Just a teaser for now. I just got my car back from the dealer and I will do a full write-up tonight.
Here's how she looks:
Here's how she looks:
Some more detail here if you can:1) Crispness of Turn-in response
thanks for the comments so far...
View attachment 308539
okay, before i get into my review i need to supply some background:
my car is not stock!
1) i swapped out my 19" msport 351m wheels and goodyear ls tires for 19" bbs rgr wheels and michelin pilot super sport non-rft tires.
What did this do? It trimmed 71lbs of unsprung weight, improved my grip, improved my road feel, lightened the my steering, and softened the ride. This was a significant improvement in the overall handling nature of the car.
2) i added dinan s1 and then s2 software
what did this do? It knocked my 0-60 down to 4 seconds and my quarter mile down to 12.5 seconds. But there was a downside, my car would suffer from significant squat during hard acceleration, which if in a turn (like pulling into traffic) meant i had to actively manage my power to control the understeer.
3) i swapped out my summer wheels for even lighter winter wheels.
What did this do? It help me draw a much needed conclusion, the stiffer winter tires firmed up the ride a bit, but it really isolated the softness of the springs when under full power, so i needed new springs.
so why am i sharing all of this history, which is already known my many here at bimmerfest? Because these mods exist working together on my car and i cannot predict how this set of springs will feel on a car with a different set-up.
So first i will start with mrs dunderhi's comments:
1) well that was undramatic!
this occurred just after i told her to brace herself right before i did a high speed emergency lane change maneuver.
2) i'm not sure what's it's going to take to brake the back end loose.
this was said after exiting a section of very sharp twisties (15 mph bends at ~45mph)
3) i'm going to need more places to hold on to!
this was said while on my favorite road with a number of sweeping bends and a chicane or two. Yes, we took the long way home tonight.
hmm, need i say anything more? I think mrs. Dunderhi has said it all. :d
okay, maybe some qualitative observations. As side note, my car is equipped with ddc and ars.
dive - reduced in all modes, but to be honest i really didn't make a big effort to get a feel for dive this evening.
squat - one of my biggest annoyances after getting dinan software. The back-end hunkered down and the front end lifted up. It's still there to some extent in comfort mode, but pretty much disappears by the time you get into sport mode.
roll - decreased in all modes, sport mode is incredibly flat in the turns.
stability - well, this means different things to different people, but i can say with confidence, i took some turns faster than i ever have and the car behaved as predicted.
responsiveness - my lighter wheels really upped my steering responsiveness, but the new springs decreased the plow that i experienced in hard turns.
emergency maneuvers - (professional driver on a closed course. Do not attempt.) i did do some sharp s-turns (think slalom testing) at highway speeds and this is one place the car's mass cannot be overcome and the momentum of the rear end of the car could be felt lagging behind the maneuvers. It was still under control and surpassed the previous setup.
turning - since there are several turning questions, i did take on a couple clover leafs at speed, and the level of control is much improved, to the point i felt comfortable accelerating while in the cloverleaf.
ride height reduction - i can't see it or feel it. The gaps in the wheel arches are about two fingers.
compliance - i lost a good bit of pothole absorption capability, so my car feels more like it did when is was equipped with rfts.
so how does this affect the driving modes of the car?
i originally had five modes for my suspension:
1) dsc inactive (pogo stick mode) - absolutely horrible! Each corner of the car moved independently in the vertical plane.
2) comfort (lincoln mode) - unacceptable! The front and the back of the car moved independently in the vertical plane.
3) normal (large sedan mode) - acceptable for cruising. The car was okay under non-performance circumstances.
4) sport (my normal mode) - good for a sport sedan. Has what it takes, unless pushing it hard under full power.
5) sport+ (hold on mode) - good for relieving stress. Didn't seem to make anything much better, just faster!
i now have five new modes for my suspension:
3.5) dsc inactive (old normal mode) - wow! If this was to only mode, i'd think most people would be okay with it. Some lean in the turns, but not that bad for normal use.
4) comfort (old sport mode) - double wow! This feels like a sport sedan! It doesn't cushion the blow as well, but it's no longer a buick!
5) normal (new sport mode) - just how i like it - most of the time. This might be my new default for the commute.
5+) sport (super sport mode) - just how i like it when i want to make the tires sing and that's what they did on tight cloverleaf today.
5++) sport+ (i'm must be afraid to try it mode) - i didn't even think to try this evening, the other modes had what i was looking for.
My perceived differences between the modes are much smaller now, hence my numbering scheme.
on the negative side, i think i have paid the most for labor thus far @1,250 + $180 for an alignment, so maybe i'll buy one less $400 flashlight or something like that. Also, unlike what my pseudo sa originally claimed, bmwss doesn't offer a bmwcca discount on non-bmw parts. At least when i would take my benz's in for service next door, they would say it was $500 or something like that and then take 10% off to make me feel good about them fleecing me.
Finally, in my opinion, if you get dinan or any other performance software for your 550, you should really consider having a firmer suspension setup to deal with the additional power. Tell your wives it's a safety issue. :thumbup:
P.s. I hit a thousand words in a single post! I must really like these springs. :roundel: