132 replies to this topic

[Megatron]

I was not sure wether to put this on the tech form or here, but here goes.....

I know that just before Chapemens death, he designed a double chassis car that effectively replaced sliding skirts.

I know it was never allowed to race, but I do have a few questions about it.

1. How, exactly did it work?

2. Was it really fast, or did the FIA just not want to create more ground effect rules/restrictions/bans.

3. Anywhere on the net where I can find a picture of the car?

[Todd]

1. How easy this is to explain is determined by how much you know about cars. If you know what a suspension upright is, than skip ahead to the second paragraph. Suspension uprights are the parts of the suspension to which the wheels mount. Imagine a simple upper and lower control arm suspension as a parallelogram. There is a top arm which mounts to the chassis of the car on one end and is parallel to the ground. There is a lower control arm which is also mounted on a pivot to the chassis and is parallel to the ground. The other ends of the two control arms are mounted to a vertical piece called a suspension upright. The Wheels are mounted directly to these suspension uprights and they travel up and down with the wheels.

The dual-chassis Lotus 88 was sort of an inner-car with a seperately suspended body. Imagine a bare tub/monocoque with the engine and suspension mounted to it. It would look sort of like a Formula Ford 1600, except with big slicks and a Cosworth DFV. This part of the car had a conventional and rather soft suspension. The 'second chassis' was essentially the seperately mounted body of the car. It consited of an aerodynamic nose mounted to ground-effects tunnel equiped side pods which flowed back into an integral rear wing. It sort of surrounded and floated around the driver/engine pod. The body-chassis was mounted by its own very-firm springs directly to the suspension uprights. This way, the downforce generated by the bodywork could act directly on the wheels without requiring the driver, engine, and transmission to ride on very hard springs. It meant that you could generate and use more downforce without beating the car and driver to pieces.

2. I don't know how fast it was. The design had some conceptual merit, at least in my eyes. By banning it, the FIA essentially created another new rule, or interpretation anyway. Another way of looking at it would be to say that rules governing suspension mounted wings should apply to the Lotus 88 as well. I think that is a sound argument.

3. I have a picture of it in David Hodges' "A-Z of Formula Racing Cars" on page 152. I haven't found one on the net yet. I might be able to post the picture, but probably not for about two weeks. Maybe someone else will help?

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Forza Michael Schumacher,
Todd

[Christiaan]

If I am correct that concept was originally design by S'Barru for a road car.

[Ray Bell]

.... and if I'm correct, it was more about double talk than double chassis.
This was perhaps the greatest example ever of someone trying to circumvent the rules by 'trying on' the governing body. As described, Chapman was trying to pass off a rigid wing arrangement as a chassis.
Mind you, if they had gone that way back in 1968, the wing bans of '69 wouldn't have happened . . . maybe?

[Xrayman]

Megatron,
I have managed to find 2 diagrams of the primary and secondary chassis of the Lotus 88, illustrating Todd’s excellent description of the basics of the car. The drawings are taken from ‘the illustrated evolution of the grand prix and F1 car’ by Simon Read.

Below is the secondary chassis (Todd’s suped up FF1600 !!)



This secondary chassis then had the primary chassis (below) attached producing the dual chassis design.



The Lotus 88 appeared for the 1981 Long Beach grand prix and a then had a record 11 objections lodged against it. The car was finally banned (Although the RAC allowed it to be raced in the British GP of that year as the Lotus 88B) as the primary chassis was seen as an illegal moving aerodynamic device.

Ray Bell; you mentioned the 88 as perhaps the greatest example of circumvention of the rules – although I would mostly agree, who can forget the Brabham 46B of 1978, the legendary Brabham fan car! If these circumventions of the rules were not attempted there would be little in the way of major car development. If there was no objections to those cars then the cars would have been seen as ground breaking and their designers heralded as heros.

Personally, I find these battles of designers vs regulations fascinating and add a lot to the drama and importance of F1.

I hope the diagrams are useful to you Megatron.


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Martin.

ICQ 53805151

[This message has been edited by Xrayman (edited 12-16-1999).]

[Megatron]

Thanks for the info and diagrams.

The car looks fairly cool, though just from looking at the diagram (and I could be way off) but it looks like it could have some severe drag (but many cars of the era did).

[Ray Bell]

The way I see it, the fan car broke new ground in circumventing the rules, the 'double chassis' was double talk to make out an old idea was something new.
By wrapping up the wings and linking them like they did, taking them off the car itself and just mounting them to the suspension, they were really just going back to what got banned.
The fan was ostensibly for another purpose altogether, and its usefulness in creating downforce was just an 'unexpected' benefit. There was no double talk about it, they just ran it and it got banned. Chapman postured his thing as something it was not.. a separate chassis.

