Top Speed of 540i 6speed Ungoverned?
- Thread starter GTMAN
- Start date
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If you find your gear ratios and do a little bit of math you can calculate the maximum theoretical top speed in 6th gear.
However, in the real world, with an atmosphere, your top speed is going to be drag limited.
I would guess an ungoverned stock 540i/6 could do about 160 before drag overcame its power, and about 175-180 theoretical (maximum you could achieve with a stock rear end and stock gears, regardless of power).
However, in the real world, with an atmosphere, your top speed is going to be drag limited.
I would guess an ungoverned stock 540i/6 could do about 160 before drag overcame its power, and about 175-180 theoretical (maximum you could achieve with a stock rear end and stock gears, regardless of power).
Yeah...that too;o) Thanks for keeping me honest. The 540i has 282 hp...ok if you look at what the guy drives it says DINAN on it. Now I was under the impression that all DINAN conversions were 350+HP Mayhap I am mis INFORMED on that area.
BRAHTW8....INFORMED Speculation? The fact that I had my 530i with an I6 at 145 MPH with 3000+ rpm to go before red line is NOT speculation...its FACT
BRAHTW8....INFORMED Speculation? The fact that I had my 530i with an I6 at 145 MPH with 3000+ rpm to go before red line is NOT speculation...its FACT
![[?|]](/images/smilies/icon_smile_banghead.gif "Bang Head [?|]"){kind=icon}
Easy there, tool fan, I don't recall referencing you in my post.
Trust me when I say that my speculation comes from a base of knowledge, not information, and there is a difference. Again, I am not calling you out.
Consider that a stock E39 M5 is only going to hit around 180 mph ungoverned. The fact that you saw 145 indicated with 3000 RPM to go in your E60 530i does not mean an E39 540i can go 180 MPH stock. Your 145 indicated was probably around 135-140 actual, as most speedometers, including BMW, read a bit on the high side.
Your car has better aerodynamics than the E39, AFAIK, and the effect of drag really starts to mount around 140-150 MPH. I would also expect that 155 is getting close to the limit for your car, governed or not, and probably difficult to achieve. My 270 hp, several hundred pound lighter NSX is geared for low 180s, but can only hit 168 before the wind says stop. 911s with 320 hp. are only hitting 170 or so.
Shelby created the Daytona Coupe to address the top speed limitations of the original Cobra design. Despite the massive power of the 427, the original could not run more than 160 or so.
Trust me when I say that my speculation comes from a base of knowledge, not information, and there is a difference. Again, I am not calling you out.
Consider that a stock E39 M5 is only going to hit around 180 mph ungoverned. The fact that you saw 145 indicated with 3000 RPM to go in your E60 530i does not mean an E39 540i can go 180 MPH stock. Your 145 indicated was probably around 135-140 actual, as most speedometers, including BMW, read a bit on the high side.
Your car has better aerodynamics than the E39, AFAIK, and the effect of drag really starts to mount around 140-150 MPH. I would also expect that 155 is getting close to the limit for your car, governed or not, and probably difficult to achieve. My 270 hp, several hundred pound lighter NSX is geared for low 180s, but can only hit 168 before the wind says stop. 911s with 320 hp. are only hitting 170 or so.
Shelby created the Daytona Coupe to address the top speed limitations of the original Cobra design. Despite the massive power of the 427, the original could not run more than 160 or so.
![[thumb]](/images/smilies/icon_smile_thumb.gif "Thumbs Up [thumb]"){kind=icon}
Its all good. I am however in love with your NSX. I love those cars. Some dude in my "hood" has one. His speedo reads 320kms. That is damn near 200mph's (I am not nieve enough to believe it will go that fast). People are under the impression that the Autobahn is so great. Yeah you can drive fast...when no one else is driving. More times that not you are stuck behind some A$$hole driving 80mph's in the fast lane ![[boxface]](/images/smilies/icon_smile_boxface.gif "Box Face [boxface]"){kind=icon}
and it is illegal to pass on the right over here. So I only achieve high speeds late at night when there are few cars on the road.WOW Tool Fan, 145mph on your 530!!! Thats impressive. I have not even cracked 105mph with my car. For some reason I have this guilty concience kicking in at 100mph ![[nono]](/images/smilies/icon_smile_nono.gif "No No [nono]")
. I did end up calculating the theoretical top speed of my car and with the gear ratios, and pushed out rev limit to 6300rpm, it will do about 201mph. Environmental effects not considered of course. I figure in real life, it 540's should be able to hit 160mph in stock form. Thats good enough for me to know.....without the guilt.
. I did end up calculating the theoretical top speed of my car and with the gear ratios, and pushed out rev limit to 6300rpm, it will do about 201mph. Environmental effects not considered of course. I figure in real life, it 540's should be able to hit 160mph in stock form. Thats good enough for me to know.....without the guilt.Why have guilt? Car was built to travel at high speeds. Hence the high performance price tag. brahtw8 is correct. I got her to 148 maybe 150 and I could really feel the drag coeffient kicking in. Crazy 145 feels like still more balls to go....148-150 kinda feels like she was being held back by something. I can only assume it was drag as you were talking about. I have to wait a couple of weeks now to try it out again. My baby was rear ended on the Autobahn and is currently being worked on.
tool fan said:
Its all good. I am however in love with your NSX. I love those cars. Some dude in my "hood" has one. His speedo reads 320kms. That is damn near 200mph's (I am not nieve enough to believe it will go that fast). People are under the impression that the Autobahn is so great. Yeah you can drive fast...when no one else is driving. More times that not you are stuck behind some A$$hole driving 80mph's in the fast lane and it is illegal to pass on the right over here. So I only achieve high speeds late at night when there are few cars on the road.