PDA

View Full Version : Traction Control Vs Limited Slip



murphypeople
03-02-2007, 07:39 PM
I have recently purchased a MM here in <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" /><st1:State w:st="on"><st1:place w:st="on">Colorado:) </st1:place></st1:State>. My understanding due to dealer written advertisement on the internet ad and window sticker was that the car had T/C. What it has is a limited slip differential. Huge difference eh. I will pursue my dispute with the dealership.
My question for the forum is: 1.) if there may be an after market mod that I can pursue to “install” T/C. 2.) Are the safety features of electronic T/C overrated? I doubt it. 3.) In short maybe some Pro & Con, from the perspective safety re: T/C vs. Limited Slip. Thanks for giving this newbie your consideration.

Breadfan
03-02-2007, 08:10 PM
Limited slip is a type of differential that uses clutches to equalize torque between two axles, allowing both wheels to spin when they loose traction.

An "open" differential does not have this feature, so if one wheel looses traction, it will spin and the other will remain stationary. Torque from the driveline takes the path of least resistance, so it will all flow to the spinning wheel unless another force (such as limited slip clutches) can split the torque and force some to the other axle with traction.

Limited slip does have it's limits though, it can only transfer so much torque to the wheel "with grip".

A "locker" mechanically locks the axles to split torque and is much more capable, but there are other concerns such as noise, chatter, etc., (or cost if you choose an electric-locking rear). Such items are great for 4-wheelin' or racing, but not all that needed on the street.



Traction control on the otherhand, is a computer controlled "helping hand" that detects wheelspin and does things to counteract it. Some items include:

- retard spark to kill power from the motor
- take fuel away to remove power (some systems only)
- apply brakes to slow a spinning wheel
- and I'm sure there are others.

It's hard to say if T/C is really worth it. For many, it is. For some, they may disagree. Once could say a computer can react quicker than a human, but often the computers have a delay built in that allows a slight bit of spin before affecting how the car drives. Often times experienced drivers can react prior to this point and know if a bad situation is ahead or if it's..um...intentional wheelspin. :)

I had a situation in my old car, a FWD car with T/C where I could not get up a snow covered hill. The system would detect wheelspin and retard spark, I'd lose power and basically the car would roll to a stop on the middle of the hill. There was no traction to get started going up again.

I turned off T/C and powered up the hill, with a bit of spin, but kept moving and easily made it up on the first try.

At the same time, there are stories and reports of folks who had the backend kick out, and T/C kicked in instantly and kept things undercontrol. Soemtimes in a situation like that even the most experienced driver will not be able to catch it in time.

So...in the end the T/C "is it worth it" boils down to:

1.) The sophistication of the system
2.) Amount of "delay" built in
3.) Experience of the driver.

Although I'm a "techie" I for one question the validity of many T/C and "stability control" systems, at least for experienced drivers. These driving aids may save unexperienced drivers, but for experienced drivers, I'm not sure a computer that cannot see the road and think about the condtions OUTSIDE of the vehicle can truly replace an experienced driver.

As for differentials, limited slip is pretty much always a good thing on the street, and is unrelated to T/C although it DOES augment it by providing more traction to the drive wheels in a limited-traction scenario.

Hope this helps!

Master
03-02-2007, 08:14 PM
First, the traction control is a pretty involved system that controls braking and ignition at different speeds and in very different ways. I would be very surprised if you could find an aftermarket system, and would highly doubt that you would relish the job of retro-fitting factory TC to your car. Secondly, for my part, I've never found traction control to be in any way useful, and I live in the snowbelt. An MM with good 16" winter tires and a driver with good winter driving skill works much better than a piece of software developed by an egghead in a California engineering facility (sorry for the acerbic description, but after experiencing TC in action, I'm sure it wasn't developed by a snowbird).
Just keep in mind: With limited slip, when you start to spin, BOTH wheel are going to spin, and that means less control at the back end of the vehicle. This is another reason most cars use the open diffs. Better control becuase one wheel continues to roll and track, less friction cornering, and I wouldn't be surprised if they are cheaper to produce. They just don't offer the performance of limited slips.
Anyone else chime in with an opinion?

