RWS by the numbers
05-25-2013, 02:09 PM
#1
Race Director
Thread Starter
RWS by the numbers
The latest Christophorus has an article on RWS. Mixed in with the usual platitudes are some numbers I haven't seen before that y'all might find interesting (or a basis for further discussion).
.5" Maximum extension of the adjustable toe link
1.5' Approximate reduction of the turning circle due to RWS
40 Nm (55 ft/lbs) Driving force required to operate the adjustment spindles
50 kW (68 HP) Estimate of the amount of additional HP that would be required to equal the Ring time improvement provided by RWS
100KG (220 lbs) Estimate of the amount of weight that would have to be shaved from the car to achieve a similar level of improvement in chassis dynamics
Gentlemen and ladies, start your critiques!
.5" Maximum extension of the adjustable toe link
1.5' Approximate reduction of the turning circle due to RWS
40 Nm (55 ft/lbs) Driving force required to operate the adjustment spindles
50 kW (68 HP) Estimate of the amount of additional HP that would be required to equal the Ring time improvement provided by RWS
100KG (220 lbs) Estimate of the amount of weight that would have to be shaved from the car to achieve a similar level of improvement in chassis dynamics
Gentlemen and ladies, start your critiques!
05-25-2013, 03:20 PM
#3
.5" Maximum extension of the adjustable toe link
1.5' Approximate reduction of the turning circle due to RWS
40 Nm (55 ft/lbs) Driving force required to operate the adjustment spindles
50 kW (68 HP) Estimate of the amount of additional HP that would be required to equal the Ring time improvement provided by RWS
100KG (220 lbs) Estimate of the amount of weight that would have to be shaved from the car to achieve a similar level of improvement in chassis dynamics
Having the ability for the driver to actually control the car: PRICELESS
05-25-2013, 03:45 PM
#4
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05-25-2013, 04:20 PM
#5
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I will bet that RWS affects driver control no more than a limited slip differential!
The e-diff in the fiat has been described as brilliant; I think RWS will simply add to the experience. AP's description of reducing phase lag, and the comments on the car's precision and turn-in by the e-diff and RWS conspiracy leaves me pretty excited.
Grip + precision, if married with a communicative chassis through the seat of your pants and steering wheel, will make the new 3 epic.
The e-diff in the fiat has been described as brilliant; I think RWS will simply add to the experience. AP's description of reducing phase lag, and the comments on the car's precision and turn-in by the e-diff and RWS conspiracy leaves me pretty excited.
Grip + precision, if married with a communicative chassis through the seat of your pants and steering wheel, will make the new 3 epic.
05-25-2013, 05:54 PM
#6
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Thread Starter
I will bet that RWS affects driver control no more than a limited slip differential!
The e-diff in the fiat has been described as brilliant; I think RWS will simply add to the experience. AP's description of reducing phase lag, and the comments on the car's precision and turn-in by the e-diff and RWS conspiracy leaves me pretty excited.
Grip + precision, if married with a communicative chassis through the seat of your pants and steering wheel, will make the new 3 epic.
The e-diff in the fiat has been described as brilliant; I think RWS will simply add to the experience. AP's description of reducing phase lag, and the comments on the car's precision and turn-in by the e-diff and RWS conspiracy leaves me pretty excited.
Grip + precision, if married with a communicative chassis through the seat of your pants and steering wheel, will make the new 3 epic.
Consistent with this, the Christophorus article says that "when the rear wheels can steer, it takes less time for them to develop cornering forces". Can't wait to try it.
05-25-2013, 06:17 PM
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I will bet that RWS affects driver control no more than a limited slip differential!
The e-diff in the fiat has been described as brilliant; I think RWS will simply add to the experience. AP's description of reducing phase lag, and the comments on the car's precision and turn-in by the e-diff and RWS conspiracy leaves me pretty excited.
Grip + precision, if married with a communicative chassis through the seat of your pants and steering wheel, will make the new 3 epic.
The e-diff in the fiat has been described as brilliant; I think RWS will simply add to the experience. AP's description of reducing phase lag, and the comments on the car's precision and turn-in by the e-diff and RWS conspiracy leaves me pretty excited.
Grip + precision, if married with a communicative chassis through the seat of your pants and steering wheel, will make the new 3 epic.
Not to mention an LSD can be tuned and adjusted. Factory set parameters on ANYTHING always leave something to be desired to anyone who will track the car seriously. LSD's, engine response, throttle response, turn in, grip, alignment. There is no reason to think RWS won't be a hassle for anyone who wants to improve the factory handling a bit.
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05-25-2013, 06:25 PM
#8
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I disagree, RWS is going to pitch in when you turn the wheels regardless. LSD is reactive and only chips in under certain parameters. The LSD is corrective in nature where as RWS is causal in nature. Two totally different schematics and will affect the driving experience differently.
Not to mention an LSD can be tuned and adjusted. Factory set parameters on ANYTHING always leave something to be desired to anyone who will track the car seriously. LSD's, engine response, throttle response, turn in, grip, alignment. There is no reason to think RWS won't be a hassle for anyone who wants to improve the factory handling a bit.
Not to mention an LSD can be tuned and adjusted. Factory set parameters on ANYTHING always leave something to be desired to anyone who will track the car seriously. LSD's, engine response, throttle response, turn in, grip, alignment. There is no reason to think RWS won't be a hassle for anyone who wants to improve the factory handling a bit.
To be frank, you are out of your league and should restrain yourself when posting comments criticizing the Porsche GT3 engineers. They know more than you.
