Ferrari made two versions: the original single piece and a later 2 piece version. Are both versions the standard 52mm length conical type ala most Ferraris from 512TR,512M,550/575,456/456M,360/430+ ? (Not including certain 355/348) I was told the OEM 2 piece may only work with certain wheels/models (488+?) and am trying to see if that’s true or hearsay Note I’m strictly referring to the over-priced OEM bolts above…aware can get most whatever sizes you want aftermarket.
I am not aware of the two piece lug bolts from Ferrari. I know the one piece are the standard 52mm conical type.
Here is example: https://www.ferrarichat.com/forum/threads/ferrari-titanium-wheel-stud-set-70004715.613107/
Some for sale listing claim the 2 piece may be slightly longer? Not sure. I’m not entirely clear on the timeline either as it looks like it went from Single>two piece> back to single construction ?
I don't think two piece were factory installed. I have had a two piece set for a car but the parts department ordered them. I am not aware of any two piece that were OEM factory installed. Sorry I can help you on the length.
I've run both styles you mentioned on my cars (single forging as well as the two piece design). As to your question regarding length, yes 52mm. They are identical to the OEM chrome bolts, so anything which uses the older standard lug bolts will accept the titanium ones (single forging design and/or two piece captive washer design). Direct replacement... works on the 360, California, 458, 488, etc. as long as you are using standard Ferrari wheels and not running spacers or anything fancy. On my 360 I had the one piece design and on the 458 and 488 I ran the two piece design. I think the later design might have been an option (the two piece design). My particular set came from a Ferrari dealer who mentioned a customer had ordered them through their parts department but failed to pick them up (or something to that effect); I ended up buying them and really loved the 2 piece design over the single forging style. As to the strength question: Ferrari may be using TC11 alloy (aka Ti-6.5Al-3.5Mo-1.5Zr-0.3Si) more recently as compared to perhaps Ti-6Al-4V in the past. I don't know that for sure, but in speaking with my own Titanium supplier regarding producing Ti lug bolts for the Ferrari, we had discussed the pros and cons of using TC11 at one point. I believe they mentioned it has a more grey / matte tone to the final product, which seems to resemble the two piece captive washer design Ferrari had on offer. Here's a picture of some lug bolts I had produced, which were two piece design and made from straight Ti-6AL-4V / Grade 5 alloy. The 2nd photo is of the Ferrari bolts, which I ran on the 458 and 488 no problem. Ray Image Unavailable, Please Login Grade 5 Titanium allow Image Unavailable, Please Login Optional Ferrari Titanium lug bolts - maybe TC11 alloy, but who knows?
None! In fact a negative to me. Increased stress riser, increased frictional surfaces, less ability to control torque application, parts to loose come to mind.
All things being equal, the use of any washer generally almost doubles the time it takes to loosen a fixing bolt. This is because you are providing a physical break between the surfaces at play when it comes to any attempts by loads, forces, etc. to loosen the bolt. I didn't design the original bolt; I just copied the previous design, but generally speaking, washers help prevent bolts from backing out when placed under loads. I would venture a guess that all the Ferrari wheels which have mysteriously come loose during track days were using the 1 piece design wheel bolts. Here's a paper on the subject that's also kinda of interesting: https://www.researchgate.net/publication/273822007_Role_of_Washers_in_Controlling_Loosening_of_Full_Threaded_Bolted_Joints Also helps (a little) against damaging the wheel itself during installation and removal, but usually still leaves a mark. Ray
Does Ferrari offer anything longer than 52mm? Looking for a slightly longer bolt for 355 Speedline Challenge wheels to run without spaces. 52mm might be a tad short.
Looking for a 55mm or close in titanium. Im aware after-market have the sizes. My issue is I prefer the Ferrari bronze-like finish, which after-market ones dont seem to have nailed down.
Im a club racer putting more stress on wheels hubs and bolts/studs/ lug nuts than 99% of users. The only bolts and nuts that come loose on a wheel were improperly torqued. Wheel bolts, studs, nuts are totally over engineered for the job well below metal yield point because oem s know how stupid people are including pros with bad torque wrenches, improper use of air guns and , improper wheel installation for example
