I'm still kind of let down by the release of the TLX and have held back on what I really want to say on AZ ... first world problems, i know. I've also cancelled my fiery email to the suits at Acura corporate. Instead I think it's a good idea to show Acura engineers some of their past greatness since I assume they troll these forums. (Besides I doubt anyone would read too far into an email that starts with Dear F***face. )

AZ'er Corey has let the cat out of the bag by revealing that Acura will be going AWD across the board with the upcoming ILX awd. With that in mind it allows Acura to play to Audis (longitudinal) front drive/awd layout, Infiniti to play to BMW and Lexus to play to Merc, although it seems that they might both be playing to BMW. Time will tell.

There are two ways that premium front wheel drive platforms with AWD have the engine mounted - longitudinal and transverse (or imo, the right way and the wrong way ). A longitudinally mounted engine looks exactly like the engine layout of any RWD car. Also, I'm pretty sure all Audis are longitudinal (as well as all Subarus.)

This is the longitudinally mounted engine from an early 90's Legend. Notice how far back against the firewall it is. Also notice the 'plus' signs are near the shock towers that approximate the center line of front wheels. The dashed line indicates the leading edge of the engine. From here we can see that a good portion of the engine is behind the center line of the front wheels.



Yes, this is an actual engine and transmission from a Legend. I know it doesn't look like it but you can see the three coils on top - (the star on the right indicates a mounting bracket and not a driveshaft). It looks just like the engine/transmission from a RWD car. The other star indicates the half shaft roughly giving you an idea of the center point of the wheel. From here we can deduce that this longitudinal oriented engine and transmission puts the bulk of the weight towards the center of the car. This layout also allows easy power take off for powering the rear wheels.




And heres the RLX with its transverse mounted engine. Notice how far forward the engine is -- enough to mount a straight shock tower directly between the shocks. The leading edge of the engine is also pretty far forward.



Heres the engine and transmission bolted together. The half shafts mounting points are (Im assuming) behind what we can see. From this picture we can deduce that a majority of the weight of this powertrain is in front of the center line of the front wheels.





Even with the weight distribution gains of having a longitudinal FWD layout, my reason for preferring it over a transverse layout is purely aesthetic. It allows for a tighter front overhang and a thicker 'prestige distance' ( i heard Peter Schreyer call it that lol) between the front wheel and the leading edge of the front door seam. It simply allows for a more upscale side profile.

Behold the 'prestige distance' and nicely snubbed front overhang. Note how much prestige exists between front door seam and front fender - this things all ate up with prestige. Okay this is a used 20 year old car.




Okay, I have to admit I really like the looks of the RLX but theres always room for 'prestige distance' improvement on future models. Red lines show a lack of prestige plus a huge honkus .



Fwiw, transverse mounted engines should allow more passenger space and definitely more footwell space. I also believe they could be better in a center oriented crash because you have basically a wall of rigidly mounted metal in front of you.

And yes I'm aware the RLX will have a vastly different powertrain in AWD form - just using it as an example.

 

Interesting analysis. As an aside, I'm glad I'm not the only weirdo who likes the looks of the RLX. The "stealth wealth" is where it's at nowadays.

So will the folken at Acura grok what you are saying?

PS--my S2000 has a longitudinally mounted engine set back behind the front axle. Honda has proven it can do it in the past.....will it do it again for handling improvement?

 

We don't need to mount our engines behind the front axle....we have PAWS and SHAWD...and super duper fantastic claws all wheel drive too.

 

Don't forget the tires....

 

obviously the J-series is important to them.

 

It's a whole hell of a lot easier to work on the transverse mounted layout.

 

Acura engineers do not come here.

 

There are two issues with the longitudinal engine layout for FWD based cars:

1. Complexity

If the Acura brand is truly going to go all AWD, then this is less of an issue since it allows it to easily add a center differential to apportion the power, and would likely allow for more power to drive the rear wheels on a regular basis. But if FWD is still going to be the order of the day, then this means the power needs to be shuffled from the transmission back up towards the front wheels. This leads to more drivetrain loss and likely reduced performance since you need to route the power around.

2. Packaging/Cost

Without a totally new platform, there is no way to make this work easily. They need to re-engineer the entire chassis to allow for all of the complex electronics that are currently housed in the tunnel area and make room for the transmission. Even if they only modify an existing platform to accept this configuration, the added costs would likely increase the production cost of the vehicle and thus the ultimate price. If people are complaining already about how much the RLX costs, what makes anyone think that an even more expensive car is likely to change people's opinions?

One thing that I have yet to see any manufacturer seriously try is to change the orientation of a transverse motor to tilt the transmission output shaft further forward in the chassis, allowing the bulk of the motor's weight to rest behind the transmission. Of course, this presents its own set of challenges, such as where to route the steering column and exhaust headers, compensating for hood height, and making it work within crash test regulations. However, if a company could make this all work, you could theoretically still have a transverse layout, but with better weight distribution while using existing technologies. The car would likely be more difficult to service with the engine oriented that way, but would probably offer substantial handling improvements due to weight balance being better.

 

As mentioned, longitudinally mounted FWD/AWD cars can be a pain to work on... Audi in particular. Though I think that's just a general VW problem.

Insightful post though.

 

And superior ground clearance....

 

And don't forget best in class aerodynamic mirrors.
Come on Kris it's all about the mirrors nowadays.

I wish my 429hp V8 had aerodynamic mirrors.
RLXs are toasting me all day long.

 

No, the RL was a whole lot easier to work on than the Legend.

 

yah since it is easier to access pretty much anything.
But that should not be part of the decision making when making a car.

They should build cars to the best that they could within budget, not so they can have an easier time to fix anything under the hood.

 

^^ As an enthusiast I agree.

As a car maker they will disagree as warranty work costs the car maker.
Adding hours to more complex repairs due to design will cost the car maker significant $$.

 

We are the consumers, if they don't give us what we wanted since we are paying "Premium" dollars for it, we will go find someone else who will

Wait.. too late we already did as well as thousands of others.