If, like me, you know little or nothing about a turbo, boost, BOVs, etc., have a quick look at this.
http://en.wikipedia.org/wiki/Turbocharger

Yea yea, I know wikipedia. Still, it is a good (very basic) introduction.

 

I have seen that Wiki entry before, and its actually full of information!

One thing I was thinking about today though, was in regard to how the tuning of turbocharged cars works. Most ECU tunes on turbo cars create gains by increasing the boost. My question is what drives this increase in boost? Do they tweak parameters like a/f ratio, timing, etc like on a N/A car, which results in an increase in boost? Or is boost tweaked as a seperate parameter? So in other words, is the increase in boost a function of the tweaked a/f ratios and timing or is it something they increase independently?

You guys must pardon my ignorance to the subject, but I really have no understand what goes in to it and would love to have a detailed explanation as to how ECU tuning on a turbo car usually works. I'm thinking someone like Ryephile would be a wealth of knowledge for this question....**paging Rye!**

 

Boost on most cars is controlled by the turbo wastegate. Here's an interesting writeup on a boost controller, which is basically a device that manipulates the wastegate vacuum to make the boost what you want it.

http://en.wikipedia.org/wiki/Boost_controller

 

Ok, so then when an ECU is tuned, they are simply increasing boost by altering the amount the wastegate opens?

 

Indeed, in most cases yes.

 

So then after that, the a/f ratios and timing are adjusted to accomadate the increased boost levels?

 

Same as the R53, modify the timing and fuel trims for peak efficiency, then modify the wastegate controls to allow additional boost. That's assuming the R56 allows for manipulation of the wastegate via software. All cars are different.

 

whenever you are reving the engine your making boost, BUT the wastegate dumps this boost unless the computer tells it not to, either partially or totally, also as stated more boost aka air requires more fuel and timing curves are altered to suit, depending what the oem or aftermarket has in the ecu, other inputs also come into the tuneup, very interesting and the newer direct injection is WONDERFUL more power and milage with less polution