Post your tips on eliminating bucking here!
10-04-2005, 02:29 PM
#41
now that there are 2 of us talking about effective area they will listen. im glad you tried it out. most people shot me down when it came to it and never tried. i think you are one of the first to try it on their own and stick with it until it was right.
even if the airflows are SLIGHTLY off, like 0.25-0.50 g/sec, you will have issues. once its dead on, enjoy the car acting like it was stock. no stalling, surging, bucking or whatever. but before you do this the timing needs to be right, then the VE needs to be set up right, then effective area, then idle airflow. effecitve area changes WILL change idle airflow if you adjust it
even if the airflows are SLIGHTLY off, like 0.25-0.50 g/sec, you will have issues. once its dead on, enjoy the car acting like it was stock. no stalling, surging, bucking or whatever. but before you do this the timing needs to be right, then the VE needs to be set up right, then effective area, then idle airflow. effecitve area changes WILL change idle airflow if you adjust it
10-04-2005, 03:20 PM
#42
Originally Posted by Patrick G
I just put my throttle cracker and throttle follower back to stock and the slight bucking I have at 1100-1200 is almost all gone.
Keys for me running practically surge free:
MAFless tune.
VE tables nailed.
Lots more timing at idle (32 degrees on all 4 spark tables at lower rpm)
IAC counts of 30 at idle with AC off, 80-90 with AC on. (combination of drill mod and throttle blade mod).
Base running airflow levels correct.
But in my opinion, the biggest contributor to ending my bucking and surging was re-doing my IAC Effective Area table. Now my Calculated Airflow (dynamic based off of VE tables) and my Desired idle airflow (Des IAC) match at various temps and airflow from 0 IAC to 150 IAC. If they don't match across all these IAC ranges, you've got room to improve. Engaging the AC should make no difference. The two airflows should still match.
Keys for me running practically surge free:
MAFless tune.
VE tables nailed.
Lots more timing at idle (32 degrees on all 4 spark tables at lower rpm)
IAC counts of 30 at idle with AC off, 80-90 with AC on. (combination of drill mod and throttle blade mod).
Base running airflow levels correct.
But in my opinion, the biggest contributor to ending my bucking and surging was re-doing my IAC Effective Area table. Now my Calculated Airflow (dynamic based off of VE tables) and my Desired idle airflow (Des IAC) match at various temps and airflow from 0 IAC to 150 IAC. If they don't match across all these IAC ranges, you've got room to improve. Engaging the AC should make no difference. The two airflows should still match.
Thanks,
Bill
10-04-2005, 04:32 PM
#43
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WS6, I have GM 28.8 lb injectors. I upgraded to them from the 26 lbers. Right now I am running about 23-25 degrees timing in the low rpm range, and I am without MAF while trying to get the tune right.
Real brief how do you go about adjusting proportional fuel? Thanks.
Real brief how do you go about adjusting proportional fuel? Thanks.
10-04-2005, 05:34 PM
#45
Originally Posted by bowtieman81
WS6, I have GM 28.8 lb injectors. I upgraded to them from the 26 lbers. Right now I am running about 23-25 degrees timing in the low rpm range, and I am without MAF while trying to get the tune right.
Real brief how do you go about adjusting proportional fuel? Thanks.
Real brief how do you go about adjusting proportional fuel? Thanks.
10-04-2005, 05:38 PM
#46
Originally Posted by Bill Bowling
What did your IAC Effective Area table look like? I know I have changed mine a while back but will have to visit it again.
Thanks,
Bill
Thanks,
Bill
