NA top speed limiter

[m3f_Sirius_880bd69485]

The wheel speed sensors are only for ASC and ABS. You can disconnect your wheel speed sensors and your spedo still works. You just get an ASC light come on your dash . If you disconnect the speed sensor in the back of the diff, your spedo cuts out, but abs and asc still function.

[m3f_WD Pro]

They must be pretty accurate on the Euro (unless I just have one with minimal error), at and indicated 90mph my GPS showed 88.



This was with worn rear tyres, in theory with new tyres it should be more accurate due to the increased circumference.

[m3f_98technovlt]

Well, looks like there is a "fudge" factor after all....Here is the response I received from BMWNA Re: spedometer error.



"Thank you for contacting BMW of North America, LLC regarding your speedometer. There are many variables that affect the accuracy of a speedometer. Among these are tire circumference, tire pressure, vehicle speed, as well as, inherent mechanical tolerances. In order to ensure your speedometer is not giving you a false reading below the speed your car is actually traveling, calibrated allowances are made for speed variables. They can accumulate and result in a reading lower than actual vehicle speed. A positive tolerance is, therefore, built into this system for your protection.



I hope this information is useful. If you have any further questions, please respond to this e-mail or contact the Customer Relations and Services Department at 1-800-831-1117, Monday through Friday from 9:00 A.M. to 9:00 P.M., Eastern Standard Time.



Sincerely,

Karen Labatzky

Customer Relations and Services

Representative"



I sit corrected!

[m3f_Sirius_880bd69485]

I love how politically correct they sound lol. Can't they just say 'Yes or no'?



Sure you have seen this.. but check this out, look at the difference in the electronic reading to the dial reading, the electronic reading starts to fall behind as the speeds get higher, suggesting a percentage



http://www.e46drivers.de/msm/video/m3be.mpg

[m3f_norris14]

Love the video....just compared my OBC with the speedo at 120 and got 116. So, not too bad. I'd say when I was doing 140 that it was around 135.

[m3f_Brent_Vino]

in that video, that car sure is slow... it takes 6 seconds or so just to hit 60mph.

[m3f_Sirius_880bd69485]

He had a bad launch and caught the dsc, which cut power. Thats why.

[m3f_gimmeone]

Took a ride to Vegas from SF a few months ago. You do need 6th gear on this trip. I was at redline right around 150, so dropped it to 6th, and it pulled way harder than I thought it would. I let off at 160. I have been thinking that either the speedo is off, or there is no speed governer. My car is bone stock, SMG with 18s, only change is a set of SO3s. Does anyone know if these cars really have a governer? dont need anyone to tell me this was stupid, thanks.

[m3f_Titanium99]

E36 M3s are speed restricted at 137 mph from the factory, and E46 M3s (along with 540i Sports and M5s) are speed restricted at 155 mph. I've been present for several on-the-limiter excursions in various BMWs. Unlike American cars where fuel shut off occurs and the car falls on its nose (try passing someone in a pre-2003 Tahoe/Suburban and hit about 98 mph for an example), BMWs will let you exceed the limiter and then incrementally bring you back to top restricted speed. It's very subtle and smooth. The E36 will let you touch 142 indicated and then walk you back down. The 540i Sport will go just a touch beyond 160 indicated and bring you back down to 155. We spent quite some time on the limiter of a 540 during a long road trip to CA once. Incredible cars, all of them.



I had never before considered why they let you go over, and then bring you back down. Perhaps it is attributable to speedometer inaccuracy at those speeds. All I know is what I've felt. Incidentally, the 5 series cars are absolutley stunning at triple digits. They feel as tight and secure at 130 as at 75. You pick up alot of A-pillar noise as you run past 140ish, and then the sensation of true speed is pretty apparent beyond that as the car begins to handle differently.



While not advocating everyone to run out and knock off 130 on the way home tonight, you do get a much higher appreciation for these cars when you have driven or ridden in one at speed and realize how much engineering there is to make them reliable, quiet, and useful daily drivers and still execute incredibly poised high speed runs without fanfare or drama.

[m3f_Flybry07_aa2e46014a]

Does anyone know what the real reason for the top speed limiter is??



Why is a e36 M3 137mph but most newer BMW's are 155mph?



I thought at first it was due to tires and speed ratings but my M has the same pilot sports as the e46 M's





C5 corvettes run right to 170ish and most porsches have no limiters at all (and many other makes)



It just dosent make much sense to me, if its a liability/safety issue then why not just limit it to 100mph or even 80 or 75????



I was also thinking that maby certain car makers decide that is the top speed their vechicle can safely travel based on aerodynamic and handeling traits of that vechicle. For instance a GT3 porsche is obviously more areodynamic than most BMW's so that would make sense why it can go all the way to 190ish with no need for a limiter.



It really makes alot sense to me why a SUV has one though, a jeep cherokee at 90mph is one sketchy ride!!!!!

[m3f_Sirius_880bd69485]

US laws. They don't want insane speeds like they got in Europe... prob afraid of massive accidents, and 100 car pileups cause some guy going 200 mph flew off the road....



Then again, doesn't Europe have the same accident rate as the US.. maybe less? :hmm:

[m3f_Titanium99]

I think the limiters have more to do with being German cars than US laws, as evidenced by the fact that cars like the Corvette, Camaro SS, etc do not have speed limiters (some Camaro convertibles did but only because of the speed ratings of their tires). Many German cars are limited. Several high line models by BMW and Mercedes have the 155 limit, while other midrange models like the VW turbo 337 have the 137 limit (despite having Pilot Sports from the factory). I thought I read somewhere that it was a German restriction. The caveat there is that I've never heard of a restricted Porsche 911!