Does a single piece driveshaft transmit more power to the rear then the stock two-piece? I was just wondering if the 17-18% drivetrain loss (for a 6 speed) is reduced with a single piece? Any studies on this?
I guess I could add transmission and engine mounts to this question.
From what I have read and understand its a combination of parts that cause the 15% loss for a 6spd.
The main components that you would want to replace are the drive shaft, motor mounts and transmission mount. Maybe a harrop diff cover or rear axles would help too but I honestly cant say...
Dont forget that if you do the motor mounts or transmission mount that it is recommended to do them both at the same time. The torque that travels down the drive train can cause problems if you stiff up the transmission mount without doing the motor mount... or vise versa.
__________________
2006 Pontiac GTO (1 of 277)
Manual 6 Speed T-56, 17" Stock Wheels
Impulse Blue Metallic Exterior & Black Leather Interior
Keep in mind that power loss from the engine to the wheels is not just a static percentage. It is based upon 2 factors.
1) Frictional/viscous losses. These can all be found/approximated using a machine design textbook and they will be efficiencies in terms of percent. This will for the most part be static.
2) Inertial losses make up the often neglected other half of the equation. The rate at which you accelerate the drivetrain/wheels will affect torque readings made at the wheel.
This is important because a driveshaft has the 'potential' to increase or decrease both causes for loss.
I will not speak for the frictional losses due to my limited knowledge of what a 1 piece replaces vs the stock 2 piece. If a bearing is eliminated then yes, small hp gains would exist - but I stress 'small'.
As for the inertial aspect: It depends on the material/density and the diameter. If the diameter is not much larger, but the material is less dense (aluminum vs. steel), then the total moment of inertia will be smaller and thus, your drivetrain will drain less torque. If it's a larger diameter, then the inertia will increase along with a subsequent increase in drivetrain loss.
However, in either case as far as inertia is concerned, the total inertia of a driveshaft is small relative to something like the flywheel. They flywhee also rotates at higher angular velocities thus increasing the effective inertia felt at the wheel (by the square of the total reduction I believe).
For this reason, a lightweight flywheel will have a much more profound effect on the street than a driveshaft would. A change in driveline inertia will be most noticed in 1st, 2nd, and to some extent, 3rd gear. Keep in mind dyno runs are done in higher gears where driveline inertia is small to begin with - thus total inertia changes have little effect on recorded torque output.
So, can you notice inertia differences on the street in low gears? Yes. Can you notice those differences on a dyno? Not unless they are huge changes.
__________________
2006 M6 GTO - 333hp/323tq stock
Kook's Sig. Series LT's, Catless Mids, Magnaflow Catback, Ported Intake, Vararam, HP Tuners & Wideband - 377 hp/386 tq.
Thanks, that makes sense. I was just pondering why other platforms typically dyno higher with similar mods compared to the GTO. Do solid axles tend to transmit the power to the wheels more efficiently than IRS as well?
Keep in mind that power loss from the engine to the wheels is not just a static percentage. It is based upon 2 factors.
1) Frictional/viscous losses. These can all be found/approximated using a machine design textbook and they will be efficiencies in terms of percent. This will for the most part be static.
2) Inertial losses make up the often neglected other half of the equation. The rate at which you accelerate the drivetrain/wheels will affect torque readings made at the wheel.
This is important because a driveshaft has the 'potential' to increase or decrease both causes for loss.
I will not speak for the frictional losses due to my limited knowledge of what a 1 piece replaces vs the stock 2 piece. If a bearing is eliminated then yes, small hp gains would exist - but I stress 'small'.
As for the inertial aspect: It depends on the material/density and the diameter. If the diameter is not much larger, but the material is less dense (aluminum vs. steel), then the total moment of inertia will be smaller and thus, your drivetrain will drain less torque. If it's a larger diameter, then the inertia will increase along with a subsequent increase in drivetrain loss.
However, in either case as far as inertia is concerned, the total inertia of a driveshaft is small relative to something like the flywheel. They flywhee also rotates at higher angular velocities thus increasing the effective inertia felt at the wheel (by the square of the total reduction I believe).!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! HEY where you been?!...Exellent post and so true,a 10 lb flywheel or converter reduction has alot more efect than a 2 lb driveshaft reduction,even that 10 lbs is minimum on a 4000 lb car. Hendrix!!!!!!!!!!!!!!!!!!!11
For this reason, a lightweight flywheel will have a much more profound effect on the street than a driveshaft would. A change in driveline inertia will be most noticed in 1st, 2nd, and to some extent, 3rd gear. Keep in mind dyno runs are done in higher gears where driveline inertia is small to begin with - thus total inertia changes have little effect on recorded torque output.
So, can you notice inertia differences on the street in low gears? Yes. Can you notice those differences on a dyno? Not unless they are huge changes.
OP the 1 piece will not relize you any gains in hp.
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Last edited by Hendrix-Engineering : 09-03-2009 at 06:10 AM.
Reason: mm
Yes, a one piece driveshaft will get more power to the wheels then a 2 piece.
Any time you add a break in the drivetrain such as a carrier bearing, cv joint or what ever, you put a little bit more parasitic loss into the equation.
