0700700

I just spoke to my dealer about some changes to the m5 software, and he told me that with the latest version installed 22.01, m5 owners are able to perform a pseudo LC (very similar to the e46 m3 smg, and described by me before, also similar to 545i smg)

Basicall you gotta turn off the dsc, put in in s6, and make sure the car is completely stationary (otherwise it shouldnt work)... hold on the brake if necessary...

then release the brake and fully press on the accelerator... the car should rev up to 2500rpm and then launch....

does it work for you guys


Also something of interest for me: if you use m-dynamic mode instead of the full dsc, are you able to spin the rear wheels when you fully depress the gas pedal at start

thanks

JamesInLV

This "pseudo LC" is often known as "emergency launch." Basically, if the clutch isn't fully engaged, and you have DSC Off, if you slam the pedal down through the kick-down, it will rev up and drop the clutch between 2500-3000rpm. In S-5, you actually get a very controlled launch, with only a little wheelspin that usually clears within a second. In S-6, you can keep the tires spinning all the way up to the 1-2 shift. I don't know if this is special to the 22.01 software, but my car was built in April 2006, has not had the software upgraded/changed since I got it, and has this "feature." A few members on m5board have posted that the get the fastest launch from slamming the throttle down, backing off to about 80-90% to modulate wheel spin, then back to 100%. I just upgraded to wider rubber, and as near as I can tell, doing the launch in S-5 doesn't require any throttle modulation to control wheel spin, and switching to S-6 before the 1-2 shift should allow me to get the fastest launch times. The shift setting doesn't affect anything but the shift speed itself, so launching in S-5 would give me a more controlled (read: fast) launch from the line, and going to S-6 for the shifts should give the fastest times there.

If you try this in MDM, you'll go bunny-hopping. MDM doesn't kick in against the throttle very often, but against a launch like this it will cut the wheel spin and bounce the car.

As far as the real launch control, most people report having it available in one way or another. In my case, the car will seemingly do the launch from a start, but it's also supposed to automatically take care of the shifts as well, and it doesn't. The launch only drops the clutch at 1400-1600rpm instead of the Euro version which is 3000-4000rpm (depends on settings).

BetterMakeWay

Well...this is a nice feature. Get performance and protect the gearbox lots more.

Now who's gonna do some runs with the pseudo LC (timed runs) and then with full LC to see what's what?

0700700

thank you for the elaborate reply! But when i have test driven m5s.. one 2005, one 2006 spec, i was unable to replicate this so called pseudo launch.. thats why i thaught that the news was exciting, as my dealer stated that this feature is *finally* available

JamesInLV

Wow...so just maybe BMW gave us USA owners a special feature without giving us the true LC the Euro-spec cars get. For now, I can't give BetterMakeWay the comparison he's looking for because my car does not do a proper LC launch...even the USA spec neutered launch control. However, I'm running 305/25 r20 tires on the rear, and with that much rubber on the ground I can definitely hook up faster than stock and expect some pretty good "emergency launch" numbers when I finally get on the track. Looks like there may be an open track event next week out here in Las Vegas.