Ford Design Analysis
The subject part is a direct 'lift' from the Lincoln LS and Jaguar which shared a platform at that time. It's a robust piece; curiously, do you have any data that would indicate to the contrary?
My thoughts as well. I am always amazed at others who know more about designing safety critical (the steering tierods serve a critical steering function) components on high performance cars than the Ford design engineers. Not that new tierods cannot be designed and made to carry higher steering loads, but is it necessary?:confused
The tierods designed and pictured by one of 101 look fantastic and likely can handle higher loads. The spherical bearings at each end are beautiful and provide inner and outer length adjustment thru threaded engagement in the tierod barrel. From an OE perspective under a very compressed design timeline (designed, developed and launched in 24 months), weight and cost targets it certainly makes perfect sense to borrow components from other product lines with a known history and structural adequacy. During my design career I was always reminded that Better is the enemy of Good Enough.
As to the structural adequacy issue, I am most certain that the Ford suspension designers instrumented critical suspension components to determine road and race track loads. Due to the high performance/speed nature of our GT’s and the risk adverse stance of corporate liability, I am again sure a large safety factor (load to fail the component/maximum operating load) was applied to the design to keep the lawyers happy.
I have no documentation or FE data on the part but I've seen quite a few that were folded up on wrecked cars. from a compression or tension standpoint the part works good.
Scott, I do not know where or how you would gain access to internal Ford documentation of the loads or Finite Element (FE) analysis the design team used to analyze the tie rod. As documented in SAE publication 2004-01-1255, “Design and Analysis of the Ford GT Spaceframe”, Ford used a number of analytical structural analysis programs (HyperMesh, NASTRAN and LS-DYNA) to design and insure component structural adequacy. Design loads were measured using test mule vehicles. Just because you see tierods which are “folded up on wrecked cars” implies nothing as to the component design for satisfying its intended function. Aircraft which crash into the ground due to pilot error can appear pretty “folded up” as well, but it means nothing about the aircraft structure while it is flying within its design envelope. Engineers typically do not design a component to function after design ultimate or crash loads have been applied.
I just have to wonder how much stress analysis and bend were measured for such a critical control part for a supercar. for a Tbird and LS I'm sure it's more than adequate but then again if it's being used on the NGT, it must be OK. all jmo
Well, perhaps you should go read the SAE report 2004-01-1255 to answer your question on how much stress analysis and bend (?) was conducted on the FGT design. For that matter you and others with a technical interest should read the full 11 report suite of technical reports published under SAE PT-113. Very good technical documentation on our cars design.:thumbsup
