Ok I'm still wrapping up some business before I purchase my 911. I had it set in my mind that I wanted the C4S Since we live in California and we might want to take trips to Tahoe, light snow rain etc, and the 4 wheel drive could be useful.


Then I went to the dealer to test out stereo's and seats but what was more interesting and Confusing was that I liked the Base model suspension better than the PASM on the Cabriolet. Both 2 wheel drive


This is confusing because in the past, and being a novice 911 driver, I felt that the Base suspension was jittery, and that the S with PASM felt more planted. Fast forward a year or so, while driving on a straight but rutted freeway in sunny Cali', I felt that the PASM equipped 911 felt Generic, like it was artificial, and maybe not keeping up with the bumps. You know like not real time.


Then I jumped into the base and on the same route It felt more direct like when the wheel hit the bumps the 911 just lifted on it's respectable wheel and it rebounded normally, pretty usual feeling. Kinda, like not electronic, and more natural feeling.


This blows me away. my Butt meter might be out of whack


CAn these Demo S's feel a little jittery due to maybe rounded edge tires or is it the PASM i'm feeling?


Anyone experience anything about either suspension?

 

I would think you are very perceptive in that by definition, active suspension has to feel different or it wouldn't be active. My 2009 C2S had PASM and I never thought it was worth it (although I never tracked it). I've heard the 991 sport setting is much better for road driving than the 997. Personally I haven't missed it and my general philosophy in order build was to keep the car as light as possible and I think virtually every option will add weight as well as cost.

Were the tires on both cars the same brand? I would think that the general ride quality would feel very different with different tires.

ChuckJ

 

How much heavier is the PASM setup than the non-PASM setup? With the "active" mechanism being valving that allows fluid to flow differently inside the shocks to change the rebound timing, I find it hard to believe that the weight difference is substantial. I also think a difference in tires would have a great effect on the perception of ride on a rough road. The OP did not mention if the wheel sizes were the same or what brand the tires were. Most higher performance tire are stiffer than less high performance tire for example, as they are optimized for handling rather than ride smoothness. Even simple variables such as inflation pressures could more than explain differences in ride feel.

 

They were both DEmo 911's and had the 20 inch Carrera wheels with the Stock rubber that comes on them from factory.


Aside from the rubber being more or less worn on either car, does anyone with the Base Suspension have insight to how their cars drive with respect to feel?


Generally speaking, would the active suspension give a driver better feel than a base setup or would it be opposite?

 

If I understand PASM correctly, there is really no way for it to feel "electronic". A selenoid allows fluid in the shock to take a path that generates faster shock rebound (pushing down the suspension at a faster rate) at one end of the spectrum than the other. The "feel" should be more stiff, less springy than a non PASM shock setup when that happens. At one end of hte PASM range, having the tire push down to be in contact with the ground faster should feel a bit "harder", but the handling feel should be "more secure", and at the other end it should feel less harsh. Another way to look at it is that by doing what is needed for a given situation, it should not have the compromise built in that the non-active shocks have.

 

I would imagine the sensor calculation and shock induced response happens in milliseconds. This would make it hard to "feel" instantaneously.

 

Yep, not a lot more weight. People should drive it and see if it's worth the weight (whatever it is) and cost. It certainly is a neat technology and drives much better than the 997 variant. I completely agree with the tires.

ChuckJ

 

You really should go try one where you can make a judgement of this one for yourself. I did, found it better than my 997 but still decided not to spend the money for the driving style I do.

ChuckJ

 

whereas only Pirellis were approved for OEM 20 inch factory fitment previously on the 991 , I believe Good Year is also now an approved factory fitted 20 inch tire..the same GY tire model that has been used on the 19 inch factory fitment from day 1
you might check to see if the two cars had same brand of rubber ...also , bring a tire gauge and see if base and PASM cars have equal pressure ...even 5 lbs either way makes a huge difference ....I've seen cars on lots with up to 45 lbs , maybe so as not to get flat spotted if sits for a long time or just PDI prepping sloppiness

 

Maybe one of the cars had PDCC? Check that first.

 

I didn't see this mentioned yet... tire pressures can play an enormous role in the "feel" of the different cars. My car feels completely different if I drop the tire pressure 5-7psi. You may want to consider that.

 

PASM would not make it feel distant, however PDCC could. I have driven both and while the PDCC car seems to ride better and remains flatter in the turns, I think it has kind of a distant feel.

 

a) This whole "test" would vary depending on which mode the PASM was in, normal or sport. Please clarify.
b) It is unfair to compare a coupe to a cabriolet. There will be more chassis flex in the cab, which directly affects suspension.

 

Their won't be much of a diff in flex in normal driving conditions. The Cab has less flex then by 335i hardtop convertible did with the top up.

 

I would try both again.

When I was testing out the seats to decide which ones to go with. I swore that the basic 4 way seats were the most comfortable. When by definition we know that the 14 and 18 way can be configured to be the exact same as the four way. Not sure if this applies, but I would try both again.