CarChips 8221 data logger

[01Z]

I'm so new with my U7198 that I'm still looking at the features. The Diagnostics shows several sensor data streams in real time. I see no logging option so I'm pretty certain the U7198 doesn't do it.

Davis Instrument markets a very basic data logger called CarChips. The 8221 version monitors and saves up to 75 hours of data. This is a stand alone part that is about the size of two 9v batteries stacked together. It plugs into any OBDII diagnostic port present on 1996 and newer cars. It uses a USB cable connection to upload each time stamped session to a PC where the accompanying software allows the stored session viewing. The user can command the CarChips to monitor and log 4 sensors out of a possible 23. These include vehicle speed, rpm, ltft, stft, o2 voltage, tps, iat, map etc...

The CarChips data logger is very affordable and that it fits in the palm of your hand, has no cables and stands alone is really enticing.

Now to the question: This logger can save the 4 sensor data in 5 second intervals or longer. I'm sure that is how it can achieve up to 75 hour sessions. Is a five second interval logging of any value or should I pass this up for something else? If so, what is the most economical but adequate alternative to data logging things like long term fuel trims? Thanks....

[mikel]

5 second intervals are not going to help much.

[01Z]

I was thinking that's what the answer would be. Being at open throttle for 6 seconds is only going to yield 2 snapshots and put me way over the speed limit.

I have done more searching and found there is a later revision - CarChip 8221/5B version claims to be able to record every second. Would a one second interval be of any value for tuning?

There's so few reviews on this data logging tool. One owner claims the 1 second interval is for vehicle speed only. The other sensors are still polled every 5 seconds. Hoping he's just confused and the advertising is not misleading.

At any rate, I'll have one in a week or so. They can be had for as low as $120. If it's inadequate I'll trade up to something else. My laptop is only a 166mhz Pentium with not so much onboard memory. AutoTap seems to require a faster processor - 233mhz (Pentium II), 64 megabytes of onboard memory - a lot for older laptops and 50 megs of HD storage.

Anyone have some advice on a good economical data logger that doesn't require a $2,500 laptop?

Thanks.

[mikel]

I'll put it like this, our Datalogger samples like every few miliseconds, so I'd say you want something faster.

Thanks

[01Z]

I hear you. My logic was that for now, I'm only interested in the LTFTs. I can watch them with my ScanMaster, Predator or even my Actron CP9145 scan tool but logging is what I want. I would think part throttle monitoring of the fuel trims even at 5 second intervals would give enough information to adjust injector slope in the sub 3000 rpm range. Open throttle is another matter I think. There's nothing regarding sampling rates for the AutoTap that I can find. Only EFIlive seems to give some idea on that but there's a whole new level of cost and learning curve.

I'm just trolling for a little more techno info so thanks for your previous reply.

[mikel]

I have heard of a few other OBDII dataloggers that are inexpensive, but cant recall who/what/where....

Thanks

[06MonteSS]

http://obddiagnostics.com/

[mikel]

Yeah, that one^^^!

[01Z]

Thanks Mike and Lew for your reply.

It looks like I would want the BR-3 (no CAN) version. The whole kit looks esoteric but long ago, I had programmed in four languages and have worked on PCs at the DOS and assembler code levels.

I've downloaded the free software, if I can determine how it well it will work with my 166mhz laptop, I'll cough up the $83 for the hardware. I wish I could find a sample of a log file. Maybe after I run the software simulation mode I'll have a better idea of what it is.

Thanks again!

[06MonteSS]

here's another good one...

http://www.myscantool.com/