Jerky at low RPMS

khtso · 08-12-2009, 12:50 PM

I've noticed this from when I first got the car, but now finally decided to ask you guys about it. At low RPMs, like in first gear leaving a stop light, the car feels jerky. I watch the RPMs, and they don't go up smoothly but the car kinda bucks slightly. It happens every time. Seems to only be an issue in 1st and maybe 2nd gear, when accelerating slowly. Does anyone else have this problem, or is it just my car?

m4a1mustang · 08-12-2009, 12:52 PM

Quote:

Originally Posted by khtso

I've noticed this from when I first got the car, but now finally decided to ask you guys about it. At low RPMs, like in first gear leaving a stop light, the car feels jerky. I watch the RPMs, and they don't go up smoothly but the car kinda bucks slightly. It happens every time. Seems to only be an issue in 1st and maybe 2nd gear, when accelerating slowly. Does anyone else have this problem, or is it just my car?

I was just thinking about this today and whether or not I should post it here to see if anyone else felt it. +1 rep for reading my mind.

As far as I know, this is normal. Sometimes it happens, sometimes it doesn't. It all depends on how you roll out of the clutch and how much throttle you have applied. My Mustang GT didn't do it with stock 3.27 gears, but when I swapped them out for 4.10s it did buck a bit at times.

Modshack · 08-12-2009, 12:53 PM

Quote:

Originally Posted by m4a1mustang

It all depends on how you roll out of the clutch and how much throttle you have applied.

Be a little more aggressive on the gas pedal...

rednek01 · 08-12-2009, 12:55 PM

Quote:

Originally Posted by m4a1mustang

I was just thinking about this today and whether or not I should post it here to see if anyone else felt it. +1 rep for reading my mind.

As far as I know, this is normal. Sometimes it happens, sometimes it doesn't. It all depends on how you roll out of the clutch and how much throttle you have applied. My Mustang GT didn't do it with stock 3.27 gears, but when I swapped them out for 4.10s it did buck a bit at times.

Man 4.10's are tempting me so bad!

I think the issue is low end torque there isnt enough for the 3.31 gear in the back of yalls cars or mine for that matter and so the engine is somewhat stalling a bit or struggling. also I think the throttle by wire in both of our cars has a hard time staying smooth at the low low RPM levels.

Nice parallel between our cars tho kind of interesting

m4a1mustang · 08-12-2009, 12:56 PM

Quote:

Originally Posted by rednek01

Man 4.10's are tempting me so bad!

I think the issue is low end torque there isnt enough for the 3.31 gear in the back of yalls cars or mine for that matter and so the engine is somewhat stalling a bit or struggling. also I think the throttle by wire in both of our cars has a hard time staying smooth at the low low RPM levels.

Nice parallel between our cars tho kind of interesting

4.10s and the Mustang will absolutely come alive. I went from running 14 flat with a bone stock 2003 GT to 13.6 with 4.10s. They effectively bitchslapped the car awake. You'll LOVE them.

m4a1mustang · 08-12-2009, 12:57 PM

Quote:

Originally Posted by Modshack

Be a little more aggressive on the gas pedal...

Yeah, I have a bit of a problem of being a nanny driver when I'm not out driving for pleasure. Sometimes I go so slow I have to save the car from stalling, and then I complain about the lack of low-end torque at 400 rpm.

Lloydy · 08-12-2009, 01:05 PM

Yep, I've noticed this too, but more gas does stop it happening

m4a1mustang · 08-12-2009, 01:10 PM

I don't know if you guys have noticed the sudden existence of torque at about 3,000 RPM. The car kind of struggles below 3 grand if you're trying to go somewhere quickly but once you cross that mark it feels like the VVEL does something and BAM you've just been hit with almost V8-like torque. It's kind of funny how driving this car reminds me of driving my old Ford 4.6L V8.

rednek01 · 08-12-2009, 01:31 PM

Quote:

Originally Posted by m4a1mustang

4.10s and the Mustang will absolutely come alive. I went from running 14 flat with a bone stock 2003 GT to 13.6 with 4.10s. They effectively bitchslapped the car awake. You'll LOVE them.

I think with 4.10's I will dip into the 12's so that would be exciting

Red370 · 08-12-2009, 01:46 PM

Quote:

Originally Posted by rednek01

I think with 4.10's I will dip into the 12's so that would be exciting

my buddy Brian has 4.10's, Vortec SDS, headers, exhaust, and to date his best time is 12.9, he says the 4.10's are great for low end tq, but fall flat on their face in the upper RPM range. They might knock a tenth or two off your time, but dont expect miracles, he says he misses his top end.

