Mercedes-Benz Forum banner

41 - 49 of 49 Posts

·
Greek God of the R129
SL500-500SEL-190E
Joined
·
8,371 Posts
Has anybody questioned,
why they start with second gear, and didn't come with limited sleep diffs?

Regards,
aam.
 

·
Outstanding Contributor
R129 500 SL 1991
Joined
·
917 Posts
LSD was an option instead of ASR, but it was very rare.
Performance times are based on mashing the throttle (kick down) in Drive. Quicker times can be elicited by forcing the transmission to start in 1st, but I would question whether this approach, if adopted persistently, could eventually damage the transmission.
 

·
Outstanding Contributor
R129 500 SL 1991
Joined
·
917 Posts
Has anybody questioned,
why they start with second gear, and didn't come with limited sleep diffs?

Regards,
aam.
Hi Albert, I suspect you know the reason? You’re going to turn this on it’s head? ha ha 🙃
Why they normally start in second gear? Comfort? To waft along without fuss? Tradition?
I am intrigued. :unsure:
 

·
Outstanding Contributor
'03 SL500, '03 SL55, '97 SL320, (2) '91 300SL, (2) '91 500SL, '00 S500 -- all for sale
Joined
·
4,212 Posts
The M113 pulled more g within a very limited rpm range...
M113 peak torque is quoted at being output from 2700 to 4250 RPM. If you compare the power curves for both engines below 3500 RPMs you will see that the M113 makes considerably more power/torque, and this is why an M113 car is more responsive accelerating from rest. The M119 has an advantage from c. 4500 RPM to 6000.

Has anybody questioned, why they start with second gear...
Mercedes cited two reasons: fuel economy and reducing "idle creep" and the added brake pedal pressure required to hold the car stationary with a 1st-gear start. As an aside, the 1st-gear start circuit I have eliminates creep by delaying the shift from 2nd to 1st to the moment the brake pedal is released to accelerate -- the car is in 2nd while being held by the brake.
 

·
Greek God of the R129
SL500-500SEL-190E
Joined
·
8,371 Posts
Hi Albert, I suspect you know the reason? You’re going to turn this on it’s head? ha ha 🙃
Why they normally start in second gear? Comfort? To waft along without fuss? Tradition?
I am intrigued. :unsure:
But if one is after faster times.
Like 0-60.
Wouldn't be a good idea to replace the differential, and maybe nothing ells?
Regards,
aam.
 

·
Greek God of the R129
SL500-500SEL-190E
Joined
·
8,371 Posts
Mercedes cited two reasons: fuel economy and reducing "idle creep" and the added brake pedal pressure required to hold the car stationary with a 1st-gear start. As an aside, the 1st-gear start circuit I have eliminates creep by delaying the shift from 2nd to 1st to the moment the brake pedal is released to accelerate -- the car is in 2nd while being held by the brake.
[/QUOTE]

You as usual correct.
But when Mercedes engineers a model. Is mostly for old mans comfort.
Not for spirited driving, and play....
Considering, weather conditions, in dry pavement, snow, ice?
The car on over 100 is a rocket. But on pushing turns?
Pushing the speed on a curve, at 25 may not be a problem, at 50 plus?
In my opinion the R129 will fishtail.
Maybe with couple bags of sand and a full gas tank...
But that will slow the times. :(
Regards,
aam.
 

·
Registered
97 SL600 Pano, ex: 96 (late 95) SL320
Joined
·
257 Posts
... only on part throttle. At 3/4 to full throttle, and at any point on the rpm range the 1991 M119 500SL will be faster than the M113 SL500.
I don't get this. Dyno test results indicate the full throttle output across the RPM range, not output at different pedal positions. So if the curve shows the M113 has more torque/power in the lower RPM range, it does so at wide open throttle.

I won't go guessing how that translates to acceleration in different situations in this particular case as I have little experience with the M119 and none with the M113.
 

·
Outstanding Contributor
'03 SL500, '03 SL55, '97 SL320, (2) '91 300SL, (2) '91 500SL, '00 S500 -- all for sale
Joined
·
4,212 Posts
If you look at the torque/power output curve for any engine it is with wide-open throttle, as juuso wrote. And below 3500 RPMs the M113 has more maximum torque/power.
 

Attachments

41 - 49 of 49 Posts
Top