[FlagMan]

Xrayman - the dual chassis car did not actually race at the British GP, although it did practice/qualify it was then protested by the other teams and banned from the race, so the team converted it to 88B spec overnight by replacing the floating bodywork by a more conventional system - I guess the team must have been prepared for this eventuality to have the alternate system available.

I am afraid I cannot remember how well the 88 did run in qualifying. The car looked quite good in the pit lane - in those days us marshals could wander up and down the pit lane and round the paddock on the Thursday before the GP - happy days.

[Marco94]

The Brabham BT-46B was preceded (conceptually), by the Chaperal 2?. That particular car used two smaller fans driven by a second, two-stroke, engine. It must have been 1969, 1970.

Does anybody know more about the S'Barru angle on this story.

[Racer.Demon]

Flagman: AFAIK (and correct me if I'm wrong), it went like this. The 88 was only entered for Long Beach and banned during pre-race scrutineering. Then Lotus worked at it for four months and turned up at the British GP with the B-spec 88, which was allowed in by the RAC but was still borrowing heavily on the double-chassis theme. They only practiced the car (Elio ended up a promising 10th in the Friday session) before it got protested again. So the team had to revert to the 'normal' 87 they had been using since Monaco. That didn't do them much good, as Elio qualified 22nd while Mansell DNQ'ed big-time. It was a truly tormenting season...

So Lotus did not convert the original 88 into the B-spec overnight but they took the four months between Long Beach and Silverstone. In fact, if I'm right, it is the Lotus 87 which was some sort of drawback from the 88. It used many parts from the 88 but used a very conventional design. The 87 then formed the basis of the later 91.

Marco94: Chaparral 2J... There's a picture right here on this forum, in the Big Banger Sportscars thread. You can also read the Fan Car Special at 8W: http://www.racer.dem.../8w/fancar.html

Cheers,
Mattijs


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[Ali_G]

I was very happy with the resonse to my thread about the Lotus 80 so could ye give me a bit of help here again.

Can anyone find a picture on the web of the Double Chassis Lotus. It only ran in practice for one race and its nearly impossible to find. Hope ye fare better.

Niall

[Ray Bell]

Tried the search in this forum? Best place to start. Otherwise, PM desmo, he's got everything.

[Ali_G]

I have tried basically every thing but thanks anyway.

Niall

[Ray Bell]

I know there are diagrams on this forum somewhere, and I think there is a photo... keep looking... it was since, say, April.

[Jhope]

my thread:

http://www.atlasf1.c...p?threadid=1734

[Ray Bell]

The picture wouldn't come up for me, but I went to the site and got it, maybe it will work here:



That work?

[Pascal]

Damn you, Ray! You beat me to it! ;)

For anyone interested, that picture was found on the Motor Racing Retro website...

[Ray Bell]

Funny... now I come back to it the stupid little 'X' is there and no picture again!

[John Cross]

Open a new browser window (Ctrl-N) and paste this URL into it - seems to work even if it doesn't show on this page (I've no idea why):

http://retro2.vsni.net/81usw11.jpg

[John Cross]

Here is another shot of the 88 at Long Beach:



And here is the 88B at Silverstone:



Piola's cutaway shows how it worked:

[Todd]

Just thought I'd pull this because of the periodic interest in the Lotus 88.

[Ali_G]

Thanks agian guys. Ugly looking car though.

Niall.

[Ray Bell]

You're all heart!
Maybe periodic interest in the BT46B as well?

[Ray Bell]

I actually did that from the first thread, John, then posted it and it worked, but not now...

[desmo]

You can see the spring/damper units for the second body inboard of the front wheels here.

[BT52]

Elio said at the time of the UK GP that the car needed at least 3 years development to become competetive.
He said it was very difficult and unpredictable to drive.

I believe Ferrari only had it banned because they knew that Gordan Murray would pick up the concept and turn it into a dominating reality for Brabham.

[Ray Bell]

A fair expectation, perhaps. But would not Chapman have done so, too?

[BT52]

Maybe, but I had the impression at the time that Chapman's 'other' activities were causing too much disruption to be able to develop things properly.

Whereas Gordan Murray was coming out with amazing things which actually worked almost week by week.

[Ray Bell]

You're probably right, but who was there working with Chapman at the time?

[BT52]

Erm Peter Warr? Not sure who else.

Gerard Ducarouge joined mid 83 and seemed to do a great job with the turbo Renault engine. But I don't know who did the car which started 1983.

[Todd]

That the Alfa fan car? I scanned a picture of it a few months ago. I don't remember the URL though.

