Basically is there a system that you can hook up a WB to and command an AFR based on TPS vs RPM or MAP vs RPM and the system will dial in fuel to achieve the commanded AFR based on programming and the feedback from the WB?
So the fuel map would have RPM on one axis, manifold aboslute pressure on another axis and desired AFR or lambda in the table. Can this group of sensors and system react fast enough to work?
Yup. Many will do it. The MS can do it and would be the cheapest solution. It will tune MAP vs. RPM and use the target AFR to do a 'auto tune' and populate the tables.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
Joshua Dearman wrote:Yup. Many will do it. The MS can do it and would be the cheapest solution. It will tune MAP vs. RPM and use the target AFR to do a 'auto tune' and populate the tables.
What tables is it populating? VE tables? Does it take constant feetback from the WBO2, sort of like a closed loop via WBO2, or does it populate tables and not look at it again unless you tell it to.
Sorry if that was unclear, but to me it seems like the ultimate method to tune fuel. No MAF calibration, no multipliers, no "off the map" values. Just a system achieving the AFR commanded by a sensor designed to measure AFR...
So, it will constantly get feedback form the WBO2 vs. TAFR table and use that info to populate the VE tables. It's really good for idle tuning and just-off-idle really. It can also do PE tables to 'update' what you have in the tables with feedback from the WBO2. Don't get me wrong, all it really does is 'update' but to even get started you have to have a decent number to begin with for the PE's and then from there it will dial them in based off the WBO2. But for a motor that you have no idea the MS can still help you out a little, all you gotta do is tell the mega what you size motor you are running and what size injectors you have an it helps with a couple of numbers but for the most part you have to come up with something that works. So it wont just populate tables that are blank to begin with...no. But lets say you have a NA tune to begin with and you add a small boost....if you let the MS 'auto tune' the setup and slowly bring the MS into the range where it needs to add fuel...it will...and it will update the tables to match what it actually needed to match the target AFR. Basically it just articulates the tables to match what you need after you have put on a power-adder. Obviously matching against the Target AFR table you setup.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
Sounds close to ideal, but is it updating tables in real time, or is it a "log and flash" ala HPTuners. If it is updating in real time, is it doing so infinately, or only when you tell it to (in which case there would have to be some kind of fuel trims).
Thanks for reading and helping out!
Here's a good how-to I've used in the past. I havn't looked back into it in years really so I'm not sure exactly if it still requires program editing, it might, it might not, but either way it's pretty easy. It's based on lag and flash but you can flash on the fly.
Linky
It wont do indefinitely unless you stay in the 'auto tune' mode indefinitely. Which I'm not sure you'd want to since the processor overhead would be pretty high. Not problem for most but if you pushing the MS to it's limits you will need damn near every clock event of the processor to run scheduled tasks. But again, pushing to the max I mean running data out the CAN, processing incoming CAN, RPM windows with fuel map swaps, ect. Most wont be pushing it that hard.
EDIT, the nice thing about it is that you can leave your parameters saved in your custom.ini file and anytime in the future you upgrade the turbo, cams, ect. You can just hop back into the 'autotune' feature and away you go....no real setup to speak of. Obviously assuming you want the same target AFR's and have the same WBO2 voltage references.
To me, it sounds like you will want to wait for the new MS3 that is in development. Still in Alpha/design of alpha, no Beta to speak of. The new MS3 will run individual WBO2's + Pyro's on each exhaust runner and actually run 1 designated processor for each cylinder(supposedly) and do real-time physics models on each cylinder. This is also nice cause it can give you statistics to compare one cylinder to the next for comparisons and performance characteristics. Basically used for diagnostics and such. It will also be scalable meaning if you only want to run 1 sensor you can use that input and send the data to each processor as an average just like the ECU's do today. One IAT, must mean all IAT's are the same, same idea. So you could run 4 WBO2 and only 1 pyro, or vise versa, whatever you think is more important. It will also be modular, meaning you can add-on more capacity in 2 cylinder modules(supposedly). So you buy a base model 4cy MS3 setup and if you want to put in on a 6cyl in the future you just buy a add-on for 2 more cylinders....comes with two more designated processors and I/O headers for the sensors. This will obviously break-the-bank as you could imagine but the cost for those wanting something like this would be worth every penny.
I can't say when this will be coming to market.... I can't even say there will be independent processors yet really since the only proto is single processor but it's a fast processor already and it is way overloaded. Either way, what is FACT in all this info is the independent sensors running full physics models on each cylinder and support for 8 cylinders will also be possible...whether it is modular or has individual processors/cylinder is still yet to be seen.
Edited 3 time(s). Last edited Wednesday, May 13, 2009 11:20 AM
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
I think it's fair to note that in order to use AutoTune you have to keep the laptop hooked to the MS unit while driving. Which may or may not be convenient to you. There's auto a feature called "automatic mixture control" which will do something like AutoTune does, however it's internal to the MS. You can set it up to do this and save to RAM (thus you need to hook up your laptop and do a fetch/burn before turning the car off to keep those tables) or you can have it re-write the flash on it's own, which will just keep re-writing the flash as you drive down the road. Not sure reflashing that much is a great idea though.
www.gmscf.com
I've never had really great results with the mix control...but to each his own. Also, like the ability to maintenance the T-AFR tables and then just let the MS tune in a new mod. I know the mix control can as well, but I feel I have alot more control and stedy results with the auto-tune.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
Hmmm so it looks like the simple answer for MS is "no". It can tune via wideband, but at best its populating VE tables, not constantly taking feedback from the WBO2, except the functionality that SHOoff mentioned. This sound's good for getting the fuel dialed in fairly quickly. But i agree it can't be ideal to have the car constantly flashing the ecu while driving.
I guess at the most basic level, i'm looking for a system that will read voltage from a WBO2 and adjust pulsewidth based on that reading. You may have to give it a slope and offset, or a set of x=voltage for y=lambda/afr, but it will take feedback from the sensor constantly and adjust the injector pulsewidth to the reading from the sensor, similar to closed loop operation on a narrowband system.
One question that comes to mind is if this is possible - will the ecu be able to adjust fueling quickly enough based on one reading to be safe and driveable?
MS will do what you're asking. In the section on what kind of O2 sensor you have, you tell it the particualr WB (if you have one that's on the list) or a Generic WB02 if it's not on the list. Which you'll have to adjust the settings for in order for it to read.
Basically the whole thing is here, you have to have settings put into the tables. Even with your stock ECU there has to be something in the tables. All your O2 sensor is used for is a correction factor. On MS you can change that correction factor to 100% if you'd like, but it's best to get your tune dialed in, then have the O2 correction be 10% or less.
Autotune or AMC on the system will eventually get things down, but it'll take a long time to get there. There is no substitute for some good tune time on the dyno.
www.gmscf.com
SHOoff wrote:Autotune or AMC on the system will eventually get things down, but it'll take a long time to get there. There is no substitute for some good tune time on the dyno.
I agree 150%. I use Auto Tune to get things close, then dyno to get the band to look nice, then update the TAFR tables to match what the dyno suggests which then will allow auto tune in the future to get that much better...or AMC...if that works well for you.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
