First, yea that's not going to work well Walker, have to go to a smaller tube or maybe run SD at idle?
BlueCat's tool has copy/paste functionality into HPTuners that lets you graphically display 06+ ECM VVE (Virtual Volumetric Efficiency) coefficients in a manner similar to that of a LS1 PCM, E40 ECM, and many other earlier factory and aftermarket controllers.
FYI, HPTuners is finally beta testing their implementation of a VVE graph in the latest 2.25 beta. I tried playing with it, but as of 3 weeks ago it was just a view-only and no modifications could be made/written back to the Coefficient tables.
This leads a big question: Why did GM move from a real VE table that let you explicitly state x% VE at a give RPM and load or grams/sec value you ask? 3 words: Variable Valve Timing.
No VVT: VE tuning is pretty straightforward as the spark timing is a known value, i.e. at 3000RPMs at 75kPa MAP, spark timing is 20* (hypothetically). The cam is statically based off the spark timing. Disable the MAF sensor, set the tune up properly so no modifiers are impacting the base VE table, and start driving/logging. Make corrections, get fuel trims within +/- 2% IMHO, and move on to MAF tuning (or do MAF first, up to you.) Straightforward.
With VVT: Spark timing is still a known value, but using exhaust cam timing (1 cam with VVT) as the example it is no longer directly related to the spark timing as through VVT the cam timing can change rapidly based on load and RPM. GM initially compensated for this by using multiple VE tables. Using the P12 in 04-06 Colorado and the 05-06 Cobalt SS S/C as an example, this controller has 5 with one for a set cam timing degrees of VVT. I.E. you'd have 1 VE table for 0* cam timing, another for 5*, another for 10*, etc. The PCM will interpolate 8* as a weighted blend of the 5* and 10* tables, just how it does for spark timing. Great, now you have to lock the VVT at a set point and tune the VE for each one. Adds extra time to building a proper calibration to accurately reflect the airflow model of the engine but still very much doable with physical (as-in defined in the PCMs memory) VE tables.
Ok so that's not horribly, we went from 1 VE to 5 VE tables and still have the MAF table. But wait, there's more: now add intake cam VVT in on a DOHC engine. We now have 2 cams with a drastic range of timing options for each. There was no feasible way for GM to build multiple VE tables (we'd be up to at least 25-30 I think) as you run into processing constraints due to the amount of processing power available while still maintaining the required feedback such as injector pulsewidth/etc. Solution: Build a crazy polynomial equation that takes all of this into consideration. It isnt pretty to tune, but the guys that do this day in and out have become pretty adept at figuring it out. Back in the day when most of the engine being tuned were LSx V8s, disabling the VVE coefficients and running MAF-only was an acceptable solutions at the cost of throttle response in some cases (SD is usually more responsive, again usually being the key word). With the I4 guys (Cobalt SS T/C really started it), this was an option but was not the best one as cam timing can drastically affect the engine's ability to breath which is the entire point of VVT.
BlueCat's tool for HPTuners graphically displays this polynomial equation as if it were a LS1 based-hardcoded VE table instead of the multiple coefficients. I believe it only allows for 1 cam at this time, so people doing calibrating both cams are using a custom solution I'm unaware of.
FWIW, EFILive has had the VVE coefficients displayed graphically in their software with editing capabilities since ~2007 IIRC.
If you're still reading this, you are either 1) dedicated and want to learn or 2) bored at home. Either way, thanks for reading and let me know if there are any questions. I glossed over some of the smaller pieces to get to the end result so dont take this as an "end-all, be-all" explanation. There's a reason powertrain engineers at GM get paid the big bucks to develop this stuff!
and sql not bad, you can google just about anything you need on a database the size to hold the data from a car.