Think of it this way, if your entire driveline was only 1 ft long it would make a lot more power. That's whay dragsters have a little bity short driveshaft and not a 5 foot long one.
The longer the drivetrain is away from the power source, the more loss there will be due to more power being used to spin the rotating mass.
Every bit helps.
Stiffer engine mounts
Stiffer transmount
One piece driveshaft
lighter driveshaft
lighter stubs, ect...
OP the 1 piece will not relize you any gains in hp.
I know I won't "gain" horsepower per sey, I was just curious as to the differences in various platforms abilities to transfer the power from the engine to the wheels, i.e. F-Body vs. GTO vs. etc.
Quote:
Originally Posted by Gforce1320...
Yes, a one piece driveshaft will get more power to the wheels then a 2 piece.
Any time you add a break in the drivetrain such as a carrier bearing, cv joint or what ever, you put a little bit more parasitic loss into the equation.
Think of it this way, if your entire driveline was only 1 ft long it would make a lot more power. That's whay dragsters have a little bity short driveshaft and not a 5 foot long one.
The longer the drivetrain is away from the power source, the more loss there will be due to more power being used to spin the rotating mass.
Every bit helps.
Stiffer engine mounts
Stiffer transmount
One piece driveshaft
lighter driveshaft
lighter stubs, ect...
Sounds like I'm ahead of the curve since I have all of those things waiting for me upon my return to the states. Thanks again Chris for holding on to the stuff I ordered till I get back. You're the man.
Keep in mind that power loss from the engine to the wheels is not just a static percentage. It is based upon 2 factors.
1) Frictional/viscous losses. These can all be found/approximated using a machine design textbook and they will be efficiencies in terms of percent. This will for the most part be static.
2) Inertial losses make up the often neglected other half of the equation. The rate at which you accelerate the drivetrain/wheels will affect torque readings made at the wheel.
This is important because a driveshaft has the 'potential' to increase or decrease both causes for loss.
I will not speak for the frictional losses due to my limited knowledge of what a 1 piece replaces vs the stock 2 piece. If a bearing is eliminated then yes, small hp gains would exist - but I stress 'small'.
As for the inertial aspect: It depends on the material/density and the diameter. If the diameter is not much larger, but the material is less dense (aluminum vs. steel), then the total moment of inertia will be smaller and thus, your drivetrain will drain less torque. If it's a larger diameter, then the inertia will increase along with a subsequent increase in drivetrain loss.
However, in either case as far as inertia is concerned, the total inertia of a driveshaft is small relative to something like the flywheel. They flywhee also rotates at higher angular velocities thus increasing the effective inertia felt at the wheel (by the square of the total reduction I believe).
For this reason, a lightweight flywheel will have a much more profound effect on the street than a driveshaft would. A change in driveline inertia will be most noticed in 1st, 2nd, and to some extent, 3rd gear. Keep in mind dyno runs are done in higher gears where driveline inertia is small to begin with - thus total inertia changes have little effect on recorded torque output.
So, can you notice inertia differences on the street in low gears? Yes. Can you notice those differences on a dyno? Not unless they are huge changes.
Yes, a one piece driveshaft will get more power to the wheels then a 2 piece.
Any time you add a break in the drivetrain such as a carrier bearing, cv joint or what ever, you put a little bit more parasitic loss into the equation.
Think of it this way, if your entire driveline was only 1 ft long it would make a lot more power. That's whay dragsters have a little bity short driveshaft and not a 5 foot long one.
The longer the drivetrain is away from the power source, the more loss there will be due to more power being used to spin the rotating mass.
Every bit helps.
Stiffer engine mounts
Stiffer transmount
One piece driveshaft
lighter driveshaft
lighter stubs, ect...
I'm not arguing with you here, but unless someone has money to burn, the marginal gains to be had from the one piece driveshaft do not seem to justify the replacement of a perfectly good 2 piece.
In your post, you mentioned the fact that dragsters use a short one-piece driveshaft. The reasons you gave for this may be true for those cars, but I'm not sure you can simply carry them over to our application on a one-to-one basis. Another reason that the dragsters have short driveshafts could be that they want the engine as close to over the rear wheels as possible to increase traction, and that the amount of torque those engines generate could snap the driveshaft if it were longer. These are just educated guesses on my part, as I have no direct knowledge of the designer's motives, but the above-listed reasons seem just as likely as simply to reduce weight and drivetrain inertial loss. Also, as I said before, while the weight and power savings may be justified for drag cars, I doubt that they will have a tangible effect for our cars, at least insofar that the money cannot be better spent elsewhere.
It's simple physics, you take out one clamping point (carrier bearing) and take out 3 pounds of rotating mass plus the adapters and rubber couplers and you WILL get more power. Might not be a bunch but you will get more to the ground.
PLUS, the carbon fiber driveshaft will twist on a hard launch to absorb drivetrain shock allowing a softer hit to the tires.
Most people see at least a tenth faster et in the 1/4 after the switch.
Its a good idea to reduce your rotating weight....but I don't think a DS will be noticeable.
