Here's my take on the subject, which is limited only to Scanmaster (SM), Turbo-Link (TL), and Direct Scan (DS). I can't speak for other tools/recorders, as I have no experience with them. I currently use all three: SM, TL, & DS.

Usually the question has to do with whether to buy SM or TL. Personally, I wouldn't be comfortable doing without either, so I recommend SM first if funds are tight and you are going racing immediately, followed by TL if you want simplicity, DS if you want every iota of data you can obtain. Although Scanmaster can't record a run, by always being there in the car, being on every time I start the car (in clear view on top of the radio pod in my case), it is invaluable as an on-the-fly scan tool. But that is about all it is, a scan tool, not a data recorder, so you can't go for a drive and then review the data later for diagnosis. On a WOT blast, it will have a "recall" available to display the lowest O2 reading at a specific MPH, and the highest knock retard reading at a specific MPH, but that's it.

TL, on the other hand, is a very easy to use data recorder that also serves the purpose of a scan tool, so if you have a laptop available, it is well worth the $150. DS is also easy to use, but the installation is a bit more complicated - mot a "plug-n-play". The disadvantage is needing to have a laptop plunked down somewhere� a bit cumbersome.

I'll presume everyone has been to Ken Mosher's http://www.turbo-link.com and checked out the Scan Tool Comparison Chart with the rest of his web-site, so I won't go into all of the specifics he already has available. If you haven't been there, do it. Also check out Kent Chu's http://www.chuengineering.com/ for additional information on DS and Modern Musclecar's http://www.modernmusclecar.com/ for SM. Lastly, check out gnttype.org to figure out what it is you see on your tool/recorder & what to do. I can't speak to any other units. They all have their positives and negatives, but in a nutshell, here are what *I* consider the biggees:

SM-
Pro: 3-wire installation (positive, negative, data-stream). Compact, always there.
Con: Only records high knock (& @ what speed) and low O2 (& @ what speed) during a WOT blast. Limited to ALDL data stream rate (1 "frame" of data every 1.5 seconds). Only shows one, sometimes two, data fields at any given time (selectable).
Summary: Fine for simple tuning and checking real-time operating parameters, but not a data recorder, just an "enhanced" scan tool, so best used with TL or DS.
NOTE: The turbo-link.com Comparison Chart may lead you to believe that a Modern Musclecar (MM) chip is necessary - not true. MM does have chips available that can increase the frame rate, but it corrupts the data stream to any other ALDL scan tools (like TL!). Also, with a bit of ingenuity, it does not have to be hard wired; some folks use various connectors (like alligator clip for the ground, female terminal plug for ALDL, and a cigarette lighter plug for power) so it is "transportable" between vehicles. Lastly, it is not only available from (or made by) MM, they have just done an exceptional marketing job! Also, there is a new version out that has additional features, though I don't know what they are.

TL-
Pro: Just plug the data cord (supplied with TL) from the laptop into the ALDL port (which makes it easy to go from one car to another) and you are ready to go. A true data recorder (up to ~7.5 minutes, so you can cruise around town, hopefully to "capture" data for an intermittent problem). Has boost sensing option (VERY desirable!!). Displays all TL available operating parameters at the same time. FANTASTIC technical support from Ken Mosher himself.
Con: Requires laptop computer. Limited to ALDL rate.
Summary: An excellent choice for a data recorder, especially considering the boost sensing which is a major parameter when you get into the fine tuning of the car.

DS-
Pro: 18.2 (maximum - selectable 18.2, 9.1, 6.1, 4.6) frames per second of data. More operating parameter readouts than TL.
Con: ECM needs modification for installation, and it doesn't always go smoothly. No boost sensing option like TL has (see NOTE). Limited record length ~104 seconds @ 18.2fps, 208 seconds 9.1 @ fps, 312 seconds @ 6.1fps, 416 seconds @ 4.6 fps.
Summary: WOW! 18 frames per second! Consider, on a full throttle launch I hit 2nd gear in -1.5 seconds. With TL, that could mean only 1, best case 2, WORST case 0, frames of data even though you just ripped through first gear up to ~5000 rpm. With DS, @ 18fps, in 2 seconds you will have 36 frames of data. In a 13 second 1/4 mile run, you would have ~9 frames on TL, ~236 on DS - a substantial difference when analyzing data.
NOTE: Supposedly Kent Chu is working on allowing 2 additional operating parameter inputs. Although the variables are endless, most folks will be using those two inputs for boost sensing and exhaust gas temperatures.

Lastly, I bought mine in this order: SM & TL at the same time, DS about 9 months later... took ~4 months to get DS to work right (friggin' ribbon cables and grounding)!!

HTH!

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Dean Nelson

[email protected]