For the past year we have been noticing the horrible torque dip when dynoing the n55 motor.
Terry's n55 135i Notice the dip after 3krpms
Shiv's n55 135i Notice dip right after 2krpms
And here is mine 335i with ar design downpipe Scary I know.
A few people have asked why there is such a dramatic drop in tq, which led me to review my dynos. After comparing AFR with tq I have come to the conclusion that for some unknown reason the engine is running extra lean through those rpms..
Notice the huge drop in tq and how the car seems to lean out and start dropping again around 3700rpms and torque is restored.
*note that was a 4th gear pull*
These next pulls were done in 3rd gear with the
now we have the first flashed n55 in the US. It isn't easy to see but it does appear that they have better control of the AFR and have a much nicer tq curve with their flash.
This car can run and it pulls hard. I can see this car hitting 11's and trapping over 120 really easy. I hit a 12.95@107 with a 12.8psi max and thats with an extremely slow track(friend with n54 FBO, dual meath, race fuel was trapping 115 all night with a 12.09 1/4).
I can only hope that shiv, terry, and or cobb can grasp the fueling issue soon. It obviously has already been down with a flash but I don't see myself sending my ecu to florida anytime soon.
I guess I'll just sit back and wait till the n54 war is over and tuners can come back and give a little focus to the n55.