Jerky at low RPMS

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...

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

ZKindaGuy · 08-16-2009, 09:53 AM

Quote:

Originally Posted by Modshack

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

Bingo! It's you....its that plain and that simple.

m4a1mustang · 08-16-2009, 09:58 AM

Quote:

Originally Posted by ZKindaGuy

Bingo! It's you....its that plain and that simple.

I love how the internet turns us all into big, bold, badasses.

ZKindaGuy · 08-16-2009, 01:11 PM

Quote:

Originally Posted by m4a1mustang

I love how the internet turns us all into big, bold, badasses.

No one is being a bad *** about anything. It's not rocket science...its just common sense...that's why it is so painfully obvious.

m4a1mustang · 08-16-2009, 01:31 PM

Quote:

Originally Posted by ZKindaGuy

No one is being a bad *** about anything. It's not rocket science...its just common sense...that's why it is so painfully obvious.

JoeD · 09-04-2009, 03:07 AM

Interesting how people mention the unusual clutch-engagement...the first time I drove a G35 several years ago, it seemed as if I was over-revving the engine on every up-ship while driving aggressively, and for the life of me I could not figure out why. It was as if I was not letting off the throttle while shifting. Shifting prior to redline, say 5500 RPM, in WOT runs would cause the tach to jump well past 7000 RPM and make me seem like a complete n00b.

I then realized the engagement-point was well off most other cars, so I had to adjust my driving accordingly. It takes about two days to get used to any new car to rid yourself of any jerkiness and/or mistake.

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.

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.

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.

rednek01 · 08-12-2009, 02:37 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.

I know a couple of people running 12.8's with CAI, tune, and 4.10's and thats on street tires. I may go with 3.73's tho for a little bit of balance and maybe F.I. someday

08-12-2009, 01:05 PM	#4 (permalink)
Lloydy Base Member Join Date: Mar 2009 Location: Dallas, TX Posts: 150 Drives: 09 370z PG 6mt T/S Rep Power: 18	Yep, I've noticed this too, but more gas does stop it happening

09-04-2009, 03:07 AM	#9 (permalink)
JoeD Banned Join Date: Aug 2009 Location: CA Posts: 495 Drives: Z Rep Power: 0	Interesting how people mention the unusual clutch-engagement...the first time I drove a G35 several years ago, it seemed as if I was over-revving the engine on every up-ship while driving aggressively, and for the life of me I could not figure out why. It was as if I was not letting off the throttle while shifting. Shifting prior to redline, say 5500 RPM, in WOT runs would cause the tach to jump well past 7000 RPM and make me seem like a complete n00b. I then realized the engagement-point was well off most other cars, so I had to adjust my driving accordingly. It takes about two days to get used to any new car to rid yourself of any jerkiness and/or mistake.