Red370 · 08-12-2009, 01:53 PM

As far as jerkyness is concerned, start @ about 1500rpms, keep the pressure on the throttle constant and slowly let the clutch out, voila! no more jerk. Self admittedly, I still cant manage a smooth shift every time, damn fat arse flywheel!

m4a1mustang · 08-12-2009, 02:01 PM

Quote:

Originally Posted by Red370

my buddy Brian has 4.10's, Vortec SDS, headers, exhaust, and to date his best time is 12.9, he says the 4.10's are great for low end tq, but fall flat on their face in the upper RPM range. They might knock a tenth or two off your time, but dont expect miracles, he says he misses his top end.

The only issue on a FI car with the 4.10s is you had to shift to 5th (overdrive on the Mustangs) at about 112 MPH.

m4a1mustang · 08-12-2009, 02:04 PM

Quote:

Originally Posted by rednek01

I think with 4.10's I will dip into the 12's so that would be exciting

With good tires I would think so.

zZSportZz · 08-12-2009, 02:07 PM

I've felt the same thing. But for me its shifting from 1st to 2nd that seems a little clunky...and no so much the start. Its like the rpms take forever to drop...I have to shift slooooooooooooow to be smooth. Maybe its just me, I don't know.

m4a1mustang · 08-12-2009, 02:10 PM

Under normal driving I have to take it easy on the 1-2 for a smooth shift.

08-12-2009, 12:50 PM	#1 (permalink)
khtso Base Member Join Date: May 2009 Location: Los Angeles Posts: 59 Drives: 2009 370Z Rep Power: 15	Jerky at low RPMS I've noticed this from when I first got the car, but now finally decided to ask you guys about it. At low RPMs, like in first gear leaving a stop light, the car feels jerky. I watch the RPMs, and they don't go up smoothly but the car kinda bucks slightly. It happens every time. Seems to only be an issue in 1st and maybe 2nd gear, when accelerating slowly. Does anyone else have this problem, or is it just my car?

08-12-2009, 01:10 PM	#8 (permalink)
m4a1mustang A True Z Fanatic Join Date: Feb 2009 Location: Northern VA Posts: 55,385 Drives: on two wheels Rep Power: 6962	I don't know if you guys have noticed the sudden existence of torque at about 3,000 RPM. The car kind of struggles below 3 grand if you're trying to go somewhere quickly but once you cross that mark it feels like the VVEL does something and BAM you've just been hit with almost V8-like torque. It's kind of funny how driving this car reminds me of driving my old Ford 4.6L V8. __________________ - Steve Zs & Coffee - Saturdays at 10AM in Fairfax, VA and Columbia, MD (Click the banner!) LIKE us on Facebook!

08-12-2009, 02:07 PM	#14 (permalink)
zZSportZz A True Z Fanatic Join Date: Mar 2009 Location: Maryland Posts: 1,095 Drives: 370z Blk on Blk 6MT Rep Power: 18	I've felt the same thing. But for me its shifting from 1st to 2nd that seems a little clunky...and no so much the start. Its like the rpms take forever to drop...I have to shift slooooooooooooow to be smooth. Maybe its just me, I don't know. __________________ --Rick

08-12-2009, 02:10 PM	#15 (permalink)
m4a1mustang A True Z Fanatic Join Date: Feb 2009 Location: Northern VA Posts: 55,385 Drives: on two wheels Rep Power: 6962	Under normal driving I have to take it easy on the 1-2 for a smooth shift. __________________ - Steve Zs & Coffee - Saturdays at 10AM in Fairfax, VA and Columbia, MD (Click the banner!) LIKE us on Facebook!

08-12-2009, 01:05 PM	#7 (permalink)
Lloydy Base Member Join Date: Mar 2009 Location: Dallas, TX Posts: 150 Drives: 09 370z PG 6mt T/S Rep Power: 16	Yep, I've noticed this too, but more gas does stop it happening

08-12-2009, 01:53 PM	#11 (permalink)
Red370 A True Z Fanatic Join Date: Jul 2009 Location: Kaiserslautern, Germany Posts: 4,391 Drives: your mom to church Rep Power: 295	As far as jerkyness is concerned, start @ about 1500rpms, keep the pressure on the throttle constant and slowly let the clutch out, voila! no more jerk. Self admittedly, I still cant manage a smooth shift every time, damn fat arse flywheel!