smlporsche

Chad in all seriousness and not trying to be a smart a$$ why don't you see about getting a fabricator to make 10 sets and price it reasonably and you could probably make enough money to get your set for free...

Brian A.

potential customer has subscribed.

m42racer

Seems so simple. I wonder why there aren't hundreds of choices out here for all to choose from.

I think you are way off in your costings. I see no where in your list any mention of heat treating. I figure along with your estimates you do not have a full understanding what is involved here. If it was only that simple. Make it cheap, means no time spent, cheap materials and then one fails and KILLS someone.

Yeah, its no wonder they are not all over the web for sale.

Go make some for what you figure, then go out and buy some liability insurance.

Again, it sounds to me like another 944 customer expecting the 944 vendor to cater to his needs and his PEP BOYS BUDGET.

Chads996

You guys make me laugh. As usual...way off base...I already have liability insurance smart guy. Before you assume...READ. Why is everyone afraid of trying something? Just because it doesn't come off a shelf at Porsche, doesn't mean it won't work. Sheesh...

Here is the source I prefer for motorsport parts.

Rod Ends:
http://www.aedmotorsport.com/FK/RodEndGuide.htm
http://www.aedmotorsport.com/FK/JMX_JMXL.htm <--Preferred Rod ends

Alloy Steel Tube:
http://www.aedmotorsport.com/4130/RoundTube.htm

READ the specifications and tolerances on the parts, sunshine. The Heim Joints I am specifying have a ULT. Static Radial Load of 45,051 pounds. Another option is the highest available at 55,690 pounds. There are larger ones (rate at over 100K pounds), but they are physically too big for the application. The tube has an approximate yield strength of 70,000-75,000 PSI while still maintaining a tensile strength of 90,000-95,000 PSI (depending on wall thickness). As I previously posted, making control arms like these is NOT new technology. It has been done for decades for all different kinds of cars.

I am a measure twice, cut once kind of person. If I am fabricating something, I make DAMN sure it will work and do its job properly. I guess my time studying Mechanical Engineering were good for something.

And before you go commenting about another person's "Pep Boys Budget", stop being a cheap *** and buy a membership to Rennlist.

m42racer

Ouch!!

KLR

Fabcar arms have failed as well -- generally at the pin. One just failed without warning on the fellow who ran a 968 in the GRM track car challenge this year.

https://rennlist.com/forums/showthre...ghlight=fabcar

Chads996

That's good info. There was a question or two about them. Thanks for posting.

C.

APKhaos

I replaced the Heim joints, pins, ann related hardware in my Fabcar arms when re-tubbing #11 last winter. The pins were pricey, but everything else was reasonable. Talking to people close to Fabcar, their analysis of the pin failure cases was inconclusive. It could have been wear, or due to imact damage, or even cracks arising from rough handling of the pins. Nothing like channel locks to create some nice stress risers that lead to failure. It should be obvious, but the pins need to be treated with respect.

Marcus Blazak's control arms have a good rep and a reasonable price. He's always been responsive when I've called him, so its worth a call.

I say go for it Chad. This is not rocket science, although the part needs to be highly reliable.

DWalker

What you should be asking yourself is why a set of fabricated upper and lower arms for a Nissan 2-chassis car is under $600 for the entire SET!Or why an entire corner for many Formula car is less than $500? The answer is not that there is more demand for them, its as simple as there is no way a Nissan or formula car owner would pay $1800 for a set of lower control arms, but obviously Porsche owners will.
Speaking from a fabricator/fabrication point of view, once a jig is made for each side the actually fabrication of each A-arm is not much of an issue. Also once you do have something made, the cost goes way down as you make say 25 or 50 of each item rahter than 1 or two.

chrisp

Wouldn't these require a post weld/heat treat maching operation to line up the bores? That will cost some $$.

Plus who would do this for only 30% mark up (equivalent of 23% margin)? Based on your numbers I would say the bare minimum is a 30% margin (retail of $1069) and realistically anyone who has overhead to absorb (which is anyone who doesn't do this in their garage) would want a 50% margin (retail of $1495).

DWalker

Depending on the jig and welding technique post-welding maching may or may not be nec.

Also you are assuming 30% mark up based on one or two sets of arms made and using pricing available off the internet, and labor pricing for custom fab work.

RedlineMan

Why do you think I made my own?...

Chads996

I know....I know!!!

Maybe we could team up. I could design you a tubular version similar to the others. With your welding/fabrication brilliance, I am sure we could knock this out of the park.

I have a spare set of control arms coming in. I can use them to base measurements off from.

Thoughts?

C.

M758

It has been discussed, but the use of rod ends as ball joints is not the proper use of these joints. They will be prone to failure due to braking loads causing bending at the threads where it goes in to the fixed arm.

Go large enough and you "might" be ok.

DWalker

Agreed, there is a much better way of solving the balljoint/pin issue than with a heim hanging out on the end of the a-arm. Remember that the entire reason you need fabricated a-arms is because of balljoint failure, so whatever solution you choose to use should solve that issue .