Driveshaft Decision. I'm torn. Advice from experienced?

[suprarx7nut]

Here I'll take a stab

CRITICAL SPEED.

but beyond me explaining... read up

http://www.krugerfan.com/brochure/publications/Tbn017.pdf

Figgie,

That says 75% of critical should not be exceeded. Using that logic, even a basic 3" single piece aluminum is good to ~150-180mph in a mk3. I've heard people say 1/2 critical shouldn't be exceeded, but i can't find any reliable source for that. :dunno:

i'd replace the bearing, the cheapest alternative

But then I'm still left with a rear bonded section on a driveshaft with 325k miles and more power than it was ever intended to hold when new.

 

[IJ.]

You roll the dice on this one...

All depends on if the car is going to see high speed, I value my life and that easily outweighs any cost.

 

[te72]

Would it be out of the question for you to make more of those Ian? Or just cost prohibitive for those of us in the US?

 

[IJ.]

It was a bit Exe Brad, shipping would be the deal breaker...

No reason a shop there can't replicate it though, all the parts are off the shelf and Hardy Spicer make the Big Ass slip Yoke to suit the A340e and the R154 now.

That Shaft went to 160Mph GPS verified at the Test track without a whimper.

 

[te72]

Good to know, thanks IJ. Ideally I'll spring for the carbon shaft and cover it with a nice under tray to keep out debris.

 

[suprarx7nut]

Bigger market, lower prices? Or just a matter of what year you bought it... Gas itself was probably a lot cheaper when you had that car too.

To the OP, who have you been working with at the Driveshaft Shop? I was planning on getting the Titan carbon driveshaft, but it may prove hard to find, so it is good to know DS can make them too.

I haven't gotten a name, which is kinda weird, but oh well. I've received good, thorough responses, but oddly enough no name. Titan Motorsports is an authorized vendor of Driveshaft Shop. I suspect very, very much that the Carbon shaft from Titan is made at DSS's place. The pricing on DSS website is slightly higher than most the authorized retailers. Probably just to pay for the extra headache of dealing with customers directly. :dunno:

You roll the dice on this one...

All depends on if the car is going to see high speed, I value my life and that easily outweighs any cost.

That is the kind of thing I was looking to do. Here are the pictures Driveshaft Shop sent me of their "Caged CV" joint they use in their 2-piece shafts. He said they can do anything though so they should be able to make something like yours. I'd be happy with a fresh Yota bearing, new beefy joints and new aluminum shafts for under ~$1000. Obviously I'm not looking to cheap out on this, but once we get over $1100 before shipping.... it's definitely a solid gut check.

Hopefully I'll talk with him soon. We were trying to catch each other this week, but it never happened. Any way I go about it, I should have a better than average aftermarket mk3 driveshaft installed by the winter.

Thanks for the tips guys, kepp em coming. So far there haven't been many poll responses. Ian went with the Mack Daddy option and lets face it, his vote is worth at least 5 other people... haha.

 

[te72]

Well I gave you my vote already. And you could be right on the pricing thing by going direct to DSS. Sometimes things are priced higher if you go direct.

 

[SideWinderGX]

Except you're ignoring why they went with a 2 piece in the first place. Which do you think would have been cheaper?

Here I'll take a stab

CRITICAL SPEED.

but beyond me explaining... read up

http://www.krugerfan.com/brochure/publications/Tbn017.pdf

I've already done the calculations and not using that brochure, critical speed for our ~40" one piecers is about 11.8k rpm. Most everyone on this board will never go above half that rotational speed, and certainly not for very long.

Almost every OEM uses two pieces for ensured sound deadening/dampening and a greater MOI so the soccer moms and old guys don't complain about a difference in driveability between carrying 5 passengers with groceries and carrying nothing. I'd rather have a one piece because of the benefits posted in this thread, and as for the negatives you really have to stretch to even get into the realm of having them be possible.

Should I do an inb4someonesaysa12kredlineisntenoughfortheircar to cover my post?

 

[suprarx7nut]

While I may only take my car to the theoretical 1/2 critical speed a couple times, those times are exactly when I'd pay just about anything to ensure my ride is as sound as possible. Single piece driveshafts may be perfectly balanced upon shipment, but what about 60k and 5 years later? That's the kind of thing I'm concerned about.

Also, soccor mom's are not the only people concerned about sound deadening and dampening. I like my Supra to drive like a Supra. To me, that means luxurious power. To others that may mean just raw power with no compromises. The more I think about it, I'm steering more and more towards a lightened two-piece.

I spent dozens of hours and over $1000 on my wiring harness when I could have simply spent a few hours and a couple hundred on a slightly better used harness. I think I need to keep my end goals in mind and continue to strive for the best I can afford.

