Can anyone tell me why my HP, TQ and boost curves aren't smooth, but wavy? Especially between 3850 and 5200. I'm guess it might be because I am on the original clutch (117k miles) and that's just because of slippage, but I can't feel the clutch slip when I'm driving it. I can feel the fluctuation in power when I do a pull, especially in 3rd gear. It's not super obnoxious, but I can notice it.
Tuning issue, Try a different tuner. Yang at Devoted Auto will take care of this as he took care of mine as I too, had a dip at about 3500rpm. All gone now as it just pulls nice and smooth the whole way
Most of it is probably a boost problem. More boost usually equals more power. So look at your graph. 3850 you are over 20psi (maybe overboost). Then your boost drops (probably from the overboost) and you HP/TQ drop a bit. Then your boost comes back and your power comes back, then you take another boost hit and power hit. There is probably some fuel and timing issues along with the boost stuff, but first things first, get that boost curve smoothed out and go from there. Russ
Care to expand on that? I usually don't expect a turbo to drop boost once it can make boost at a lower rpm. I might expect flattening off the boost riding the surge line, but I'm not sure where you end up dropping boost.
