quite staggering for the team which had pioneered the concept.

[Tony Matthews]

Originally posted by Victor_RO
I was thinking about the movement of the softly-sprung chassis when it came to the driveshafts. Apart from the rotation, there would have been a lot of oscilatiory movement over the bumps.

I don't think so Victor, assumong that Colin Chapman would have stuck by his long-held belief that a chassis should be sofly sprung but firmly damped. If the inner chassis is able to behave like a well-sorted conventional racecar, but with the benefits of substantial earo loading I can't see that the driveshafts, or any other mechanical parts, would be over-stressed. I agree that it does seem odd that the ruling about aero loads not being put directly to the hubs was ignored - perhaps there was a loop-hole in the regs...

DaveW, my drawing does show the direct connection, via a small fabricated triangulation - why I showed it like that I can't remember, it was either factual information from Hethel or I had to 'design' it! The choice of viewpoint is probably not what I would have chosen, but it was based on a sketch given to me by 'Chunky' and I was too much in awe of him to produce something completely different. If I can find his little drawing I'll post it!

[DaveW]

Actually, the Lotus 88 was entirely legal. Both the "mechanical" and "aero" chassis' were suspended from the uprights (hubs) by springs and dampers. It is likely that its legality would not have been questioned had skirts not been banned. The problem (for the competition), was that the twin chassis concept allowed the venturis and their side walls to be held accurately relative to the ground plane, thus recovering most of the down force lost by the removal of skirts.

The logic for the ban was (I suppose) rather similar to that used to prohibit Renault's dynamic absorber - we don't like it so we'll invent something. The aero chassis was, of course, intended to run coil-bound on-track, but that was only different by degree to the bump rubbers used to limit platform travel in conventional vehicles, and the rules made no reference to coil-binding.

Victor_RO suggested that Lotus had fallen behind in the ground effect race. With respect, I don't think that was quite the case. Arguably, they were some way ahead of the field (Peter Wright, under his aerodynamicist's hat, observed once that the 80 was "capable of going round any corner at any speed"), but they encountered problems that required time (and lateral thought) to solve. The Lotus 88 was one solution. Dynamic absorbers attached to each upright was another. Active suspension followed when all esle failed (for one reason or another).

[Tony Matthews]

Originally posted by DaveW
Actually, the Lotus 88 was entirely legal. Both the "mechanical" and "aero" chassis' were suspended from the uprights (hubs) by springs and dampers.

Of course, I had forgotten!

[gruntguru]

The obvious interpretation of the concept (and one that nobody seems to be making in this thread) is that the 88 was circumventing the "no movable skirts" rule by having "fixed" skirts that were in effect following the vertical wheel travel and therefore following the road just like the banned "movable" skirts.

[phantom II]

That's what happens to old farts. Since we are talking bout Chapan's genious,may I add one or two more of his achievements? I would assume that you would be interested to know that Collin and his son Clive deigned furniture amongst other things. I have a picture of Colin's composite ultru modern chair somewhere. What furniture do you design? My house has ultru ultru modern stuff from Italy, Germany and the US and some of my own. The Porsche dealer down here makes their own furniture in their race shop. Real cool stuff.



http://www.lotusespr...glassfibre.html

Here is some more stuff on his airplane. Too bad that Tony Rudd's engine wasnt put into production.(crono33 RDV ???)
Patrick Peal, Chapman's son-in-law, pilot and (in 1996) Head of Communications at Lotus gave us this description:

"I'll now try to produce a potted history of the microlight... incidentally, the late Hugh Haskell's book "Colin Chapman - Lotus Engineering" is full of good stuff about cars, boats (including Clive Chapman's racing monohulls..), aircraft, and even furniture. The story about the flying saucer was considered too wacky...

Rumour has it that in the very early days of board-sailing someone suggested to the OLD Man that he should get into the manufacture of said boards - "no, it'll never catch on" he is reputed to have said.

