Limited slip - slip up by Chevy

[mjf]

I'm having trouble understanding GM's reasoning on this.
The standard camaro comes with a v-6, a 6 speed manual and a limited slip. When you pay almost a thousand dollars extra for a 6 speed automatic, GM removes the Limited slip [2 wheel drive] and gives you one wheel drive or a conventional axle that supplies the power to the wheel with the least traction. First 300 hp in a vehicle like the camaro would require 2 wheel drive on anything less that dry road conditions. Don't count on traction control because a car with posi and no traction control can out accelerate a vehicle without posi and traction control on wet surfaces. The posi car has double the amount of contact between the tires and the road. Also keep in mind that the axle ratio on the manual and auto are both 3.27 adding insult to injury. GM needs to get their heads straight on this issue. Does anyone know who I can write to at Chevy that will listen to reasoning.

[Muscle Master]

Originally Posted by mjf

I'm having trouble understanding GM's reasoning on this.
The standard camaro comes with a v-6, a 6 speed manual and a limited slip. When you pay almost a thousand dollars extra for a 6 speed automatic, GM removes the Limited slip [2 wheel drive] and gives you one wheel drive or a conventional axle that supplies the power to the wheel with the least traction. First 300 hp in a vehicle like the camaro would require 2 wheel drive on anything less that dry road conditions. Don't count on traction control because a car with posi and no traction control can out accelerate a vehicle without posi and traction control on wet surfaces. The posi car has double the amount of contact between the tires and the road. Also keep in mind that the axle ratio on the manual and auto are both 3.27 adding insult to injury. GM needs to get their heads straight on this issue. Does anyone know who I can write to at Chevy that will listen to reasoning.

IDK why they did that, maybe because it interferes with mileage

[theholycow]

It's available as an option. Folks buying the V6 automatic are largely not concerned with it, and are more concerned with the cost difference.

[kanys]

First off welcome! This was an issue that really bothered me as well. What we have come to conclude is that GM wants to save money since the V6 automatic will eventually be the best-selling Camaro of the 4 engine/tranny combos. Their reasoning is that since most of these buyers will not mod their Camaros to the extent that a LSD is necessary, which is true. Also, the stability/traction control system will take care of most of the problems regarding wheel spin and such. The only time this may not be enough is if you are driving like speed racer in the snow or doing donuts in an ice rink. (lol ok it will be an issue in less severe conditions than that but my point is 99.9% of the time 99.9% of the V6 auto buyers will not need it, and those that do can buy an aftermarket one). Hope that kinda answered your question. If you really want an official answer I suppose you could PM fbodfather . Again I can almost gaurantee you (as I have been assured) that you will not notice the absence of a LSD on your Camaro.

[mjf]

Thanks for the reply and information. I will check with my local dealer about availability because I would not purchase a new camaro without LSD.

[SScattergunSS]

I was REALLY considering getting an LT, but this along with a few other things made me finally decide on getting an SS. In the end, I know I'll be happier!!!

[fierodeletre]

Just a few thoughts:

A traditional axle is not one-wheel-drive. It is two-wheel drive, all the time. What you're probably thinking of is the fact that an open differential can allow for virtually unlimited wheelspin with one tire blocked. As a previous poster stated, GM's stability and traction control will largely make this effect irrelevant this as it affects normal driving in poor traction conditions. Also: the final drive ratios are NOT the same in the M6 and A6 V6 Camaros. The combination of 1st gear and final drive in the M6 V6 camaro is the deepest ratio of any camaro in the lineup, including the SS models. The Auto's is a much longer final drive, which would be less prone to inducing wheelspin in a full power launch than the deeper final drive of the manual car anyway. I do not know the precise reason for why GM set the two configurations up that way, other than a guess that GM engineers wanted to make sure the auto V6 had as good of mpg numbers as the more efficient manual trans cars, and making the final drive longer is a sure way to do just that. It will mean, however, that the auto will not be as quick to accelerate in any given gear, and just how much that disadvantage plays against the ability of the auto to shift much faster than the manual will have to be seen at the strip. The other effect, which, depending on whom you ask could be a good or a bad thing, is that the auto V6 will not be as prone/able to 'peel out' or lose traction, whether intentionally or no. Yes, if it does, only one wheel will burn. Is this a deal breaker for you? Get a manual car then if you need to light up both tires in your rental Camaro.

[theholycow]

Originally Posted by fierodeletre

A traditional axle is not one-wheel-drive. It is two-wheel drive, all the time. What you're probably thinking of is the fact that an open differential can allow for virtually unlimited wheelspin with one tire blocked.

That's a cop-out. While an open differential is technically two wheel drive, it's effectively one wheel drive. I don't know exactly what you mean by "blocked", but for one wheel to spin, all you need is a slight loss of traction at one wheel, or slightly too much power even with equal good traction at both.

I agree that traction control will surely be good enough compensation.

I do not know the precise reason for why GM set the two configurations up that way, other than a guess that GM engineers wanted to make sure the auto V6 had as good of mpg numbers as the more efficient manual trans cars, and making the final drive longer is a sure way to do just that.

AFAIK it's quite common to do that, and your MPG idea is a big part of it.

It will mean, however, that the auto will not be as quick to accelerate in any given gear, and just how much that disadvantage plays against the ability of the auto to shift much faster than the manual will have to be seen at the strip.

Did you forget the torque converter letting the engine rev up? It's never locked in 1st. The auto will be pretty close, though maybe not close enough for the drag strip (but V6 auto Camaro buyers will mostly NOT be going to drag strips anyway).

The other effect, which, depending on whom you ask could be a good or a bad thing, is that the auto V6 will not be as prone/able to 'peel out' or lose traction, whether intentionally or no. Yes, if it does, only one wheel will burn.