murphypeople
03-02-2007, 09:13 PM
Thank you both for your reply. The education was received. I am sure my MM is 100% stock...esp. the Differential. So...do I have limited slip or open Diff's?:rolleyes: Ahh the life of a newbie...gota love their questions:o .<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
I am not opposed to having more than one set of rims/rubber for my MM. I do this for my E350.<o:p></o:p>
2nd Question: Do the rims need to be CVPI? And what...the rubber needs to be speed rated too? I would think not...esp. if I go with studs.<o:p></o:p>
3rd Q: and since I don't have T/C...do I need to be concerned with different tire sizes front-to-rear?:burnout:

StevenJ
03-02-2007, 10:53 PM
You have standard Fordtrack lock. You can get the snow tire and wheel package form www.tirerack.com for about $600-700 for all four tires/ wheels I believe that is the cost. It is not a big deal really and it will last you one or two seasons. Have fun anyway and yes the 16s should be CVPIs. You don't want to drive aluminum rims in the winter, cough road salt cough.

FordNut
03-03-2007, 12:54 AM
All Marauders have limited slip. If it has two buttons on the panel to the left of the steering column, it has traction control also. If it only has one button on that panel, it does not have traction control.

rayjay
03-03-2007, 02:57 AM
1) The TC on my 04 DTR has saved me from wrecking on ice twice.

2) I live in the upstate New York snowbelt, in the hills. I burned up my 1st pair of rear snow tires in two seasons. This winter I went with studded rears. Vast improvement, especially on hills.

3) The TC kicking on during a ice storm last night reminded me to slow down as the road only looked wet, not icy.

4) I really did not care for the TC the 1st year I owned the car, I have come to appreciate it and have learned how and when to use it.

snowbird
03-03-2007, 05:06 AM
First, the traction control is a pretty involved system that controls braking and ignition at different speeds and in very different ways. I would be very surprised if you could find an aftermarket system, and would highly doubt that you would relish the job of retro-fitting factory TC to your car. Secondly, for my part, I've never found traction control to be in any way useful, and I live in the snowbelt. An MM with good 16" winter tires and a driver with good winter driving skill works much better than a piece of software developed by an egghead in a California engineering facility (sorry for the acerbic description, but after experiencing TC in action, I'm sure it wasn't developed by a snowbird).
Just keep in mind: With limited slip, when you start to spin, BOTH wheel are going to spin, and that means less control at the back end of the vehicle. This is another reason most cars use the open diffs. Better control becuase one wheel continues to roll and track, less friction cornering, and I wouldn't be surprised if they are cheaper to produce. They just don't offer the performance of limited slips.
Anyone else chime in with an opinion?

Thanks Master !! :)

Jocking aside, You guys hit it on the nail. I'm not a big fan of TC and they probably put a switch to put it off for good reasons= in the deep snow, when you need to go uphill or out a ditch, you leave it at off. If not, the timing pulling and brake acting will make more harm.

At faster speed with an unexperienced driver and/or in the rain and/or on ice or black ice, it can sometimes detect and react faster to keep you out of trouble, especially in a curve. Glad I have it sometimes but would sell the car if there wasn't a switch to put it at off since in the snowbelt, it is not a panacea at all. IMO, a good TC system also have to do with a good computer programming. Some work better than others and the Ford system is not the best one but they have made good progress over the years.

Lastly, a good aftermarket limited slip is also a great help over the standard Ford unit for the deep snow and it is always the first thing I change with a rear drive but you have to learn how to make the salmon fish dance with your tail ...

jdando
03-03-2007, 05:45 AM
All good posts!

I have Traction Control and like it. It saved my butt a couple of times when the rear end stepped out on the highway.

TC vs. limited slip; You can not really compare them. I think they serve very different functions.

Retro fitting a TC; Doubtful it is a complicated system.


It appears you have a 300a model, earlier 2003 production. I would go back to the selling dealer and suggest to them they misrepresented the car. Have them pony up the cost of winter wheels and tires. The good news is that you can run a variety of tire/wheel sizes size you do not have traction control.

Hope you will enjoy the car!

jeremy

cyclopsram
03-03-2007, 05:58 AM
Most "normal" drivers will never see or feel the benefits of either device.. Only we who appreciate nice options will "use" them intentionally. If you are going to enter the 0-100 crew you may want to shut off the TC to keep it from operating under intentional wheel spin...

