Specification Info for different 356s?

[neilbardsley]

Anybody have a link? I was just wondering, as one does, what was the difference in weight between a 356a and lighten GT.

The power goes up from 75 hp to 130hp with the 4 Cam?

[Arenarot]

I would be interested in this as well.

[Mike Smith]

I have never checked it but at the time it was always quoted as --- 160Lbs

Having now perused the question over dinner - it rather matters what you are comparing

There are

Standard Road Trimmed Pushrod Engined Cars

Standard Road Trimmed Carrera Engined cars

Carrera GS/GT`s

Pushrod Lightweight Cars (known as Super 90 GT`s)

Add to this the fact that the Early GS/GT`s still had Steel Doors and Lids PLUS the Carrera engine got heavier as it moved from 1500 through 1600 and then 2.00 Litre
and the answer becomes more complicated

[steve wright]

plus it's also worth considering the fact that the four cam motor with all it's extra ancillaries (dry sump pump, separate oil tank, large air-filters, etc) actually made the motor heavier than the pushrod motor, so the weight saving was in the ally panels and lightweight trim, so you're not gaining a weight advantage with the four cam per se, but in other aspects of the GT specification....

[neilbardsley]

160lbs isn't a lot

I was originally thinking

"Standard Road Trimmed Pushrod Engined Cars" v "Carrera GS/GT`s"

IE My 56a v the carrera of the day. Which is looks like it would of been

1500 GS? http://www.supercars.net/cars/1508.html

115 hp / weight 923kg curb weight (the link must be wrong?)

v

60hp / weight 820kg?

v as I think you are suggesting that a push rod lighten & warmed up can be faster than a period GS/GT

Warmed up & light pushrod

140hp / weight <800kg?

[roy mawbey]

Neil,

If you look in the 356A drivers manual the weights of the 356a coupe /convertible and hardtop are stated as:

Dry weight : 820kg
Empty weight: 850kg

The speedster version is:

Dry weight: 730kg
Empty weight: 760kg

What is strange to me is the fact the power to weight ratio's of both the 356A normal and the 75 hp super are stated for both the coupe and the speedster version and they vary because of the weight difference but, the top speed values are the same 100mph for the normal and 109mph for the super. ( or 112mph with super sport tyres)

To me it would seem the speedster should be slightly faster overall?

They state the power/weight ratio ( empty Din std ) 20.7 lbs/HP 356A 1600s ( Coupe)

and 18.8lbs/HP for the Speedster with a 1600s motor.

Never could quite understand that? If the same engine is used in two cars and one is much lighter surely the top speed is increased on the lighter car or does the aero dynamics all come into it from the speedster to the coupe?

Or, is it really acceleration that improves more with a cars lower dry weight and the top speed is governed more by the gear ratio set up in the box. Again losing weight on a car in the wrong places probably affects the handling at speed which would act like a detriment
rather than an advantage.

It would be nice if someone could explain?

Roy

[neilbardsley]

Or, is it really acceleration that improves more with a cars lower dry weight and the top speed is governed more by the gear ratio set up in the box. Again losing weight on a car in the wrong places probably affects the handling at speed which would act like a detriment
rather than an advantage.
Roy

I guess that.

Once you get up to high speed weight is less important and aero dynamics take over. You accerlate quicker in the light car but you don't go any quicker because you are still at max rev with the same engine/gearbox?

[Bruce M]

Acceleration is caused by an imbalance of forces. At max speed the force of the engine via the torque multiplier (gearbox) is balanced by the air friction/drag and the mechanical friction (subject to rev limits) so there is no more acceleration. Under acceleration, another dynamic force comes into play, inertia and that is due to mass (weight).

[roy mawbey]

Thanks Bruce, its getting clearer to me, but more to it than meets the eye. I found copies of Road and Track road tests from the 50's for a 356 A normal, a Speedster super and a 356A Carrera. All interesting road tests that also advised the curb weight for each car.

356A Normal Coupe: Curb weight 1930 lbs ( 875 Kg ) Top average speed 101.4mph

356A Carrera Coupe: Curb weight 2035 lbs (922 Kg ) Top average speed 120 mph

356 Super Speedster: Curb weight 1790 lbs (811 Kg ) Top average speed 105.2 mph

The difference in curb weight between the Speedster super and the Carrera is 245 lbs or 111Kg. ( that is equivalent to a 17.5 stone man !!)

All that extra money to get a 15mph increase. But surprising the 356A super coupe not detailed above but with a top speed of 112mph max was no doubt a little faster than the Speedster super. Aerodynamics?

Roy

[higs356]

Thanks Bruce, its getting clearer to me, but more to it than meets the eye. I found copies of Road and Track road tests from the 50's for a 356 A normal, a Speedster super and a 356A Carrera. All interesting road tests that also advised the curb weight for each car.

356A Normal Coupe: Curb weight 1930 lbs ( 875 Kg ) Top average speed 101.4mph

356A Carrera Coupe: Curb weight 2035 lbs (922 Kg ) Top average speed 120 mph

356 Super Speedster: Curb weight 1790 lbs (811 Kg ) Top average speed 105.2 mph

The difference in curb weight between the Speedster super and the Carrera is 245 lbs or 111Kg. ( that is equivalent to a 17.5 stone man !!)

All that extra money to get a 15mph increase. But surprising the 356A super coupe not detailed above but with a top speed of 112mph max was no doubt a little faster than the Speedster super. Aerodynamics?

Roy

I cant find my copies of those road tests but I believe there are a couple of things to consider in addition
#Gearing ... Most Speedsters had BBAB ...Carrera coupe probably had a D or C longer leg (and if I remember the C was longer than the D longer than the B)
#Aerodynamics ....As you said the speedster is not very slippery (remember the hardtops they put on the 550 s for LeMans long straights)

If I had to bet on this I think a speedster with a plastic hardtop , pushrod super engine and same transmission would beat a Carrera coupe ...Anyone here got a pair of these they would like to try it out on ??

Also ..it was probably a necessity for marketing and sales that the top speed of the Carrera was greater than that of the Speedster in the same way you will never see a modern RSR 911 engine offered in a Boxster.