pgeorg

I was driving last week on 128 north right at the route 9 exits. They are a 2-3 big dips on the road, because they have scrapped some of the blacktop (construction). My speed was about 75-80mph, and the compression of the suspension while in the dip was very good. What did surprise me was the rebound behavior.....I think it was at full extension and at that point the rear end of the car wiggled. It felt like i was going to loose the rear end, but it was just the feeling i got. A split second later the rear end was planted and felt very secure. It did the same thing at all 3 dips, but again it was just the feeling the car gave me. I mean it did wiggle, but aside from that there was never any fear of loosing the rear end (i think). The rebound of the suspension on my 2012 TL SH-AWD never behaved like this.
Has anyone else experienced anything like this? Would this be because the rebound is not correct for the P-AWS, or would this be cause from the AWS?
I don't know if i explained this correctly, or even if it makes sense......
One thing i know is this suspension is extremely capable when driven fast, especially on a road like the Merrit Parkway in CT, and the Hutchinson Parkway in NY.

Thank you.

Limelight

I know exactly what you are referring to and what you're comparing it against - as I also had a 2012 TL SH-AWD before the RLX and feel the same way.

My wife is not an aggressive driver but even she noted the TL just felt more 'planted' than the RLX - in her words it really hugged the road. The RLX has more of a loose/floaty feel to it. I say that tongue-in-cheek though as I know it handles better than the average vehicle out there - certainly for a vehicle of the RLX's size. But I do know exactly what you're feeling and I've experienced it too.

Good news is your car isn't faulty - bad news is it is what it is

justnspace

iTrader: (1)

how does P-AWS work?
could it be that it was designed to do that?

pgeorg

Thank you CanadacuraTL! I am also glad you wrote the above statement, because my intention is not to bash the RLX suspension!

pgeorg

This will explain it much better that i can:
It could be, but i am hoping the older more experienced guys will answer that for us:-)

justnspace

iTrader: (1)

ahhh, the way it toes-in and out will have an affect on bumps, as im assuming that its trying to either toe-in or out at the same time you roll over the bump/dip.

RLX-Sport Hybrid

This I believe is unique to the PAWS version as the SH does not have active steering, just torque vectoring. I know what section of road you are talking about pgeorg and have to drive that way tomorrow so I will do the same 75-80 mph to see how the SH handles the rebound and report back. My guess is the fast unloading and reloading of weight on the rear suspension creates some strange angles in conjunction with the PAWS actuators. That has to be it because those are the only moving components other than the static angles created by the suspension geometry. What do you think? Does that make any sense? Maybe I'm wrong. I'm not an engineer.

pgeorg

Yes that is what i was thinking also, but i am also not sure. It does make sense, but i am also not an expert:-). In general the RLX P-AWS feels a little floaty-looser (compared to the TL) like Canadacura said, but that is the initial feel. As soon as the suspension gets a little "loaded", then it works marvelously! I am hoping that George will chime in, since he had both the P-AWS and the Sport Hybrid......he also know a hell of a lot more than i do about these things.......
I am very interested to your findings, so please let us know whenever you get a chance!

Thanks RLX-Sport Hybrid!

holografique

Yes, I have experienced this before on a very particular section of Atlanta (Where Roswell Rd. Merges onto Peachtree Rd heading southbound). There is a part where you hit about 3-4 successive bumps that match in size and are evenly spaced out, and it's on a bit of a turn. You hit that turn at 35-40mph and foot on the gas pedal, I feel the backend pop out a bit, just like you explained it.

I brought it up once before on another post and can't remember what George's response was other than to say "is that a bad thing?"

The one thing he did confirm in some other posts was that the suspension design in the RLX is shared between both model types (PAWS and SH). So our guess has been that since the PAWS is about 1000lbs+ lighter (due to the lack of the batteries and other components of the SH-AWD system), the suspension ends up being somewhat "bouncier" than it should be, thus further attributing to the "loosey-goosey" feeling you get going over just about any bumps. The chassis feels too light, and thus takes on an inordinate amount of energy transfer from what should be absorbed by the dampers and the suspension system. This is what I have always complained about when talking about the RLX suspension.

