[Exce]

I am not a gear head, so I only know what I have read online about how engines work. My scenario is this: You are in first gear with a manual transmission, you speed up to 8 mph then immediatly let off the gas. The engine starts to slow down the car. Now if I bearly push the gas down, the car will lurch forward from the state of being slowed by the engine, to the state of the engine accelerating the car. If I continue this method of letting off the gas and gently pushing the gas down, the car will bounce back and fourth between the two engine states, such as when we are in a really back traffic jam and theres no choice but to do this.

Okay if you are still with me, then my question is: What is happening in between the car accelerating with the pedal pushed in, and then letting off the pedal and the engine slowing the car? What is that neutral zone between the two engine states? What is being connected or disconnected in the drivetrain? Also I should mention this only happens at low RPMs, at high RPM's this neutral zone doesn't seem to exist. At 4000 RPMs, going from 0% pedal to 20% pedal doesnt make the car jump a round as it does when you are at say 1300 RPMs.

It seems to me that the only way to make this neutral area of discomfort go away, is to use the clutch at lower RPMs, then it provides a smoother ride.


Thanks for trying to understand this.:notallthere:

 

[dodgetime]

at low rpm's what you experience and what you are hearing is the slack inherint in the drive train,clutch,driveshaft ujoints and the differential all have a bit of backlash at low rpm it will be evident and can cycle making noise and the best way to get control it at slow mph is to push the clutch in to let the forces relax. At high rpm the slack is not evident due to centrifigal forces on the drive train. Every manual trans from model T to present will act this way

 

[bwbike]

^^^^^^^
What he said; plus, the clutch has stiff springs built into it to help it engage it smoothly. Once you start the car bucking, the clutch springs can make it worse.

You don't notice drivetrain lash on an automatic car because of the fluid coupling (torque converter) which absorbs most if not all of it.

 

[Exce]

^^^^^^^
What he said; plus, the clutch has stiff springs built into it to help it engage it smoothly. Once you start the car bucking, the clutch springs can make it worse.

Ha, car bucking. Thats the best way to describe it. Thanks for the reply guys, that what I was looking for. I wasn't sure if most drivers ride the clutch in this situation or not. It seems like a good way to burn up your clutch in traffic, but its probably wrose on your drive train to make the car constantly buck. Just my guess though.

 

[shadowmelder]

Sounds like this is your first manual (correct me if I'm wrong). Getting on and off the gas pedal is a privilege reserved for automatics. You have to be smooth with the gas pedal and try not to let off the gas completely so there's always a "load" on the drivetrain. Consistency is key.

Then again, I find the drive-by-wire makes it hard to be consistent and exact. In my experience, I haven't been able to make it recognize the minute changes in pedal distance needed to make a manual truly smooth.

 

[deezlman]

I agree with slipping the clutch a bit. Trying to leave it fully engaged at very low speeds is uncomfortable to say the least.

When practical, I choose to stop and wait until the traffic ahead has moved some distance instead of trying to take up every 4 foot gap. You'll see truckers do this. They hate it even worse than we do.

Stop and go is tough on your drive train, your fuel mileage and your NERVES, so increase the cycle time whenever you can. You can then take up the greater distance with the clutch fully engaged, stop again and put it in neutral if there's time.

 

[Exce]

Sounds like this is your first manual (correct me if I'm wrong). Getting on and off the gas pedal is a privilege reserved for automatics. You have to be smooth with the gas pedal and try not to let off the gas completely so there's always a "load" on the drivetrain. Consistency is key.

Then again, I find the drive-by-wire makes it hard to be consistent and exact. In my experience, I haven't been able to make it recognize the minute changes in pedal distance needed to make a manual truly smooth.

Definatly not my first manual. I drove a manual Dodge Ram for 8 years prior to this one. It was a v6, and while the slack was there, it wasnt nearly the same as in this high powered engine. And also the truck wasnt drive by wire.

 

[homerzeppelin]

In stop and go, I like to take off then immediately throw it into neutral until it is time to stop.

You can make it go VROOM that way.

 

[bwbike]

. . . I find the drive-by-wire makes it hard to be consistent and exact. . .

Yes, the drive-by-wire certainly makes it more difficult to drive smoothly when just creeping along under 5 mph. Actually, it's quite annoying since you give it some pedal input--nothing happens--and then the computer gives it too much gas.

Too bad there wasn't such a thing as a throttle cable kit. I'd buy one.

Unfortunately, the cars today with the ESP, throttle retard, and computer controlled cruise control, the days of a throttle cable are gone.

 

[shadowmelder]

Definatly not my first manual. I drove a manual Dodge Ram for 8 years prior to this one. It was a v6, and while the slack was there, it wasnt nearly the same as in this high powered engine. And also the truck wasnt drive by wire.

D'oh! Sorry about that. Well, you can still try not letting off the gas 100% and keeping a very slight pressure on the pedal. Just enough to keep the driveline engaged but not enough to overcome friction and have the car speed up.

Too bad there wasn't such a thing as a throttle cable kit. I'd buy one.

Unfortunately, the cars today with the ESP, throttle retard, and computer controlled cruise control, the days of a throttle cable are gone.

I wish I could get one too; I'd trade all those things for a cable throttle... then again, I'd give those things away for nothing.