TCU TurboLamik

M4comp wrote: 30 Jul 2025, 23:05 Also you need to make sure your TPS in the TCU software is at 0.0% when your foot is not on the throttle. If your TPS is not at 0% when at idle enable DBW Input Sensor Cal -> Sensor Input -> DBW Input. This must match your 'TPS Input' value normally 13. This is a mistake I see over and over at the track when we have meet ups. The software is looking for the PPS (pedal position sensor) but allows you to zero out your idle tps value.

Hi, quick clarification please. In the above ref DBW do I only need to set DBW if TPS is not at 0% or do I need DBW anyway.

My TPS shows 0% when off throttle but the DBW is set to zero so inactive.

Thanks

Richard

Only if dbw is not showing 0% in tcu software.

M4comp wrote: 06 Aug 2025, 16:32 Only if dbw is not showing 0% in tcu software.

Thanks

I'll add to this, but you'll have issues with down shifts when TPS values are not at 0% when off throttle and braking. There is a brake setting that increases the RPM value for Min / Max RPM shift up or down tables. You'll get weirdness when hard braking at speed will cause an up shift and this typically solves it.

M4comp wrote: 30 Jul 2025, 23:05 Read this and set up your program modes accordingly or skip and go full manual if you want max control - just an option, Automatic mode: 0-OFF in the Program Selector table. The TCU will fall back to the 'Max. RPM Limit' table and force a shift if you exceed the table value.
https://manual.turbolamik.eu/docs/tunin ... up-tuning/

Another quick question, is the above the only time the "Max. RPM Limit" table is used?

Just asking as the table contains rpm values well above the redline for my V8, not sure if this table impacts other calculations in the TCU and if I should bring more inline with my engine.

For instance cells in this table go up to 9000, my V8 has a redline around 6500

Thanks

Richard

The question you’re asking relates to the link I provided, which outlines the flow of how the system decides which gear to shift up or down to.

Max. RPM Limit – This forces a shift in either auto or manual mode. You cannot exceed this RPM; if you do, it will shift. If you raise this value over your engine RPM limit - you'll be in true manual mode.

Max RPM Gearbox – This is the absolute RPM the transmission will allow. Exceeding it will trigger limp mode. Typically set around 9000 RPM.

To kinda show you how it's used in the TCU...
In the attached picture, blue represents 1st gear with Program Switch 1 (P1) active. The Max RPM Limit is set to 5300 RPM — that’s its maximum. However, the “Automatic Gear Change UP TPS%” table in AUTO mode commands a shift at 4800 RPM. In P3 (Mode 3), the Max RPM is lower than the shift point in AUTO, so the actual shift happens at 6100 RPM instead of the 6200 RPM the table specifies.

The reason I bring this up is, this configuration file is for a bone-stock BMW — idles at ~500 RPM, makes minimal torque. The Mode 8 (P8) - 9000 RPM values you’re seeing are used for dyno testing, where there’s no risk of the rear tires unloading. On the track, however, if the car gets light over a crest at WOT, the RPM can spike instantly, and that’s when these limits protect the gearbox. The 9000 RPM values in the vertical column are for 8th gear, which typically would not be close to this RPM even if unloading occurred.

Thankyou I really appreciate the added explanation.