Gauging interest- Titanium wheel studs
05-11-2016, 02:34 PM
#16
Pwdrhound is correct, the max tensile strength of Titanium is around 1200 MPa where Steel Alloy can have a max TS of around 2000 MPa. The problem is when torquing the bolts down, there is a greater risk of fracturing the Ti if over torqued.
05-11-2016, 02:36 PM
#17
Rennlist Member
A couple weeks back I pulled the rear seatbacks and was surprised at how much they weigh. That was free and so is the spare/frunk emptying. Remove the manual from the GB, if you have one. The heated electric seats are tanks too, compared manual buckets.
Makes me think of pudgy middle aged road cyclists talking about their lightweight bikes over bacon burgers and wheat beers.
05-11-2016, 02:56 PM
#18
Three Wheelin'
My lug bolts are made from 6AL-4V Ti alloy. It has ultimate tensile of 950 Mpa, Yield of 880 and modulus of 113. 1020 cold rolled steel by comparison is 420, 350 and 186 respectively. There are steels that are much stronger than Ti alloys for sure. Typically Ti is considered the same strength as steel and 1/3 the weight, and slightly less rigid.
05-11-2016, 03:40 PM
#19
Three Wheelin'
clsund1 said, "possibly making titanium wheel studs to reduce rotational inertia"
I was taught rotational inertia, is the resistance of objects to changes in their rotation. In other words, a rotating object will stay rotating and a non-rotating object will stay non-rotating unless acted on by a torque. This should remind you of Newton's First Law.
How much do you think titanium lug nuts are going to change the rotational inertia and does that affect my trip to my local ice cream parlour? [the only place my hagerty insurance policy allows me to visit].
Inquiring minds want o know.
I was taught rotational inertia, is the resistance of objects to changes in their rotation. In other words, a rotating object will stay rotating and a non-rotating object will stay non-rotating unless acted on by a torque. This should remind you of Newton's First Law.
How much do you think titanium lug nuts are going to change the rotational inertia and does that affect my trip to my local ice cream parlour? [the only place my hagerty insurance policy allows me to visit].
Inquiring minds want o know.
05-11-2016, 04:07 PM
#20
Three Wheelin'
It totally changes the trip to the ice cream parlour. Everyone there will say "wow, look at your nuts"
Rotational inertia does not have as big an effect on the wheels lugs as it does on say a crankshaft. I would say almost non-existent. However un-sprung weight does have a significant effect on suspension performance.
Rotational inertia does not have as big an effect on the wheels lugs as it does on say a crankshaft. I would say almost non-existent. However un-sprung weight does have a significant effect on suspension performance.
05-11-2016, 04:47 PM
#21
Rennlist Member
Third-Reef
I've never told another man this, but those are nice looking nuts.
Just stop it! You guys are going to make me cry about my new jewelry. I feel so superficial. Oh, and I totally feel the difference just sitting in my car.
05-11-2016, 04:54 PM
#22
Bill,
I respect your opinion immensely since you've demonstrated time and time again a vast knowledge about our cars (which I don't come close to matching), but I'm having a really hard time reconciling what you're saying about Ti as a material and what I've seen and experienced with these applications.
There are different grades of Ti and the grade that would be used here is frequently used in the aerospace industry exactly because it is strong and light (it's an aluminum alloy). Perhaps you've seen Ti fail in the past? Perhaps it was a different grade?
As for the weight saving comments, no, it's not like removing your phone or CDs. while it is correct that the weight would be only removed from the center of the wheel and weight removed from the outer circumference makes a bigger difference in rotational inertia, it all adds up and this seems like a relatively cheap way to achieve that weight saving.
Reduction of rotational inertia is not a player here as you would be reducing mass from the center of the wheel instead of the perimeter. You would get a small amount of reduction in unsprung mass however.
I'm not going to get into a pissing contest about this matter. If there's no interest, I'll just leave it at that.
I respect your opinion immensely since you've demonstrated time and time again a vast knowledge about our cars (which I don't come close to matching), but I'm having a really hard time reconciling what you're saying about Ti as a material and what I've seen and experienced with these applications.
There are different grades of Ti and the grade that would be used here is frequently used in the aerospace industry exactly because it is strong and light (it's an aluminum alloy). Perhaps you've seen Ti fail in the past? Perhaps it was a different grade?
As for the weight saving comments, no, it's not like removing your phone or CDs. while it is correct that the weight would be only removed from the center of the wheel and weight removed from the outer circumference makes a bigger difference in rotational inertia, it all adds up and this seems like a relatively cheap way to achieve that weight saving.
Reduction of rotational inertia is not a player here as you would be reducing mass from the center of the wheel instead of the perimeter. You would get a small amount of reduction in unsprung mass however.
I'm not going to get into a pissing contest about this matter. If there's no interest, I'll just leave it at that.
Reduction of rotational inertia is not a player here as you would be reducing mass from the center of the wheel as opposed to the perimeter of the wheel. You would have a very slight reduction of unsprung mass however.
05-11-2016, 05:09 PM
#24
Rennlist Member
Ok, so I spoke with the manufacturer and they stated that Ti has excellent heat resistance qualities that make it ideal for this type of application and that steel has the tendency to become brittle due to heat, especially for track type activities.
Here's something I found on the properties of Ti online. "One of titanium’s useful properties is a high melting point of 3135°F (1725°C). This melting point is approximately 400°F above the melting point of steel and approximately 2000°F above that of aluminum."
http://www.totalmateria.com/page.asp...operties&LN=EN
Here's something I found on the properties of Ti online. "One of titanium’s useful properties is a high melting point of 3135°F (1725°C). This melting point is approximately 400°F above the melting point of steel and approximately 2000°F above that of aluminum."
http://www.totalmateria.com/page.asp...operties&LN=EN
05-11-2016, 05:34 PM
#25
Three Wheelin'
They are "Functional Jewelry" on my car and as such they are doing a great job. I am no where near the limit on anything but my belt size. i don't know of any race series that would allow 60 year old knucklehead engineers without roll bars either.
Hard to beat alloy steel for things that need to be strong, tough and small.
Perhaps i should change my screen name to "Nads of Ti"
Hard to beat alloy steel for things that need to be strong, tough and small.
Perhaps i should change my screen name to "Nads of Ti"
05-11-2016, 06:02 PM
#26
Instructor
05-12-2016, 06:04 PM
#30
Rennlist Member