So when ultralights/microlights began to appear on the scene, and with his love of flying to encourage him, Chapman "got into" microlights very fast and deeply. I think it was Summer 1980 when we got taught to fly behind the Chapman house in a Double Eagle, driven by two two-stroke paint stirrer engines.... it hardly flew, and bits fell off every hour or so. ACBC believed that Lotus composites know-how could be applied to build a "proper" aircraft that still met ultralight rules (and hence would be cheap and easy to fly i.e. very attractive to buyers). He commissioned Burt Rutan of Mojave, Ca to design a new type of microlight, based on Rutan's love of composites, efficiency, and the use of the "canard" wing layout for which Rutan is famous. (He designed Voyager, which flew round the world, and the Starship, which has nearly broken Beech). At the same time, Lotus were set the task of designing a small lightweight 4-stroke aero engine, which would fix the inherent two-stroke problems of noise and gas-guzzling. (Ian Doble, the engineer given the task, went on the lead the LT5 engine programme, the Elan programme, and has just finished the Vector in Florida.)

First, the aircraft - two-seat side by side enclosed cockpit, retract front wheel, unique design. Tragically and ironically, the maiden flight was December 16, 1982 - the day ACBC passed away. Trials continued with a little Italian two-stroke engine, to the end of the proof-of-concept phase. I watched some test flights in Mojave, and was totally impressed with the machine. Next time I saw it was August 1983, when it arrived in a crate at Hethel - two days before the Open Day Mike Causer referred to. We assembled it on Friday and Saturday, I taxied in daylight on Saturday afternoon, and "accidentally" hopped in the dusk. My first proper flight was Sunday morning, with the demo flight in the afternoon for the crowds. It was exciting, terrifying, and very emotional for me.

(Yes, it did appear at a Brands Hatch CTL event, but I thought that was `84?)

We wanted to build a business for it, and sought company backing to continue alone. When that wasn't approved, we went looking for partners. We eventually teamed up with Eipper (a big ultralight builder in those days) to distribute it in the USA, and Malcolm Lawrence's Aviation Composites in UK and Europe. We originally planned to build the basic structure, with AC to finish and distribute it. We then decided that the materials (epoxy glass) and the quality control techniques were not part of our core business, and AC agreed to take over the development and build, with the help of Specialised Mouldings (well known in motorsport). As we were struggling to cope with the aftermath of ACBC's death, AC's move into taking over the whole project lock, stock and barrel, was a godsend. They built at least one more prototype, with various modifications from the Rutan design, showed it and test-flew it. Sadly, their prototype apparently exhibited some less-than-attractive characteristics, and they sued Rutan. The case dragged on (way beyond Lotus being taken over by GM in `86) and eventually was either dropped or Rutan won - I can't remember which. The backers disappeared, and AC went into liquidation. I don't know where the Rutan prototype is, but I'd love to find it again... it flew beautifully - just what Chapman would've wanted.

The engine was a brilliant concept - a modular monobloc design (crankcase half, barrel and head cast in one piece) which could be built as a two- or four-cylinder (25 or 50 hp). To keep the weight down, the castings were intricate with minimal fixings and parts count. The prop drive came off the camshaft to use the inherent 2:1 reduction drive - brilliant thinking! (You need a big prop turning slow for efficiency, and a small engine turning fast for good fuel economy). However, we didn't have the sophisticated CAE systems we have now, and we experienced severe torsional vibration problems.

After slogging on, we got up to 150 hour durability (way below our hoped-for 1000 hour goal) about the same time GM spotted we had a connection with the aircraft business...The engine project was closed down very fast to prevent any possibility of aviation-sized product liability lawsuits. Sad, because the world is still crying out for a light, cheap, four-stroke aero-engine. The Rotax is nearly there, but... even Porsche failed with the PFM aero-engine based on the 911 motor!

We have one of the 4-cyl engines on display at the factory - it is still a gem and sits proudly alongside the LT5 engine and the 1.5 litre compound-supercharged F1 engine we were doing about the same time..... what would it be like if we used our second new Cray to support the analysis today?

We were close to supplying the engine for use in target and reconnaissance drones (some flight testing was carried out) but it didn't happen.

TO KCLAIBORNE: yes, the Lotus microlight was a dream - for aircraft spotters it had a pointy nose, little wing at the front, and the prop at the back behind the big wing - and it was FAST! No, we didn't get to Paradise/Hawaii on any durability flights, sadly...

Regards,
Patrick Peal, Head of Communications, Lotus Cars Ltd."

Originally posted by Tony Matthews


Of course, I had forgotten!

