Cobb AccessPORT Discussion
I'm starting to winder if my lean condition was just a problem with lag in reporting....
I switched to the Cobb Stage 1 map yesterday and my car is running pretty good. Its pulling no LTFT. So i romp on it in 2nd gear this morning and watch the AP display for the afr's. I'm getting up to speed and by 7k again i'm seeing 14's again! I'm thinking WTF! Right at the time I leave completely off the gas around 8k, i see 13.6, 13.1, 12.6 flash quickly on the display and then it goes to the 20.3 ratio i would expect with my being off the gas and engine braking.
So it looked like that I didn't get the afr displayed I expected (the 20.3) for a good 2 sec or so... which in 2nd gear 2 sec can be a pretty large amount of rpms at WOT. So i'm wondering if the problem is just in reality lag in the AP display. Perhaps I will risk melting my cat tonight and log with the CANScan.
I switched to the Cobb Stage 1 map yesterday and my car is running pretty good. Its pulling no LTFT. So i romp on it in 2nd gear this morning and watch the AP display for the afr's. I'm getting up to speed and by 7k again i'm seeing 14's again! I'm thinking WTF! Right at the time I leave completely off the gas around 8k, i see 13.6, 13.1, 12.6 flash quickly on the display and then it goes to the 20.3 ratio i would expect with my being off the gas and engine braking.
So it looked like that I didn't get the afr displayed I expected (the 20.3) for a good 2 sec or so... which in 2nd gear 2 sec can be a pretty large amount of rpms at WOT. So i'm wondering if the problem is just in reality lag in the AP display. Perhaps I will risk melting my cat tonight and log with the CANScan.
On a WOT run for example, the AFR displayed was/is probably the AFR from 1-2 seconds prior...
It makes sense as any digital readout needs to take a number and hold it for a second to allow a human to understand it... just depends on the programming how it decides what to display and what not to display with the data changing 10 or more times a second
Just can be a bit scary though...
Just can be a bit scary though...
I know everyone has been using the accessport to display AFR's. I wanted to remind everyone that the MSD Dashhawk is a product that plugs into your OBD II port and is capable of reading the O2 sensor AFR reading in real time as well as STFT and LTFT.
It can display up to 7 different types of information as well as perform logging capability.
Check it out at www.dashhawk.com
Just as a means of helping everyone out!
It can display up to 7 different types of information as well as perform logging capability.
Check it out at www.dashhawk.com
Just as a means of helping everyone out!
For N/A applications the stock wide band should be just fine. Your assumptions for having an aftermarket wide band are no doubt correct for FI people. I'd be scared to have a turbo/SC without one.
I know everyone has been using the accessport to display AFR's. I wanted to remind everyone that the MSD Dashhawk is a product that plugs into your OBD II port and is capable of reading the O2 sensor AFR reading in real time as well as STFT and LTFT.
It can display up to 7 different types of information as well as perform logging capability.
Check it out at www.dashhawk.com
Just as a means of helping everyone out!
It can display up to 7 different types of information as well as perform logging capability.
Check it out at www.dashhawk.com
Just as a means of helping everyone out!
I grabbed my video camera today. Will take a little bit of video tonight on the way home. Stuff like how the car starts up, how it cruises, transition into boost, etc. Let me know if there's any requests. Unfortunately I still haven't found my camera mount, so I'm stuck holding the camera with one hand and steering/shifting with the other.
I want both and guess just a lil impatient.
Xcodes??? I can't read afrs w/mine
Last edited by Derex'8; Mar 21, 2008 at 09:01 AM.
I haven't had time to play with it yet to see if it works on our cars, but there is an open source OBD-II reader/logger that Cobb supports for datalogging if you have an AP and a laptop
http://forums.cobbtuning.com/forums/...ad.php?t=36743
http://forums.cobbtuning.com/forums/...ad.php?t=36743
Everyone's basing these findings off the live data screens on the AP, correct? I'm going to do data logging this weekend with my scanalyser. I am not seeing the lean conditions you guys are seeing on the AP, and I don't have the answer why. I'm seeing AFR's around 13 to 12.5 at WOT.
Everyone's basing these findings off the live data screens on the AP, correct? I'm going to do data logging this weekend with my scanalyser. I am not seeing the lean conditions you guys are seeing on the AP, and I don't have the answer why. I'm seeing AFR's around 13 to 12.5 at WOT.
I have the RB REVi, Unorthodox Underdrive Pulleys, RP Supercat, and RB REV8 currently. Next week I'll have the Mazsport ignition and catless midpipe to add to the equation. Maybe then I can make that comparison.
From what I've read the ODB2 port really isnt difficult, it's similar to an RS232 port, building a connector shouldnt be very hard and I might even be able to (ab)use the COBB connector. If this is the case we are getting severely ripped off on datalogging hardware as there are plenty of open source software readers out there!
http://www.accessecu.com/support/ecu...plorer-src.zip
I'm hoping to do some logging on Ngo's car with my scanalyzer this weekend and see what we can come up with.
Jeff: I'll get to work on a dyno day, just let me know what weekends are not good for you in April / Early May.
Jeff: I'll get to work on a dyno day, just let me know what weekends are not good for you in April / Early May.
It does seem like the AP display is really laggy.
To tell the truth, I hadn't hardly used it. The software has logging built in, so I use that on my EeePC (or the CarPC).
To tell the truth, I hadn't hardly used it. The software has logging built in, so I use that on my EeePC (or the CarPC).
I initially flashed MM's 1_0 map and after a little while my STFT dropped to 0, but my LTFT during acceleration was around 8, IIRC. It seemed to run just fine with 1_0 map, but the trims were a little off. I guess what I'm getting at is...is this normal?? Am I going in the right direction?? Should I quit messing with it?
I'm a little bit confused. Here's what I've got...I'm on 1_1b flash right now. My STFT has stabilized and it hovers around zero +/- 2 at idle. My LTFT at idle or coasting (no load) will stay anywhere between 18 and 22. My LTFT under load during accelleration drops to 1 and will stay that way until I let off the gas.
I initially flashed MM's 1_0 map and after a little while my STFT dropped to 0, but my LTFT during acceleration was around 8, IIRC. It seemed to run just fine with 1_0 map, but the trims were a little off. I guess what I'm getting at is...is this normal?? Am I going in the right direction?? Should I quit messing with it?
I initially flashed MM's 1_0 map and after a little while my STFT dropped to 0, but my LTFT during acceleration was around 8, IIRC. It seemed to run just fine with 1_0 map, but the trims were a little off. I guess what I'm getting at is...is this normal?? Am I going in the right direction?? Should I quit messing with it?
I thought positive LTFT and STFT numbers meant go up the "a" map scale? Maybe I have been doing it backwards. I started with the 1_0 map at first of course and now am using the 1_2a map since my LTFT at idle ended up around +5. Haven't driven enough on that one yet to see if I need to make another change but it does seem a little rough occasionally at idle at the moment. I'm runing a MS CAI and a midpipe. BTW I've resorted to using my canscan to monitor trims and AFR.
Clarification -
If your fuel trims are POSITIVE, you go with the "a" series to lower them.
If your trims are NEGATIVE, you use the "b" series to raise them.


