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Old 03-13-2006, 10:46 AM   #1
fliz
Scooby Guru
 
Member#: 30342
Join Date: Nov 2002
Location: Grafton, WI
Default AP Stage 2.5: Bucking after lift at mid-RPMs

I've got an AP stage 2.5 w/ protune.

Running VF-34 & supporting, catless exhaust, K&N Intake, Perrin inlet, Helix TMIC, stock BOV.

Occasionally, I get some bucking after I lift in second at 4K-5K rpms.

It sounds very similar to what some '04 owners have experienced in this thread, and have cured by going to a Cobb AP.

Basically, I'll be in second, go around a corner, go to WOT for 1-2 seconds, then lift. The car will start to decelerate, unloading the transmission for a split second, then go back to full power for a split second, completely shocking the gears.

This has only happened three times in the last month. The first two weren't too bad, but the last time it happened it chipped a tooth on my Gimmie Gears transmission.

Has anybody had any experience with anything like this?

In the '04 thread, there was somebody who claimed that the problem is caused by the BOV releasing too much air and running air out the MAF. They claimed that an aftermarket partially atmospheric BOV will cure the problem. Can anybody confirm or deny this?

Thanks for the help.
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Old 03-15-2006, 02:38 AM   #2
zuczek
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Member#: 64971
Join Date: Jun 2004
Chapter/Region: W. Canada
Location: Calgary
Vehicle:
BP05

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I have an 02 with stage 2 that has the same symptoms and a 50/50 bov DID NOT cure this problem. What did help was putting a restrictive resonator in the tip of my muffler. More backpressure?? Maybe, I took it out as there was a significant performance decrease but ALOT smoother.
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Old 03-15-2006, 12:27 PM   #3
fliz
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Member#: 30342
Join Date: Nov 2002
Location: Grafton, WI
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Quote:
Originally Posted by zuczek
I have an 02 with stage 2 that has the same symptoms and a 50/50 bov DID NOT cure this problem. What did help was putting a restrictive resonator in the tip of my muffler. More backpressure?? Maybe, I took it out as there was a significant performance decrease but ALOT smoother.
Thanks for the input. I guess I'll hold off on the BOV.

I downloaded some free logging software. I'm going to try to recreate the situation in first or third (hopefully I won't break anything else), and see exactly what is happening.
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Old 12-28-2006, 03:24 PM   #4
fliz
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Member#: 30342
Join Date: Nov 2002
Location: Grafton, WI
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Back from the dead...I finally logged the car today.

Unfortunately, it doesn't tell me anything...maybe somebody else can decode. The car bucked when I lifted on both of these pulls.

Code:
Time,Throttle Opening Angle (%),Mass Air Flow (g/s),Intake Air Temperature (°C),Ignition Timing (°BTDC),Vehicle Speed (KPH),Atmospheric Pressure (PSI),Knock Correction (°BTDC),Fuel Injector #1 Pulse Width (ms),Throttle Sensor Voltage (V),Manifold Relative Pressure (PSI),Primary Wastegate Duty Cycle (%),Fuel Pump Duty (%),Engine Speed (RPM),Manifold Absolute Pressure (PSI)

