RPG's new Steering Tie Rods!!!!

[BlueSVT]

Where is your shop?

 

[RPG]

We are located in San Juan but will be coming up your way on Wed if you would like us to stop by.

 

[BlueSVT]

I'm in need of a few other goodies before this... so a trip to me wouldn't be necessary although I appreciate the offer! Likely I'll see you guys next time you have another day of desert fun, heard the last get together was a blast!

 

[bstoner59]

I can't wait for the campfire talk between Corey and Mark!

 

[RPG]

I can't wait for the campfire talk between Corey and Mark!

Lol, I'm just glad I'm meeting you guys in Barstow. You saw how crappy I am at shooting guns, just imagine me trying to set up a tent..
Dropped out of Indian guides at age 6 and never camped again. But I'm sure you guys will have a blast listening to mathematical equations.

 

[RPG COREY]

I can't wait for the campfire talk between Corey and Mark!

Who's Bringing the Coffee??

 

[MarkT]

Hello MarkT,
I thank you for your question and comments,
Once again, We have taken what we have learned in School and in Racing and applied it to our material choice.
Let's just look at one Trophy Truck in particular and see if you can name it before I mention the owners.

1. HEAVY, HEAVY, HEAVY oh did I mention HEAVY.

2. 4 Wheel Drive (a HUGE INCREASE in tie rod forces over 2wd applications)

3. 900+HP Leon Patton Horse Power

4. Red, Everything Red.. Until Monster came along.

5. Very well funded team.

6. Highly respected designers that made sure the owners made it home safely.

Herbst Motorsports

It was up to Mike Smith to ensure that the Multi-Million dollar vehicles went around the race course safely ensuring that the drivers made it home. Herbst had one of the most open-minded design teams with a great supporting budget. They also used aluminum tie rods on their 2wd vehicles.

http://i234.photobucket.com/albums/ee244/gmcwop/Herbst_TieRods2.jpg
http://i234.photobucket.com/albums/ee244/gmcwop/Herbst_TieRods1.jpg

Proprietary Information:
I am not willing to disclose true engineering calculations for a few reasons.

1. I would be giving away Knowledge to the internet. If you look hard enough on the internet you will find all of the knowledge but not the forethought on how to apply it. I spent many years studying Engineering in school to be able to create sound designs. Engineering is AWESOME. The machinery handbook is an awesome tool. If you don't have one, go buy two. One for you and one for your best friend, but make sure to write your name in it.. Otherwise yours may come up missing.

2. Could you image how bad I would feel if I posted a Euler Colum Buckling equation, Heat Treatment or axial thread loading equation, which then gave someone the ambition to make tie rod kits and have parts heat treated.. Intentionally I didn't mention Hydrogen Embrittlement.. The kits get onto the road and instantly SNAP.. That would suck... Don't buy Kits from NON-ENGINEERS... (Don't worry, we took care of this.)

Note, Our Aluminum Tie Rods are Anodized Blue. What surface benefits do you get from an anodized surface?? Increases surface hardness..

Destructive testing is fun as long as there are a few requirements met

1. PARTS ARE BROKEN IN A TESTING LAB... Breaking parts in the field or on the race track is not fun.

2. I am not paying the testing lab bill. Anyone on this forum work for Stork Testing Labs in Huntington Beach? Hugo has always taken great care of me, but it is still very expensive. Tooling alone to hold the apparatus would be in the Thousands. Anyone still in College that wants to do a report on this project? I will be happy to supply a set for testing... Cal Poly Pomona has a few BIG Instron's, but they are not calibrated. Still a good tool for comparing the two apparatus.

I think that your values are a little off for thread load bearing %'s.. check that value again. I think that you assumed similar materials. In this application, we have Steel Rod Ends and Aluminum Tie Rods.

Additional Thread engagement is necessary for our application. Remember this is a rod that varies in length. We need to allow our customers to align their trucks.

It is obvious that you have GREAT engineering / real world experiences. I am going to attending the Mojave run this weekend. I look forward to talking with someone like yourself and bounce a few ideas off you.

Corey

I'll admit I'm confused by your response. On one hand you say that you won't post information because it might inspire someone with lesser knowledge than yourself to make or market their own set. Then in the next breath you say you purposely didn't mention the dangers of hydrogen embrittlement during heat treatment? It's this kind of information that would keep people from buying from critical parts from people who don't know what they're doing! And it would keep anyone with a drill press and a lathe from thinking they could just throw their own kit together.

As far as Herbst and the aluminum rods... I know aluminum tie rods have been used by many racers. I've used them myself. But it's very possible that they use much larger and stronger threads. (I'm not up on trophy trucks but my guess is 1" or 1.25" is used... much stronger than 0.75")

Oh, one thing I'm pretty sure of is that most trophy trucks weigh less than a Raptor.

But you didn't claim your tie rods were made from aluminum like the trophy trucks... you made specific claims when someone asked you about thread strength.

What caught my eye was your claim that a 3/4" thread in aluminum was stronger than the stock 0.472" steel threads... that fine threads are stronger than coarse threads... and the implication that more thread engagement than stock adds substantially to thread strength.

All of those claims are hard for me to believe and you aren't backing them up with any engineering or test data.

As far as thread engagement? If I'm wrong, show me where. As counter-intuitive as it sounds, the first few threads carry about 80% of the load. In softer materials, the loads spread out a little more but there is no significant increase in thread strength once you exceed an engagement 1.5 times the bolt diameter in aluminum.

In reality? Ford's tie rod threads might be 10 times stronger than they need to be. Your threads might only be 7 or 8 times stronger than they need to be. Both might be overkill. But that still doesn't make it right to claim something is stronger than stock when it may not be.

 

[f16YODA]

 

[MiloX]

Annnnnnd.... It's on.

 

[Reptar]

I wouldn't say "it's on", but a very interesting discussion is certainly ongoing, and I hope it can keep going forward.

An engineer here as well, I'm electrical, but have always had a strong interest in mechanical engineering and one of my projects was building a hybrid formula-sae racecar, and I actually did some of the work for the mechanical team on tapping tierods for rod ends, staking bearings in a-arms, etc., so very interested on the engineering behind these pieces.