05-25-2013, 07:48 PM
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You obviously have a good working knowledge of cars. But seriously, do you believe Porsche engineers are dunces? Don't you think with all their experience (the team has worked together on eight GT3's) they know something about automobile dynamics?
To be frank, you are out of your league and should restrain yourself when posting comments criticizing the Porsche GT3 engineers. They know more than you.
To be frank, you are out of your league and should restrain yourself when posting comments criticizing the Porsche GT3 engineers. They know more than you.
Yeah, I'll be sure to thank them for gluing my coolant hoses together so they could fail at anytime, putting the best LSD known to man in the GT3's to go with the excellent clutches and PP's.
Surely wont forget to tell them the awesome job they did on the Gen I centerlocks.
Do you have a decent counter point aside from "omg porsche made it so it must be perfect omg"?
05-25-2013, 09:21 PM
#11
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Thread Starter
I disagree, RWS is going to pitch in when you turn the wheels regardless. LSD is reactive and only chips in under certain parameters. The LSD is corrective in nature where as RWS is causal in nature. Two totally different schematics and will affect the driving experience differently.
Not to mention an LSD can be tuned and adjusted. Factory set parameters on ANYTHING always leave something to be desired to anyone who will track the car seriously. LSD's, engine response, throttle response, turn in, grip, alignment. There is no reason to think RWS won't be a hassle for anyone who wants to improve the factory handling a bit.
Not to mention an LSD can be tuned and adjusted. Factory set parameters on ANYTHING always leave something to be desired to anyone who will track the car seriously. LSD's, engine response, throttle response, turn in, grip, alignment. There is no reason to think RWS won't be a hassle for anyone who wants to improve the factory handling a bit.
My only other comment would be that front wheel steering is also causal in nature but no one sees that as a problem. Since RWS is tied directly and solely to the driver's FWS input, and it's response is repeatable and predictable (it doesn't correct or react on it's own like PSM) I don't see why it should have a negative effect on the driving experience.
05-25-2013, 10:17 PM
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Nick, take notes, decent counter response below.......
Possibly, but the fact that there is no option not to have it leads me to believe it will be a major undertaking. Not to mention the electrical connection it has with the other systems will more than likely need to be messed with. Sounds like a total headache.
I see your point but front wheel steering is necessary, RWS (only) is not unless we intend to drive the cars like boats. Steering from one end is certainly less complicated than steering from two ends. Add to that, track setups are complicated enough already and it seems to be a headache that's not really worth it,as especially when you consider stepping outside of the range of parameters set by the engineers. It may work great stock, my question is what about when you modify or change suspension settings.
I wouldn't want to be the first guy on a set of very sensitive slicks to try slicks and a race alignment. These are the things you can be pretty confident Porsche has not tested (race alignment and slicks).
I think you have a point, wanna911, re: the ability to tune the RWS system. Whether it would be to the driver's advantage to do that is an open question but regardless it may be something that can eventually be modified the way engine maps are now modified, or the system could be removed entirely and replaced with a conventional link.
My only other comment would be that front wheel steering is also causal in nature but no one sees that as a problem. Since RWS is tied directly and solely to the driver's FWS input, and it's response is repeatable and predictable (it doesn't correct or react on it's own like PSM) I don't see why it should have a negative effect on the driving experience.
My only other comment would be that front wheel steering is also causal in nature but no one sees that as a problem. Since RWS is tied directly and solely to the driver's FWS input, and it's response is repeatable and predictable (it doesn't correct or react on it's own like PSM) I don't see why it should have a negative effect on the driving experience.
I see your point but front wheel steering is necessary, RWS (only) is not unless we intend to drive the cars like boats. Steering from one end is certainly less complicated than steering from two ends. Add to that, track setups are complicated enough already and it seems to be a headache that's not really worth it,as especially when you consider stepping outside of the range of parameters set by the engineers. It may work great stock, my question is what about when you modify or change suspension settings.
I wouldn't want to be the first guy on a set of very sensitive slicks to try slicks and a race alignment. These are the things you can be pretty confident Porsche has not tested (race alignment and slicks).
05-26-2013, 12:25 AM
#13
Race Director
How will RWS affect tire wear?
Currently the typical starting point for track alignment is -2.5 front zero toe and -2 rear 2mm toe in per side as a rule of thumb. How will RWS change alignment for track driving?
Currently the typical starting point for track alignment is -2.5 front zero toe and -2 rear 2mm toe in per side as a rule of thumb. How will RWS change alignment for track driving?
05-26-2013, 05:24 AM
#14
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My biggest objection to technology loaded cars for achieving a fast time once or twice is the complexity and associated reliability with ongoing use or ownership... sure its fine for those buying, flogging them for a year and flicking them off but I like to hold onto and appreciate what I buy without having to spend its original purchase price all over again in keeping complex **** working... If its track oriented, keep it simple...
Weight loss is simple and reliable and I bet the drive dynamics would be far improved...
Yeah, I'll be sure to thank them for gluing my coolant hoses together so they could fail at anytime, putting the best LSD known to man in the GT3's to go with the excellent clutches and PP's.
Surely wont forget to tell them the awesome job they did on the Gen I centerlocks.
Do you have a decent counter point aside from "omg porsche made it so it must be perfect omg"?
Surely wont forget to tell them the awesome job they did on the Gen I centerlocks.
Do you have a decent counter point aside from "omg porsche made it so it must be perfect omg"?