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Originally Posted by tyoneal
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That will not be a possibility due to the design of the Corvette upright on the DSE sub. Our spindle cannot bolt to the upper control arm with the current config that is on the frame due to the inverted upper ball joint. Maybe DSE will make a provision for our AFX spindle? Can't hurt to hope...
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Originally Posted by Stuart Adams
I would be very interested in the stress testing that was put into the AFX spindle also. GM puts alot of testing in their spindle and had problems with breakage in the past that caused projects to be shut down until fixed.
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Stuart-
We did lots of engineering, FEA, and actual physical destructive testing on our spindles. I can say that without a doubt they are stronger than the C5/C6 spindle by quite a bit. The C6 spindle is a pressure casting from A356-T6 aluminum vs our forging in 6061-T6 aircraft grade aluminum. I'm going to save my typing fingers, and cut and paste a response toa Chevelles.com thread where people questioned our spindle:
Here is the link to the thread:
http://www.chevelles.com/forums/show...&highlight=ATs
Here is the response that Shane wrote:
Alright guys I'll try and layout our design process for these spindles based on your inquiries and concerns. First let me state that yes it is extremely expensive (especially for a two man team) to replicate all the tests that parts have to endure in the OE's, but we have tried to cover all the aspects of the test and design phases to our capabilities by contacting multiple engineers in GM, other suspension engineers, and different vendors involved in designing the C5 knuckle in order to achieve these goals.
In the initial stages we fabricated a test spindle much like the Stielow spindle but utilizing a C5 bearing cartridge and an adjustable steer arm. We acquired control arms from Global West, DSE, and Speetech and did camber curves, caster curves, plotted pivot points, in both the stock location and gulstrand location for both the AFX spindle and stock spindle. This was done to know our baselines and to be able to tell the customer how our spindle will work with any combination and how it will affect their application. We are currently in the process of working with SC&C to do the same for the A-body platform so we can accomodate those that have already done the B-Body spindle conversions and have the shorter UCAs and also to design an UCA that is specific and optimized for the AFX spindle.
All the components for the orginal fabricated spindle and current forged spindle were modeled in Solidworks and had simple wheel load FEA done on them by both myself and the forging company since we already knew the fabricated spindle has taken a ton of abuse on the Thrasher Camaro. I have taken specialty classes in both finite analysis using ANSYS and strain gauge testing. Next we got in contact with one of the original reps that worked for the manufacturing company that did the C5 pressure cast aluminum spindle. He was able to tell us the constaints and requirements that GM demanded for their design. The C5 spindle is actually a pressure cast A356-T6 alloy while ours is a must stronger forged 6061-T6. For those that want numbers The UTS is 228 MPa vs. 310 MPa, Tensile YS is 152 MPa vs. 276 MPa, and Elongation at break is 3% vs. 12% for the C5 vs. the AFX materials. Our selection of material was discussed in long detail and initial FEA was done based on our current model by both myself and the forging company taking in to account a safety factor of 5. Not only is our spindle more ductile but it is also a lot stronger and those that know how forging works know how the grain structure is worked so that it flows in the direction of the part for optimal strength. The AFX is also almost 1.5x thicker everywhere than a C5 spindle. Now let me say that the FEA was used just as a tool for the design process not as a corner stone. I will get into the true destructive testing later.
Other aspects that we looked into and talked with GM engineers on was one thing that was stated above about the new Z06 twisting the brake bracket which I can concur was true. They had to redesign the spindle to be beefier for the 6-piston calipers. We took this knowledge and also incorporated about a 50% thicker caliper bracket which is also reinforced into the lower ball joint with stratigically placed variable fillets. Another issue plaguing the C5 knuckle was the lower ball joint taper fatiquing after each torque cycle of the ball joint. We took care of this issue by introducing harder 7075-T6 inserts that are frozen in liquid nitrogen and placed into the extremely precision machined holes of the spindle, which upon reaching room temperature maintain an adequete interference fit. On top of the interferance fit we use heavy duty spiral locks with an additional tensile strength of 211,000 psi to prevent any initial backing out on top of the interferance fit and mostly to reduce the risk of tampering.
Now onto the manufacturing. Number one is quality control and precision. The forging company we chose is in the USA and has been in business for over 40 years doing stuff for both military and the OEs. Each and every raw forging is inspected and 1 out of 10 has a tensile sample ran with it to check the material properties and their consitancy. Also we recieve a certification sheet showing the critical dimensions for each part and their tolerances. The machine process involves a 7-axis CNC with an integrated CMM probe to maintain all the stringent tolerances that are called out. I personally have 2 years of experience working with quality control and operating a CMM so I have a really good grasp on what I am looking for and what is required. Some may argue that some of this is over kill, but all our products must be top notch regardless if this is just the aftermarket.
Now on to the testing. We are in the process of contructing a pretty elaborate test station that will simulate wheel loads on the spindle and record the loads and deflection in the spindle. We plan on taking it to the point of failure multiple times. We are also putting a few sets on some Camaros right now that will be running on some road racing events later this month and running very wide tires. They will be putting some serious loads on these spindles. The road testing will be an on going operation that we will be tracking even after we start selling the AFX spindles. We are also working with another GM engineer to meet any other validating tests that he thinks are necessary. With all this said you can see we are going all out to make sure that these are safe, sound, and proven. As an engineer myself I can understand some worries with such a critical part of your vehicle and thats why we are being so aggressive with them and I am personally going to run them on my 87 Grand National. We have worked with the experts on these and I can guarentee we have a product that is of high caliber. Please let me know if you have any other concerns or questions.
I also wanted to add that our pricing currently is $625 a pair with brand new C5 hubs and all the hardware. BTW dennis thanks for the nice comments and as for the spindle height the tall version is 8.5" tall and with 1" taller upper and lower ball joints that would get you your 10" tall spindle along with a 1 7/8" drop. Like I said we are working with the A/G body guru Marcus at SC&C since he has a test frame to optimize this for that platform.
EDIT- Upon further reading of this post, there is 1 item that is incorrect- We do not use a 7075 T6 lower ball joint insert, and it is not pressed in place. We use 4130 steel lower inserts that screw into the spindle to help distribute the load into the spindle. It is now even stronger than it was when we first designed it. Our spindle failed after it saw 12x's the load it was designed for. We cycle loaded the spindle to 10 tons, and took it back down to zero, and multiple dial indicators showed ZERO deformation upon release of the load. We took it back up to find the breaking point, and it was just over 24,000 lbs.
I still need to take out some classified info from our excel spreadsheet, and then make it a .jpg for you guys to view. I'll be working on that later tonight, as I'm tied up de-bugging our new shopping cart.
Tyler
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