[Tony Matthews]

Originally posted by phantom II
That's what happens to old farts. Since we are talking bout Chapan's genious,may I add one or two more of his achievements?

I thought we were talking about the Lotus 88. I knew that the regulations banned direct aero loads fed directly to the uprights, I had forgotten, briefly, that the 88 got round this by using coil spring which under full load became coil-bound. That's all. No big deal.

[phantom II]

His other activities are connected. His 88 experience caused him to change carreers.

Originally posted by Tony Matthews


I thought we were talking about the Lotus 88. I knew that the regulations banned direct aero loads fed directly to the uprights, I had forgotten, briefly, that the 88 got round this by using coil spring which under full load became coil-bound. That's all. No big deal.

[mariner]

I admit to being a fan of Colin Chapman's design and racing talent so to me the real signifigance of the Lotus 88 was that it represented the end of F1 innovation at the architectural level. I don't mean that all innovation ended then but I do think that the F1 establishment felt that enough was enough with innovation from Chapman in particular and the process that gives us today's "rules designed " cars stated with the banning of the 88.

You have to put the car in it's context - ground effects was new and it clearly changed the basic paridigms of cornering for ever. You could say that Jim Hall started that with the 2J but that concept, briliant though it was, could not work in a capacity limited series like F1 because of the need for two engines both of whom's capacity would have to count. The Lotus GE creation had driven up cornering speeds very fast and the 88 threatened to do that again. Whether it would have worked was never proven, it did havea penalty in that it was relatively narrow ( reputedly because Chapman thought a plan area limit was likely), this may have limited total downforce but that was fixable within the concept.

Also just prior to the 88 Gordon Murray had blown a hole in the "no skirts" ban which required the cars going into the pits to pass over a block which a skirt would hit by using hydraulic ams on the spring units to simply pump the car up at very low speeds. Not to demean Gordon Murray but that was a very blatant way round the rules which had no real innovation or design benefit. But it was not protested because any team could fix up a copy quickly on their existing car. the 88 wasa whole new architecture which allowed for maximum low speed mechanical grip along with maiximum high speed downforce without putting the driver at risk from a super hard ride which was big problem at eh time.

So a new architecture was banned but the pit entry rams were not. That is what made Lotus and Chapman so angry, nobody ever explained why it was illegal they just black flagged it. Lawyers got hired etc. and if you look up the Oxford English Dictionary you will find that the word "chassis" is the same in the singular and the plural so a twin chassis car had a chassis just as did a single chassis one!

That was the argument - that it had a primary and secondary chassis both suspended on springs as required by the FIA. so it was legal.

I thinkt he real signifigance of the row was the first point above - the other teams could see that radical innovation was not in their interest of making a good living moving design slowly forward.
This was one of the factors which led to the current situation where the overall archictecture of the cars is precisely limited to prevent any big leaps forward. You may not agree with that view but in evidence I would offer a trip to Tom Wheatcroft's fabulous Museum at Donnington and a look at the McLaren hall there. If you ignore the paint schemes and mentally remove the bargeboards and a few fins you can see that every McLaren from 1996 to 2007 is basically the same shape and architecture.

[desmo]

Only innovations that spring from the fecund, scintillating and inimitable brilliance of Mosely and Bernard can be countenanced. Why would the inferior thoughts of lesser men be encouraged?

[Victor_RO]

Originally posted by desmo
Only innovations that spring from the fecund, scintillating and inimitable brilliance of Mosely and Bernard can be countenanced. Why would the inferior thoughts of lesser men be encouraged?

You're partly right, since the banning of the Lotus 88 diverted attention from the hydropneumatic suspension on the BT49C Brabhams, which were equally illegal.

[Powersteer]

The Lotus 88 would have a near perfect center of pressure with that layout. Would have been the most stable car aerodynamically, under braking, over curbs etc with changes only via tyre pressure.

[MODE]

I uploaded a little video on the 88B running in Fia Historic F1:
http://www.gurneyfla...eolotus88b.html

[Tony Matthews]

Originally posted by MODE
I uploaded a little video on the 88B running in Fia Historic F1:

Thanks for that MODE, I probably wouldn't have seen it but for your promt - what a fascinating car, such a shame it wasn't allowed to compete...

