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This is a rant. But I hate being mislead.

:swearin: :irate:

I remember being told and led to belive that honda/acura's SH-AWD was the worlds most advanced awd system, and that it could transfer 100% of the power to any of the 4 wheels. But after watching dealer testing I started to question this.

At the dealer test they had CX7, Murano, X3 etc. When they wanted to show how good their AWD was they drove two wheels of an RDX onto slipery plastic, and jambed a piece of fire wood under the front tire on the other side. When they started to give it gas the two wheels (left side) where spinning before any of the others, with more gas came more spin until it was able to overcome the fire wood. But the left side wheels kept spinning. This made me wonder and start questioning what I was told. Then they did the same thing with a CX7, and had the same result, although it appreard to require less throttle input. This made me wonder even more. Since our AWD system and the CX7 was supposed to be inferior to the mighty SH-AWD

After looking into it more it looks like there is some word games going on in the Honda commercials. Their system can only transfer 45% of the power to the rear wheels, under hard exceleration or when the fronts start to slip. Then it can split that 45 between the two rears. Not all 100% to any one wheel. And the front diff is open so there is not torque split capabilities up front.

So what I think this means is that the SH-AWD is only able to do a 55/45 versus our 50/50, but then the rear diff is a computer controlled rather than our mechanical diff. Suddenly our system doesnt sound so bad to me.
 

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Where did you see this? I know the one time a really used my AWD I had some spin from the front and wheel hop, products of an open diff, but it still pulled alot better than it would have FWD only!
 

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I'm not sure how good the SH-AWD system in terms of it's "4 wheel drive-ness", but from what I've read in car mag reviews, the real benefit of the system is the ability to actually apply more torque to the outside rear tire than a conventional differential would. This allows the engineers to use the SH-AWD to reduce understeer by making the the rear outside tire rotate further. This tucks the front end in, similar in effect to backing off the throttle in a FWD car when the front end starts to push (understeer). The new RL has it and assessments of it's handling are very positive.

I think that's why Acura/Honda calls it "SH" for Super Handling. IE. the focus of the system is to enhance handling. The AWD nomenclature is applied and appropriate because they're adding power to the rear wheels on a car that has driven front wheels. It's also good for marketing.

Maybe the dealers doiing the demo were clueless about the real benefits of the system, and set up the wrong things to demo? Not the first time this has happened. :)
 

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I wonder what the difference is between SH awd and the AWD on the S60 R? The R does the same thing.
 

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I wonder what the difference is between SH awd and the AWD on the S60 R? The R does the same thing.
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the S60R does not transfer more torque to the outside rear wheel when cornering....the honda sh system is the only one to do that I believe.
 

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The SH AWD system is a true full time diffrential based AWD system whose primary purpose is to bias more speed to the outside tire in a turn to help in handling. It is not meant to be a hardcore offroad AWD system.

The demonstration targets a weakness in the AWD system in an artifical scenario that will probably never happen in real life. Thus the beauty in marketing.

The worlds most advanced AWD systems such as the attessa, and porches PSK share the same weakness when placed in the same artifical scenario. But if you put any of these systems on the track or real world conditions they will outperform almost everything out there.
 

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I heard somewhere that they can transfer up to 70%. But anyhow, I think there is no doubt that the SH-AWD is a better system than Mazda's.
 

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I wonder how the newish Haldex Instant Traction makes a difference?

"Instant Traction adds a one-way pre-charging valve to the AWD system that maintains a torque load of 59 foot pounds, which is available instantly. Prior to Instant Traction, if the AWD system sensed that the front wheels were losing traction, one-seventh of a wheel rotation occurred before it began redirecting torque to the wheel with traction. That rotation could influence performance under certain conditions."

http://www.haldex-traction.com/technical_i...acteristics.htm

"So what makes the new improved Haldex AWD better? It now incorporates a non-return valve within the hydraulic control system so that its hydraulic fluid doesnt completely drain out of the system when pressure would normally abate, the result of slowing the vehicle. How does the upgrade make a difference? The outgoing Haldex system allows a one-seventh tire rotation before redistributing power to the rear wheels, but with the new system the non-return valve pre-charges the AWD system with as little as 59 lb-ft of torque turning the front wheels. In other words, the rear wheels are now called into service much sooner, and reduced wheel spin means greater control and less chance of getting stuck in the muck."

"A non-return valve in the hydraulic control system prevents the AWD system from being completely drained of hydraulic fluid (and pressure) as the vehicle slows to a stop. When starting from standstill, 59 lb.-ft (80 Nm) of torque is pre-charged in the system. As a result, the pre-charged torque engages the rear wheels much faster than previous AWD systems, which required wheel spin of a one-seventh turn of the front wheels before power was redistributed."

I just wonder how fast the SH-AWD can react?

I'll shut up now.
 

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I wonder how the newish Haldex Instant Traction makes a difference?

