Last post on Feb 16, 2013 at 11:05 PM
You are in the BMW 5-Series
What is this discussion about?
BMW 5 Series, Sedan
#8822 of 12737 Enjoy the Car "As Is"
May 01, 2004 (7:39 am)
diver110... LSD = limited slip differential. On BMWs, it is only available on M3 and M5 (standard on both). LSD used to be available as an option on pretty much all BMWs built before around 1993.
LSD is an acceleration enhancer. It helps both off the line as well as while accelerating in corners. With an open (i.e., non-LSD) differential, power goes to the wheel spinning the fastest. So if a wheel is just spinning (say on ice) that wheel gets all the power (which is thus wasted). Wheels spin at different speeds while cornering.
540ia means a 540i with automatic transmission ("a" = AT). This is just an identifier that people use. BMW doesn't actually label their cars with an "a".
The Sport Pkg gets you the Sport seats, the 3-spoke M-steering wheel, shadowline trim, 3.15:1 differential, high performance summer tires, revised suspension set up, etc.
If you have a 540ia Sport, I would NOT spend $8K just to get a Dinan differential. I'm not a big fan of expensive mods, even Dinan ones. Though Dinan are some of the best.
#8823 of 12737 Driver110
May 01, 2004 (7:53 am)
For the E39s there were 3 different 540i models, the "A" is used to indicate an automatic transmission. Typically folks refer to their cars in the following manner:
540iA -- Base 540i with an automatic transmission
540iA SP -- 540i with the Sport Package and the Automatic transmission
540i6 -- 540i with the 6-Speed manual gearbox and the Sport Package
As for LSD, that stands for "Limited Slip Differential", which is a rear end that drives the wheel with the most grip as opposed to the default setup that drives the wheel with the least grip. As for the mechanical method to achieve this, there are at least two or three methods that I have read about over the years, and basically it is a marvelous arrangement of gears and clutches.
Regarding how the Dinan 3.45 rear end is able to increase power by 10 percent, it is quite simple, the higher the axle ratio is, the faster the engine spins in any given gear at any given speed. It's just like driving around in a slightly lower gear all of the time. Hmmm, $8,000 for the 3.45 LSD? Ouch, that's a bit steep.
#8824 of 12737 Seems that Riez beat me to the punch. ;-)
May 01, 2004 (7:54 am)
#8825 of 12737 Re: This and That [riez #8820], 3.45 differential
May 01, 2004 (8:36 am)
Riez, Yes, I got the sport package. Actually, I thought the "A" in 540iA stood for that, is that right? What does LSD stand for (I assume you are not talking about the hallucenogen)? So I do have the 3.15 differential. I was thinking in terms of the Dinan 3.45 limited slip, which they say gives a 10% across the board torque and horsepower increase. I don't fully understand how "limited slip" works, however, or how it increases power by 10% other than somehow it transfers power to the wheels more efficiently. I would appreciate any feedback you or others can give in this regard. The Dinan 3.45 ain't cheap BTW, around $8000 with labor.
#8826 of 12737 Hey Riez...
May 01, 2004 (8:45 am)
...I guess we both forgot to switch off our cloaking devices.
May 01, 2004 (10:48 am)
Dropped the machine off for service, needing Insp 1. Did 28.5K before the indicator came on, and aboout 600 miles since then. Ironically, on the way to the dealer this morning the brake light (service indicator, not failure) came on, so I guess 30K would be about what my location and driving style gives as a brake life expectancy. Does that sound low/norm/high considering the amount of city driving this car does? I know that in the past I have gotten significantly less than that from the front end of nose heavy front wheel drive cars, so I am not unhappy, just curious. At 30K a year I should probably establish a good relationship (between dealer oil, filter changes etc) with a good independent shop, since I will be out of warranty around the time the machine is 2 years old.
#8828 of 12737 Ultimate DRIVING Machine?
May 01, 2004 (10:48 am)
Folks, I'd like to have a conversation about something that struck me today; Dropped the 5 off for service, picked up the loaner (2002 325 auto, touring, with step), and took it down one of my favorite roads just to see how it felt. So here is my question: Are our cars overengineered for real "driving?" Don't get me wrong - I love my 540, and also see most of the technology as a good thing, for safety, convenience etc. I will also agree that something like rain sensing wipers (as posted previously) can be seen as a plus, removing a distraction from the pure act of driving. However, I sometimes find myself wondering if the fact that my car has enough technology to correct most of my sins electronically, or to beat them to submission (gumball tires, no drift allowed) has in some ways diminished the driving skill, or driving pleasure. Again, I am not saying that I don't appreciate the safety advances etc. Let me give examples of what I mean. 20 years ago, when I rode motorcycles, my Kawasaki KZ1000 was a pretty impressive bike, and no one ever really wrung one out. Now you can buy off the shelf crotch-rockets that would blow the KZ into the weeds without breaking a sweat. Very few riders even come close to really exploiting the performance envelope. When I go on vacation I rent something like a "Mexican Porsche" - a woefully underpowered VW convertible, skinny tired, 4 or 5 speed manual, maybe power brakes, but a hoot to drive... and you practice your shifting, you have no ABS, and you think about your next pass, or how to get out of the way of people who can pass . I think we are coming pretty close to "The Ultimate TRANSIT Module" and i am not sure if that's a good thing everyday.
#8829 of 12737 Re: Just bought 2001 540ia [diver110 #8815]
by kyfdx HOST
May 01, 2004 (12:16 pm)
Congratulations.. boy, when you said you were thinking about trading, you weren't kidding.. I wouldn't waste money upgrading the rear differential... You won't get anything out of it come trade-in time, and only a little out of it in the meantime. Enjoy your "new" car!!
#8830 of 12737 Re: Ultimate DRIVING Machine? [ny540i6 #8828]
by kyfdx HOST
May 01, 2004 (12:20 pm)
The "ultimate" intrusion to the driving experience is DSC. I have no idea how fast my car will go through a turn, and really don't have any way of finding out with the DSC turned on. All of the cues you were used to getting are gone and replaced by a flashing amber light on the dash. The only thing you have to rely on are your eyeballs and the rising G-forces.
I'm not sure this is a bad thing... I'm not even sure how I feel about it..
#8831 of 12737 Re: Ny540i6 [shipo #8818]
by kyfdx HOST
May 01, 2004 (12:24 pm)
shipo... I follow a few other 3-series forums besides edmunds and I read a lot of complaints about noise from the Yokos... Not at first, but after about 7-8K miles. The new favorite tire other than the S-03s seems to be the Goodyear F1 GS-D3. A little cheaper than the Bridgestones.