Why didn't Ford do it??
12/6/12, 07:10 AM
#1
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Why didn't Ford do it??
The one piece aluminum driveshaft, why didn't Ford do this if it is that much better than the stock 2 piece unit?
The aluminum DS is supposed to offer better driveability, better throttle response and a lighter car which should improve gas mileage.
If that is all true, why wouldn't Ford design that in the car since every car maker struggles to improve performance and gas mileage?
Are there negative side effects to installing an aluminum DS?
So that is the question, I love the idea of the lighter stronger driveshaft, but is there a reason it is not done at the factory, besides the often quoted theory "It is too expensive so the carmaker won't do it" I personally don't buy that logic since the carmakers are doing al they can to increase performance and mileage.
I am a big fan of personalizing cars and a huge fan of making things better, you guessed it I am a perfectionist. So what say you on this perplexing issue???
The aluminum DS is supposed to offer better driveability, better throttle response and a lighter car which should improve gas mileage.
If that is all true, why wouldn't Ford design that in the car since every car maker struggles to improve performance and gas mileage?
Are there negative side effects to installing an aluminum DS?
So that is the question, I love the idea of the lighter stronger driveshaft, but is there a reason it is not done at the factory, besides the often quoted theory "It is too expensive so the carmaker won't do it" I personally don't buy that logic since the carmakers are doing al they can to increase performance and mileage.
I am a big fan of personalizing cars and a huge fan of making things better, you guessed it I am a perfectionist. So what say you on this perplexing issue???
12/6/12, 09:07 AM
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The fact that Ford put a carbon fiber one piece in the new gt500 makes you wonder as well.
Since I can't help but think that it is no cheaper to make the multi component two piece, I suspect that its the same story as the factory tune; it is primarily designed for the general public. The two piece probably makes the mustang a little softer and gentler to drive. Like the factory throttle response.
Since I can't help but think that it is no cheaper to make the multi component two piece, I suspect that its the same story as the factory tune; it is primarily designed for the general public. The two piece probably makes the mustang a little softer and gentler to drive. Like the factory throttle response.
12/6/12, 01:15 PM
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Originally Posted by TheDivaDanielle
My GTO also had a two-piece driveshaft. I never understood it then, either. It's for NVH mostly.
12/6/12, 05:52 PM
#10
Let's put this in perspective....Ford was putting torque tube driveshafts in the old foxbodies for the same reason. As the classic front engine, live axle driveline moves under power and load, the multi piece CB driveshaft soaks up annoying vibes and noises, etc. better than a single piece. Single piece is a performance part and most buyers want a quiet cool car to tool around in, not a dragstrip terror.
As for rear impact, anything that can mash this car past the rear axle isn't going to stop folding up any kind of driveshaft you have and poking it through the floor if it wishes. I doubt that'd be you biggest worry if this happens to you.
As for rear impact, anything that can mash this car past the rear axle isn't going to stop folding up any kind of driveshaft you have and poking it through the floor if it wishes. I doubt that'd be you biggest worry if this happens to you.
Last edited by 5LHO; 12/6/12 at 05:56 PM.
12/7/12, 08:53 AM
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really guys? I would say NVH, rear crash safety, etc be damned - it is all the almighty dollar. Cheaper to bolt together 2 pieces of so/so metal than to spend time and effort source one piece of good metal.
I'd rather see a ~$35k MSRP everyman sports car than boutique parts that never really see benefit in street driving.
I'd rather see a ~$35k MSRP everyman sports car than boutique parts that never really see benefit in street driving.
12/7/12, 09:52 AM
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Let's put this in perspective....Ford was putting torque tube driveshafts in the old foxbodies for the same reason. As the classic front engine, live axle driveline moves under power and load, the multi piece CB driveshaft soaks up annoying vibes and noises, etc. better than a single piece. Single piece is a performance part and most buyers want a quiet cool car to tool around in, not a dragstrip terror.
As for rear impact, anything that can mash this car past the rear axle isn't going to stop folding up any kind of driveshaft you have and poking it through the floor if it wishes. I doubt that'd be you biggest worry if this happens to you.
As for rear impact, anything that can mash this car past the rear axle isn't going to stop folding up any kind of driveshaft you have and poking it through the floor if it wishes. I doubt that'd be you biggest worry if this happens to you.
12/8/12, 11:46 AM
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J Tennu
Let us know what your impressions are after the driveshaft install, particularly about the NVH your driveability impressions.
Let us know what your impressions are after the driveshaft install, particularly about the NVH your driveability impressions.