[John Cross]

BT52 - I believe it was Peter Wright and Martin Ogilvie. Ducarouge joined in June 1983 after being dismissed by Alfa Romeo. Chapman had been impressed by him since his Matra sports car days.

[FW11B]

Originally posted by Ali_G
I was very happy with the resonse to my thread about the Lotus 80 so could ye give me a bit of help here again.

Can anyone find a picture on the web of the Double Chassis Lotus. It only ran in practice for one race and its nearly impossible to find. Hope ye fare better.

Niall

You Might like to try these sites:
http://www.race-cars...dl/88modlss.htm
or
http://www.clubm.co....rame/f1/88.html

[Ali_G]

Thanks Fw11b for the pictures. Welcome to AtlasF1 aswel.

Niall

[paulb]

Love the Long Beach picture. I is makes the car look very clean. Not having an airbox helps.

Got any more pictures?

[desmo]

[mat1]

Hi TNF-ers,

I have a question of which I hope some of you can help me. It has to do with the Lotus 88 of 1981.

As far as I know, the story is as follows: Lotus came up with the twin-chassis 88. It had a normal chassis containing the cockpit, the engine, gearbox, fuel tank and so on, suspended in a normal way. And there was a secondary chassis, in fact the sheet metal of the car, including the groundeffect underside of the car, etc. This secondary chassis was suspended independent of the primary chassis directly to the uprights of the wheels.

The advantages were, I suppose, the possibility of controlling the aerodynamic part of the car more precisely, related to the road, and (the other way around), the fact that the suspension of the primary chassis only had to take the (mass-induced) load of the car itself, i.e., without the downforce (which was taken directly to the wheels by the suspension of the secondary chassis. Therefore the spring rates etc of the primary chassis could be much more comfortable to the driver and the mechanical parts than otherwise possible.

As we know, this was forbidden, because this construction was considered to be a violation of the rule that aerodynamic devices (the secondary chassis) were to be attached to the sprung weight of the car. In this case, the aerodynamic devices were directly sprung themselves, but it was still considered to be a violation.

This rule originated ftom the problems with the wings in 1969, when wings, especially those directly connected to the wheel suspension, flew from the car, creating very dangerous situations. Especially the Lotuses 49 gave problems.

I don't want to go into the judicial matter, even if it is very interesting.

My question is this one: it seems to me a possibility to circumvent this would have been to suspend the PRIMARY chassis (the one containing the cockpit, engine etc) not from the wheels, but from the secondary chassis. The secondary chassis becomes the main chassis, and the chassis containing the main weight of the car is a kind of internal (more softly sprung) part within. If this internal chassis does not have any aerodynamic devices, it does not fall under the 1969-rule, and still at least part of the advantages envisioned with thje original desing of the Lotus 88 could be attained.

Is this indeed possible, and if so, has it been tried?

Perhaps you know….

mat

[greenlynx]

Just been working on one of the real 88's not that T car that never raced. The steel work is carbon fibre composite. The car works like this.... The tub and suspension are as per normal. the outer side body work /pontoons are floating and have skids on the bottom. at rest the car passes ride height controls but when moving the negative pressure below the car causes the outer body to be sucked down. the increased sealing caused by the lowering of the outer body increases the negative pressure and so sucks not only the outer body but also the chassis further down. You can continue this at infinitum but the outer body will finally be on the floor at the edges, skimming the track with its sacrificial skids. The chassis would benifit from very high downforce lower c of g and superior tyre grip. It was within the letter of the regulations which is why it passed scruteneering. A typically wonderful Lotus inovation resulting in typical FIA threats of sanctions.

[Gary C]

Is this the car that is running in the FIA Cup for Thoroughbred GP Cars this year?

[Wolf]

Mat1, how about making a car extremly stiff (as little suspension as it goes) and then properly suspending cockpit only (we don't want to waste a driver per race, only because vibrations broke all the bones in his body)?

[AyePirate]

Originally posted by greenlynx
Just been working on one of the real 88's not that T car that never raced.

Do you mean a model of the 88?

[John Cross]

Mat1 and Wolf,

I think you are missing the point of the Lotus 88 - the idea was not primarily for the benefit of the driver, but to reduce the stiffness of the suspension to improve roadholding.

Remember that the ideal chassis would be very stiff and the ideal suspension would be soft so the wheels could follow the road irregularities more easily. The first GP car to really apply this was the 1937 Mercedes W125. Of course, roll should be minimised as well - the classical compromise.

