Has anyone been datalogging? I've done one or two with my AutoTap for Palm and I'm getting some strange stuff.

First off, let it be known that I have not done a lot of logging and I am not skilled yet at reading them. I'm seeing timing advance being pulled on some hard accelerations. I'll do some more runs to see if I can make any sence of it. I'm just curious if anyone else is datalogging?

 

How is autotap on palm? I've been thinking of getting it....
I have an M505... Will it do a good job?

 

It doesnt surprise me to see timing getting pulled under heavy load.. especially on warmer days, or with 92 or so octane gas.. What gas were you running and what was the temp when you caught it? Also are you running any modifications? I always run 93 or 94 octane gas, but gas quality definitely seems to vary a bit in my area, because I got Ultra 94 from a Sunoco station, and the car ran great.. And I got 94 from another Sunoco in another location, and the car ran pretty aweful.. to the point that I suspect that they either mixed, or mis-filled their tanks with lower octane gas..

 

I prefer Amaco gas instead of Sunoco. Seems to me that every car I ran Amaco93 in ran better then the Ultra94.

 

Hi where did you get your autoTap from? If you purchase the port adapter, do you have to buy the software too? (i see it as a free download on their site).
note : above post edited for clarity.

 

www.autotap.com

They are actually a division of B&B electronics. www.bb-elec.com

Yes, I bought the software and hardware.

 

Its funny you mention that.. I'd been using Ultra94 almost exclusively, however I found I was getting poor gas mileage and what seemed like poor performance.. The other day I filled up with Premium from my local gas station (I think its Shell or Gulf) at 93 octane, and my mileage went up dramatically.. 250+ miles on a tank full, as opposed to 200 or so with Ultra, and I haven't changed my driving style. Not to mention the car feels a little nicer now.. So who knows..

 

From what you are saying the Ultra94 is probably oxygenated gas. Oxygenated gas has less power (BTU/gallon) than "normal", non-oxygenated, gas. This translates into worse gas milage and less performance.

 

Here is a screenshot of the Windows AutoTap Client :
(running a sample history log)

http://209.95.108.219/jemm/evo/autotap.gif

 

Does autotap just tap into the ECU and begin recording what the ECU is seeing? I'm seeing the timing changes are viewable, I guess the Knock sensor is viewable as well?
Lastly for the autotap users, is this software good enough for minor home tuners? AWD dynos are not easily accessible and I want to be able to just keep a close eye on the engine and engine management when changing boost and A/F settings.

 

Datalog fewer items. 3 at most, 2 or 1 is best. OBDII can only send around 8 to 10 samples per second total. So if you datalog 4 items, you get 2 samples per second per item. One sample every half second SUCKS! You can't figure out anything from that.

I'd datalog RPM and timing only. The third item I might add just to see where it is at is front O2 sensor voltage. But it is likely to just sit at 1.00V the whole time you are at WOT, which isn't useful.

With just RPM and timing, you get 4 to 5 samples per second. You are more likely to see a small dip in timing with twice as many samples per second. Just datalogging timing might actually be best, but the spot where the timing event occured is harder to figure out.

 

Oh, and Ultra 94 isn't a fuel that I've had good luck with. I use Mobil 93 almost exclusively.

 

Can somebody explain to me what this is?
Datalogging is recording what the ECU/car is doing, right?
How does this all work?
plugs into ECU, or taps in?
Do I use a laptop, or Palm?
How much is this?

Thanks in advance.

 

Incognito,
I'm researching and learning the ropes to datalogging too. So far I've found that you can measure anything that the ECU measures. Timing, fuel, coolant temps, MAF,O2, Knock...etc If it has a sensor on it stock the ECU sees it. So yes, it records what the ECU/car is doing.
The loggers I've seen hook to the OBII connection.
I've seen applications for both Palm and PC/Laptop
I'm looking into pocketlogger. Do a search for it on google and you'll find someone that sells them. Probably around $250 for the software and ?? for the Palm.

Someone step in and let me know if any of this is wrong. LIke I said I'm just now researching and learning myself this stuff.
While we're on the topic does anyone have any recommendations for loggers? I think I'm going the Palm direction with pocketlogger as I don't want to pay for a laptop.

 

Most loggers use the OBDII port(on board diagnostics). All cars sold in the US since 1996 have an OBDII port. It is possible that the ECU can have a sensor that will not be available on the OBDII port. OBDII requires certain sensor availability. Some software allows you to see some sensors that are not required; extra ones.

There are 3 different OBDII protocal standards. Why 3? I have no clue, but it sucks. The pocketlogger can only be used on one standard; Chrysler(sp) and imports I believe. It looks like a great interface, but its limited to that one protocal. I wanted one that could read all 3. There are a couple out there that do read all 3. I chose the AutoTap. Auterra is another brand.

With the AutoTap you can upload the log files into the Windows software for analysis. I like that too...

Laptops are too cumbersome to have in the car. Just setup a Palm to log the runs/trips, then analyse them later.