[macoran]

P. d'Alessio's take on how the 88 fit together

[Direct Drive]

Originally posted by phantom II
Chapman’s knowledge of composites and engine design culminated into the planned design and production of an ultru light aircraft that Chapman had been developing and flying for years. Chapman designed an ultru light engine for the joint effort that took place in the Moab Desert in California.

Christ if you thought his racing cars were fragile, how many pilots would have died flying these fragile **** boxes?

[Chezrome]

Strange. I think the 88 was the most beautiful F1 car ever built. At the same time I am rather sceptical about its potential. I remember reading comments from ex-Lotus mechanics that the car gave them fits during testing - just like the Ligier JS19 (if I am correct) and the Lotus 80 gave their respective designers fits. There's something about radical aerodynamic designs that work well in the windtunnel and work terribly on the track.

[Rogue]

Agreed, absolutely beautiful F1 car, surely one of the best looking ever, and not just because of the lovely JPS paint job.

[Chezrome]

Originally posted by Rogue
Agreed, absolutely beautiful F1 car, surely one of the best looking ever, and not just because of the lovely JPS paint job.

Well, actually... the original 88 had Essex sponsoring... even better than the JPS, methinks.

J.

[DOHC]

Chapman explains it on Youtube

[Chezrome]

I stand corrected. The Lotus 88 tested in the off season with Essex sponsoring, but JPS returned to sponsor Lotus.

[bigbrickz]

Originally posted by Chezrome
I stand corrected. The Lotus 88 tested in the off season with Essex sponsoring, but JPS returned to sponsor Lotus.

If I remember correctly in 1981 Lotus raced in Essex colours for the first few races. I think JPS returned around Monaco or Jarama. I'm pretty sure the 88 that ran in free practice at Long Beach, before being rejected, was in Essex colours.

I don't actually remember the 88 being in JPS colors at a race. When they tried to get the 88b past scrutineers at Silverstone I think it was in black & gold "Courage" livery (Courage was a brewery belonging to JPS). Off the top of my head, probably all mixed up, it was a long time ago...

[phantom II]

Also gone is Pontiac. Their Trans-Ams were once emblazoned with JPS colors inspired by the 88 livery.

Originally posted by Chezrome
I stand corrected. The Lotus 88 tested in the off season with Essex sponsoring, but JPS returned to sponsor Lotus.

[Chezrome]

Originally posted by bigbrickz


If I remember correctly in 1981 Lotus raced in Essex colours for the first few races. I think JPS returned around Monaco or Jarama. I'm pretty sure the 88 that ran in free practice at Long Beach, before being rejected, was in Essex colours.

I don't actually remember the 88 being in JPS colors at a race. When they tried to get the 88b past scrutineers at Silverstone I think it was in black & gold "Courage" livery (Courage was a brewery belonging to JPS). Off the top of my head, probably all mixed up, it was a long time ago...

I think you are correct. In Brazil the 88 still had the Essex colors, before the black flag dropped.

[Wirra]

Donington Park, 30th August 1981 - A non-championship motorcycle meeting with all the 500cc riders competing. A few exhibition laps in the 88.

[Chezrome]

Originally posted by Wirra
Donington Park, 30th August 1981 - A non-championship motorcycle meeting with all the 500cc riders competing. A few exhibition laps in the 88.

Hehehe. Both Essex and JPS.

But now the question. Would the 88 have worked? I mean, the technique would have worked all right. But would it have worked dependable enough to win races? Like I said before, I have my doubts...

[Greg Locock]

Well, in the best spirit of Chapman's designs it actually solved a fundamental problem, if anything as a system it was a better solution than the alternatives, so I'd say yes it would have swept all before it after a bit of debugging. Of course there weren't that many subtleties, other teams could easily copy it, every decent farm tractor today uses the same technology. Isolate the man, not the structure.

[gruntguru]

Interesting note. Looking at the Donnington Park photos, there is quite a lot of clearance under the skirts. Obviously the secondary chassis was set high for the demonstration laps, ironically defeating the purpose of the whole controversial twin chassis concept.

[Chezrome]

Originally posted by Greg Locock
Well, in the best spirit of Chapman's designs it actually solved a fundamental problem, if anything as a system it was a better solution than the alternatives, so I'd say yes it would have swept all before it after a bit of debugging. Of course there weren't that many subtleties, other teams could easily copy it, every decent farm tractor today uses the same technology. Isolate the man, not the structure.

