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Autolite Lotus 29 freebie model, offset Indy cars


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#1 Philip Whiteman

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Posted 13 December 2003 - 18:31

Browsing Team Lotus - The Indianapolis Years (Andrew Ferguson's super book), I came across his reference to a model of the Lotus Type 29, given away in the USA by Autolite in the early 1960s. This was a plastic ready-made item, some 7 inches long - very well done, according to Ferguson. Anybody seen one, or have one in their collection?

Also, maybe a silly question, how do you make an offset machine like the 29 or 38 accelerate or - perhaps more importantly - stop in a straight line? I can imagine the brake pads and or disks might be differently sized for this reason, but what do you do with the transaxle?

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#2 D-Type

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Posted 15 December 2003 - 23:40

Originally posted by Philip Whiteman
~ how do you make an offset machine like the 29 or 38 accelerate or - perhaps more importantly - stop in a straight line? I can imagine the brake pads and or disks might be differently sized for this reason, but what do you do with the transaxle?


I'm confused. I thought the Lotus 29 suspension was offset not staggered . I'm probably totally wrong but I always understood that the Indianapolis Lotuses and the Cooper T54 ( model?) before them had unequal length wishbones so that the centre of gravity was offset relative to the centre of track. However the axles were set at right angles to the centreline of the chassis so that the rear wheels tracked the fronts.

If the suspension is staggered, the axles are not at right angles to the axis and may not be parallel to each other. The result is that when the car is coming towards you in a straight line it crabs and you can see all four wheels with one of the rears visible between the front wheels and the other out to one side. So when cornering neutrally the car appears to be understeering or oversteering.

I once owned a Triumph Herald that had had a very poor chassis weld up done. The back axle was not at right angles to the chassis, so when I was going straight the nearside rear wheel was nearer the kerb than the front one. I never noticed it was crabbing until I saw my wheel tracks. Under heavy braking it did slew slightly as the centre of mass was off the (average) centreline of the wheels but I simply put it down to the camber. I suppose it was a bit like a boat and handled better (or it being a Herald less worse) on left handers than on right handers or vice versa but it wasn't enough to notice.

I know that these days NASCAR and Indy cars are set up with a degree of stagger (I don't know whether this is 'tail out' or 'tail in') but I don't know if the idea was around in the early sixties.

This is probably one for the technical forum or over on ten-tenths where a lot of posters race cars.

#3 Aanderson

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Posted 16 December 2003 - 12:40

Originally posted by D-Type


I'm confused. I thought the Lotus 29 suspension was offset not staggered . I'm probably totally wrong but I always understood that the Indianapolis Lotuses and the Cooper T54 ( model?) before them had unequal length wishbones so that the centre of gravity was offset relative to the centre of track. However the axles were set at right angles to the centreline of the chassis so that the rear wheels tracked the fronts.

If the suspension is staggered, the axles are not at right angles to the axis and may not be parallel to each other. The result is that when the car is coming towards you in a straight line it crabs and you can see all four wheels with one of the rears visible between the front wheels and the other out to one side. So when cornering neutrally the car appears to be understeering or oversteering.

I once owned a Triumph Herald that had had a very poor chassis weld up done. The back axle was not at right angles to the chassis, so when I was going straight the nearside rear wheel was nearer the kerb than the front one. I never noticed it was crabbing until I saw my wheel tracks. Under heavy braking it did slew slightly as the centre of mass was off the (average) centreline of the wheels but I simply put it down to the camber. I suppose it was a bit like a boat and handled better (or it being a Herald less worse) on left handers than on right handers or vice versa but it wasn't enough to notice.

I know that these days NASCAR and Indy cars are set up with a degree of stagger (I don't know whether this is 'tail out' or 'tail in') but I don't know if the idea was around in the early sixties.

"Offset" and "stagger" are two completely different things. Offsetting the engine on oval tracks seriously began with Frank Kurtis' KK-500A roadster, the one driven by Vukovich in 52-54, by the expedient of mounting the engine to the left of the driver, then laying it over at an angle to the right (the first to give some added weight to the left side of the chassis for better turn speed, the second to lower the frontal area for a slippery profile). This carried on throughout the roadster era, with Watson and others adding offset to the front and rear axle for more of the same weight bias to the left for the turns.

Team Lotus achieved much the same result by the use of unequal length suspension (longer on the right side, shorter on the left).

Offset would have little if any effect on the ability of the car to track in a straight line, after all, there is no differential in the rear end gearing.

"Stagger", in oval track racing, generally means a difference in outside diameter of the tires, from one side to the other. Almost always, this means slightly higher tire pressure on the right side tires, which of course, given their larger diameter, particularly in the rear, with a locked rear end, will cause the car to tend to veer left. Of course, on large superspeedways, this is a very, very delicate operation, tire diameters measured by milimeters. On short ovals, particularly dirt tracks, sprint cars run dramatically larger tires on the right rear to get an exaggerated stagger effect.

Art Anderson

This is probably one for the technical forum or over on ten-tenths where a lot of posters race cars.



#4 Tom Glowacki

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Posted 17 December 2003 - 03:07

The Indy Lotuses were offset to the left by a combination of unequal length suspension components and mounting brackets. The wheel base was the same on both sides, so the question was not stopping or accelerating in a straight line, but rather turning right, if need be. The effect of the suspension offset was to create a weight bias to the left, to facilitate left turns. Some of the NASCAR types in the 1960's actually did staggered wheelbases as NASCAR only measure on one side. The shorter wheelbase was on the left side.

The Autolite Lotus model was recently on E-Bay. It was a built version of the IMC model kit. AMT also produced a Lotus 29. The IMC had a more accurate nose shape and windshield shape and better tires. The AMT was otherwise superior, except for the tires and a somewhat undersize engine. Seen with modern eyes, there are problems with both kits and kit-bashing the two together would still leave you well short of what Tamiya, for example, would do today.