What's funny is that between my exhaust, wiring harness and potential driveshaft alone I have more into my car than the Blue book value. Kinda sad. I think I need "As stated" collector style insurance pretty soon...

 

[SideWinderGX]

What's funny is that between my exhaust, wiring harness and potential driveshaft alone I have more into my car than the Blue book value. Kinda sad. I think I need "As stated" collector style insurance pretty soon...

I think that's awesome Going through harness repair right now, tedious job.

I can't see the DS ever going out of balance unless it is hit with a brick.

 

[1986.5supra_kid]

Since you dont race your car at 125mph for LOOONG periods of time id go with a one peice but i didnt think you were going to exceed 350-400hp? so with the hp in mind you could stay with the 2 piece and cheaply replace the carrier with a ford ranger bearing for under 25$ IF u did spin the bonded part you can always get the another used rear section since there all the same lenght at the rear half. high revving then clutch kicking is what with will turn the bonded half if ur at the 400hp range so this is just my 2 cent to save you 200-900 until your ds is truely the weakest part.

 

[1986.5supra_kid]

steel one piece is cheaper and in my opinion its plenty enough for the supras out there being daily driven by good drivers

 

[Poodles]

I've already done the calculations and not using that brochure, critical speed for our ~40" one piecers is about 11.8k rpm. Most everyone on this board will never go above half that rotational speed, and certainly not for very long.

Almost every OEM uses two pieces for ensured sound deadening/dampening and a greater MOI so the soccer moms and old guys don't complain about a difference in driveability between carrying 5 passengers with groceries and carrying nothing. I'd rather have a one piece because of the benefits posted in this thread, and as for the negatives you really have to stretch to even get into the realm of having them be possible.

Should I do an inb4someonesaysa12kredlineisntenoughfortheircar to cover my post?

What measurements are you basing the calculations on? Also, 11.8K RPM at the shaft is far different from the speed at the engine...

 

[Mr Bojangles]

I like my DSS aluminium drive shaft

 

[te72]

I've already done the calculations and not using that brochure, critical speed for our ~40" one piecers is about 11.8k rpm. Most everyone on this board will never go above half that rotational speed, and certainly not for very long.

Should I do an inb4someonesaysa12kredlineisntenoughfortheircar to cover my post?

The thing that I would be most concerned with is this... 5th gear in our car is a .7x ratio, correct?

11,800 x .7= 8260 (on the lowest end)
11,800 x .79 = 9322 (on the highest end)

Now, the word "critical" implies a certain amount of "oh shit" factor to me. In my industry (wire rope and other rigging materials) there are safety factors, or as I like to call them, "idiot factors". How much of that "critical speed" is reasonably safe to push things to? Half of critical seems to be a prudent (read: smart) measurement that we can work with, does it not? If that is the case, cut those numbers above in half.

I can tell you with absolute certainty, that even with a taller tire and the 3.73 diff, it isn't hard to get shaft speeds over 4500 rpm...

While I may only take my car to the theoretical 1/2 critical speed a couple times, those times are exactly when I'd pay just about anything to ensure my ride is as sound as possible.

I agree 100% here. This is one of those things that you never want to figure out that you screwed something up...

What's funny is that between my exhaust, wiring harness and potential driveshaft alone I have more into my car than the Blue book value. Kinda sad. I think I need "As stated" collector style insurance pretty soon...

Eh, join the club man. I probably have more into my head than the car would be likely to sell for.

 

[IJ.]

[video=youtube;CHjo5693plo]http://www.youtube.com/watch?v=CHjo5693plo&feature=player_embedded[/video]

 

[Mr Bojangles]

That was exciting, like a jack in the box.

 

[1986.5supra_kid]

cool video, im glad i dont race cars.....lol so did i mention i have a steel 3'' one piece with standard universals and that almost every consumer car/trucks right now has either one piece steel or alum and are speed limited to 155mph.

 

[Poodles]

cool video, im glad i dont race cars.....lol so did i mention i have a steel 3'' one piece with standard universals and that almost every consumer car/trucks right now has either one piece steel or alum and are speed limited to 155mph.

You'd be very wrong...

 

[suprarx7nut]

Damn IJ, that thing spun him around in an instant. If that happens one a two lane highway that could easily be deadly

cool video, im glad i dont race cars.....lol so did i mention i have a steel 3'' one piece with standard universals and that almost every consumer car/trucks right now has either one piece steel or alum and are speed limited to 155mph.

I dont even know what you're trying to say here...


I should talk to DSS today if we can catch each other. Here's to hoping a basic two piece in aluminum isn't more expensive than a one-piece carbon...