Can we start a self tuner thread? Or section? Or sticky?
I had to put the file in a zip folder, (any folder renamed .zip, or compressed into a zip folder via the windows option) to email it. Once in a zip folder it was visible to my yahoo mail attachments.
Hope this helps.
ZACH
I had to put the file in a zip folder, (any folder renamed .zip, or compressed into a zip folder via the windows option) to email it. Once in a zip folder it was visible to my yahoo mail attachments.
Hope this helps.
ZACH
UP TOP!
I have a modded Grand Prix GTP, and pretty much everyone that runs 13.5's or lower tunes their own cars, and there is a huge wealth of information on tuning on both public and private forums along with a basic 100 page tuning guide. Maybe it is because they are FI and require more tweaking due to temp/humidity changes. I have been tuning my car for 3 years with a DHP Powrtuner that has access to about 200 tables.
After the initial learning curve, tuning is surprisingly easy.
Hoping to pick up a tuner soon for my LT1. On the GTP forums one of the first things recommended when people ask about mods is a tuner.
Key on engine off MAP reading 103.5 KPA
Max WOT MAP was 102.1, stayed over 100 the whole run. I was told that excellent, no intake restriction to speak of.
Max maf reading was 367 Gs
Iat started at 97.4 degrees by the end of the run was 93.7, gotta love that ram air hood.
Left o2 866-884
Right o2 895-928
Spark advance 34*
1-2 shift occured at 6200, WTF kinda low huh?
Why is the RPM/RPM 16 readings not in snyc? Sometimes they are as much as 500rpm apart.
Looks to be rich by the O2's.
Question, why is the RPM/RPM16 not in sync? As as 500 rpm off
Last edited by FASTFATBOY; Aug 15, 2009 at 04:18 PM.
This displays the current engine RPM. Note that sometimes during initial engine starting this value will be shown as extremely high as the PCM attempts to sync-up with the engine. If the RPM value falls below 500 RPM, the label will turn yellow to indicate a pending stall condition. Note that the GM datastream limits this value to 6375 RPM maximum.
RPM16
This displays the current engine RPM as calculated from the Distributor Reference Pulse (DRP) rate. This allows displaying RPM Values well above the 8-bit datastream limit of 6375 RPM.
Note that because DRP is measured at a slightly different point in time, and with greater precision than the ‘normal’ RPM calculation, the value is often 10-15 RPM different than the ‘normal’ RPM reading. This will be particularly evident during hard acceleration.
the above is from the datamaster help section
The Best V8 Stories One Small Block at Time
Key on engine off MAP reading 103.5 KPA
Max WOT MAP was 102.1, stayed over 100 the whole run. I was told that excellent, no intake restriction to speak of.
Max maf reading was 367 Gs
Iat started at 97.4 degrees by the end of the run was 93.7, gotta love that ram air hood.
Left o2 866-884
Right o2 895-928
Spark advance 34*
1-2 shift occured at 6200, WTF kinda low huh?
Why is the RPM/RPM 16 readings not in snyc? Sometimes they are as much as 500rpm apart.
Looks to be rich by the O2's.
Question, why is the RPM/RPM16 not in sync? As as 500 rpm off
Your maf reading seems far too low for the power you are making, I guess whoever tuned it made up for that in the pe tables. Its not a ported maf or something weird is it?
Narrow band o2 readings look ok to me but you can't trust them as far as you can throw them. On my car 930-940mV is 13.2 air fuel on the wideband. Then there are a lot of people who try to tune to 900 with narrow bands. Let me tell you it can be all over the place with mV to a/f depending on the car the day and the brand of o2 even ambient temps will mess with the o2 readings at wot.
If you enable the ability to see file extensions for the logs like .uni you can just go in and manually change the extension just like renaming a file to something safe like .jpg or .bmp and then it will trick the virus software into thinking the file is ok 99% of the time. It just looks at the extension to tell if the file type is dangerous most of the time.
Your maf reading seems far too low for the power you are making, I guess whoever tuned it made up for that in the pe tables. Its not a ported maf or something weird is it?
Narrow band o2 readings look ok to me but you can't trust them as far as you can throw them. On my car 930-940mV is 13.2 air fuel on the wideband. Then there are a lot of people who try to tune to 900 with narrow bands. Let me tell you it can be all over the place with mV to a/f depending on the car the day and the brand of o2 even ambient temps will mess with the o2 readings at wot.
If you enable the ability to see file extensions for the logs like .uni you can just go in and manually change the extension just like renaming a file to something safe like .jpg or .bmp and then it will trick the virus software into thinking the file is ok 99% of the time. It just looks at the extension to tell if the file type is dangerous most of the time.
Also when I logged the first time I saw I had a bad o2 sensor, was a flatline. why didnt it code? Does it have to have a heater failure to code?
Last edited by FASTFATBOY; Aug 16, 2009 at 10:02 AM.
Post the procedure Skip.
As far as posting the Autologing procedure, I can't post the whole procedure, but I can email it to someone to put on here if they would. It' a Word document.
Seems datalogging provides MUCH info, this Datamaster is incredible.
Sorry no way to really tell about knock, the black smoke out of the tailpipes is a surefire sign of it most of the time if the a/f is correct.
When I tune I use datamaster to log the wideband, but the way I tune is a bit different than average. I look at the pe tables to see what air fuel ratio they are commanding and then change the calibration of the maf until the wideband is reporting what the pe tables are commanding. The trick is to adjust certain zones of the maf table by half the % difference between target and commanded air fuel ratio. With a good tune pe vs rpm should be pretty much flat leaning out slightly after peak torque. Flat is ok until you get the maf calibrated.
Once you get the maf calibrated properly, It will allow you to change parts or do whatever and the air fuel ratio will be very close. You can also manipulate the air fuel ratio in any way you want vs rpm to to adjust the fuel curve.
When the maf is a strange one like you have transient fueling will be off so will heavy load at part throttle. As a side effect of that usually you end up with a bunch of trouble with knock retard. Which is why tuners hate ported and aftermarket mafs.
I dont know if you want to get that deep into it but if I were you I would be looking at an open loop speed density tune. The only snag there is it takes a very skilled hand and a bunch of time. Your pcm can loop up values from a table miles ahead of the maf reacting to change in airflow. However it is cake with the ls1 pcm and software now.
I hope there is something useful in there somewhere. Tuning discussions lead to rambling because either you get it all or you don't