Bluerauder
03-03-2007, 06:23 AM
It's hard to say if T/C is really worth it. For many, it is. For some, they may disagree. Once could say a computer can react quicker than a human, but often the computers have a delay built in that allows a slight bit of spin before affecting how the car drives. Often times experienced drivers can react prior to this point and know if a bad situation is ahead or if it's..um...intentional wheelspin. :)
I consider myself an experienced driver with pretty quick reaction & anticipation skills. :D Last summer I had an incident on a rain and oil slick turn where the back end stepped out on me in the middle of the turn -just as she shifted. Although I came off the accelerator pretty quickly, the T/C was already working the problem because I caught the T/C light flash on and off about the same time as I got that "seat of the pants" loose feeling as the rear broke free.

Could I have corrected this myself --- Maybe ..... probably. ;) But I can't deny the fact that the T/C was working on the problem before I even knew about it (maybe 1/2 second or less). Would it have come around without T/C, I don't know. Others here have found out how quickly that can happen. :(

Master
03-03-2007, 08:31 AM
Its a real shame that we need something like T/C to help counteract the effects of another negative engineering trait, the automatic transmission. There is absolutely nothing worse than having to drive a vehicle through a corner when that vehicle has its own mind about shifting. Nothing but a manual transmission gives an operator the kind of complete vehicle control that is needed to be truly in charge of each and every action. Adding T/C to cover up the flaws of an automatic is just adding insult to injury.

GreekGod
03-03-2007, 12:24 PM
Its a real shame that we need something like T/C to help counteract the effects of another negative engineering trait, the automatic transmission. There is absolutely nothing worse than having to drive a vehicle through a corner when that vehicle has its own mind about shifting. Nothing but a manual transmission gives an operator the kind of complete vehicle control that is needed to be truly in charge of each and every action. Adding T/C to cover up the flaws of an automatic is just adding insult to injury.

Black ice, or oil on a rain slicked road will get you in a whole bunch of trouble with a stick or auto trans.

I once crashed, going up a hill on an asphalt paved road, where a tanker had spilled some gasoline, and softened the road. It was extremely slippery, and totally invisible on a hot summer day.

I would ask your dealer to refund the blue book difference between the TC option and without. The winter tire and wheel compensation from the dealer might be a good alternative.

murphypeople
03-03-2007, 09:49 PM
G~G thanks for the .02 regarding dealing with the dealership...I was thinking along the same lines +/- swapping for a "comperable" G-Marquis. Monday will be an interesting day:coolman:

purelux
03-12-2007, 09:26 AM
I had tc on my towncar when i bought it and with tc and not limited slip winter driving was not fun. Tc helps on say black ice, ice corners. But as far as take-off and hills forget it without winter tires. I have continental extreme contacts with but a few thousand miles on them now, michelin symmetries then. I now also have a limited slip and 3.55's added in and even takeoffs in 2nd on snowy roads wasn't good then or now. However with the pirelli scorpion ice&snow tires on it. It goes great stop, turn take-off awesome with or without tc. I do leave it on if ice is to be expected but it really just lets you be a bit complacent. I would keep the MM versus getting a gm just for traction control. It's really not that helpful and no replacement for snow tires or even good all seasons in case of rain.

High-C
03-12-2007, 09:38 AM
I have recently purchased a MM here in ffice:smarttags" /><?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-comhttp://www.mercurymarauder.net/forums/ /><st1:State w:st=<st1:place w:st="on">Colorado:) </st1:place></st1:State>. My understanding due to dealer written advertisement on the internet ad and window sticker was that the car had T/C. What it has is a limited slip differential. Huge difference eh. I will pursue my dispute with the dealership.
My question for the forum is: 1.) if there may be an after market mod that I can pursue to “install” T/C. 2.) Are the safety features of electronic T/C overrated? I doubt it. 3.) In short maybe some Pro & Con, from the perspective safety re: T/C vs. Limited Slip. Thanks for giving this newbie your consideration.

Someone needs to watch Marisa Tomei's courtroom testimony in "My Cousin Vinnie"... That'll explain everything... ;)

purelux
03-12-2007, 11:00 PM
yup, that and independant rear suspension to explain the type of rubber marks on the road cause one car had it and one didn't that were identical in appearance.

metroplex
03-13-2007, 05:34 AM
Trac Ctrl + Limited Slip = for t3h win.

Honestly, a RWD w/o limited slip isn't the right way to go. At least Ford had the intelligence to include LSDs for the Marauders, unlike the other Panthers. The LSD is an $87 option on the CVPI.