119001,0.00,10.39,17.00,32,60,14.365,0,1.28,0.520,-10.737,0.00,66.67,3807,3.627
119192,0.00,9.62,17.00,21,59,14.365,0,1.28,0.520,-11.027,0.00,66.67,3757,3.337
119382,0.00,8.27,17.00,14,59,14.365,0,0.00,0.520,-11.027,0.00,66.67,3707,3.337
119572,0.00,7.10,17.00,12,59,14.365,0,0.00,0.520,-11.173,0.00,66.67,3664,3.192
119772,0.00,6.30,17.00,12,59,14.365,0,0.00,0.520,-11.318,0.00,66.67,3599,3.047
119963,0.00,6.15,17.00,12,59,14.365,0,0.00,0.520,-11.318,0.00,66.67,3563,3.047
120153,0.00,6.15,17.00,12,57,14.365,0,0.00,0.520,-11.318,0.00,66.67,3554,3.047
120343,0.00,10.04,17.00,12,57,14.365,0,0.00,0.520,-10.737,0.00,66.67,3516,3.627
120533,0.00,6.23,17.00,12,57,14.365,0,0.00,0.520,-11.027,0.00,66.67,3475,3.337
120724,8.24,12.19,17.00,24,56,14.365,0,1.54,0.820,-10.157,30.59,66.67,3420,4.208
120924,12.16,25.39,17.00,42,56,14.365,0,2.56,0.920,-7.690,30.59,66.67,3511,6.675
121114,17.25,37.79,17.00,19,54,14.365,0,3.58,1.080,-5.224,32.55,66.67,3472,9.141
121305,24.71,51.23,18.00,34,54,14.365,0,4.86,1.380,-2.322,35.29,66.67,3546,12.043
121505,35.29,66.11,18.00,33,54,14.365,7,6.14,1.680,0.000,39.22,66.67,3590,14.365
121685,43.92,74.83,18.00,29,54,14.365,8,7.42,1.960,2.176,42.35,66.67,3696,16.541
121885,50.98,94.31,17.00,26,54,14.365,8,8.96,2.180,4.643,45.10,100.00,3846,19.008
122076,58.82,119.27,17.00,20,56,14.365,10,12.03,2.440,8.416,52.94,100.00,4013,22.780
122266,68.24,160.70,17.00,15,56,14.365,11,15.62,2.740,13.349,61.57,100.00,4206,27.714
122456,72.55,196.93,17.00,12,56,14.365,11,17.15,2.840,16.251,64.31,100.00,4462,31.631
122647,73.33,212.54,17.00,12,60,14.365,11,17.66,2.880,18.427,62.35,100.00,4621,32.792
122847,31.76,195.44,17.00,13,60,14.365,11,5.89,1.460,16.396,41.96,100.00,4937,30.761
125060,0.00,20.52,17.00,12,75,14.365,0,0.00,0.520,-9.722,0.00,66.67,4886,4.643
125060,0.00,20.52,17.00,12,75,14.365,0,0.00,0.520,-9.722,0.00,66.67,4886,4.643
125070,0.00,20.52,17.00,12,75,14.365,0,0.00,0.520,-9.722,0.00,66.67,4886,4.643
125070,0.00,20.52,17.00,12,75,14.365,0,0.00,0.520,-9.722,0.00,66.67,4886,4.643
125070,0.00,20.52,17.00,12,75,14.365,0,0.00,0.520,-9.722,0.00,66.67,4886,4.643
125080,0.00,20.52,17.00,12,75,14.365,0,0.00,0.520,-9.722,0.00,66.67,4886,4.643
125250,0.00,10.99,17.00,12,74,14.365,0,0.00,0.520,-11.027,0.00,66.67,4510,3.337
125441,0.00,10.54,17.00,12,73,14.365,0,0.00,0.520,-11.173,0.00,66.67,4478,3.192
125631,0.00,9.94,17.00,12,73,14.365,0,0.00,0.520,-11.173,0.00,66.67,4430,3.192
125821,0.00,9.40,17.00,12,71,14.365,0,0.00,0.520,-11.318,0.00,66.67,4388,3.047
126021,0.00,9.18,17.00,12,71,14.365,0,0.00,0.520,-11.318,0.00,66.67,4345,3.047
126212,0.00,8.87,17.00,12,71,14.365,0,0.00,0.520,-11.318,0.00,66.67,4296,3.047
126402,0.00,8.92,17.00,12,70,14.365,0,0.00,0.520,-11.318,0.00,66.67,4278,3.047
126602,0.00,8.74,17.00,12,70,14.365,0,0.00,0.520,-11.318,0.00,66.67,4244,3.047
126782,0.00,8.74,17.00,12,68,14.365,0,0.00,0.540,-11.318,0.00,66.67,4199,3.047
126983,2.75,11.65,17.00,25,68,14.365,0,1.28,0.620,-10.882,30.59,66.67,4197,3.482
127173,5.88,15.29,17.00,43,68,14.365,0,1.54,0.720,-10.447,30.59,66.67,4183,3.918
127363,12.16,27.53,17.00,43,66,14.365,0,2.82,0.940,-8.851,30.59,66.67,4244,5.514
127554,19.61,37.77,17.00,39,66,14.365,0,3.84,1.160,-5.514,33.73,66.67,4249,8.851
127754,26.27,59.87,17.00,17,65,14.365,0,5.38,1.380,-2.467,36.47,66.67,4240,11.898
127944,36.86,83.35,17.00,32,65,14.365,6,6.66,1.740,-0.290,39.61,66.67,4360,15.235
128144,45.10,114.81,17.00,27,65,14.365,8,8.96,1.980,3.192,42.75,100.00,4399,17.557
128335,53.73,164.58,17.00,17,65,14.365,11,13.31,2.280,8.996,45.88,100.00,4573,23.361
128525,63.92,202.62,17.00,13,65,14.365,11,16.38,2.600,14.800,53.33,100.00,4795,29.165
128725,68.24,219.32,17.00,12,68,14.365,11,17.15,2.700,16.541,54.12,100.00,5050,31.341
128916,30.98,189.88,17.00,15,68,14.365,11,3.07,1.300,13.929,41.18,100.00,5256,28.294
131139,0.00,21.20,17.00,12,78,14.365,0,0.00,0.520,-9.867,0.00,66.67,4987,4.498
131139,0.00,21.20,17.00,12,78,14.365,0,0.00,0.520,-9.867,0.00,66.67,4987,4.498
131149,0.00,21.20,17.00,12,78,14.365,0,0.00,0.520,-9.867,0.00,66.67,4987,4.498
131149,0.00,21.20,17.00,12,78,14.365,0,0.00,0.520,-9.867,0.00,66.67,4987,4.498
131169,0.00,22.33,17.00,12,78,14.365,0,0.00,0.520,-9.722,0.00,66.67,5212,4.643
131229,7.06,19.83,17.00,38,79,14.365,0,2.30,0.740,-8.416,0.78,2.35,3201,24.376
I have more logs (about 15-20 pulls) if anybody wants them.
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Old 01-02-2007, 01:04 PM   #5
RiftsWRX
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Member#: 6124
Join Date: Apr 2001
Chapter/Region: MWSOC
Location: Glendale Hts, IL, USA
Vehicle:
2000 NFR AP1 S2000
'07 Honda FIT sport (5MT)

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Email me the csv files themselves.

jorge@pandlmotorsports.com

Jorge (RiftsWRX)
www.ProjectWRX.com
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Old 01-02-2007, 08:58 PM   #6
fliz
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Member#: 30342
Join Date: Nov 2002
Location: Grafton, WI
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email sent.
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