Only pics I can find is broken aftermarket driveshafts.
I think I'm interested in a qa1 cf driveshaft. Shoot me a message and we can discuss it.
Wow, that was a lot of fantastic information! If I were competitively racing my car I would probably go down this rabbit hole because I am a numbers type of guy but this is just a fun street car. It may see the drag strip a few times but since it's a 6 speed manual it will most likely be a heart breaker at the track. My car is just a FBO e85 car currently but I dontblike to buy things twice because I skimped out the first time hence me getting the sage 3 calimers transmission and the mantic clutch. That being said I did bite the bullet and ordered the qa1 rev 1 sfi certified carbon fiber drive shaft. It seems to be great quality and of all of the manufacturers I haven't heard any bad things about their carbon fiber drive shafts. I won't know for a month or more how it turns out because my transmission hasn't even arrived at calimers yet (damn fedex). I will definitely post and update once it's all back together.Of nearly all the rotational mass components in a typical rwd vehicle.
The driveshaft. As a component, has the least benefit from weight reduction, due in part to both the "pitch circle" diameter of the tube, regardless of its material of aluminum, steel, or carbon. Adding in the fact that its between the transmission multiplication ratios, & the rear differential ratio, & not being unsprung wt#, or amplified by the torque multiplication if it were after the rear gear ratio.
Aluminum aftermarket driveline builders have had issues with balancing there products for yrs. There is a reason for this spoken to later.
On high end race stuff, we usually like to hammer on alum, & them re-inspect/check for the yokes being out of time on a granite surface plate, as well as having them re-balanced, after putting torque to them.
People would be shocked how often eelded alum shafts are not in balance after being loaded. Mark Williams Ent. does the best job we have seen, of anyone, in all aspects of these pitfalls. W/their proprietary loading/spinning equipment that can test to failure, & torque load a shaft in house.
I would at least consider a properly calculated 1 pcs
(to your own critical speed needs)
steel tube sized shaft, vs the same critical speed rpm of aluminum & carbon sizes, which dictate the wt# of each.
Doing this can help you to quantify the static weight saving itself. The dynamic weight differences of a driveshaft, (inertial rotational mass when spun) by & large, has the least effect on 'rate of accelerate effects' of nearly any other driveline component.
The driveshaft is probably the 1 component where the weight savings, beyond going to a 1 pcs, is even measurable ontrack, as it pertains to rotational wt# penalties.
If your a Bucks Down person, I'd at least consider a properly sized steel shaft.
Or just go for it & save up for carbon. If you do go aluminum, make sure your manufacturer understands your own critical speed RPM needs. Cuz oversizing the driveshaft in alum by a less skilled manufacturer, just defeats what wt# savings benefit you should have gained from going w/aluminum to start with.
Mark Williams is 1 Co. that offers a critical speed chart available to compare the various diameters/wall thicknesses, & material choices.
Yes, they are over engineered beyond recommendations.
Don't get us wrong, as we have ran them all, including many alum, for decades. Having an alum in our own track only, not street legal racecar. We also have muti driveshaft loops in that car, to protect it from the helicopter-ing,
fling wing effect.
Driveshaft strength & critical speed velocities largely come from the diameter of a properly sized diam tube.
Yet, it's still effected by the material choices. Wall thickness is certainly a factor, but torsional rigidity, 'jump roping', is largely a function of girth/diameter.
That's what she says, anyway
Bonded aluminum is better than welded in aluminum if that can be done fir your own needs. Not sure who offers this option for S550s. Mark does do it.
You can never regain the tensile & yield strength of the parent heat treated aluminum alloy tubing, in the heat effected weld zone, & @ the welded joint itself...
Welded vs bonded, where the yoke to the tube joint itself, w/not soften the material, like it would by welding it.
Low carbon steel welded joints usually raises the tensile strength some, unlike 6061 aluminum.
7075 aluminum is not a good weldable choice, but is bondable. This loss of heat treat appears to be a possibility of why aluminum shafts seem to have issues maintaining balance/parallel, & perpendicular yoke timing.
If you feel like your drinkin from a firehouse from reading this, than talk to reputable manufacturers, to get squared away in congruence w/your budget.