-Will
I agree,we have been testing a new 4 inch driveshaft in T-bones car as well as Magnum GTOs and alltho it did weigh a little more we saw ZEREO difference in track times.I do feel if i had a 1800 lb rail dragster i would not use a two piece drive shaft
Yea a solid driveshaft should lower losses and CF should help more.
When My motor hits about 600RWHP I can feel the 2 part shaft jumping around under the car. Which has to be sucking major power. Its one my list of parts to Get
__________________
Blaze orange GTO Warhawk 427 and F1C numbers to come
from what ive read the 1 piece is no bueno for the gto because of its suspension/body layout.... is this true?
__________________
Quote:
Originally Posted by Animalwarfest...
my dad doesn't let me take the car out on weekends Duh!
13.4 @ 105.8mph 2.1 60ft (before mods, 2000ft DA)
MSD wires, LoneStar ported TB & Intake, Corsa Sport Cat back (mufflers removed) Tuned by Waltred 360/353
Torrid Red/Black/M6/17 1 of 641 "The beauty of the Second Amendment is that it will not be needed until they try to take it." ~Who cares~
Keep in mind that power loss from the engine to the wheels is not just a static percentage. It is based upon 2 factors.
1) Frictional/viscous losses. These can all be found/approximated using a machine design textbook and they will be efficiencies in terms of percent. This will for the most part be static.
2) Inertial losses make up the often neglected other half of the equation. The rate at which you accelerate the drivetrain/wheels will affect torque readings made at the wheel.
This is important because a driveshaft has the 'potential' to increase or decrease both causes for loss.
I will not speak for the frictional losses due to my limited knowledge of what a 1 piece replaces vs the stock 2 piece. If a bearing is eliminated then yes, small hp gains would exist - but I stress 'small'.
As for the inertial aspect: It depends on the material/density and the diameter. If the diameter is not much larger, but the material is less dense (aluminum vs. steel), then the total moment of inertia will be smaller and thus, your drivetrain will drain less torque. If it's a larger diameter, then the inertia will increase along with a subsequent increase in drivetrain loss.
However, in either case as far as inertia is concerned, the total inertia of a driveshaft is small relative to something like the flywheel. They flywhee also rotates at higher angular velocities thus increasing the effective inertia felt at the wheel (by the square of the total reduction I believe).
For this reason, a lightweight flywheel will have a much more profound effect on the street than a driveshaft would. A change in driveline inertia will be most noticed in 1st, 2nd, and to some extent, 3rd gear. Keep in mind dyno runs are done in higher gears where driveline inertia is small to begin with - thus total inertia changes have little effect on recorded torque output.
So, can you notice inertia differences on the street in low gears? Yes. Can you notice those differences on a dyno? Not unless they are huge changes.
I have a steel/steel 2 pc. by hendrix. I bought it primarily for strength. I dont want the stocker checking out while I'm WOT, at the track or on the street! Who really cares if it free's up any ponies. If it does (which i doubt cuz its bigger, heavier, and steel) its nothing to write home about. Its your motor's job to make power, not the driveline.
The main reason for switching over to a one piece driveshaft and a solid rear axle is to reduce the amount of joints in the driveline. The more joints in the driveline, the greater the chance of failure.
The main reason for switching over to a one piece driveshaft and a solid rear axle is to reduce the amount of joints in the driveline. The more joints in the driveline, the greater the chance of failure.
In exchange for less joints, dosent it make for a louder driveline, with a more exaggerated jerking motion when loading and unloading the car. More so if the one pc. is aluminum = loud and clangy.
Either way, driveline upgrades should not be sought out to source power. The power/dollar ratio on hp gains from drivelines parts is far too little.
i could feel a difference in power once i installed my new driveshaft. stock two piece is a killer.
__________________
k&n cai,flowmaster catback,gm hot cam, slp catted long tubes,mccord tune,lss,pedders drag springs,big bore rear shocks,pedders front struts and springs,pedders street one kit,05/06 brake conversion, 05/06 hood,throttle body bypass,gforce driveshaft,green axls,and stubs 377 rwhp&365 rwtq
The main reason for switching over to a one piece driveshaft and a solid rear axle is to reduce the amount of joints in the driveline. The more joints in the driveline, the greater the chance of failure.
With that reasoning you could say switching to a 4 cylnder would give you less failure.
I have a question swapping stock driveshaft to 1 piece
I still have the stock drive shaft on my 04 GTO along with the axle stubs &cvs shafts.
The question I have is has anyone with a consistent car that goes to the track all the time tested this ,Meaning similar conditions same track no other changes except from going from the stocker to the 1 piece drive shaft. Has anyone documented any gains or losses on this? I would appreciate any input from those that have tested this.
I still have the stock drive shaft on my 04 GTO along with the axle stubs &cvs shafts.
The question I have is has anyone with a consistent car that goes to the track all the time tested this ,Meaning similar conditions same track no other changes except from going from the stocker to the 1 piece drive shaft. Has anyone documented any gains or losses on this? I would appreciate any input from those that have tested this.
2006 GTO Owner
IBM/Blue M6 
