DangerousDan

iTrader: (8)

The wideband is actually a slang term that we've been using to refer to the whole setup:a wideband oxygen sensor, the controller, and datalogging software. Usually all this comes bundled, such as the zeitronix equipment that RRM sells. If you are worried about price I think that the innovate motorsports lc1 (what I have) is probably the cheapest you could reliably get this equipment. (needs to be calibrated on a regular schedule, others don't. you can do this yourself, just push a button )

A little note about the wideband UEGO(universal exhaust gas oxygen) sensor, it has to either replace the stock O2 sensor or you need to have a bung welded in so it can mounted itself. If you decide to replace it with the wideband sensor make sure you follow the directions exactly as written. The sensor wires have to be hooked into the ECU at the right points or the sensor will not function, or will not function correctly. The ECU has a few independent grounds to choose from, so it's easy to make an error. And you definitely can't just ground it to the chassis or battery. If you are adding a third bung then just follow the directions that come with the kit.

You need two of those serial to usb cables, because you need to log AFR to RPM and RPM to Voltage, in order to get maximum benefit. The LC-1 will only log AFR, and the piggyback is the only thing that logs the MAF correctly so far (unless one of the more expensive wideband units has an input you can use) so I bought the obdii cable from www.tactrix.com to log AFR to RPM, and I use the piggy back to log RPM to voltage so I can just use the RPM signal on each graph to combine the three. I have not been able to get the obdii cable to log my maf voltage properly, or I would just log all three from evoscan. They haven't been able to read our ROM, which means only the addresses in our ecu that are part of the obdii system can be read, so at this point I consider myself lucky to be able to do what I can.

You take the AFR and figure out whether you need more fuel or less (target for NA is 13.3 or so) and find the corresponding RPM. Take that RPM and cross it to the voltage to figure out what cell you need to use to create the 13.3 AFR. You will probably need to change the surrounding cells as well, because the airflow fluctuates a little as does the accuracy (and therefor the reading) of the MAF sensor. After you do the initial changes to get to where you think you should be to obtain a 13.3 make another set of logs (road dyno ) in the same gears as before and take new readings. Doing this a few times should smooth out your AFR a lot.

You should notice a difference in how the car pics up down low, and maybe notice a little more on the top end. Don't be afraid to add more fuel, especially around the mivec swithover. Take a look at the map I am running on my car and you will see what I am talking about. The mivec switchover leans the car out dramatically for a second or two, so you have to compensate by dumping fuel at the switchover. It makes for a much smoother transition and a whole lot taller wideband. when I first started doing stuff to my car it had a weak low end and didn't pull real hard until around 4100 RPM's, and when it hit 4100(when the engine starts getting the fuel it needs again) it started to pull harder. Even the map I am running now needs improvement. I just got the obdii cable and I can already see more areas I can improve. I can also see that the warmer weather is going to affect the tune.

Keep in mind that this programming is only good for wide open throttle. Under normal driving conditions the ECU uses the oxygen sensor to maintain a 14.7 AFR. The only real way to change that is to modify the ROM(see above )

DangerousDan

iTrader: (8)

I was going to pm this to a member and thought someone else might want to read it. Let me know if I need to correct anything.

superalf574

doesnt the tactrix cable only reflash 02-03 models so the ra is out the question

DangerousDan

iTrader: (8)

for more information about the tactrix cable and flashing ROM's visit openecu.org or the ecuflash subforum in the evo forums.

As of today noone has been able to read the ROM from a RA, at least to my knowledge. As stated above, however, the cable does have it's uses for tuning our cars now. There are one or two data items that I have noticed that are off a little bit. Little is known about the ecu and, as I stated above, the only addresses we can read accurately from the ECU are the ones that are part of the obdii system, as this system is government regulated.

I believe the Evo5-8 and the later model Wrx's can be read and flashed from the tactrix cable and ecuflash. And I think they recently added support for the new Eclipse AT and Evo9, although I am not sure how much they have mapped out on these Ecu's.

If someone with some knowledge about ecu's and programming would step up and take a look at our car we may be able to flash someday, but until then we do what we can do.

otter

iTrader: (14)

Thanks for the write-up, Dan, nicely done The only thing I have to add should be common sense, but there are people who do it and have gotten into accidents. When road tuning, let your logs do the work! Do not go flying down the road/on-ramp/whatever doing your 3rd gear pull while staring at your laptop screen. Please. Log your pull, pull over, make adjustments, do another pull.

Edit: Or what Mysz said down there.

Myszkewicz

iTrader: (2)

Or better yet, have a friend operate either the car or the computer for you.

DangerousDan

iTrader: (8)

I never tune realtime, and it seems so much like common sense to me that I didn't even mention this fact.

For one thing, it would be almost impossible to follow what the car is doing, even if you aren't driving, without looking at the logs. Logworks2 will let you graph realtime, but the refresh rate it uses for the obdii cable creates a stepped graph instead of a realtime graph. Evoscan will let you log realtime, but you can't watch the graph while datalogging, only the actual numbers.

A trick I use to mark my graphs, especially the long ones (30 minutes yesterday,) is to hit the clutch and rev the engine from idle to like 5k and let off. When you hit the gas the RPM graph will abruptly go from 7-800 and then spike to 5k, the AFR graph will spike to lean when you let off the gas. I don't even keep the laptop open anymore, and do all my changes on my 21" CRT when I get home so I can really check out the curves in detail.

Another tip, if you are doing quick runs for a base tune instead of logging to gather lot's of data, you can turn on the graph for throttle position and when it tops out and stays flat is your WOT part of the graph.

DangerousDan

iTrader: (8)

double post

superalf574

i tune on a dyno hahaha dyno queen ftw

DangerousDan

iTrader: (8)

This is a few runs I did, some in the morning before work and some on the way home so the temps are different, with the piggy back set to all 10's(stock map). I took out the parts where I wasn't in WOT, since that is what we are tuning for, so the files wouldn't be so large.

MODS: SRI, Pulley, DP, highflow cat, high flow muffler.

basically, it's lean down low and rich up top, at least for the mods I have installed. So when I go to change the tune I need to add fuel down low and remove some up top. "pig rich" comes to mind when I think about a car with no mods on the stock maps.

ralliart329

iTrader: (6)

tuning question:

I was looking at RRMs map just now and the whole 5500rpm colum has all fuel values in green, is their any significance to this?

DangerousDan

iTrader: (8)

that is because the options are not set to voltage but to pressure, I believe.

ralliart329

iTrader: (6)

thats it.

MITVRX

So with a wideband we can actually tune our car from our laptop correct? The only thing is we don't know how much whp we obviously have gained (or lossed). But I guess with the help of evom, we share maps I am to believe?

DangerousDan

iTrader: (8)

we can't share vendor maps, but if it's your tune you can do what you want with it. The goal is to obtain an optimal air to fuel ratio (~13.3 for NA) which in turn usually yields the ideal power output. This is why retuning is required after modifying the engine. With a wideband and a laptop you can tune your car, but if the AFR isn't plotted against RPM it will be more difficult and take longer to accomplish a flat AFR curve.

Check out the maps I have posted around, there is a "map B" I have posted that will assist you a whole lot in the final stages of your tune if you know what RPM is causing the AFR to change.

EDIT: here's the post