The 88 fed the aerodynamic loads directly to the wheel uprights (via the secondary chassis) and not via the primary chassis. This was recognised many years previously during the days of the big wings - Jim Hall was the first to feed the loads directly to the uprights with his gorgeous Chaparrals and I think Lotus were the first F1 team to use strutted wings at the 1968 French GP.

[Timekeeper]

I think that you are all actually on the same wavelength. The 88 was designed to solve the problem of how can you have maximum downforce, but maintain driveability and roadholding. The issue of driver comfort isn't really one of making it a pleasant ride for the driver but allowing him to drive in competitively.

This came from the problems with the Lotus 80 during 1979. This car, with its full length venturis, was brilliant in the wind tunnel but hopeless on the track. A contempory article by Giorgio Piola in that great magazine Grand Prix International explains that while the 80 had massive downforce, the car became unbalanced as the downforce was transferred around the car during braking, acceleration and cornering. The critical factor was to maintain ride height. At the time could this only be done by fitting really stiff springs but this made the car virtually undriveable and the 80 had to abandoned after only a few races.

So the 88 was also a solution to this ride height problem without resorting to ultra stiff springs. It was also an attempt to beat the new regulations banning sliding skirts and fixing the skirts 6cm above the track. Teams would eventually get around this with hydro-pneumatic suspension but if you look at photos during practice at Long Beach in 1981 most cars skirts look about 6cm off the ground but the 88s look only about 1cm!

The issue of balancing aerodynamic pressure under the car was a problem with all ground effect cars, (Williams tested something like 30 underwing profiles during 1982 and rejected most) but it was a much bigger problem with the cars with full length sidepods. I think what was needed for these full length venturi cars to work properly (the Arrows A2 and Ligier JS19 were the others) was active suspension. This would of course be eventually developed by Lotus and I'm sure their experiences with the 80 and 88 were a big influence on this. The g forces that a car with full length side pods and active suspension would have been pulling would have been truly frightening.

[fines]

Well, active suspension was first tested by Lotus in 1982, with the 92. Most people don't know/forget that!

[Allen Brown]

The 88 was up to second in the TGP race this afternoon before a crash at the hairpin forced a restart from the original grid positions. Hitchins barged his way back up to second after the restart and then had the possibly unique experience of being overtaken by three cars of the same type (all Williams FW08s) at one corner when he went very wide at the hairpin on lap 7. He retired a lap later - looked like something had broken in the suspension.

It's quite a car - nothing like the other front runners in TGP.

Berridge won in his Arrows A4. Which says more about Berridge and his budget than it does about the A4.

Allen

[mat1]

Well, thanks, TNF-ers.

Did Lotus/Chapman consider the possibility of making the aerodynamic chassis the primary one, thus circumventing the rules, which say there are no aerodynamic devices allowed which are not belonging to the sprung mass?

(Because that was the rule under which the L 88 was outlawed, I believe).

mat1

[Timekeeper]

Mat, interseting thread you've started. I think the thing with the 88 was that Chapman considered it legal as it was. He had specifically designed it to beat the letter of the regulations as he saw them. As greenlynx said the 88B passed scrutineering at the British GP and took part in practice but the FIA demanded that it be withdrawn. I think they just decided that ground effects had caused enough problems and they weren't going to have it go an any strange new directions. In the opinion of many people the 88 was no more illegal than the cars with hydro-pnematic suspensions.

The real issue was that the authorities couldn't or wouldn't police hydro-pneumatic suspension systems but it was easy to declare the 88 illegal on the moveable aerodynamic device law. I don't know if Lotus ever considered making the aerodynamic chassis the primary chassis but I'm sure that Chapman realised that there was no way that the 88 or any twin chassis type car was ever going to be allowed to race.

The other element is that the 88 never actually showed any particularly great speed. It was difficult to set up, handling was nothing special and de Angelis apparently hated it. He was quoted at the British GP "It may be a potential world beater but not for another three years. It feels so bad that I think I'd rather be in jail than trying to qualify it here". (The jail reference is because of contract issues with his former team Shadow).

[Gary C]

thanx for that last comment Allen. Ha!

[mat1]

Thanks for your info, Timekeeper.

I have always been under the impression the 88 was quick, but apparently it wasn't. Still, it seemed an interesting innovation.

Concerning the hydrp-pneumatic suspensions: I have never understood why they weren't outlawed. Clearly contrary to the spirit of the rules, and it would have taken a small addition to the rules to disallow them unequivocally.


m

[MrAerodynamicist]

Didn't a magazine recently test one at Goodwood? Can't remember which as I didn't buy it, but IIRC they said itr handled okay except that under braking for the chicane the bodywork would suddnly pop up as aerodynmaic pressure was lost! - Can anyone confirm that I didn't imagine all this?