"Instant Traction adds a one-way pre-charging valve to the AWD system that maintains a torque load of 59 foot pounds, which is available instantly. Prior to Instant Traction, if the AWD system sensed that the front wheels were losing traction, one-seventh of a wheel rotation occurred before it began redirecting torque to the wheel with traction. That rotation could influence performance under certain conditions."

http://www.haldex-traction.com/technical_i...acteristics.htm

"So what makes the new improved Haldex AWD better? It now incorporates a non-return valve within the hydraulic control system so that its hydraulic fluid doesnt completely drain out of the system when pressure would normally abate, the result of slowing the vehicle. How does the upgrade make a difference? The outgoing Haldex system allows a one-seventh tire rotation before redistributing power to the rear wheels, but with the new system the non-return valve pre-charges the AWD system with as little as 59 lb-ft of torque turning the front wheels. In other words, the rear wheels are now called into service much sooner, and reduced wheel spin means greater control and less chance of getting stuck in the muck."

"A non-return valve in the hydraulic control system prevents the AWD system from being completely drained of hydraulic fluid (and pressure) as the vehicle slows to a stop. When starting from standstill, 59 lb.-ft (80 Nm) of torque is pre-charged in the system. As a result, the pre-charged torque engages the rear wheels much faster than previous AWD systems, which required wheel spin of a one-seventh turn of the front wheels before power was redistributed."

I just wonder how fast the SH-AWD can react?

I'll shut up now.
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It dosent need to react, its full time AWD. All the driven wheels get power all the time. The rear wheels arent called into service they are in service all the time.

The new haldex is basicly haldex with a bit of preload in the system.
 

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full time AWD FTW. haldex FTL.
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I've become more appreciative of our haladex-type system. It can perform a 100-50 split...the same that and EVO can perform. A week ago I was driving with my friend who owns a 05 S4 (as full time an AWD as you can get) and he says he wished his car could break his rear end and overstear as simply as it is for me in my MS6. A slight blip of the throttle in a turn and you are on your way to some rear end fun (with DSC off of course)
 

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I've become more appreciative of our haladex-type system. It can perform a 100-50 split...the same that and EVO can perform. A week ago I was driving with my friend who owns a 05 S4 (as full time an AWD as you can get) and he says he wished his car could break his rear end and overstear as simply as it is for me in my MS6. A slight blip of the throttle in a turn and you are on your way to some rear end fun (with DSC off of course)
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100-50 split? Wow - that means instead of 274hp to all four wheels, we would then have 274hp going to the front and 137hp to the rear. :nana:
 

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I've become more appreciative of our haladex-type system. It can perform a 100-50 split...the same that and EVO can perform. [/b]
Gee, and the same as a 40 year-old pickup truck. 100 to the rear, or 50 to the front! The systems are different. Haldex-like systems are a computer controlled/clutch locking version of a truck 4WD system. There is NO central diff.

The Evo, all Subarus, some Audis are AWD just driving down the street without the wheels slipping. They already are starting off with all wheels driving, not just sending power to the rear wheels when slip is detected, or when one of the sensors detects a problem.

Real-world does it matter? I don't think so, especially if the sensor/software system is good with a Haldex-like system, which I think the MS6 has. Maybe track driving at 10/10s it might appear.
 

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Gee, and the same as a 40 year-old pickup truck. 100 to the rear, or 50 to the front! The systems are different. Haldex-like systems are a computer controlled/clutch locking version of a truck 4WD system. There is NO central diff.

The Evo, all Subarus, some Audis are AWD just driving down the street without the wheels slipping. They already are starting off with all wheels driving, not just sending power to the rear wheels when slip is detected, or when one of the sensors detects a problem.

Real-world does it matter? I don't think so, especially if the sensor/software system is good with a Haldex-like system, which I think the MS6 has. Maybe track driving at 10/10s it might appear.
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I don't need a lecture on how my AWD system works...
 

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Real-world does it matter? I don't think so, especially if the sensor/software system is good with a Haldex-like system, which I think the MS6 has. Maybe track driving at 10/10s it might appear.
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i dont like the computer controlled AWD, since the car's driving characteristics change seemingly almost randomly from FWD to AWD. it happens at annoying times too. i'd rather have it FWD all the time or AWD all the time so you aren't caught off guard when it suddenly switches.

you dont have to drive it 10/10s to notice. 5/10s will do nicely.
 

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Actually the "super handling" part of their AWD system, I believe, has to do with power application while in motion. In other words, it is able to reapply power to the wheel best suited to help pull you through a turn when cornering and such. To that end it is pretty impressive.
 

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i dont like the computer controlled AWD, since the car's driving characteristics change seemingly almost randomly from FWD to AWD. it happens at annoying times too. i'd rather have it FWD all the time or AWD all the time so you aren't caught off guard when it suddenly switches.

you dont have to drive it 10/10s to notice. 5/10s will do nicely.
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Really? Hadn't heard that about the MS6. But that's a big advantage to actual fulltime systems, you don't have the dynamics of the car changing on you. Going fullbore into a corner, going from 100/0 to partial lock or full lock is much more drastic change than from say 40/60 to 50/50. Didn't think it was as noticable at less-than-full-attack though.

With the big improvement in coupling-based systems over the past few years, wouldn't be surprised if they get a lot better at sensor input/partial locked state of coupler to smooth the transitions out.

Anybody actually find out what caused the rear wheels to kick it? WOT, heavy braking, ???
 
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