Everyone here thinks I complain that the ride is too "stiff" or "brittle" and that's actually not the case at all. I like the "stiffness" of Acura's suspension, of which I came to love on my 3G TL and is also apparent in the 2015 TLX. Sporty, but compliant. I've even mentioned it dozens of times that as long as you aren't going over bad road conditions, the RLX ride feel is amazing, laser accurate, extremely responsive, and super tight. I love it.

The problem I've always had with the RLX is when the vehicle hits bumps, it doesn't recover well when compared to EVERY other Acura I've driven. It either slams down excessively hard (unlike any other stiff suspension sports car I've driven) or it bounces around in a very sloppy manner, causing the chassis to jumble around like a bobble-head ornament. And it's extremely noticeable driving in inner-city roads.

pgeorg

I can see George saying that:-). I will try to not let him off the hook that easy this time:-).

Thank you for the detail explanation, I really appreciate it! I know that you have had the car much much longer that I have, so I make sure I always read what you write! I value your opinion highly!

George Knighton

It is a split second. It's ridiculously minor, like ⅛ second.

The problem is...it is within human perception, the time it takes for the event to initiate and the time it takes for the rear end to set its angle.

You get used to it, but you're right it's not like the experience with SH-AWD, and they're right it's not like the experience with the Sport Hybrid.

The tuning tries to make sure that you have as close to zero slip angles as possible; however, failing that, it tries to keep the slip angles as close to the same on all four wheels as it can manage.

If you've been driving front wheel drive cars for 20 years and then slip into a high powered P-AWS car, you'll swear that it is oversteering, and major automobile reviewers have gone to print saying that the car oversteers. That doesn't help the car's reputation at all.

But they're wrong. It's just trying to stay as close to neutral as it can, and people aren't used to a front wheel drive car that can do things quickly.

It's just that damned nagging little ⅛ second that you can just barely feel....

George Knighton

"Loose is fast."

pgeorg

Thank you very much for the detailed explanation George. Also thank you for putting it in words i can understand, and not making me go look up stuff:-)
When i first bought the car, i also thought that car was oversteering! I was trying to convince myself that it was just the feeling that P-AWS was giving, because of the way i had read it worked. You bringing this point up, makes me feel much better about my driving perceptions.....the driving dynamics of this car have puzzled me more than any other car I've owned.

George Knighton

The most ridiculously handling car I think I've ever owned, and one of the biggest automobile mistakes that I ever made, was a 1969 6.3 litre der Grosser Mercedes.

It had an air suspension that was made long before we had any kind of intelligent electronics to control such things.

So the end result was that when you went into a corner hard, you'd set the wheel angle required, and then like ½ second later the air suspension would take its set.

This would cause the car to change angles, usually by quite a bit.

Let's just say that counter steering in U's became a way of life. You didn't have any other choice if you didn't want to slow down...although it was work, it was still the fastest way through.

The car was slower in switchbacks and the Carousel because of this delay with the suspension. You'd only have to not make that third turn one time before you realized that you'd just have to bloody slow down and be slow there, and there wasn't any way around it.

A long U, though...that could be very entertaining if you didn't mind your wheels pointing the wrong way!

pgeorg

George, when you get a chance can you maybe point out a few more (if any) differences of the handling between the Sport Hybrid and the P-AWS?

Thank you!

RLX-Sport Hybrid

I have to say that I think the car (Sport Hybrid) is as planted as the best BMW M5 current or past has ever been. That is a big statement. The way you can position the car in a turn and know exactly what the tires are doing while maintaining extreme levels of balance and grip is physics defying. The car feels both substantial as its weight would suggest, but also very controllable at the same time as evidenced by the limited roll mid-turn. I can't speak to the PAWS for how it feels in the turns, but my assumption is the steering action mimics a rear bias weight and/or drive line feel. The exit from a turn and getting on the throttle earlier than one might expect is a benefit of the AWD function of the Sport Hybrid. That is different than the PAWS, but likely similar to any performance AWD car.

Did I mention this car is just awesome to drive? It has been a minute since I said that.