12/8/12, 01:47 PM
#15
really guys? I would say NVH, rear crash safety, etc be damned - it is all the almighty dollar. Cheaper to bolt together 2 pieces of so/so metal than to spend time and effort source one piece of good metal.
I'd rather see a ~$35k MSRP everyman sports car than boutique parts that never really see benefit in street driving.
I'd rather see a ~$35k MSRP everyman sports car than boutique parts that never really see benefit in street driving.
You have the cost of a centre bearing, a special weighted flange at the axle end and the "two pieces of metal". I can guarantee you it would be cheaper to just slap a length of tube and two yokes and unis on there.
It's clearly designed to diminish NVH, if you look at how its made.
12/8/12, 06:16 PM
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I most certainly will... want to have measurements taken before end of month. I would like to have it bolted up during next month, weather permitting.
12/8/12, 08:06 PM
#17
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Have you actually looked at the stock shaft? It's actually a pretty complex piece of engineering; not just "bolting together 2 pieces of metal".
You have the cost of a centre bearing, a special weighted flange at the axle end and the "two pieces of metal". I can guarantee you it would be cheaper to just slap a length of tube and two yokes and unis on there.
It's clearly designed to diminish NVH, if you look at how its made.
You have the cost of a centre bearing, a special weighted flange at the axle end and the "two pieces of metal". I can guarantee you it would be cheaper to just slap a length of tube and two yokes and unis on there.
It's clearly designed to diminish NVH, if you look at how its made.
12/12/12, 07:48 AM
#18
Shelby GT350 Member
Just a guess here...
As for the production costs, it's possible that there's not much difference since IIRC, a single piece shaft has to be carefully balanced... which might negate any manufacturing costs of the multi-piece unit.
Add in the driveline lash/vibration issues, and it's possibly an explanation.
As for the production costs, it's possible that there's not much difference since IIRC, a single piece shaft has to be carefully balanced... which might negate any manufacturing costs of the multi-piece unit.
Add in the driveline lash/vibration issues, and it's possibly an explanation.
12/12/12, 08:04 AM
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These were comments from a Ford engineer on the 08 Bullitt that used to post on forums:
s_____
I don't recalling "dis"ing anyones products. It's up to you to believe what you want. Whatever criteria you have for something being superior or inferior may not match mine or others. I've met Gary Patterson- he's a nice guy.... I'm just here to answer questions and try to be of help.
The post mentions high speed and 160mph - The Mustang (as it leaves AAI) is speed limited well below that for a reason. Like I said before, I do not know specifics about the dynotech piece, what it does or does not do. I do know about the 2-piece in the factory car. It is a fairly robust piece. Vibration is not an issue unless the centerbearing shims are not installed properly, the shaft has a balance issue or the pinion angle is off. These would be quality issues (that I'm not aware of having in production), not design. The 2-pc has no roll in whether or not you have a random vibration. U-joint angles, run-out (flange or shaft), balance and system modal (resonance) response govern vibration.
****************************
s_____ 2 piece drive shaft and rust
The 2-piece driveshaft is required to meet internal engineering requirements for safe operation at max vehicle speed. Basically, it is designed to provide a driveline system resonance well above what the speed limiter will allow you to operate at. If you put your driveline into resonance, bad things may happen! I've seen what it does to a car and it isn't pretty.
The driveshaft CV joints are required components on this type of driveshaft when combined with a live axle. If the rear suspension were IRS, simple flex couplings would be used (look at the new Camaro, Challenger, etc...) and would make for a lighter driveshaft.
The driveshaft also has an internal torsional damper (ITD) which is soley there to attenuate axle whine. If package allowed, the ITD would be mounted on the exterior of the driveshaft as a much lighter ring design. Since the equivalent inertia is required out of the smaller diameter part when installed inside the driveshaft, the mass has to increase. So, you get a heavier ITD vs a lightweight ETD.
A single piece steel or aluminum 1-piece would have to be larger in diameter than the current package allows. Basically, you would have contact with the fuel tank at full rear suspension jounce. 1-piece carbon fiber was explored at one time...
Hope this helps.
Oh, and as far as the rust is concerned, we hate it too. All I can say is write lots of letters to Ford asking them to make your Mustang's steel powertrain components (driveshaft, axle, etc...) come painted from the factory because you don't like rusty car parts. Customer feedback is sometimes absolutely necessary to make a change that, to many of us, should seem so obvious and simple. Fill out those customer surveys that you get in the mail. They really matter.
