Topic: 6.9 top speed

[raueda1]

Today was a big day.  I decided to go on a desert highway joyride and see how fast I could go after all the endless work.  To my amazement the old girl managed a real 140 mph!!  [GPS verified]  She might have even gone a tiny bit faster but my testosterone reserves were depleted and I backed off.  But I do think that's pretty amazing.  This was altitude so at sea level maybe it would have done a little better, or at least gotten there faster.  This episode conclusively proves to me that it's as good as can get per my "declaring victory" thread.

But....  at 140 the tach was exactly redlined.  I guess that's as it should be given gearing, MB specs on the car, etc etc.  Yet there were numerous press reports of the car doing better.  Somebody reported even 150 mph if I recall.  So I can only assume that this means that the car was being pushed past redline.  How bad is that to do?  I don't plan to try it, just curious.  Cheers,

[John Moore Jr]

Being a ‘76 Euro 6.9, I am thinking your redline should be 5k RPM. If I am not mistaken, it was a model year change that increased the redline on the tachometer to 5300 RPM. My #142 6.9 is supposed to have the 5k redline, whereas my Dad’s #4630 has a 5300 RPM redline.

We’ve taken that #4630 to redline at 5300 RPM, it came out to be around ~145 mph.

Hope this clears something up.

John Moore Jr. 

[daantjie]

Man if I try that here its bye bye Benz for me   cops here do not have a sense of humour...
Nonetheless that's quite a feat, nicely done

[ptashek]

Sounds about right for a 6.9. Isn't the official max about 150mph?

For comparison, I've topped 137.9mph (222kph) on the Autobahn in my standard 450SE, with some room to push harder still, but I've ran out of free road at the time. The official max is 130mph.

Driving these cars at such speeds is quite an experience...

[Squiggle Dog]

Wow! It's nice to see what your car is actually capable of with your own eyes. I had my 300SD up to about 100 MPH briefly on a Utah highway where the speed limit was 80 MPH and traffic was flowing pretty fast. I didn't feel like I wanted to continue at that speed, but it was interesting. Oh, and yes, that was with GPS because my speedometer only goes up to 85. Haha. Apparently the new SSC Tuatara supercar can do 316 MPH; that's just stupid.

[rumb]

Last weekend drove the CLS550 to the far NE corner of Nebraska where the elevation is 4000' lower.  Car accelerated much faster!  Did peg 133 on a very empty road which is rev limited top speed. Maybe someday chip that car and remove limiter.

[raueda1]

Fun and interesting! I forget to mention one detail, however, and that unclarifies a bit.  The car is a Euro, #923, BUT my instrument cluster is from a 1977 or 1978 USA car (not sure what number).  The "new" tach redlines at 5000 as noted above.  I swapped because the USA speedo was spot-on accurate and the light dimmer worked.  Just now I went to the garage and looked at the the cluster that came in the car.  Guess what?  5300 redline!  Another difference is that suspension light on the older (?) cluster is just red.  There's no cute little logo of the up/down car.  It's the only 6.9 cluster I've seen with no suspension light logo. I assume that it's original, but we all know how that goes.  John, what's the suspension light on your #142 car?  Any logo?  Seems like maybe there's also a Euro/USA thing in the mix as well as just age.  Anyway, at lower altitude I have no doubt that the car would get to 5300 rpm and 145 mph. 

Still, I wonder why the redline difference and the thinking behind it all.  Cheers,

[John Moore Jr]

The suspension light on #142 is the little car and arrows. It is the same on US #4630. The speedometer and tachometer has been changed in #142, they’re dated 1978 I think. It still has the Euro gauges though. Temp, Oel, etc.

[raueda1]

The suspension light on #142 is the little car and arrows. It is the same on US #4630. The speedometer and tachometer has been changed in #142, they’re dated 1978 I think. It still has the Euro gauges though. Temp, Oel, etc.

Seems like I have a weird suspension light.  Wonder how that came to be? 

[slfan]

Dave,

Very nice run.  Good to know.

Regards