Stick shift: when change gear? - PeachParts Mercedes-Benz Forum

Vronsky · #1 10-07-2002, 10:48 AM

To all owners of stick-shift models: am curious to know at what rev's you change gear? Myself change at ca. 4.000 rpm. Allows car to accelerate quick & smooth.

Cheers!

Piotr · #2 10-07-2002, 11:46 AM

Regardless of a car I'm driving, I always shift at the peak torque for the car (car "tells" me when to shift). Usually it's 500 - 1000 rpms before redline

pentoman · #3 10-07-2002, 12:44 PM

There's no specific point to change gear, but whatever makes the drive smoothest is generally the best way. I think changing up just 1000rpm before redline every time is a great way not to be smooth or sympathetic to the car... I hope that's only when driving quickly!

Not trying to be prejudiced here in any way, but Piotr have you noticed generally there are far more Americans who are inexperienced at driving manual gearbox cars and ask questions about how to drive them.. I guess as they're more common in Europe everybody learns them when they learn to drive, so it becomes completely natural

later

yal · #4 10-07-2002, 12:53 PM

Quote:

Originally posted by pentoman
There's no specific point to change gear, but whatever makes the drive smoothest is generally the best way.

later

Exactly! There might be an optimum shift point for your car, engine in a certain driving condition but shift points vary depending on all sorts of variables. The car and what you are trying to obtain from it performance wise and road enviroment dictates when you shift. Its not quite an exact science, thats what makes it fun

.

Jim Anderson · #5 10-07-2002, 03:34 PM

I shift when I get enough power, low when I'm not in a hurry or stuck behind some slow diesel

and higher like when I'm merging onto the freeway.

bobbyv · #6 10-07-2002, 06:48 PM

in addition to what TKamiya wrote:

* for smooth shifting, one has to rev-match on both upshifts and downshifts. For upshifts, the rpm at which you engage the target higher gear is lower than that when you release the previous gear.

This rpm difference between 2 adjacent gears varies linearly with rpm. For example, in my 5spd 190e2.6, if I release 4th gear at 6000rpm, I will have to wait for the tach to reach around 4900rpm for a good rev-match, a difference of around 1100rpm. If on the other hand, I release 4th at 3000rpm, I will need an engine speed reduction to around 2450rpm, a difference of only 550rpm.

Cars with sporting intentions, like the 2.3-16 or 2.5-16, have close-ratio gearboxes, which reduce the spacings between gear ratios for quicker shifting and keeping the engine in its sweet spot.

* one has to also take load into consideration. In high-load conditions, like going uphill, I would shift at a higher rpm, so that the rear wheels will have sufficient road torque in the next gear.

* in low-traction conditions (like in the winter), I don't want too much torque at the rear wheels, so I upshift at a lower rpm.

#7 10-10-2002, 10:26 AM

My shift points vary depending upon final target speed, and whether I'm running on level pavement. If I want to reach 40 MPH, then I usually shift at around 2,500 RPM out of first, with each subsequent shift at a slightly lower RPM level.

My shifts are ALWAYS a two-step process. Current gear to neutral, then neutral to next gear. Matching engine speed with next gear will allow your synchronizers to last forever. When upshifting to a shorter gear, I double-clutch by releasing the clutch while in neutral, and blipping the RPM up to match the anticipated gear. I rarely "skip" a gear, although I sometimes start off in 2nd if on a downhill.

I view shifting as more of an art than a science. I gain great pleasure from accomplishing shifts so smoothly that they cannot be felt in the seat of your pants.

Jim Anderson · #8 10-10-2002, 10:57 AM

When shifting, when I put the clutch in and close the throttle the engine revs stay up for a moment, they don't drop. Is this normal for this engine?

william rogers · #9 10-10-2002, 09:56 PM

Jim, don't have to worry about getting stuck behind my old diesel cause all you are going to see is disapearing tail lights.he he........
William Rogers.........

Limited Edition · #10 10-10-2002, 10:07 PM

allen,

When you double-clutch your 300E, does it sound like Steve McQueen in Bullit?

j/k I double clutch my 67 mustang but I don't need to on my 93 190E.

Regards,

Don

haasman · #11 10-11-2002, 03:22 AM

Don
'67 Mustang? Fastback? Pictures?

#12 10-11-2002, 08:54 AM

"When you double-clutch your 300E, does it sound like Steve McQueen in Bullit? "

Actually, with the double firewall and excellent sound deadening hood blanket, I can hardly hear the mechanicals of my 300E 5-speed. I usually just glance at the tach.

These cars have very long legs. At 80 MPH in 5th, it's putt-putting along at a measley 2900 revs.

The Getrag gearbox is a pleasure. Although the "throw" is a bit long, the gears are quite evenly spaced, and you get a definite "snick" when the gear is engaged.

What a great car !

#13 10-11-2002, 12:04 PM

I don't think anybody can say with precision when and how to shift . Like someone said, it is more of an art than a mechanical thing.
I have never ask myself '' OK now, is it time to shift or should I wait, or let's look at the tach, do I let it go for an other 1397RPM wait, no let's shift''. It has to be a natural thing, if you're in tune with the car, the road/traffic conditions, your next move, your right/left feet.
Just imagine a truck driver having to deal with 14/17 gears. Can you imagine his brain going through this motion.
Shifting in normal conditions has to be as natural as walking down the street.
JackD

Kestas · #14 10-11-2002, 01:52 PM

Ever driven an automatic?... The transmission is designed to shift at the optimum points for power and economy. The optimum shift points depend on engine load (required acceleration) and speed. Low for easy takeoffs...delayed shifts for heavy acceleration. An equivalent car with a stick should be driven the same way.

I've seen too many people "show" me how to drive a stick when they really just enjoy listening to a highly revving engine.

#15 10-11-2002, 02:14 PM

Hi Vronsky.

I've got a 300CE-24 with 5 speed manual box. and to be honest it depends on you driving style.

If you want to be smooth and not waste petrol/gas then at about 2,000 rpm but no above 3,000 rpm.

I've had mine close to red line at 7,000rpm and you can almost see the fuel/gas gauge go down.

Neil