14mm to 12mm stud for 944 alum arms

[flat]

I noticed some guys are talking about the the reducing studs for the alum 944 rear arms. As a general rule, a machined (lathe turned) thread can never be as strong as a bolt (rolled) thread. When you roll a thread you compress the surface of the thread leaving a residual compressive stress. This prevents crack propagation. In a turned thread, the base of each thread is a stress riser and prone to failure.

Ofcourse, I'm talking of large loads that can lead to failure. This loading will never be seen of a street car. Also, the shock bolt is loaded in single shear. This is a bad situation for a bolt to be in, so keeping the diameter of the bolt as large as possible would be a good idea.

What I'm suggesting is that you replace the lower bushing in the shock to allow for a M14 bolt rather than a stepped stud. Also, I'm pretty sure I can market a replacement bushing at a much lower price than a turned piece. I'll throw out an guestimate of about $C45 for the set (four half bushings and two sleeves). The bushing material will be UHMW(Ultra High Molecular Weight) polymer, which is much denser than rubber and will not deflect much. The installation would require you to remove the stock bushing in your shock and install the replacement.

Let me know how much interest there is for this product.

Easy,
Lanner

[zen]

i'm all for it. just haven't found anyone that could pull it off. the plan for the studs i am looking to have made are not turned down 14mm. they would be rolled and heat treated. but i have yet to meet the manufacterer and figure out any details. no reason to do it halfa$$ed if i'm going to go through the trouble of having them made. they would come out at less than $10US a piece. i would prefer using the stock 14mm Porsche bolt though if the option is available. what kind of timing are you talking about?

[flat]

Turnaround would be quick if you're interested, I have the material in stock. The biggest hurdle I see is to gather the information for different shocks. The outside diameter(OD) and length of the bushings would most likely be specific to the model of shock (stock, kyb, etc..). I have stock and KYB gas-a-justs here for some 'reverse-engineering'.

[Alex]

I have two. They are also spaced out so that the shock angle is better.
You can have them as a demo.

Alex

[zen]

that's cool alex. what shock are they for? i haven't decided on which shocks i am going to run. the KYBs are going back on for now with the bushing reemed juyst so i can get to dyno day next weekend. then i will be making a shock decision and am interested in this possibility. i am thinking probably Koni. not sure if red or yellow though. flat, maybe we can work something out to get them to you for a model. let me know thoughts.

[Alex]

THey are for swing axle shocks.....so all the aftermarket shocks for swing axles will fit. I was told that this was done to get a better angle for the shock to make them work better.

Alex

[zen]

Turnaround would be quick if you're interested, I have the material in stock. The biggest hurdle I see is to gather the information for different shocks. The outside diameter(OD) and length of the bushings would most likely be specific to the model of shock (stock, kyb, etc..). I have stock and KYB gas-a-justs here for some 'reverse-engineering'.

flat, did you ever get anywhere with this? i need to make a shock decision within the next week or so and also decide how i am going to mount them. let me know.

zen

[zen]

normally posting is not done/allowed in these forums, but thought it worth noting that i just got some of the bushing/sleeve replacements for my Koni's from flat. perfect fit. the low deflection quality of these bushing make the needed angle for wide ali 944 arms a little challenging, but it worked out fine.

i am much more satisfied with this solution than the other routes i thought i would have to go.

thanks Lanner. payment on the way.