one piece driveshaft advice

[Rollus]

I strongly disagree. No amount of computer testing (excusing situations where its the only possibility) will ever be as good as real world testing. Not every part is FEA tested, every part IS however physically tested.

I strongly disagree with this disagreement. p)

Actually, I work as an electrical engineering manager for a supplier of emergency diesel generator in nuclear power plants.
Not every single part is actually tested. Every single part that play a role in the nuclear safety is at least FEA tested. Special Studies Engineering teams use ANSYS. A requirement is that software must be qualified for the application, with real word testing validating computed results. Seismic qualification is also very important, and can be done by analysis (comparison) with known equivalent products.
Active components (electrical relays, etc..) are physically tested. Passive applications (structures, etc.) are usually modeled and computed, even if it can go in a weather tunnel or on a seismic table.

I seat back in my chair again, and read this interesting discussion. I won't argue here, because that's not in my skills.

Sorry for my english.

 

[chevyguyjoe]

Im going to bring it back to something non engineers can understand.

And/or have different gearing == lower rotational speed of the d/s.

I mentioned Silverado's have a one piece aluminum drive shaft earlier. These trucks are top speed limited to roughly 100 mph. With the factory size tires and the shortest available gear ratio (4.56), the drive shaft will be spinning at 5100 rpm.

In comparison, a mkiii turbo Supra at 100 mph with stock diameter tires and the 3.73 rear gears they came with would have a driveshaft speed of 5013 rpm. This is not faster than the Silverado.

Neither of which can do 150 mph stock.

Anybody going faster than the 100 mph above is going to be doing it on a race track. At 150 mph the Supra drive shaft is spinning at 7520 rpm. The vast majority, if not all of the race events with speeds that will approach 150 mph, are going to mandate drive shaft loops anyway.

This particular post is not an argument in either direction, it is simply laying out some information for people to decide for themselves.

 

[3p141592654]

Race track or not,the Supra turbo stock could hit 150mph and this was verified by all the car mags of that era. Having the car throw a drive shaft would be a pretty embarrassing event for Toyota on their flagship car. Also, only the auto came with 3.73,so that is your best case compared to the Silverado worst case of a 4.56, when I suspect most come with a 3.42 or 3.08.

 

[Rollus]

Actually here are differential ratios, that are valid for EUDM at least (we made a list we some local members to confirm this except for 3.25 and 4.556)

3.25 = 39/12 = MA70 Group A (Special race class)
3.727 = 41/11 = code G305 = MA70 3.0 GT turbo
3.909 = 43/11 = code G315 = GA70 M/T, most N/A MA70
4.100 = 41/10 = code G299 = JZA70 M/T and some A/T, some N/A MA70
4.300 = 43/10 = code G28x = GA70 A/T, also some MA70
4.556 = 41/09 = GA70 GT

 

[rhs]

Race track or not,the Supra turbo stock could hit 150mph and this was verified by all the car mags of that era. Having the car throw a drive shaft would be a pretty embarrassing event for Toyota on their flagship car. Also, only the auto came with 3.73,so that is your best case compared to the Silverado worst case of a 4.56, when I suspect most come with a 3.42 or 3.08.

A Mid Night Club MK3 hit 190mph. Terrifying.

 

[SideWinderGX]

I strongly disagree with this disagreement. p)

Actually, I work as an electrical engineering manager for a supplier of emergency diesel generator in nuclear power plants.
Not every single part is actually tested. Every single part that play a role in the nuclear safety is at least FEA tested. Special Studies Engineering teams use ANSYS. A requirement is that software must be qualified for the application, with real word testing validating computed results. Seismic qualification is also very important, and can be done by analysis (comparison) with known equivalent products.
Active components (electrical relays, etc..) are physically tested. Passive applications (structures, etc.) are usually modeled and computed, even if it can go in a weather tunnel or on a seismic table.

I seat back in my chair again, and read this interesting discussion. I won't argue here, because that's not in my skills.

Sorry for my english.

Thanks for the info! I didn't think about fields outside of car manufacturers. I could see FEA testing being done on structures rather than a seismic table, that would be tedious.

 

[rhs]

Thanks for the info! I didn't think about fields outside of car manufacturers. I could see FEA testing being done on structures rather than a seismic table, that would be tedious.

I'll add on since I worked in metals testing for a bit. Typically a couple parts from a lot are tested as representative of the whole. So it is possible that a defective part slips through since there are factors that can influence differences in strength in parts despite all going through the same processing at the same time.

 

[chevyguyjoe]

Race track or not,the Supra turbo stock could hit 150mph and this was verified by all the car mags of that era. Having the car throw a drive shaft would be a pretty embarrassing event for Toyota on their flagship car. Also, only the auto came with 3.73,so that is your best case compared to the Silverado worst case of a 4.56, when I suspect most come with a 3.42 or 3.08.

The best i could gather was the majority of 5 speed turbo cars had 3.73 gears.

 

[3p141592654]

N/A is 4.30:1 all years, 87-88 Turbo is 3.91:1, 89-92 Turbo is 3.73:1.

 

[suprarx7nut]

N/A is 4.30:1 all years, 87-88 Turbo is 3.91:1, 89-92 Turbo is 3.73:1.

Typo above? You said only auto came with 3.73. That's not right.

89+ turbo was 3.73, regardless of trans choice.

 

[Rollus]

In Europe (at list), differential ratio is function if the engine and year, not about the gearbox.

 

[Asterix]

For what it's worth, my impression is, without any measured data, that a 1-piece driveshaft wears out the trans output bearing way faster than the 2-piece one. This is for the W58. I tried two different 1-piece aluminum shafts from two different places and they always vibrated. I had one balanced, which helped, but the vibration was always there over about 60mph. Recently I went back to the 2-piece stock driveshaft, and now I'm looking into rebuilding my transmission because I'm very tired of the noise the output bearing makes.

Sure, the lighter driveshaft was noticeable, but only just. Putting on a free-flowing exhaust made a much bigger difference.