CarChip E/X data

[Donald]

OK, got the chip. And collecting data like crazy.

Now what? :help:

Just got back from Vegas.

181.5 miles, 2:49:24, max speed 95, 10 hard brakings, 1 hard accel, max coolant temp 208.4, max intake temp 96.8, max throttle 93%

[TAF]

Originally posted by Donald
10 hard brakings, 1 hard accel,

Shouldn't those numbers be "switched"...;)

[Donald]

TAF,

Can't on a Sunday return from Vegas. ;)

[Slowpoke]

All that data and what to do with it?? I am still trying to figure it out; but I do know that for keeping track of trip length it is perfect. Over time I hope to gather and analyze trends in my driving habits, mileage, etc. It's just another toy - to quote SargntMac, "I love toys"

[Donald]

I found my trip to work is 53 miles. And it seems to take around 55 minutes. On a good day.

[SergntMac]

I've had my Car Chip a week now, and in measuring some things, it's neat. Monitoring engine temps, RPM, speed and so on, it's great at collecting data. But, what does some of this data mean? How can I use short and long term "fuel trim" data to any advantage? Unfortunately, the 63 page .pdf that comes on the CD isn't much help. It tells you how to manipulate the program, but offers no advice on what this data means. Anyone know of an equaison I can apply to combine fuel trim and air flow data into something useful like AFR numbers? Hope I don't have to be an aircraft engineer to figure this out.

I am also disappointed in the software limitations. I left the chip in for 380 miles, only to find out that the program cannot display all of the collected data "due to a windows limitation." Eh? That seems enough for me to ask for a refund, but OTOH, I don't think the argument with Davis industries is worth the bother.

Well, I guess it's handy in monitoring some stuff, and time will tell if there is going to be any better use for this item. So, if any of y'all from my area want to play with this..."toy," give me a shout, I'll loan it out to you. Anyone thinking of buying one of these, borrow one first.

[prchrman]

Bought a G tech and got it going...now got to find someplace flat enough to get good results (live in mountains/all curves and hills/I do know how good the handling is in the MM, WOW!!)...obtw it was used but in great shape and $50...the amazing thing is it's not bigger than a post it note pad...but it works...:burnout:

[martyo]

Old thread, but worth a revival. What data are you guys collecting with the Carchip? Any interesting findings?

[Slowpoke]

I use it for several things:

I am using it mostly to measure dstance and times on the occassions i use the car for business purposes.

I can also make sure the building car valets dont go for a joyride.

I am storing the data in excel and wipe the chip clean about every 6 weeks.

I think I am tracking speed, RPM's engine temp, fuel trim, etc. The manual does indeed suck, but the benefit of having all the trip data far exceeds the limitations of the software. Perhaps I should have bought the cheaper version which holds less data [since i do not srive all that much]

when life slows down a bit i will add the MPG info i am keeping in a separate Excel workheet to do a regression analysis to learn exactly how my car sucks gas, and under what conditions it performs best.

either way, for the car enthusiast who also loves data and computers, this chip is a most rewarding toy. I would be happy to send out the manual - in PDF form - to anyony thinking of using it.

At the chicken meet, other people could take a spin in their car on the highway using my chip and I can email them the info from their trip. I would bring a laptop but i dont have a power inverter for the 110 volt AC power cord for the cable that hooks into my computer.

like I said in the original post 6 months ago about this product - i nicknamed it "The poor man's dyno" !

[Donald]

I don't know why I am using it. :-) I have found that, on a good day, my commute is about 55 mins. And the trip home is 1 mile less that the trip to work. I am surprised at the number of hard brakes I do in a day. And at my top speed during the commute and the time spent at that speed. Right now I am collecting coolant temp, intake air temp and timing advance. I am doing the temps because the daytime temps where I live/work have been around 100. I wanted to see what the car saw. I plan on installing the 'Dennis' stat and plugs today. Will see if there is a diff in my log.

[SergntMac]

I found a few more uses for it, like 'Poke says, it's a great security device. It also records when it's unpluged, even with the ignition off. It records an "accident file," which captures the last 20 seconds of data prior to a hard stop. Great if you have teen drivers. But, this data could save you, or hang you, as evidence.

Lots of this stuff is saved in the ECM anyway, when I took over the Kenny Brown MM, I put it in for the ride home. I collected my trip, as well as the last few trips before I took possession. Don't know what Kenny was doing, but he was doing it at 137 and 139 miles per hour. If the AutoWeek special was filmed April 9th, this makes sense.

I also used it to monitor my engine temps at the drag strip. This car heats up fast, it will climb to 100 degrees in two minutes, and full operating temp in seven. Dennis said I should run at my full operating temp for ideal combustion, and the chip confirmed that I was. I also use it to monitor the charging system when I added the underdrive pulleys, my MM never dips below 12v

I do wish it had other features, still can't figure out what to do with the four choices on fuel trim...There has to be some important data there, but I know little about fuel trim.

And I wish the connecting cord was USB, I have to pull my computer away from the wall to get at a serial port, both home and office.

All in all, it's a handy device, but pricey for being just handy.

[TripleTransAm]

Originally posted by SergntMac

I do wish it had other features, still can't figure out what to do with the four choices on fuel trim...There has to be some important data there, but I know little about fuel trim.


I am curious about these 4 choices on fuel trim. Can you tell me more about them? If they are what I think they are, this may influence whether I decide to buy this item or not.

For those who are wondering what fuel trim is, it's the offset that's applied to the car's fuel tables, to richen or lean out the mixture based on different driving conditions:

For example, if the tables say one should run x amount of fuel at y throttle at z RPM for a certain air flow, the computer will read the oxygen sensor values and determine whether that base value of fuel makes it run too rich or too lean. It then corrects that base value by setting an offset for this driving condition. There are usually short term offsets/trims (the ones that are very dynamic and change very quickly, and there are long term trims that serve as a more average adjustment to the currently-loaded fuel tables).

Reading these trims is useful when looking for vacuum leaks or bad injectors etc. In my GTA, cruising around will show beautiful numbers for both long term and short term trims, meaning the factory tables are doing a great job of maintaining a 14.7 air/fuel ratio. However, at a complete stop at idle, I'll see the short term numbers shoot up quickly and then eventually the long term values will slowly creep up as well, indicating the computer wants more fuel at that RPM to maintain 14.7 air/fuel ratio. And this tells me I have a vacuum leak somewhere near my throttle body, which I will address one of these days when it affects my driveability (that's the beauty of electronic engine management... I must have a small vacuum leak somewhere and yet the car drives normally thanks to corrective measure by the ECM!).

[Slowpoke]

who needs teenagers when Kenny will drive your car at 130+ mph!