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Discussion Starter · #1 ·
A while ago there was a post indicating that the 2008s would get an improved handling system based on an overdrive outside rear wheel like the Acura Sh-awd system. Has anyone seen any indication that this change has really occurred?
 

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Re: Is the 2008 AWD drivetrain really upgraded

Bump....heard about this via the USA Today article, know admin was going to try to ask Nico about it, but I never saw any more confirmation or other mentions of this....anyone know? Did I miss the post where this was resolved elsewhere?

Our 08 Enclave with AWD handles very nicely...have not put it to serious AWD test yet but moderate moves and sharp curve interstate ramps have shown it to track solidly without feeling any issues at all....very pleased with the AWD so far....
 

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Discussion Starter · #3 ·
Re: Is the 2008 AWD drivetrain really upgraded

Although no one seems to have been able to verify it, this media site mentions several 2008 upgrades to the AWD system. Thes include dynamic issues (side to side transfer like Acura's sh-awd) for handling and also a shift to more RWD proportion in a number of circumstances. Apparently no one whose driven both has noticed enough to mention. It will be interesting to see what the GMC site says when it is upgraded for 2008.

http://media.gm.com/us/gmc/en/product_services/r_cars/r_c_acadia/index.html
 

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Re: Is the 2008 AWD drivetrain really upgraded

According to the Service manager (saturn) i spoke to they did make the change as they got a quick brief about it It is not EXACTLY like the Acura system but is very close
 

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Discussion Starter · #5 ·
Interesting, I guess the service department would have the best technical info. The GMC website has been updated but I cannot find a single word of technical description on the AWD system. One would think if they made changes to be more competitive that they would want to tell us about it.
 

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Wow, I guess I'm getting senile in my old age. Running three separate forums is getting to me ;) I answered this on the enclave forum, apparently, but not here. I did talk to Mr Nico (the Lambda Vehicle line director) about this. And here's a reprint of my original post:


Hey guys,

I have a little information on this topic from a VERY reliable source at GM. Here is a (slightly paraphrased to protect the innocent) quote on the topic of the new MDXesque system in the 08s. Now let me state that it wasn't made clear if this is included in all three Lambdas, but it was implied...

[The Lambdas] have all the elements that MDX has except for the locking rear differential. Additionally, it is a Bosch system. For '08 [GM has] a calibration that performs like the MDX in that it can apply power when appropriate to the rear differential ... You have to drive the system meaning you must be calling for power, and if you do, you will get better performance than the '07 system since it will send power to the rear if that's appropriate to maintain vehicle control ... with the '07 system, if you begin to lose control, it will begin to reduce power and apply brakes...this is consistent with most systems. The '08 system includes a hardware and a software change so the '08 calibration cannot be applied "backwards" into the '07. The hardware change is in the brake control system and involves memory and logic controls ... both systems provide an extremely high level of safety and performance, but the '08 offers improved performance at the limits!
This was in response to my query for more details on the new system and if it would be, in any way, backward compatible with 07 models. The answer is obviously 'no'.
 

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Discussion Starter · #7 ·
That does make some sense of the whole thing because the other release indicates there is a significant change in the electronic braking module and this information ties the AWD changes at least in part, to that module (which is not in place on the '07). Thanks.
 

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admin said:
Wow, I guess I'm getting senile in my old age. Running three separate forums is getting to me ;) I answered this on the enclave forum, apparently, but not here. I did talk to Mr Nico (the Lambda Vehicle line director) about this. And here's a reprint of my original post:


Hey guys,

I have a little information on this topic from a VERY reliable source at GM. Here is a (slightly paraphrased to protect the innocent) quote on the topic of the new MDXesque system in the 08s. Now let me state that it wasn't made clear if this is included in all three Lambdas, but it was implied...

[The Lambdas] have all the elements that MDX has except for the locking rear differential. Additionally, it is a Bosch system. For '08 [GM has] a calibration that performs like the MDX in that it can apply power when appropriate to the rear differential ... You have to drive the system meaning you must be calling for power, and if you do, you will get better performance than the '07 system since it will send power to the rear if that's appropriate to maintain vehicle control ... with the '07 system, if you begin to lose control, it will begin to reduce power and apply brakes...this is consistent with most systems. The '08 system includes a hardware and a software change so the '08 calibration cannot be applied "backwards" into the '07. The hardware change is in the brake control system and involves memory and logic controls ... both systems provide an extremely high level of safety and performance, but the '08 offers improved performance at the limits!
This was in response to my query for more details on the new system and if it would be, in any way, backward compatible with 07 models. The answer is obviously 'no'.
i dont think its the same system as an MDX, base on his description the locking rear differential is the only thing that seperates the Acadia from the MDX ??? i dont think so as thats a given to all AWD system imploying the latest design, his also stating the power transfer only between the front and the rear differential is the only changed between the 07 and 08 after the calibration...to summarize it all -- its just a minor system and software upgrade the way i see it. While the Acura's SHAWD system works by transfering power both front and rear plus side to side at any location where power and traction is needed, a feat that no software or hardware upgrade can duplicate. as of now only Acura and Audi has this technology.
 

