Engine management and tuning, stock and aftermarket systems can be discussed here. Information found here is mostly of very advanced nature and as such should not be approached lightly.
Forum Post / Reply
You must log in before you can post or reply to messages.
So does anyone else now realize why it took so long for them to write? Anybody? I know one of the guys who wrote the program and a lot of the walls they ran into. All it took was some patient people. I hated how people were ragging on them because they didnt release it fast enoug. Look at the list shifted posted, look at all the options there are, just look at everythign that program can do. I have messed with their F-body application and trust me they know what they are doing. I have had full faith in them as far as their tuning programs go. Nice Sticky Shifted.
How long does the cable datalog for before filling it's memory? 5 minutes? Longer? Shorter?
I assume you can set it to datalog... go for a drive... and then look up exactly what the AFR was at a certain RPM at a certain throttle position, etc., right? Then change the values and go for another drive to repeat?
Is that the big advantage of the EIO over the base unit?
Good question, Im wondering if you have the option to choose what you log or if it just logs all the inputs. If you could choose then maybe you would have more memory to work with for longer log sessions.
A tuning forum would be good. An HPTuners forum would not. It's realistic to expect other companies to release tuners now that someone has done all the legwork to solve the lock/unlock issues and work out the software within the PCM. If you want an HPTuners forum, well, go to the HPTuners forum.
To do a good job of tuning you have to know a fair amount about different systems. I have never seen any one book that handles everything. I have "How To Tune and Modify Engine Management Systems" by Jeff Hartman here in front of me. It's mainly focused on aftermarket engine controllers, but he does cover a fair amount of basics. There are probably 3 reasons why one book doesn't have everything.
1) You need to understand the fundamentals of an internal combustion engine. So many people are at so many different levels in this regard, where should an author start?
2) You need to have good information about the engine control system you're working with. This is probably the hardest part of the whole process to get correct. People who write tuning software often aren't engine tuning gurus. People who tune engines rarely speak ecm at the level of the software coders. I don't believe I know Chris, but once upon a time I was on a couple of mailing lists with Keith and I can say he's one of the guys that can live on both the tuning and coding side of this game.
3) You need to have specific instructions for the tuning software you are using. There are at least 4 companies that I can think of selling OBDII tuning software right now and no single one seems to be dominant. So it's not likely for an author to focus on one software package.
When carburetors ruled, there were perhaps a hundred variables to worry about on the most complex systems. With OBDI efi you could get tied into over 2 thousand bytes of variables to play with. OBDII?? Well, I'm looking at one file here which is 334 k . It's too easy to get lost in this stuff when you're just starting out.
The best thing is to try and get a tuners forum here or somewhere else, where the J car guys can hang out and share stories. As far as basic tuning you can get started by reading up on how the factory emissions and efi system is supposed to work. Books for someone taking college automotive repair classes might help. The factory service manual actually tells you quite a bit, too. And the Hartman book might be helpful when you're just starting out. If you want to be better at tuning than the average guy on the 'net, you'll have to use sources that aren't on the net.
Maybe Chris or Shifted can tell us if it's worth it to read questions on the HPTuners board about other vehicles. How close is the 4 cylinder control and tuning software to the LS engine truck or car software? Is there anything to learn there? Or are we just gonna have to do it all on our own?
I am just getting around to seeing this. lol
This is news is just as good as the invention of sliced bread.
When I get time, I will have to read up on this. And see if it works with my S/C.
Not really, I just got back from a business trip, need to get the car in drivable order so I can put it in storage for the next 30 days I'll be taking a trip to Texas on business for 30 days, coming back for 21 days to finish a project for work here, then moving to texas permanantly.
i see that its for 97 and up but whats the difference between 96 and 97 they have the same motor and same ecu im guessing coan some one tell me the difference
"A N/A ecotec is not gonna give Honda's and Mitsu's that much of a run for their
money unless their blown or bottle fed.GM is still smokin crack!"
~1QWKZ24
www.streetracing.org, 08/2001
does any one know if there a plans to make a version for the 96 or should some one just e-mail them and ask i know people with the 96 would love this tooo
If the tuning is entirely based on the TPS and RPM, what does it use the MAP sensor and O2 sensors for? I always thought these were most important.
What's the difference then between a program that supports a 2 bar MAP and one that doesn't? Is the 2 bar program just doing the "spoofing" that we've discussed here for ECU's without a 2-bar program?
Wouldn't all our cars run really rich in the winter when the air is colder if no compensation was made for the air temperature?
Remember, there are 2 modes of fueling. Open loop and Closed loop. Open loop uses the TPS, RPM, and other fueling tables. The Closed Loop operation uses feedback from the O2 sensor to control fuel. You usually don't see boost in closed loop, or even care about performance in closed loop operation (basically when you are cruising or coasting).
The only table with the IAT in it that I've seen so far is the IAT vs Spark table, where it retards the spark when the air is hot (first retard cell above 0 is 154 degrees and 90kpa manifold vac).
I haven't seen the 2 bar program yet, so I'm going to wait to say what exactly the differences are, but I'm assuming that yes, the 2 bar sensor just takes care of the "spoofing" that I described earlier. It allows the tables to have a true 0-210kpa with 5kpa increments.
Sorry, trying to get info on how many frames the EIO unit holds...
Yes, open loop is also used during startup, but thats not the only time:
Open Loop is used when:
1. Startup conditions for closed loop enable are not met (certain coolant temp based on what the startup coolant temp was).
2. Engine "limp" mode where the primary O2 sensor fails.
3. During "power enrich" mode. Power enrich mode is configurable, see screenshots below. During PE, the ECU does use the O2 sensor for feedback, but its not trying to hit a 14.7:1 ratio, stock its actually trying to hit ratio's in the 11.5:1 range depending on RPM. PE mode may also be delayed based on RPM (stock is like 3500 RPM before PE is enabled).
So, open loop is not just for startup, its where pretty much all the tuning will get done. Here's a screenshot of my PE table, where the engine enters PE mode.
I'll be taking a trip to Texas on business for 30 days, coming back for 21 days to finish a project for work here, then moving to texas permanantly.
