Need answers to aluminum driveshaft questions

[shaftmasters]

Yes I do...it's a very well made, balanced 1 piece. I get some vibration at 60-70 MPH that is not noticible at higher or lower speeds. My concern is the harmonics at high speed...IJ has his act together...I was not as "educated' on drive shaft critical speed when I purchased it.

I'm going to do a few motor mods in the coming months...the HP and speed I'll be able to generate has me a bit concerned on how well the 1 piece is going to handle it. I do have safety loops though

Hey jdub,
We were wondering if you still have your original 2 piece shaft? If you do we would like to make you an offer. We would like to send you one of our single piece aluminum shafts at no cost to you. We are betting we can eliminate your vibration at 60-70mph. It would also get us some feedback after your upcoming motor mods. We will pay ground UPS to you and also UPS for return of your 2 piece shaft. We would like you to call us at 1-866-912-2004 to discuss things. We are open 7-5 EST weekdays and 7-12 noon EST saturdays.
Thanks, David

 

[jdub]

You got it David...a heads up. The driveshafts are different depending on the trannys. The section closest to the tranny is a different length for an auto (A340E). vs the R154...I *think* the W58 (used on the NA version MkIII) is different as well. Mine is an auto.

 

[CPT Furious]

I also still have my factory two piece in the garage if you need a test mule. It's from a 89 turbo manual.

 

[suprahero]

Before everyone offers to give them a two piece drive shaft..............I've already beat you to it, and they only wanted one, and that chosen one is Jdub................:biglaugh:

Kinda reminds me of a old Rod Stewart song............Some guys have all the luck, some guys..............you know the rest.

 

[shaftmasters]

Well, jdubs results are in. It seems that the single piece aluminum shaft we sent him has eliminated all his vibration/resonance issues. You can read his review here:
http://www.supramania.com/forums/showthread.php?t=58994

and here:
http://www.supramania.com/forums/showthread.php?t=58990

jdub says "The shaft has no vibration of any kind, at any speed up to 120 mph"

 

[suprahero]

I'll be ordering mine next week, and I hope I have the same results as the others. I'm sure I will, but it's easier to enjoy a product when it's free. When you pay $300.00 for something, you're more likely to find a fault in it somewhere..............:evil2:

I'm going to sit a glass of wine in the passengers seat and hope it doesn't spill over due to vibrations. You know my car doesn't have enough torque to make the glass fall over, so it'll have to be the driveshafts fault.

 

[AJ'S 88NA]

I'll be ordering mine next week, and I hope I have the same results as the others. I'm sure I will, but it's easier to enjoy a product when it's free. When you pay $300.00 for something, you're more likely to find a fault in it somewhere..............:evil2:

I'm going to sit a glass of wine in the passengers seat and hope it doesn't spill over due to vibrations. You know my car doesn't have enough torque to make the glass fall over, so it'll have to be the driveshafts fault.

Or the driver:biglaugh:

 

[suprahero]

I'll never take blame........only credit.

 

[jdub]

Well if it tips over fore/aft, it's gotta be a fat footed driver or tips sideways the driver is meat fisting the steering wheel...the 1J doesn't have enough torque to tip a glass sitting on the seat :biglaugh:

 

[suprahero]

I googled 1jz torque................it said still searching............:wtc:

 

[Piratetip]

LOL

 

[Johnysupra]

Im not sure of the angle on stock supras but I do know at my university they teach that an Aluminum DS is purportionally stronger then a steel drive shaft. Becuase aluminum has more flexibility before failure. Also back to the angle thing, it is criticle on a one peice shaft to have the same pinion and output angle +/- 1 Degree. so if the stock supra Output and pinion angles are not in synch this could be the major contributing factor. Like many have said before U joints dont travel in a circle they travel in an Elipse.Basicly you have two U-joints if each is at the same angle but but opposite slop then both elipses cancle each other out, this is the biggest problem with u-joints. if this very simple thing is out it causes a Huge variation in Pinion speed. Even just 2 degrees out can make a huge differance, becuae the pinion speeds up and slows down TWICE a revolution.

I know thats a whole lot and some of you already know this but the reason i state this is i do not know the stock angles of the Output and Pinion because my car is a shell ATM. But if this is the problem you can shim the diff or trans mount to make the angles proper, and one an IRS car its a one time fix.

Tons of IRS high horsepower cars are running 1P DS even alot of SRS cars.
its all about angles, if their right you'd never notice. If their barely off, well most of you know the result.

Also indexing is another problem you can try turning the shaft90 degrees at the pinion flang

 

[LordLo]

Yep that's exactly what I did. I shimmed the transmission mount to angle the driveshaft more straight. That reduced quite a bit of the vibration, but still not silky smooth like the two piece. :biglaugh:

 

[jdub]

Well I was skeptical, but the single piece aluminum DS I got from Shaftmasters for my auto tranny has produced zero vibration at highway speed where you usually see a harmonic develop. Been driving it 4 days now...same result...no harmonic, no noise.

 

[suprahero]

Been driving it 4 days now...same result...no harmonic, no noise.

Good enough for me. Now I just need the college to give me my check tomorrow for the work I'm doing and I'll be ordering me one.

 

[Reign_Maker]

Well I was skeptical, but the single piece aluminum DS I got from Shaftmasters for my auto tranny has produced zero vibration at highway speed where you usually see a harmonic develop. Been driving it 4 days now...same result...no harmonic, no noise.

WOW! This some A+ feedback right here...

 

[86_sports_1jz]

hey jdub, have you taken it past 120 to see if you felt any vibrations or anything funny?

 

[jdub]

No, I have not. 120 mph was right at 1/2 critical speed rpm for this DS...if a harmonic was going to develop, that's when it would happen (or before). That's why I wanted to get to 120 mph

 

[86_sports_1jz]

so in other words anything after 120 should be okay?

 

[jdub]

Yes...and even if it was, it would have to be sustained for a long period.