Festiva - Aspire Steering Rack Comparison

[TominMO]

I strongly suspect that a few die-cut threads on the inner end would not be an issue.

For two reasons:
a. if you had to add die-cut threads, that would mean you are already using all the other threads first, which are presumably stronger than die-cut threads.
2. I find it hard to believe that the forces/stresses on the tie rod threads moving the wheel and knuckle mass back and forth would harm the threads, even if they were all die-cut, since the tie rod end would be well screwed into the tie rod, not just one or two threads, and locked into place with the nut.

But this is just my WAG/intuition; maybe someone on here has an understanding actually based on engineering that indicates I am wrong.

[TominMO]

TominMo,
I did consider that and I believe that I have a die.

In considering that, I'm gonna bet that the threads that are on the tie-rod are rollformed and not cut which produces a smoother and, in a sense, a forged thread.

I know that there is not so much stress on a stock Festy but If I were to cut the threads I'd never get it out of my mind that a die cut thread on a steering component like the tie-rod could develop a crack and fail at some point and if it were to happen to me, it'd probably be at speed.

If you die cut the threads on the inner side, never drive it over 38 mph. At that speed, if your steering fails, you can hit the parking brake (hopefully after upgrading to Aspire brakes), which will slow the car down enough to open the door and roll out.

Caution: do not try this on a two-lane road during rush hour. If driving a Festiva during rush hour on a two-lane road with die-cut tie rods, never exceeding 38 mph of course, have an inflated beach ball between you and the steering wheel to act as an air bag, since bailing might not be the optimal choice.

Another very helpful safety feature would be a sail that normally lays flat on the roof, but will pop up when you pull the parking brake, thus slowing you even further. According to my research, physics works pretty much the same in OK as in MO, so I think this will be a viable option.

Oops! The alarm went off, time for my medication.....

[difrangia]

http://www.melfast.com/blog/2014/03/what-are-the-main-differences-between-cut-thread-and-rolled-thread-bolts/

http://www.vallorbs.com/wp-content/uploads/2015/10/Vallorbs-Guide-Cut-vs-Rolled-Threads.pdf

[FestYboy]

Ok so after reading both links, why is there even an option for cut threads. Commercially, cutting isn't a viable option and from an engineering stand point, rolling is superior and therefore the better option.

[Dragonhealer]

Thank you.
Just like a straight punch flexes when you strike it, the side rod assembly flexes too, not much, not at all on a smooth road, but every bump and pothole will cause a flex. Bad place for a cut thread.