Blow Thru Setup, Help! Ptuning anyone!
what the afrs again before stalling? and it does it when coming off gear or clutch pedal pressed? is it during deceleration? what is the vacuum reading before stalling? It might be that the maf needs to be recalibrated for your pipe or maybe just afr/ignition issue
ill have to go drive around again to check, it happens if like im in gear at above 3k rpms and i press the clutch in and hold for like 5+ more seconds then it stalls, also sometimes i shift it will act is if its trying to stall (i think this might be cuz of a leaking bov or thats its not recirc'd)?
no surging in rpms at idle? not sure about the ultimate but try datalogging a run and when it does this and see how much timing you have and compare with your afrs and other data.. maybe the problem is with the maf, doesnt like his new piping environment like elevation said it may want a different afr or ignition at idle so compensate.. Out stock maf isnt calibrated for that setup..
well i cant tell u what the afr's are when it stalls because everytime i let off the throttle in any gear my aem gauge says " - - - " lol and it will continue to say "- - -" until i either downshift or give it gas,
Take it easy...
Luiggi
If your MAF sensor is now located on the upper intercooler pipe, chances are with your kit it is 2.25" in diameter. At very mininum, you will want to alter the airflow map on your EMU to reduce the amount of airflow the stock ECU sees at idle and you will certainly need to clamp the overall voltage on the MAF so that it does not see above 5V, which on a 2.25 diameter pipe will occur very quickly. This will prevent the ECU from throwing codes pertaining to invalid airflow voltages under certain engine conditions.
Secondly, having the airflow values that are so far off for a given load point will result in timing values that are now too low (loss of power under these lower engine loads). This assumes of course, that your tuner isn't already aware of this and tunes the timing map occordingly.
As far as the BOV location goes, your tuner may be right, the only way to find out is by disconnecting the vacuum line going to the BOV to keep it closed (see how the engine reacts). It may be possible that the close proximity of your BOV to your MAF sensor will cause excessive turbulence near the MAF probe causing it to go nuts everytime the BOV opens. If you can, it would probably benefit you to locate the BOV as far in front of the MAF sensor as possible. Hint, look at our Spec-SS Turbo Kit.
- Toan
Secondly, having the airflow values that are so far off for a given load point will result in timing values that are now too low (loss of power under these lower engine loads). This assumes of course, that your tuner isn't already aware of this and tunes the timing map occordingly.
As far as the BOV location goes, your tuner may be right, the only way to find out is by disconnecting the vacuum line going to the BOV to keep it closed (see how the engine reacts). It may be possible that the close proximity of your BOV to your MAF sensor will cause excessive turbulence near the MAF probe causing it to go nuts everytime the BOV opens. If you can, it would probably benefit you to locate the BOV as far in front of the MAF sensor as possible. Hint, look at our Spec-SS Turbo Kit.
- Toan
i thought the dezod pipe to throttle body was 2.5" maybe im wrong, so if it is 2.25" ur advising that i get a piece of 2.5" piping and place the MAF on that piece?
ill have the maf moved further back
ill have the maf moved further back
Last edited by SoFloTC; Aug 3, 2009 at 10:51 PM.






