Series I L67 tuning

[J Wikoff]

If I want to tune my Series I L67 myself, what are my options?

[Matts75]

Dude I've been reading lots o forums and gobs of information. Being that we got almost the same computer the guy Ryan at Sinister Performance is the way to roll.

[dirtracr95]

http://www.tunercat.com/

I am going to buy the Romulator and all the other stuff to tune my LN3 once I get done building it.

[willwren]

Burn the prom, trial and error. We have a Gearhead that does them.

(for himself, not for other members)
IIRC, he uses tunercat also.

[GoldenBullet]

i would like to get in this someday myself, is there anyway said gearhead could post some info and/or maybe a techinfo?

[J Wikoff]

What all equipment would I need? Is there a good tutorial somewhere?

I talked to Ryan a few years ago, but I still had mod plans I was working on, so I never followed through with meeting up with him to get it done.

[dirtracr95]

What will I need to tune my vehicle?
In terms of software, you'll need to purchase the C.A.T.S. Tuner program and the appropriate ECM Definition File for the type of vehicle you're working on.

In addition to the software described above, you'll also need some hardware. What hardware you'll need depends somewhat on what type of vehicle you're working on. There are two basic types of ECMs; the older ECMs stored the calibration information in a removable EPROM and the newer ECMs which store the calibration information in FLASH memory (94 - 95 LT1 cars).

If you working with an ECM that has an EPROM, you'll need an EPROM programmer and an EPROM eraser. Virtually any EPROM programmer will work with the EPROM's used in these ECMs. We recommend the Pocket Programmer from Xtronics (www.xtronics.com). It is very reasonably priced and works well. Like the programmer, almost any EPROM eraser will work. Xtronics also carries an inexpensive eraser that works fine. It also makes things easier if you have a few spare EPROMs as well.

If you would like to be able to tune your vehicle in 'real-time', that is while the engine is running, you'll need the RT Tuner program ($99.95) instead of the standard Tuner program, the appropriate ECM Definition File and the Romulator EPROM emulator from Xtronics or the Ostrich or AutoProm emulator from Craig Moates (http://moates.net). Real-time tuning allows you to immediately see the affects of any changes you are making and can significantly shorten the tuning process. The RT Tuner program does everything the standard Tuner program does in addition to real-time tuning support so you don't need both programs. When you're finished tuning, you'll want to program an EPROM with your final calibration and disconnect the emulator so you'll still need an EPROM programmer.

If you are working on a FLASH based ECM (94 - 95 LT1 cars), you don't need an EPROM programmer or eraser because you can re-program the FLASH in the ECM by connecting your PC to your vehicles ALDL connector. You will, however, need a special ALDL interface cable to connect your PC to the ALDL connector in the vehicle. We recommend the cables from AKM Electronics (www.akmcables.com), TTS Power Systems (www.ttspowersystems.com) or Craig Moates (http://moates.net).

Please note that since the Flash based ECMs do not have a removable EPROM there's no way to connect an emulator to these ECMs so you can't do real-time tuning on these cars.

[clm2112]

TunerCat is probably the least expensive method of tuning the Calibrator Prom based PCM's. It's an inexpensive piece of software and you purchase the maps to work on specific types of calibrator proms seperately. Here's the list of supported PCM's (L67's are about 2/3rds of the way down the page.)

http://www.tunercat.com/tnr_desc/ecm_sup.html

To make it work, you need an EPROM burner/reader, a UV eraser, and a few little convieniece items from somebody like Craig Motes (a little adapter to let you plug the entire calibrator module into the eprom reader.)

I did a write-up a while back on how to modify a GM calibrator prom so the EPROM can be removed for erasing it.

For a burner/reader I'm using this neat little one made by Batronix in Germany

http://www.progshop.com/shop/programmer ... ammer.html

It's a cool little one that runs on the USB only (no extra power needed, so you can run it off a laptop.)

And for an EPROM eraser, I use a DataeraseII UV eraser that I bought from DigiKey years ago. Not sure if it is still available, but any inexpensive UV eraser will do.

You can also get a couple of spare EPROMS that match the car you are working on, like 27C512 eproms ( they are standard sizes, "27" is common designator "C" is for CMOS transistor types and the "512" means 512 kilobits of storage space.)

You'll have about $350 tied up in this gear. You don't need to get it all at once, start with the Tunercat software & map, then see what values are available for you to modify within the prom. I can give you a few binary files read from GM calibrator proms as examples.

The tuning proceedure goes like this:

1.) take the calibrator prom out of the car and read it's contents using the EPROM reader/burner into a Binary file on your PC.

2.) use Tunercat (or any other editing software) to read the binary and edit the values. Make your changes and save the binary file.

3.) use the UV eraser to blank the EPROM so it is ready to be reprogrammed.

4.) use the EPROM reader/burner again to take your modified binary file and program the EPROM

5.) install the EPROM into the car and try it out. Use your own favorite diagnostic tools to figure out if the change to the Calibrator Prom is what you expected.

Repeat the process until you get the car behaving the way you want it to. Make small changes to the binary file and burn an EPROM for testing. The tuning process is best described as "successive approximation"...you never hit the mark on the first try.

You can also read the calibrator prom, then send it to Ryan to let him make the first round of changes for you, then read it again when he is done. That way you can learn by example.