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From what i read about it the SHAWD can go side to side and inward and outward of the tire. The 08 Lambda is supposed to be able to go Side to side but not both in and out. I cant find the **** article now

Once i find it i will post it but the GM guy saidthat although it wasnt exactly like the SHAWD, it performed just as good except in one extreme test
 

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compnurd said:
From what i read about it the SHAWD can go side to side and inward and outward of the tire. The 08 Lambda is supposed to be able to go Side to side but not both in and out. I cant find the **** article now

Once i find it i will post it but the GM guy saidthat although it wasnt exactly like the SHAWD, it performed just as good except in one extreme test
dont forget that Acuras SHAWD can also change both rotational speed between the left and right wheels independently perpendicular to the front and rear differential, when it comes to cornering prowess nothing comes close to the MDX unless your driving an AWD sports car. that what makes the MDX beyond the reach of the Acadia in terms of technology and hardware... and what makes it a better drivers SUV. if only it comes a much spacious 3rd seat it could be my hand down choice... :thumb:
 

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SioXie said:
compnurd said:
From what i read about it the SHAWD can go side to side and inward and outward of the tire. The 08 Lambda is supposed to be able to go Side to side but not both in and out. I cant find the **** article now

Once i find it i will post it but the GM guy saidthat although it wasnt exactly like the SHAWD, it performed just as good except in one extreme test
dont forget that Acuras SHAWD can also change both rotational speed between the left and right wheels independently perpendicular to the front and rear differential, when it comes to cornering prowess nothing comes close to the MDX unless your driving an AWD sports car. that what makes the MDX beyond the reach of the Acadia in terms of technology and hardware... and what makes it a better drivers SUV. if only it comes a much spacious 3rd seat it could be my hand down choice... :thumb:
All the MDX's technological prowess does nothing to change the fact that it has looks only a mother could love. Yes, this is entirely subjective, but I honestly cannot fathom where Acura's design direction has come from.
 

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How does the 07 AWD system work? Part of the admins quote stated '...better performance than the '07 system since it will send power to the rear if that's appropriate to maintain vehicle control ... with the '07 system, if you begin to lose control, it will begin to reduce power and apply brakes...'

The 07 sends power to the rear wheels when needed, so what is so special about the 08 sending power to the rear wheels when needed? Can someone summarize the 07 function?
 

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With all cars, AWD, FWD, or RWD, whenever you turn, the inner wheel will always rotate at a slower speed than the outer wheel. That's why the differential was invented, to allow the inner wheel to spin slower than the outer wheel when turning. Most systems, like the 07, will accomplish this task in the differential by reducing the power (torque) to the inner wheel, essentially slowing it down so the turn can be accomplished. The 08 models (and Acura) accomplish this task by sending more power to the rear differential, and the rear differential over-spins the rear outer wheel by giving it excess torque, while still maintaining the same torque on the inner wheel. So, instead of the inner rear wheel being dragged along in a turn, the outer rear wheel is being over-driven to accomplish the turn with a gain in control and handling.

Imagine you are pushing a shopping cart. While you are turning it, say to the left, instead of you slowing down the left side of the cart to turn, you push the right side of the cart harder to make the turn, which is what the AWD system in the Acadia and Acuras are doing.

In the 07, it only sent more torque to the rear if the front was slipping, but I believe for the 08 is sends torque when the front slips as well as during turning I believe to accomplish the over-spinning

I think that's how it works, but please correct me if I'm wrong. Glad I didn't take auto shop this year :confused:
 

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If this is how the 07 and 08 differ, it makes sense. I could see the advantage of over-spinning, especially on a sports car, to hug a corner.
 

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jonv112 said:
With all cars, AWD, FWD, or RWD, whenever you turn, the inner wheel will always rotate at a slower speed than the outer wheel. That's why the differential was invented, to allow the inner wheel to spin slower than the outer wheel when turning. Most systems, like the 07, will accomplish this task in the differential by reducing the power (torque) to the inner wheel, essentially slowing it down so the turn can be accomplished. The 08 models (and Acura) accomplish this task by sending more power to the rear differential, and the rear differential over-spins the rear outer wheel by giving it excess torque, while still maintaining the same torque on the inner wheel. So, instead of the inner rear wheel being dragged along in a turn, the outer rear wheel is being over-driven to accomplish the turn with a gain in control and handling.

Imagine you are pushing a shopping cart. While you are turning it, say to the left, instead of you slowing down the left side of the cart to turn, you push the right side of the cart harder to make the turn, which is what the AWD system in the Acadia and Acuras are doing.

I think that's how it works, but please correct me if I'm wrong. Glad I didn't take auto shop this year :confused:
you got it right and well said... :clap2: that is the basic function of all awd systems today but with the Acura SHAWD it takes it to another level for it can change both rear and front inner wheels rotation speed individually depending on how much torque you need not just slowing both inner wheels during turning. You have a system capable of redirecting torque individually to all 4 wheels not just an inner to outer transfer system. :thumb:
 

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All the MDX's technological prowess does nothing to change the fact that it has looks only a mother could love. Yes, this is entirely subjective, but I honestly cannot fathom where Acura's design direction has come from.
[/quote]
maybe too much of the techno look.... thats why ill go for the black if ever i decide for that one to kinda hide the "face".... ;D
 

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And dont even get me started on that center console that looks like it was pulled off of a $20 boom box. My wife was test driving the car and I couldn't draw my attention away from that mess, kind of like a car wreck. I just kept complaining to the salesperson about it. How could they do that to an otherwise nicely appointed car? :confused:
 

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JeffL said:
And dont even get me started on that center console that looks like it was pulled off of a $20 boom box. My wife was test driving the car and I couldn't draw my attention away from that mess, kind of like a car wreck. I just kept complaining to the salesperson about it. How could they do that to an otherwise nicely appointed car? :confused:
:ditto: its one of its negative attributes, too many buttons, too cluttered = distraction!
 
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