This has an additional advantage that people don't consider very often. People think a LSD is better for snow/ice. Well, with RWD, it's less safe than an open diff. Getting stuck means you're not going anywhere, no big deal...it's also protecting you from driving in conditions that you're not skilled enough to handle (as proven by your getting so stuck that you can't get out). OTOH, spinning both rear tires means the rear is likely to kick out sideways. You don't have to light 'em up spinning at +80mph to make it happen; an undetectable +2mph spin (you're going 50mph, but the tires under steady throttle hit a slippery spot and get up to 52mph) will do it. With only one tire spinning, the other will retain lateral traction and keep you steady.

[fierodeletre]

Originally Posted by theholycow

That's a cop-out. While an open differential is technically two wheel drive, it's effectively one wheel drive. I don't know exactly what you mean by "blocked", but for one wheel to spin, all you need is a slight loss of traction at one wheel, or slightly too much power even with equal good traction at both.

I agree that traction control will surely be good enough compensation.


AFAIK it's quite common to do that, and your MPG idea is a big part of it.


Did you forget the torque converter letting the engine rev up? It's never locked in 1st. The auto will be pretty close, though maybe not close enough for the drag strip (but V6 auto Camaro buyers will mostly NOT be going to drag strips anyway).


This has an additional advantage that people don't consider very often. People think a LSD is better for snow/ice. Well, with RWD, it's less safe than an open diff. Getting stuck means you're not going anywhere, no big deal...it's also protecting you from driving in conditions that you're not skilled enough to handle (as proven by your getting so stuck that you can't get out). OTOH, spinning both rear tires means the rear is likely to kick out sideways. You don't have to light 'em up spinning at +80mph to make it happen; an undetectable +2mph spin (you're going 50mph, but the tires under steady throttle hit a slippery spot and get up to 52mph) will do it. With only one tire spinning, the other will retain lateral traction and keep you steady.

theholycow, all excellent points. What I mean by "blocked" was simply for theoretical explanation. In practice, this "block" could very well be one tire on a stickier surface than the other. In this case, when the other tire spins on the less tractive surface, you effectively have "no-wheel drive" as neither the stationary nor spinning wheel is providing effective traction to move the vehicle. My point in the above, however was simply to say that saying "one-wheel-drive" is a mechanical misnomer, because there is equal power being sent to both wheels, the differential just isn't designed to make sure it stays there. The rotational energy is NOT being channeled into a single wheel. You can imagine what kind of steering problems this would cause were it actually true. (think tank tracks.)

I agree that V6 auto buyers for the vast majority will not be visiting the drag strip. For this reason, I understand why GM made the cost cut to eliminate the LSD for it. (I'm sure someone who was well acquainted with costs, demands, changes in assembly, marketing made the decision and that it made sense to that person fiduciarily.) As far as times though, when a torque converter isn't locked up, it's similar to a slipping clutch, which transfers a significant amount of the engine's energy to heat via friction. Sure, this allows the engine to operate at a more powerful RPM, but how much is lost to slippage? Contrarily, while the time between clutch take-up and the shift to second gear is mechanically much more efficient than a 1st gear run with an unlocked TC, the engine is running at RPMs that are linear to the acceleration of the vehicle (assuming the tires are planted), which are (potentially) not as powerful as the setup in the auto. Obviously, neither of us has these exact figures in front of us, but with as flat and wide a torque curve as this engine has, I'm still placing my bets on the manual by .2 seconds if the driver's good.

Very good insight on the open-diff lateral traction versus posi. Which brings up another point though: What type of LSD is it? Because it it's a centrifugal type, the vast majority of the time it behaves just like an open diff. If it's viscuous, though, then it very well could be a racetrack-only-friendly option (not that it's optional.)

And I don't know why I said rental. Even an LS looks like a sexual experience on wheels.

[Xanthos]

Originally Posted by fierodeletre

And I don't know why I said rental. Even an LS looks like a sexual experience on wheels.

Force of habit. Things are changing.

And I'll be taking my V6 to the track. Probably not a strip though - I'm more interested in actually turning.
- Xanthos

[mjf]

I'm trying to replace a 95 4.6 t-bird with an American rear wheel drive with independent suspension all around. This car had the traction-loc axle which was a $ 95. option. While on business trips I would rent the same vehicle without posi and there was a big difference in the traction on wet roads. I guess I will have to wait and drive the 2010 camaro on wet roads to see how it handles before I purchase it.

[fierodeletre]

No chance of going with the manual? I'd at least drive the auto and see how the TC and SC work. I've driven a 95 TB with the lock, (very nice car btw, shame Ford ruined the car later on) and the system seemed a bit intrusive, but handy in a tight spot to be sure. I'm sure that this 2010 model year car will have a muich more sophisticated system that you may not even notice the car doesn't have posi in bad weather. Who knows? At this point, the only drives of the V6 we have on record were manuals, I think. Both at Milford and Number 3's captured test fleet 1LT.

[TFord]

Originally Posted by mjf

Also keep in mind that the axle ratio on the manual and auto are both 3.27 adding insult to injury.

I dont see your point with the gears???

4th gen A4 fbodys with the "performance axel" package (GU5) came with 3.23 gears
Standard 4th gen A4's (GU2) came with 2.73 gears

[mjf]

My point was, why can't GM leave the limited slip differential in the base camaro when you opt for the 6 speed auto. I know the finial ratio is different because of the auto and manual transmission but the gear ratio in both differentials are the same, 3.27 The only thing I can think of is that the 6 cyl. automatic is not strong enough to handle the LSD. If you remember back in [I think it was 90-92] there was a sport package available with the 6 cyl camaro and it came with 16 inch wheels, rear sway bar, limited slip and some other things that I can't remember. I hope Chevy can do something like this again.