Do I just need a tune?
06-01-2006, 06:35 PM
#1
Launching!
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Do I just need a tune? Ok, don't know if this is exactly tuning or my transmission, or what exactly. Before i put the stall in and since i bought the car in april 05 it has went into this "mode" i call it where it shifts really hard, it only does this after a 3/4 to full throttle instance. It also doesnt do it every time. To help explain it, if i shifted anywhere above 2500 rpm, its an A4, out of first gear, it would bark the tires. Then i got a stall and it doesnt shift as hard anymore, or do it as much, however, I do not have shift points now, whenever it shifted perfectly and never hittin rev limiter before the stall. It started this the day after the stall was put in on first full throttle which leads me towards a tuning issue. One last thing, whenever i dynoed it without the stall we had to take it up to 4200 rpm before it wouldnt downshift on the dyno. Now that i have a cam kit in now, i would like some help whether on deciding to rebuild/buy my 4l60e or try tuning it first and setting shift points. Which way would you go, or what should i check to make sure it isnt a line or anything else just causing this. I will take any opinion or comment or just random ideas at what it might be. Thanks
Last edited by 1WICKDZ; 06-01-2006 at 06:44 PM.
06-01-2006, 07:41 PM
#2
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I guess I'll copy and paste in this thread as well...there's not much reason to start multiple threads of the same topic, FYI.
A higher stall converter will soak up a lot of the "bang" of a hard shift. Also, there are MPH and RPM shift points in the engine computer that it has to meet before it will command a shift, sounds like you might need to adjust those to compensate. Your RPM's will probably be way off from your speed now since the engine can rev much higher before the car starts to move.
Say your rev limiter is set to 6000 RPM, and your 1-2 WOT shift is set to 5600, and your WOT shift speed is set to 40 mph (I have no idea if those are right, just giving an example). With the stock converter, you might have been right at 40mph at 5600 RPM, both conditions are met, PCM commands a shift. Now, you might hit the rev limiter at 6000 RPM before you hit 40mph, so the PCM never commands the shift and you are left bouncing off the limiter.
A higher stall converter will soak up a lot of the "bang" of a hard shift. Also, there are MPH and RPM shift points in the engine computer that it has to meet before it will command a shift, sounds like you might need to adjust those to compensate. Your RPM's will probably be way off from your speed now since the engine can rev much higher before the car starts to move.
Say your rev limiter is set to 6000 RPM, and your 1-2 WOT shift is set to 5600, and your WOT shift speed is set to 40 mph (I have no idea if those are right, just giving an example). With the stock converter, you might have been right at 40mph at 5600 RPM, both conditions are met, PCM commands a shift. Now, you might hit the rev limiter at 6000 RPM before you hit 40mph, so the PCM never commands the shift and you are left bouncing off the limiter.
06-02-2006, 10:20 AM
#3
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The sponsor who installed my converter recommended a transgo shift improver/B&M cooler at the same time as the converter install. I was very happy with the results.
I would recommend this, not any tuning to increase line pressure/firmness of shifts.
-Doug
I would recommend this, not any tuning to increase line pressure/firmness of shifts.
-Doug