I would not assume an aftermarket piece "solves" a problem. Yes, you can stuff a massive driveshaft into the tunnel but it will not meet standard vehicle engineering requirements. Our requirements take many factors into account, with the biggest one being your personal safety under a wide variety of operating conditions. Our parts are engineered to work in one big system. Aftermarket parts are generally not engineered. By this, I mean that they are designed to fit properly (usually) and improve one or two attributes specific to your application.
For example, if you want a lighter weight driveshaft that gives you less rotating inertia, you can buy this aluminum 1-pc driveshaft. But, that's all you get - lighter weight. Not proven durability, safety (how does the driveshaft react in a rear impact?, clearance to other parts like the fuel tank?), NVH, ride (driveshaft plunge force actually affects your ride quality), etc...
But that's the great part about it being your car. You get to decide what you want your Mustang to be. Just be cautious and think about how these parts may affect the rest of your driving experience, safety and wallet if it breaks or breaks something else in the car.
I've been in your shoes (which is why I became an engineer and worked my way onto the Mustang team!) and know exactly where you are coming from, though. I don't know specifics about the d/s you are referring to but I'm just giving you some things to think about and consider.
Thanks for buying a Bullitt!
s_____
I don't recalling "dis"ing anyones products. It's up to you to believe what you want. Whatever criteria you have for something being superior or inferior may not match mine or others. I've met Gary Patterson- he's a nice guy.... I'm just here to answer questions and try to be of help.
The post mentions high speed and 160mph - The Mustang (as it leaves AAI) is speed limited well below that for a reason. Like I said before, I do not know specifics about the dynotech piece, what it does or does not do. I do know about the 2-piece in the factory car. It is a fairly robust piece. Vibration is not an issue unless the centerbearing shims are not installed properly, the shaft has a balance issue or the pinion angle is off. These would be quality issues (that I'm not aware of having in production), not design. The 2-pc has no roll in whether or not you have a random vibration. U-joint angles, run-out (flange or shaft), balance and system modal (resonance) response govern vibration.
****************************
s_____ 2 piece drive shaft and rust
The 2-piece driveshaft is required to meet internal engineering requirements for safe operation at max vehicle speed. Basically, it is designed to provide a driveline system resonance well above what the speed limiter will allow you to operate at. If you put your driveline into resonance, bad things may happen! I've seen what it does to a car and it isn't pretty.
The driveshaft CV joints are required components on this type of driveshaft when combined with a live axle. If the rear suspension were IRS, simple flex couplings would be used (look at the new Camaro, Challenger, etc...) and would make for a lighter driveshaft.
The driveshaft also has an internal torsional damper (ITD) which is soley there to attenuate axle whine. If package allowed, the ITD would be mounted on the exterior of the driveshaft as a much lighter ring design. Since the equivalent inertia is required out of the smaller diameter part when installed inside the driveshaft, the mass has to increase. So, you get a heavier ITD vs a lightweight ETD.
A single piece steel or aluminum 1-piece would have to be larger in diameter than the current package allows. Basically, you would have contact with the fuel tank at full rear suspension jounce. 1-piece carbon fiber was explored at one time...
Hope this helps.
Oh, and as far as the rust is concerned, we hate it too. All I can say is write lots of letters to Ford asking them to make your Mustang's steel powertrain components (driveshaft, axle, etc...) come painted from the factory because you don't like rusty car parts. Customer feedback is sometimes absolutely necessary to make a change that, to many of us, should seem so obvious and simple. Fill out those customer surveys that you get in the mail. They really matter.
I would not assume an aftermarket piece "solves" a problem. Yes, you can stuff a massive driveshaft into the tunnel but it will not meet standard vehicle engineering requirements. Our requirements take many factors into account, with the biggest one being your personal safety under a wide variety of operating conditions. Our parts are engineered to work in one big system. Aftermarket parts are generally not engineered. By this, I mean that they are designed to fit properly (usually) and improve one or two attributes specific to your application.
For example, if you want a lighter weight driveshaft that gives you less rotating inertia, you can buy this aluminum 1-pc driveshaft. But, that's all you get - lighter weight. Not proven durability, safety (how does the driveshaft react in a rear impact?, clearance to other parts like the fuel tank?), NVH, ride (driveshaft plunge force actually affects your ride quality), etc...
But that's the great part about it being your car. You get to decide what you want your Mustang to be. Just be cautious and think about how these parts may affect the rest of your driving experience, safety and wallet if it breaks or breaks something else in the car.
I've been in your shoes (which is why I became an engineer and worked my way onto the Mustang team!) and know exactly where you are coming from, though. I don't know specifics about the d/s you are referring to but I'm just giving you some things to think about and consider.
Thanks for buying a Bullitt!
12/12/12, 11:03 AM
#20
MOTM Committee Member
