i noticed recently that ever since i installed the z-tube, at low speeds, my 5mt coupe "hiccups" as i press on the gas from coasting speeds. so, as i'm coasting at about 15 mph, when i press on the accelerator, there is a slight delay then a "thump" and slight jerk forward almost like i just learned how to drive a stick shift and let go of the clutch too soon. however, this is an auto. i don't know if the z-tube has anything to do with it. but i just realized they both coincided -- that is, it started right after i install the z-tube. has anyone else had this experience?

 

did you try resetting the ECU??

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Yes I've noticed the same issue both with the Z-tube I had on, and the K&N Typhoon I have on now. It was more noticeable with the Typhoon in 'CAI' mode (long inlet), than in 'WAI' mode (short inlet).

This phonomenon is especially noticeable at low speeds in 5th gear (about 35 mph minimum) and as you say, accellerating after slowing. (5A/T) The transition from decellerating to accellerating isn't a smooth at stock.

I attribute it to the A/F ratio being changed slightly, but am not worried about it since it's not intrusive.

An ECU reset did nothing to change it.
C.

<font color=red>GSM</font color=red>
<font color=red>GSM</font color=red>
<font color=black>Silverstone Coupe</font color=black>

 

wat about for 6mt's?

 

oops, typo......i meant 5at coupe. i'm just relieved others have experienced it too. thanks, gsedanman

 

I haven't noticed any change in the car whatsoever except it's noisy starting at 2800 thereabouts. Honestly, after looking down the barrel of the Z tube vs. the stock tube, I don't know how the car could possibly behave any differently. There's no difference except for the sound baffles, which don't appear to obstruct airflow anyway (especially at low speeds, how could they). I would check to make sure the connections are solid.

 

Sounds like an air leak somewhere in your intake line. I had the same problem after a bolt broke off my crawford plenum....all of a suddne, the car felt like death and I had to hold the gas slightly in neutral to keep from stalling at traffic lights. Under acceleration, it felt dead, then alive, creating a jerky feeling as it went down the road. Id make sure your connections are solid.

2003.5 G Coupe premium. 6MT Black/black
JWT/Z tube, UR pulley set (chrome), Crawford v5 plenum (black), Crawford Cats.

Proud to have more hp than a stock 05 =)

 

yep... sounds like an air leak...

2003.5 G35C 5AT
Premium Package
Tire/Wheel Package
K&N Filter, Z-Tube, EGK

 

since the "hiccups" only occurs occasionally (about 1-2 times a week), would an air leak be the reason? wouldn't an air leak cause it to occur very often and perhaps every time i accelerate? either way, i'll check the connections to make sure.