What Do You Call It When...

[StealthX]

I'm gonna venture a guess into that jerky feel you get when coming off the throttle in a manual...

I've noticed it heaps too, coast along in 1st gear with half throttle, then take your foot off the accelerator, and you'll feel a real jerky situation.

Not sure, but its something to do with your ECU turning off your injectors when there's no throttle input, then it upsets the gearbox and all the slack in the drivetrain (clutch, gearbox, diff, final drive etc.). The jerky feeling is the shock that by turning off the injectors, the engine is no longer turning the drivetrain and the wheels, but rather the car's motion along the road causes the wheel to turn the drivetrain and engine instead... The shocking back and forth is all the slack in the drivetrain being taken up and let off etc...

Anyone get my drift?

Edited October 29, 2009 by turbo x-trail

[stormtrooper]

I here what your saying X-trail, sounds very plausible. Best way to combat it is if you are coming completely off throttle in such a low gear, clutch in a little and problem solved. Because you are then no longer engaging the driveline

[Tony de Wonderful]

You've read it a few times and still didn't know what he was talking about?

How about you shut up now.

Yeah it's not to do with speed bumps as such or the jerky spaz clutch action that beginners/learners have.

I was thinking it may be something to do with my seat position also, like it's giving my leg/foot too much freedom (or something) to move back/fwd or up/down involuntarily?

What I am basically saying is...hit bump and G's force foot on throttle, car accelerates...acceleration moves weight back and foot lifts off throttle a bit, car then decelerates, weight moves forward and foot is forced on throttle...car accelerates moves weight back and foot lifts off and process repeats.

Like I said it's in 1st and 2nd mostly. If I'm in 3rd then there seems to be more a dampening effect, as the car doesn't accelerate or decelerate so much with the same throttle inputs.

[SKYRYAN]

What I am basically saying is...hit bump and G's force foot on throttle, car accelerates...acceleration moves weight back and foot lifts off throttle a bit, car then decelerates, weight moves forward and foot is forced on throttle...car accelerates moves weight back and foot lifts off and process repeats.

wtf is your seat sitting on a single spring bouncing around in your cabin?

[stormtrooper]

HAHAHAHAH awesome mental image on that one....

[payback21]

Ive got a set of cusco's in mine and its a hard ride. I know what you mean about the bumps with your foot. Quite normal mate.

[Ten Four]

Haha same as stormtrooper.

TBH with speed bumps, I just put in first, clutch in, over bump, and accelerate away... Whats the big issue...

[bubba]

Haha same as stormtrooper.

TBH with speed bumps, I just put in first, clutch in, over bump, and accelerate away... Whats the big issue...

THE ORIGINAL POSTER WAS NOT TALKING ABOUT SPEED BUMPS

[Nic_A31]

Bad time of month Bubba ?

[stormtrooper]

Bubba will shoot the next person with his paintball gun, who says ANYTHING about bloody speedhumps... he's a damn good shot too...

[Nic_A31]

I bet he's a good aim, but, just before he takes his shot, his driver goes over a speed bump and f**ks it up for him....bugger

[SKYRYAN]

On a semi-related note... has anyone ever had trouble with atmospheric BOVs causing your car to shudder hardcore when you release the throttle slowly? Does that mean it's too tight?

I think I had a turbosmart on for a while for funsies but have gone back to a stock GTR bov.

[Dani Boi]

Man I still dont get it haha Mine doesn't do this thing you speak of and my suspension is pretty stiff.

[SKYRYAN]

Man I still dont get it haha Mine doesn't do this thing you speak of and my suspension is pretty stiff.

I don't either man, wanna be dumb-asses together?

[stormtrooper]

Man, this thread is going to end up on bash.org or some shit.

[ZENNON]

not sure what its called but know how you prevent it

its called "throttle control" - it sounds stupid I know..

(dad taught me when I started 4WDing)

[bubba]

Bad time of month Bubba ?

No, I just get pissed off when people post up bullshit responses without reading the thread.

[Dani Boi]

I don't either man, wanna be dumb-asses together?

Yeah I'm all for it Rysies, let's walk.

[Tony de Wonderful]

I just drove to subi and did some experimenting on the terrible roads around there.

I think my driving style has been to control the throttle with the middle/arch of my foot, this means that any involuntary movements of my foot due to acceleration/deceleration have quite alot of leverage over the throttle. If I use my toes or ball of foot then bumps have less effect.

It just feels a bit unnatural and I'll have to get used to it.

[Hanaldo]

not sure what its called but know how you prevent it

its called "throttle control" - it sounds stupid I know..

(dad taught me when I started 4WDing)

Wait so you dont know what its called... but its called throttle control

Lol i love how this thread is two pages of trying to figure out what the OP means haha.

I have definitely experienced what X-Trail was saying, with the too low revs causing the car to lurch horribly. Because of that, i engine brake down to about 20kms if im slowing to a stop, but i don't bother going to 1st, i just put it in neutral otherwise it jumps a bit.

But i don't see how going over a bump would cause that. From what Joe is saying it is the bump causing the car to bounce up which brings the accelerator up against his foot (I can't imagine it is G-forces pushing your foot down lol, that would be some insane vertical G's), and then this occurs several times causing the car to lurch... Am i on the right track Joe?