Turbochargers: Am I missing something?

[russc2542]

The motor on the throttle blade can snap the blade open and closed as fast as you can mash the pedal, as stated all manufacturers have placed a nanny between your foot and the motor. My 2 cents is that this is to increase their MPG by a fractional amount and help less attentive drivers have a smooth driving experience. This is even more true with the higher horsepower cars to prevent those with more money than driving skill from immediately sending the vehicle sideways from every stop.

MPG is a secondary goal, emissions is the more easily quantifiable part. Transients are the hardest thing to program around. How do you get around it? make the transients less transient.

In my experience it's just the opposite: compacts, especially eco boxes are the worst about it due to the goal of good mpg/emissions and the driver's are the least interested in performance. Performance models, while they do have a larger risk of loss of control, also have the loudest complaints about poor throttle response. Couple years in a shop driving customer cars gave me a pretty wide cross section though admittedly it's been a few years since then. The worst I've driven was a mid-00s Aveo or Cobalt: coming in after the test drive I tried double clutching it slowing down into the lot and it acted like I didn't touch the gas.

An ECU's preference for slowing (slightly) and smoothing the closing of the throttle makes heel-toeing much more of an adventure, too

Edit: to avoid confusion, when I talk about the opening or closing of the throttle I mean the triggering of the desired result in fuel flow to the engine, not simply the speed with which the mechanical parts in the circuit can be moved. My apologies if this is too inexact but usually we are talking about acheiving the desired results in a timely manner and less about how we actually got there

Heel-toeing anything but a performance car programmed to expect it can be very disappointing since many mfrs limit the torque request during brake pedal application. Some may be no WOT, some are nada.

Given the range of knowledge/experience of the people involved, some generality is to be expected. not many want to read a patent or engineering paper.

This is a pretty good discussion of the mapping issues/opportunities. https://forums.nasioc.com/forums/showthread.php?t=1537010

I wasn't aware that you might have already done extensive changes to the system, and custom designed mapping can only do so much as well as mechanical issues like turbo lag requiring mechanical 'fixes' (lower mass, twin sequential etc, exhaust improvements)

Apologies if I'm preaching to the choir, but tuner shops are the way to go unless you're comfortable doing some of this yourself. The sampling and mapping are labor intensive and a real PIA. Commercially available add-ons in NIB form will always be limited because; lawyers

I've been through that thread before, not sure if it was from your suggestion or reading up on it for something else. the original post is from '08 but might be worth a reread for new developments. It is interesting what it says about how the ECM reads the tables (r-l, b-t). Maybe it was another TBW thread where I brought up my in-law's 05 Forester which had a crazy-aggressive pedal for the first 20% then flatlined?

yea couple mods ... cone filter (which is getting replaced), turbo inlet, VF39, STI intecooler, TGV delete, bellmouth open DP, 3" open the rest of the way back. BCS table's zerod out and it hits 7psi at 2k and creeps to ~20 by 5.5k.