550isport

I'm curious to hear feedback. Stock, my 550 feels like it has a two stage throttle, where stage one is less powerful. For example, if you put the steptronic in a high gear manually, say 3rd at 25 mph, and then repeatedly floor the throttle for a few seconds at a time, you'll notice you don't get full torque immediately. It comes in a few seconds after you push the throttle, almost like a turbo. Maybe its intentional to reduce wheelspin, maybe its just the way valvetronic works. I don't think its variable valve timing becasue all my previous BMWs had dual vannos and they didn't have this two stage feel to them. So I'm wondering if the Dinan software eliminates this behavior and gives you full power immediately.

Has anyone installed the software yet?

DRP

jet190rs

the behavior you described sounds like normal steptronic behavior (i.e. automatic transmission kickdown)
were your previous bmw's automatic?

i have smg and my car's throttle response is very linear.

gwf545

I think what you are experiencing is the torque convertor lock-up clutch releasing and the engine RPM increasing due to the torque converter "slipping". I don't think it is downshifting. Auto transmissions now all have torque convertor lock-up clutches that result in true direct drive, just like a manual transmission. This is primarily to improve mileage while cruising, but it also improves acceleration performance at higher RPM's where the torque convertor becomes less useful. The ZF transmission in your car has a lock up clutch controlled by computer that can be engaged and disengaged in any gear. When you accelerate heavily, the clutch releases to allow the torque convertor to do its job of converting RPM into torque (slipping) and it resembles a downshift when it does this.

The Dinan software might change this behavior, but since I don't have it, I can't comment on that.

EuroCarFan

I may be way off but what you're describing could also be attributed to throttle response? I have the Dinan Stage 3 software and the throttle response is great! I'll have to try what you've described above though cause I always find myself in the meat of the power band from around 4000rpm on in any gear cause I just love to blip the throttle at that engine speed and feel the car jump.....I don't think I'm ever in 3rd gear at 25mph; either in 1st or 2nd.