Well, I am not sure that the debugging would have been that easy. For three reasons. 1. I seem to remember comments from Lotus-mechanics at the time, and much later, that they were actually deadhappy the 88 was not the racecar of 1981, because it was such a pain. Perhaps other posters have more substantials memories, it was some time ago I read those reports. 2. Elio de Angelis did not like the car (as I seem to remember). 3. As I mentioned earlier in this thread: to me, the 88 seems one of those cars that work brilliantly in the windtunnel and on paper... and are a nightmare on the real track. Which is kind of a repetition of point 1, I realise.

Does anyone remember the quotes I mentioned at 1.?

[ferrarifan2000]

FWIW



http://www.grandprix...ft/ftpw021.html

[cheapracer]

Interesting note. Looking at the Donnington Park photos, there is quite a lot of clearance under the skirts. Obviously the secondary chassis was set high for the demonstration laps, ironically defeating the purpose of the whole controversial twin chassis concept.

I think you'll find the aero tub is on very light springs and comes down rapidly as speed increases.

I just read that link above, thanks ferrarifan, and yes it was on light gas struts as per hatchback tailgates to both; have 6cm clearance and actually have suspension as per the rules.

Edited by cheapracer, 01 May 2009 - 07:37.

[ensign14]

The few practice sessions where it participated had it well down the timing sheets. Was it actually a flawed concept, or just teething troubles whilst the thing was being set up?

[cheapracer]

The few practice sessions where it participated had it well down the timing sheets. Was it actually a flawed concept, or just teething troubles whilst the thing was being set up?

The article above is a good read by the designer.

Knowing Chapman he may well have had his drivers go slow to show that it wasn't such a threat after all.

[DOF_power]

>
^ With active suspensions, active diffs, TC-ABS-ESC and adjustable wings (flaps) it would not just work but downright destroyed the opposition IMO.

Don't current DTMs use a sort of a twin chassis approach (monocoque + space frame) ?!

[gruntguru]

I think you'll find the aero tub is on very light springs and comes down rapidly as speed increases.

I just read that link above, thanks ferrarifan, and yes it was on light gas struts as per hatchback tailgates to both; have 6cm clearance and actually have suspension as per the rules.

The skirts are stiffly sprung so that they follow the road surface closely. This was the main thrust of the twin chassis concept - movable skirts to follow the road had been banned and this was Chapman's answer.

[Victor_RO]

The few practice sessions where it participated had it well down the timing sheets. Was it actually a flawed concept, or just teething troubles whilst the thing was being set up?

My guess would be teething trouble, especially as it was a new car and the concept was not yet fully developed.

[cheapracer]

The skirts are stiffly sprung so that they follow the road surface closely.

Now please read my post again or the article or look at the pictures closely.

[gruntguru]

Now please read my post again or the article or look at the pictures closely.

Got it now. The skirts aren't stiffly sprung until the second chassis finds the bump stops.

[cheapracer]

Got it now. The skirts aren't stiffly sprung until the second chassis finds the bump stops.

Yup - Its on very light springs for the ground clearance rule and when a little speed gets some downforce the aero chassis comes down to its stops.

Those springs allow for individual wheel droop as well as I see it.

[Aitchjay]

Saw it Goodwood FoS four or five years ago and, I know beauty is in the eye of the beholder, but I thought it looked gorgeous.
The upper body or chassis was indeed extremely softly sprung and, whilst maintaining the 50mm clearance at rest, was very easy to push down to close the gap.

[gruntguru]

Those springs allow for individual wheel droop as well as I see it.

I think it would be preferable for the chassis to warp enough to stay on the four stops. That way the two skirts would follow the road better. No idea whether it does or not. This drawing suggests possibly? How the top is fitted to the two sides would determine whether the aero chassis is rigid in longitudinal torsion.

Edited by gruntguru, 04 May 2009 - 10:08.

[Craven Morehead]

It was a superb concept and would likely have 'swept all before it' once it was sorted out. I think that all the other teams would have had no choice but to follow the design the following season. Imo, FISA screwed Tean Lotus over royally.