18 replies to this topic

[John Fransson]

One thing I can't understand is how BRM set up their model type numbers.
In 1959; Jo Bonnier drove the P25 to victory t Zandvoort, in 1965 they had a couple of P261's for Hill and Stewart, while in 1967 they took a step backwards (?) with the P83 and P115.
In 1973 they used the P160, only to use the P277 (I think) in 1977.

Can someone explain if there was a pattern behind this?
The same goes for Lotus and their models, I don't understand that, they just seems chaotically chosen.

Thank goodness for Ferrari and logic.

- John

[Ray Bell]

I'm sure a lot of this has been explained (principally by Doug?) in a previous thread...

Use 'search bb' with keywords 'type' and 'number*' and you might find something.

[Vitesse2]

Lotus F1 type numbers were part of their normal sequence, which ran from the original Mark 1 to the type 116. Production Lotus cars were part of this sequence too:

http://www.lotuscarclub.org/types.htm

Where's the chaos anyway? They appeared in sequence: 12, 16, 20, 24, 25, 33, 43, 49 etc etc ...

[Allen Brown]

It's the P261 that's confusing you. That was actually shorthand for the M61 Mk II.

Also the P578 was just the V8 version of the P57. Again, a form of shorthand.

If you allow for those two, you'll find they go pretty much in sequence.

And it was the P207 in 1977.

Allen

[Vitesse2]

Ah - Allen beat me to the explanation on that one - I was just composing something similar!

Just to add though that the P refers to the BRM project number, which could refer to anything they might be designing or building - chassis, engines, widgets etc.

For example, the BRM V8 engine in the P578 was called the P56, the F2 engine from the mid-60s was the P80 and the H16 was the P75 ...

[Doug Nye]

And...of course...termination of employment was marked by a P45...

BUT the P25 was the 4-cylinder 2 1/2-litre engine project - the chassis propelled by that engine were built under the P27 heading - BUT the combination complete car was the BRM TYPE 25...as previously explained here.

DCN

[Roger Clark]

Were both the stressed skin and space frame 2.5-litre cars known as P27? I don't think this question is answered in BRM Vol 1 - but I've been wrong on that before. And was it purely coincidence that the P15 was 1.5-litres while the P25 was 2.5-litres?

[Doug Nye]

Roger - the answers (as I have ever been able to verify) are Yes, no and no. Documentation and drawing identifications are NOT entirely consistent but on balance both of them where they relate to the front-engined 2 1/2-litre programme from 1955 debut to 1960 final outing generally use P25 for the engine and P27 where the chassis frame was concerned,. The all-tube frames had '27/?' serial numbers stamped into them while I presume the 'overstressed-skin specials' were similarly marked somewhere, although of course I was never able to examine any of them in the metal. 'P15' was definitely selected to indicate '1.5 litres' - there were NOT 14 preceding projects - and P25 simply followed that style.

DCN

[arttidesco]

'P15' was definitely selected to indicate '1.5 litres' - there were NOT 14 preceding projects - and P25 simply followed that style.

DCN

But presumably the P30 Mark II which followed P15 and preceded P25 did not follow 'that style'

On the subject of the P30 Mark II any idea why the Donington example driven by Kevin Wheatcroft is listed in the BRM Day programme as P18 Mk 2 V16 (P18/1) ?

Are there some factory markings P18/1 perhaps on the chassis ?

[Doug Nye]

Cock-up.

DCN

[arttidesco]

Cock-up.

DCN

[JtP1]

Lotus F1 type numbers were part of their normal sequence, which ran from the original Mark 1 to the type 116. Production Lotus cars were part of this sequence too:

http://www.lotuscarclub.org/types.htm

Where's the chaos anyway? They appeared in sequence: 12, 16, 20, 24, 25, 33, 43, 49 etc etc ...

Should that not be 12,16,18,21,24,25,33, (39),43,49 etc

[Doug Nye]

Lotus cars' numbering system is not as logical as has been described above. For example there's a gap between Type 52 twin-cam Europa prototype project and Type 54 Europa S2 which is accounted for by Type 53 having been allocated to a still-born Lotus Components sports car notion.

Then there's a celebrated hiccup at Types 66-67-68, the Type 71 is another hiatus, and there are two very different Types 74 - the 1971 production Lotus Europa Twin-Cam and the Texaco Star F2 design of 1973. There are also duplicate Types 76 - the 1974 F1 design and the 1975 Eclat - while the Types 79 Esprits clash with the F1 JPS Mark IV '79'. The most jaw dropping clash of all seems to be between the Type 81 1979 Sunbeam Lotus saloon and the 1980 F1 car, after which point I must confess I began to lose the will to care any more...

Regarding BRM Project numbers I do have a complete list somewhere - including that given to Tony Southgate's new daughter...but it will take time to unearth it.

DCN

Edited by Doug Nye, 10 October 2012 - 17:32.

[kayemod]

Lotus cars' numbering system is not as logical as has been described above. .

And it's probably even less logical than you think, the Lotus type numbers 'understood' by the outside world, are sometimes different from the ones used by the factory. To give just one example, the 1970s Elite has the fairly official type number Type 75, but I spent a lot of time working on the thing, and the only number ever used in-house was M50, that was the number on all the drawings etc. I wasn't involved much with the racing side, but I think that there's similar confusion over the T74 Texaco Star, a few of the drawings for that one passed over my desk, and whatever they were labelled, it wasn't 74.

[Tim Murray]

Regarding BRM Project numbers I do have a complete list somewhere - including that given to Tony Southgate's new daughter...but it will take time to unearth it.

DCN

That would be fascinating to read, Doug.

[Doug Nye]

Oh b------r. I'd better find it now then...

DCN

[arttidesco]

Oh b------r. I'd better find it now then...

DCN

[Glengavel]

Then there's a celebrated hiccup at Types 66-67-68, the Type 71 is another hiatus, and there are two very different Types 74 - the 1971 production Lotus Europa Twin-Cam and the Texaco Star F2 design of 1973. There are also duplicate Types 76 - the 1974 F1 design and the 1975 Eclat - while the Types 79 Esprits clash with the F1 JPS Mark IV '79'. The most jaw dropping clash of all seems to be between the Type 81 1979 Sunbeam Lotus saloon and the 1980 F1 car, after which point I must confess I began to lose the will to care any more...

DCN

Many years ago Classic and Sports Car gave away a supplement listing all Lotus cars and it was mentioned that the register of type numbers went missing, resulting in duplicate numbers being allocated. When Chapman found out, there was a great deal of screaming and shouting and the book quickly reappeared...

[kayemod]

The most jaw dropping clash of all seems to be between the Type 81 1979 Sunbeam Lotus saloon and the 1980 F1 car, after which point I must confess I began to lose the will to care any more...

The rot seemed to set in when Lotus type numbers began to coincide, more or less, with the years they were raced in. In 1979 they brought out the T80 to follow from the T79, new year, new car, so plus one from the previous year, and to make it appear more advanced, plus one from the calendar as well. They had a new car the following year, so of course at the press launch it was announced as "The new Lotus 81", a number chosen to appeal to journalists and the public, no matter that the factory had been busy for some time working on something completely different with the same number, and of course the same thing happened on several other occasions with road cars sharing numbers with racers. There was almost no interplay between Team and the production side other than socially, so it really didn't matter that they were running parallel numbering systems, that only caused problems when journalists wrote about the company as an entity, when in practice it was not like that at all.