View Single Post
      06-13-2019, 10:22 PM   #2753

Drives: 135i
Join Date: Sep 2012
Location: Australia

iTrader: (4)

RBT-Tuning ???

Originally Posted by 135 View Post
See below...

Originally Posted by RBT-Tuning View Post
Originally Posted by Saif2018 View Post

I know you mentioned Linear Throttle in MHD would screw things up, but...

Is it possible to add this improved Throttle response mod ...?

Either for D mode or S/M?

In the XHP app, or would this have to tuned in via MHD etc?
Throttle response and linear throttle are 2 different things. Response means how direct the throttle blade/engine load reacts to input changes on the pedal. That does not change anything for the trans. (well, not anything really important)

Linear changes the relation between stationary pedal value and the load so in effect it changes the Shiftpoints. (as thats based on pedal value) Maybe "screwed" is the wrong word, but the trans will just not shift like the mapper (being it us or BMW) had it in mind it should do it.

Yes, throttle response and linear throttle are two different things as mentioned in the throttle sensitivity threads...
Originally Posted by PeterY View Post
Be mindful that throttle plate response and its actuation speed are a completely different thing to the "Linear Throttle" option that can be ticked in MHD, and of course different to turbo lag too. I only ever use linear throttle on my car under any case, not to be confused with the transient throttle response of an engine which is being discussed here.
Originally Posted by PeterY View Post
Lastly, this throttle response fix is not the same as switching linear throttle on/off, people don't get it! Linear throttle option in MHD has to do with torque request table in the tune bin. I.e. if you press 10% throttle, the DME will target 10% of the available torque at the current rpm. Linear throttle means a 1:1 relationship, so 20% accelerator travel = 20% of the available torque, 40% accelerator = 40% torque... etc. The reason MHD included the linear throttle tick box is because from factory these cars have a non-linear throttle, for example: 10% throttle is 20% torque, 40% throttle is 80% torque... etc. by the time you get to 60% accelerator travel, the engine is already producing 100% of its torque, so it's basically full throttle at only 60% accelerator pedal travel, and the remaining 40% of the pedal travel is just a deadzone that doesn't do anything. In my opinion, ticking that MHD linear throttle option is a must, specially when these engines are tuned, the torque is very hard to control, and the longer pedal travel really helps applying the torque smoothly on corner exit without spinning the wheels.

The throttle fix that has been recently discovered is completely different to the throttle mapping and torque request tables, I thought I should clarify that because it's very easy to mix between a sharp throttle response, and a stupid bloated over-reactive accelerator input where 30% accelerator travel is equal to 60% of the available engine torque.

... but the throttle sensitivity threads also indicate that the throttle sensitivity table changes work best with a linear throttle.

A linear throttle (in conjunction with a more sensitive throttle) would be particular useful on a track/circuit so there is more pedal modulation (usable travel) available on corner entry/exit (percentage throttle).
Imagine if only 10mm of pedal travel was equal to 100% throttle - that would be impossible to modulate. Equally, 50% of usable pedal travel is twice as difficult to modulate compared to full (100% usable) pedal travel when you want to be as precise as possible with percentage throttle.

[COLOR="Red"]So the question is, how can the 6AT be tuned in xHP to work with a linear throttle?[/COLOR]
Maybe the shift points need to be based on the throttle position (not the pedal position).