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Old 10-14-2003, 08:48 PM   #236
Scooby Newbie
Member#: 40416
Join Date: Jul 2003
Location: CA
68 Porsche VW Bus



Sorry I have not looked into this thread in a while (was dead for a while). Please use our Yahoo forum (see our web-site) for LM-1 questions. It is impossible for us to monitor all threads about the LM-1 on all forums. There are just too many now. And I am busier than a one-armed juggler trying to get a lot of stuff ready for SEMA.

But here some updates:

1. Remote display kit.
There are 2 versions.
First version will be out in a couple of weeks, waiting for first run of production units from manufacturer. Was a screw-up with the front logo, otherwise would be out by now (Murphy strikes again).
The first version (low price) is a 2-1/16 analog meter (8-18 AFR) that hooks up to analog out 2. This is a needle instrument, not a LED bar thingy. Settings for output 2 to be published.

Second version is a 2-1/16 round instrument, hardware finished, software in development. Round 270 degree LED row with 3-digit LED number display in center. Also has 'record' button. Hooks up to serial out of the LM-1. Also has a female Mini-DIN8 'dongle' on the back to hook up a laptop for real-time datalogging and download of logs from LM-1 and LM-1x. Expected to be out in about a month (I am putting very heavy pressure on the engineers that are doing it, many people want it).

2. Glitchy bar on bottom of display
The numeric display is AFR and Lambda averaged over 1/3 second. The bar on the bottom is 'instant' AFR or Lambda as measured. If it jumps around a lot, it is because of valve overlap. Some of the mixture (specially at idle) will pass unburned into the exhaust, supplying free oxygen. A WB sensor (if it's fast enough to react) measures that as lean peak. The same happens for a missed ignition. The 'instant' bar allows you to see that.
Analog outs (at least with the 1.1 firmware) are also derived from instant lambda. A new upcoming firmware release allows you to select the output speed for each output from instant, 1/12, 1/6 or 1/3 second rate. Hopefully out in a week or so.

3. Sensor overheating issues (infamous Error 08).
There are three solutions (in order of preference):

a. Relocate the sensor to a cooler location.

b. Install a heat sink
Take a sheet of 4" x 4" x 0.06" copper, drill a hole in the center the size of the sensor thread. Bend two sides up 45 degrees to form a V with flat bottom the width of the sensor. Mount this between the sensor body and the bung (using the sensor itself). Put the sensor's sealing washer between the heat-sink and the bung. The problem is that the sensor body is overheating from heat conduction from the bung. The heat-sink dissipates some of the heat conducted by the bung. You can use aluminum instead of copper, but al. conducts heat only half as good.

c. If all that does not help, send in your unit. We will install a hardware modification that allows the unit to work with an overheated sensor (within reason). The disadvantage is that the response time of the meter will be slowed down somewhat and it does not change the fact that the sensor runs too hot and therefore has a dramatically shorter lifetime.

4. RPM converter

Beta units are shipping this Friday. Uses tach pulses from 1Vpp to 300Vpp. Optionally uses inductive clamp. Can be calibrated to the number of rpm pulses/crank rotation by pressing a 'setup' button and then holding engine rpm to 2000 +- 200 RPM for 15 seconds.
Precision 1.5% of indicated. Measures 400 ... 10230 RPM in 10 RPM steps.

Some more tuning tips for the LM-1 and some real-world test results can be found here:

Check the posts on the second page by RICE RACING.

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Klaus is offline   Reply With Quote