GT Stall Prevention?

[ManBearPig]

I noticed by accident that these (GT if it matters) cars seem to have some sort of computer wizardry that prevents the car from stalling. Once I discovered this I noticed that you can engage the clutch without any throttle and even with the parking brake on, the RPM will only drop so far, and then actually rises back up even if the clutch is engaged even further. Now I don't like to make a habit of just burning up a clutch needlessly so I didn't experiment much but now I'm curious. First...is this normal for these cars? And second...how is it achieved? Considering the throttle is computer controlled, does the pcm just signal to feed more throttle when it detects the RPM dropping below X value? Lastly....can this be disabled? I've got the hill assist turned off, wondering if this is something that can be disabled, too?
Thanks

Sponsored

 

[Boosted5.0_NY]

I noticed by accident that these (GT if it matters) cars seem to have some sort of computer wizardry that prevents the car from stalling. Once I discovered this I noticed that you can engage the clutch without any throttle and even with the parking brake on, the RPM will only drop so far, and then actually rises back up even if the clutch is engaged even further. Now I don't like to make a habit of just burning up a clutch needlessly so I didn't experiment much but now I'm curious. First...is this normal for these cars? And second...how is it achieved? Considering the throttle is computer controlled, does the pcm just signal to feed more throttle when it detects the RPM dropping below X value? Lastly....can this be disabled? I've got the hill assist turned off, wondering if this is something that can be disabled, too?
Thanks

News to me if there is some sort of "computer wizardry" that would prevent the car from stalling. As far as being able to engage the clutch in 1st with no throttle and no stall - thats due to the low end torque of the engine. As far and not stalling with parking brake engaged - if you can place the car in gear, with the emergency brake engaged, and release the clutch without stalling - you probably have a problem with your clutch.

 

[BmacIL]

I noticed by accident that these (GT if it matters) cars seem to have some sort of computer wizardry that prevents the car from stalling. Once I discovered this I noticed that you can engage the clutch without any throttle and even with the parking brake on, the RPM will only drop so far, and then actually rises back up even if the clutch is engaged even further. Now I don't like to make a habit of just burning up a clutch needlessly so I didn't experiment much but now I'm curious. First...is this normal for these cars? And second...how is it achieved? Considering the throttle is computer controlled, does the pcm just signal to feed more throttle when it detects the RPM dropping below X value? Lastly....can this be disabled? I've got the hill assist turned off, wondering if this is something that can be disabled, too?
Thanks

Yes it's that way on purpose. It will only happen from a stop. The PCM will detect an increase in load at low or no throttle from a stop and open the throttle a little to allow you to launch.

 

[NoVaGT]

I've realized you can put the car in 1st gear, slow to idle, and just put along at 1MPH, with no throttle input. I'd say it's just the car making sure it doesn't stall, and adding throttle.

 

[hiccup]

Ive used this feature since day one. The throttle begins the rev by just by just lifting off the clutch a hair. And with the perfpack its enough rev to start off in second gear. Doubt there is much difference in clutch wear than if I was reving myself.

 

[Boosted5.0_NY]

Call it a feature if you like but it really boils down to the engines torque. My issue with the OP's comment is being able to engage the clutch with the emergency brake and not stall. Sorry but that ain't happening unless the clutch is slipping really bad.

 

[ForYourOwnGood]

News to me if there is some sort of "computer wizardry" that would prevent the car from stalling. As far as being able to engage the clutch in 1st with no throttle and no stall - thats due to the low end torque of the engine. As far and not stalling with parking brake engaged - if you can place the car in gear, with the emergency brake engaged, and release the clutch without stalling - you probably have a problem with your clutch.

Its certainly is a computer feature of some kind, although why it would be needed is beyond me. My ecoboost does it too as I recently found out trying to get my car up the driveway in a snowstorm. I thought it stalled and pulled the parking brake and it was still running with the clutch out at about 700rpm in 1st. I haven't noticed any negative effects on the clutch but I imagine it had to be slipping for a split second before I realized what was happening and recovered or it was powering through the parking brake which would need a lot of throttle input.

 

[ManBearPig]

Call it a feature if you like but it really boils down to the engines torque. My issue with the OP's comment is being able to engage the clutch with the emergency brake and not stall. Sorry but that ain't happening unless the clutch is slipping really bad.

I'm sure the car would stall if the clutch was completely engaged but I'm not going to try. This is not just the "lots of torque" effect. My powerstroke diesel 6 speed doesn't act this way and it makes more than twice the torque of the car. There is clearly some kind of computer aided anti-stall effect going on here. Just wondering if it can be disabled or tuned out. Not really a problem though do I guess this post is more an observation than anything else.

 

[Boosted5.0_NY]

My '04 Jetta TDI and '13 Jetta TDI both did the same. This is nothing new for manual cars and I wouldn't call it a feature. By design the ECM wants to maintain idle speed so it will try to correct in order to not stall. Again, not a feature, just basic design.

 

[BmacIL]

My '04 Jetta TDI and '13 Jetta TDI both did the same. This is nothing new for manual cars and I wouldn't call it a feature.

Except it is. One of my best friends used to do powertrain features calibration for Ford (now does drivability) and this is deliberate and is calibrated. New? No, but the engine doesn't just do that by itself.

 

[Boosted5.0_NY]

Except it is. One of my best friends used to do powertrain features calibration for Ford (now does drivability) and this is deliberate and is calibrated. New? No, but the engine doesn't just do that by itself.

Whatevs, call it a feature if it makes you feel good and sleep better at night. If you let the clutch out slow enough on a flat plane just about any manual car will do the same. Again, basic design.... Try slipping the clutch on a hill with no throttle and see what happens. The "feature" won't do squat and you will stall.

 

[Legionofone]

MLC Stang is right, it isn't any specific feature, the car just has a computer set min RPM, it tries to maintain that RPM. When you let the clutch out it simply opens the throttle a tad to keep its idle RPM.

So, while it isn't a direct feature it works as anti stall.

 

[BmacIL]

:doh:

 

[dogiebitt]

fun fact: if you're on the brakes, this is disabled.

When I was learning to drive manual, I kept holding the brake too long as I was releasing the clutch in 1st. It wouldn't keep the throttle open and I'd stall. As soon as I figured out that you can just let the clutch out without any throttle (but without brakes engaged), it was easy peasy.

 

[StephanPooter83]

Accidentally take off in third thinking you're in first and it will stall haha.

Sponsored