[Scalewoodman]

One of the cool technical details of Alfa Romeo (Giulia AND Stelvio) is the use of a CARBON FIBER driveshaft to transmit power to the rear wheels. Through Our Eyes: Carbon and Aluminum Drive Shaft Overview - theATTACK.rallysportdirect.com >Check out this link!<


Carbon fiber was chosen because it is lighter to achieve the perfect 50:50 weight balance and minimize the weight of the vehicle - improving fuel mileage and acceleration. Carbon fiber has less than half the spun weight of steel, meaning there is less inertia when slowing down and less resistance when accelerating making driver inputs feel more responsive (because they are). CF shafts have smaller diameter and greater tensile strength but also cost more than the usual steel or aluminum shafts. Also this gets more power to the wheels.


I have noticed a difference in 'the torsional spring rate' in day-to-day driving vs. other vehicles-- there is some play in the power to the rear wheels (feels like soft motor mounts) which I would attribute to a slight twisting in the shaft. However because there is a lower spin weight, the drivetrain is much more responsive (reflexive) to accelerator inputs and I have noticed affecting the braking action as the ZF 8-speed downshifts needing a little more attention to get a smooth stop (which many may be incorrectly attributing to the Continental braking system). Interesting to note the point that the torsional twisting actually prolongs the life of the other driveline components by absorbing some of stresses associated with enthusiastic driving habits.


Anyway, hope you find this interesting as I am. Here is another interesting link to a commercial site: Driveshaft Technology And Selecting The Proper Shaft For Your Ride - StangTV

 

[CalgaryStelvio]

Thanks for the link, interesting article. One of the reasons they put so much power to the wheels vs their engine ratings.

 

[stelviofan]

I read the CF driveshaft was really meant for the QV. The engineers somehow managed to get the bean counters to let them use it on the base. I wonder if this story was made up or not.

 

[Scalewoodman]

In manufacturing, fewer part numbers and interchangeable parts = surprising efficiency and cost savings. Wonder what the cost differential would be but if you factor in the above it might have not been that significant, especially if the vendor has capacity to deliver the goods. Interesting story.

Stelvio definitely feels light on its feet - aware of this I can see the advantages and appreciate the differentiation as part of the brand experience.

Cool story.

 

[onno]

Very interesting. Thanks. This helps explain an aspect of the overall responsiveness.

I'm looking forward to reviews of the in-line 48V Mitsubishi electric motor in the new Benz, and others. It should give similar dynamic feel, maybe with a few more advantages. (See my post in Questions for factory thread for explanation.)

 

[Fiver]

I read the CF driveshaft was really meant for the QV. The engineers somehow managed to get the bean counters to let them use it on the base. I wonder if this story was made up or not.

If this really is true, we have the engineers to thank and makes me wonder what else they manages to get past the finance department.

 

[Flunx]

and for the "LSD"?
Did someone order the pack Performance AT8 ? (8LW = 939 + 4WE + SDD)

 

[CalgaryStelvio]

and for the "LSD"?
Did someone order the pack Performance AT8 ? (8LW = 939 + 4WE + SDD)

I've got the Performance Pack on order with the LSD and active suspension. Due in a week or two

 

[Flunx]

I've got the Performance Pack on order with the LSD and active suspension. Due in a week or two

I also order it. :devil