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#16
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Anything that will release some of the torsional stress on the drivetrain is worth the money in my eyes.
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"That which can be asserted without evidence can be dismissed without evidence." '92 Dark Teal SVX LS-L, >146,000m 3 pedals, 5 speeds., restoration underway. 2012 Honda Insight, slow but cute. Last edited by NikFu S.; 05-21-2005 at 10:22 PM. |
#17
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#18
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"That which can be asserted without evidence can be dismissed without evidence." '92 Dark Teal SVX LS-L, >146,000m 3 pedals, 5 speeds., restoration underway. 2012 Honda Insight, slow but cute. |
#19
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-Chike P.S. While a slightly lighter weight, one-piece aluminum driveshaft would be nice, I'm wary of switching to an aftermarket piece due to safety reasons. If you've ever held the stock unit, you'd realize that it has been precisely balanced to eliminate harmonic vibrations in the high rpm ranges - most aftermarket companies don't have a quarter of the R&D $$$ invested into their driveshafts that OE manufacturers put into theirs. This is another reason why you wouldn't see an under-drive pulley listed in my mods.
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"Wise men talk because they have something to say; fools, because they have to say something." - Plato 2013 Cosmic Blue 5spd Evo X GSR 2006 Galaxy Gray 6MT RX-8 (sold) 2006 Steel Gray WRX TR (sold) 1996 Brilliant Red SVX L (sold) |
#20
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Thanks Chike,
we can always count on you to contribute sound reasoning to any discussion.
While the idea of lightening components has an obvious appeal for me, I never considered the issue of vibration. For me, that's v. important because I really like and appreciate the inherent smootheness of the flat six engine and driveline. It's a major contributor to the SVX's quietness. WGJ |
#21
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my main interest lies in the replacement of a broken part though. Say my center bearing craps out or the universal joints fail....It would probobly be cheaper for me to invest in a lightweight one peice rather than a new oem or lengthen my spare. I am curious, not bent on getting one a I have many other mods for my car listed up pretty well.
Tom |
#22
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If it only weighs 35 lbs at most I'm not going to worry about it. I figured the thing was a massive cylindrical hunk of gargantuan steel.
Where the heck is all the weight in this car?
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"That which can be asserted without evidence can be dismissed without evidence." '92 Dark Teal SVX LS-L, >146,000m 3 pedals, 5 speeds., restoration underway. 2012 Honda Insight, slow but cute. |
#23
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First, I strongly doubt that Chevrolet ever used Carbon fiber for a stock driveshaft in a pickup truck, CF's only advantage over aluminum is only *slightly* less mass, and the way it breaks. Many ultra-high power drag & race cars use CF as a driveshaft material because when it breaks it doesn't pole vault the car, it just shreds itself into dust.
Many MK3 Supra owners are ditching the stock driveshaft (around 35lbs) and replacing it with one piece aluminum units that often weigh around 11-12 lbs. There have been no failures reported and the engine response gained from dropping over 20 lbs from the rotating mass of the drivetrain is easily equal to if not more of a gain than doing an underdrive crank pulley and a lightweight flywheel. The improvement in engine response while in gear is well worth the effort and money. Naturally it would be smart to have a driveshaft loop made to prevent the car from getting vaulted if for any reason it failed, but I doubt that a quality unit would ever fail at the power levels any SVX could be expecting to make. A aluminum driveshaft is vastly favored for Supras over a crank pulley because the crank pulley is of even greater significance in an inline 6 such as the supra because the crank is twice as long and has vastly more vibration for the crank dampener to help abate. A flat 6 design would be much less sensitive to losing that dampening. Beyond that, the mass of the driveshaft and the presence of its carrier bearing is due to NVH purposes (Noise, Vibration, Harshness). Segmenting the driveshaft makes it quieter and makes the driveshaft require much less exact balancing procedures. An aluminum driveshaft may make the drivetrain slightly more noisy at highway speeds but with how much insulation the SVX has I doubt anyone would notice, particularly in the wake of how much more responsive and fun the car would be. Furthermore, balancing a driveshaft properly can be done at any driveshaft shop, and I've never seen a stock driveshaft that didn't have little balance weights welded to the surface of the shaft somewhere. |
#24
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And then BAM! knowledge flies out.
Haha, ok, you are reaffirming what my friend is ranting about. I'll know something come Monday evening.
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"That which can be asserted without evidence can be dismissed without evidence." '92 Dark Teal SVX LS-L, >146,000m 3 pedals, 5 speeds., restoration underway. 2012 Honda Insight, slow but cute. |
#25
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Tom |
#26
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Mychailo :: 2006 Silver Mitsubishi Evolution 9, E85, 34 psi peak, 425wtq/505whp DJ :: 1995 Laguna Blue SVX L AWD 5MT (sold) Visit my locker SVX Mods: ND iridium spark plugs, Impreza RS fpr, afr tuned to 13.2:1 using a custom MAF bypass, custom exhaust, WRX 5MT w/ STi RA 1st-4th gear & stock WRX 5th gear, Exedy 13 lb flywheel & Sport Clutch, STi Group N tranny & engine mounts, urethane spacers in rear subframe, rear diff mounts, and pitch stopper, SVX Sport Strut Springs (185f/150r), custom 19 mm rear swaybar, urethane swaybar mounts, Rota Torque 17x8", 225/45-17 Proxes 4 tires, Axxis Deluxe Plus organic brake pads. Last edited by mbtoloczko; 05-23-2005 at 02:06 PM. |
#27
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However, I did some quick research of my own and found that in 1988 GM started using a one piece driveshaft of "fiberglass reinforced vinyl ester pultruded over an aluminum tube" (from the strongwell website) which would be fantastically light and being that it was built over an alumnium tube that explains how it would still pole vault a truck that had a yoke failure, as a true CF driveshaft would not, it would just crumble and break. Cheers for keeping me honest As for the output shaft angles, how much of an angle is it? The MK3 Supra's is far from perfect either (somewhere around 11 degrees) and people have relied on the two U joints at the diff and the output shaft without incident. Last edited by Wreckless; 05-23-2005 at 02:44 PM. |
#28
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well in any sense it had the same pattern as carbon fiber does and I know GM wouldn't have made these to just look like CF. So i guess I was wrong in that respect.
Tom |
#29
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From the strongwell website:
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#30
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Mychailo :: 2006 Silver Mitsubishi Evolution 9, E85, 34 psi peak, 425wtq/505whp DJ :: 1995 Laguna Blue SVX L AWD 5MT (sold) Visit my locker SVX Mods: ND iridium spark plugs, Impreza RS fpr, afr tuned to 13.2:1 using a custom MAF bypass, custom exhaust, WRX 5MT w/ STi RA 1st-4th gear & stock WRX 5th gear, Exedy 13 lb flywheel & Sport Clutch, STi Group N tranny & engine mounts, urethane spacers in rear subframe, rear diff mounts, and pitch stopper, SVX Sport Strut Springs (185f/150r), custom 19 mm rear swaybar, urethane swaybar mounts, Rota Torque 17x8", 225/45-17 Proxes 4 tires, Axxis Deluxe Plus organic brake pads. |
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