I noticed some traffic on my web site from HybridZ and was pleasantly surprised to see a thread opened on the CV axles. Thanks John!
Mods, I'm new to this 'vendor' role, please let me know if I'm breaking procedures etc...
I'll keep this theme to simply answering some of the questions raised above. Please don't hesitate to add questions and I'll continue to answer as best as I can - w/o giving up too much R&D.
"...he seems to be quite a regular in the "Dime" community" - that I am. For the past 7 years I've been a proud owner of a 1972 Datsun 510 2 door, orange. I also own a 1976 280z that currently being built up into another fun toy and R&D test bed for future products. Much of my involvement on 'The Realm' has been sharing in my experimentation (Yamaha R1 carbs on a KA24e and MegaJolt EDIS ignition etc...) and learnings.
"..I wonder if he is just cutting flanges off old u-joint axles and welding them on to "CV" axles..." - nope. I manufacture brand new adapters/flanges, accurate up to 4 thousands of an inch on centering/mounting to make them dead smooth. The flange's bolt-hole placement is left to CNC machining for repeatable accuracy.
"...Not sure that they're much better than a u-joint axle though. What's the benefit?" - Several benefits:
As the U-joints in our axles fail, finding replacements has been difficult, at least for me.
Also, with lowered Datsuns, the larger angles within the axle exaggerates a U joint's inability to rotate at a constant speed. These newer CV axles (short for Constant Velocity), can rotate at more consistent speeds with larger angles. The end result is a noticeably smoother ride - even for Datsuns with seemingly fine stock axles. Another reputed benefit is more drivetrain efficiency and a couple percent increase power to the wheels.
"I wonder where the came up with the torque limit. Breaking welds? " :
A LOT of engineering went into these CVs - down to shear calculations, metals selected for the adapters and how it interfaces with the CV, impacts from tempering, redundancy in fastening etc... Calculations showed that the fastening/welding technique is ~20-30% higher than the stubs at their weakest point.
Back to the question, the torque limit was placed because that's the approximate OEM limit that the axle is designed for, and I wanted to limit anyone trying these axles on over the top machines.
As previously posted the axles are comparable to the Subaru STI which are quite capable. My guess on the weakest link now lies in either the axle splines or the shoulder/D bolts themselves.
" Being that the stub axle is such a weak spot..." - I'm not sure where on the stub you are referring to but I do offer an integrated stub CV where an OEM STI stub is directly fastened onto the CV housing - in 3 different manners (it's NOT coming off!). It's really slick with only 4 bolts to fasten the axle onto a clip-in diff setup. A similar R200 version is in the plans for this spring as well.
I hope that answers the questions.
My CV axles are designed to fill a niche market and not directly compete with existing products/vendors. There are already several options for owners with massive HP and/or heavy track duty needs. My CVs, and frankly the basis of all my future products, are intended to be an affordable & original solution that offers a level of reliability (read: lack of maintenance) you expect from a street car, be it stock or with a moderate swap/upgrade powerplant.