Innovative RPM converter.

[Cheeseburger]

I would like to hook up more then rpm to this for data logging, what have the users of this hooked up to it with a 5 volt or less source?

I am thinking tps/map/volts/iac/etc.

TIA.

 

[ijames]

I plan on tps and maybe map. The iac won't work because its position is controlled by pulses from the ecm, and volts won't work (without a resistor voltage divider) because the input range is only 0-5 V not 0-15 V. VSS also won't work because it's also a pulse train. Actually, mat could be nice if you already have a boost sensing harness and are using the mat input for map through the ecm.

 

[ijames]

Well, this last weekend I got enthused, pulled the dp and had our welder put on a SS bung about even with the spark plugs (just above the ac box, tilted towards the motor some), and I tapped into the ecm harness to bring out the tps, crank sensor, and the ground that the tps and cts and a couple of other sensors share. I had a spare set of plugs with about 4" of wire snipped off a harness from a junkyard car, so I popped out the corresponding wires from the junkyard connectors and my harness, stripped the ends back on the junkyard pigtails, and twisted them plus a piece of hookup wire around the pins from my connectors. Put a small wire tie on to hold it (I know it's not great but it's easily reversible and good enough) and a piece of heat shrink over it for cover. Ran the hookup wire to the aux input screws, and wire tied the aux input to the ecm harness to keep it secure. My laptop is a PI 166 MHz with MMX and Windows 95, and every time I tried to setup the rpm converter I got an illegal instruction crash. I gave up and snatched the rpm converter back out of the car and went inside to my desktop system (PIII 1000, XP Pro) and it set up just fine with no problems at all. Back out to the car, reinstalled everything, and fired every thing up, and Voila! Data! I can run DS and the LogWorks program at the same time and log with both. The tps is about .2 V lower through the LM1, so I probably have a small ground loop problem but I'm not going to bother about it. The only weird thing is that the rpm is also a little lower on the LM1, maybe 100-200 rpm at 2000 rpm. I logged a couple of passes so I can check the max rpm at the shifts to see how they correlate, but for now I'm happyyyyy. Next step is to get a 3 bar map sensor to replace the factory 2 bar unit, and tap into that wire under the dash to log boost at well.

 

[S10xGN]

Hi Carl (and others),

I just got my LM-1 today! On the RPM converter (which I do not have yet) can it be rescaled? The logworks shows some unGodly high number (10,375?) which would be totally out of line on our cars.

I just set up a 3 bar MAP by using instructions on the Innovate forum: set 0 to 1.66V and 29.4 to 5.00V. This will show vacuum and boost. I don't actually have any inputs yet, but my "dash" is ready.

Also looking for setups on:

0-100 electric fuel pressure sender (Dakota Digital)
0-1600 EGT (also Dakota Digital)

TIA!

 

[ijames]

Well, you can double it to 20,000 rpm , but you can't scale it down. At 10,000 full scale it has 10 rpm resolution so I don't think that's an issue. I set it up as 3 pulses per revolution. Oh, using my laptop I also tried the on car at 2000 rpm method instead of the sound card output but still got the crash.

That map setup will show vacuum as negative psi, right?

 

[Cheeseburger]

I have 4 datalogs of my passes.............but it looks like chinease to me!

 

[S10xGN]

Originally posted by ijames
That map setup will show vacuum as negative psi, right?

Yup, it (should) show -14.7 to 29.4...

 

[ijames]

I reinitialized the rpm converter with my desktop pc making sure the volume was all the way up, since I'm not positive it was the first time, and for whatever reason now the rpms are pretty much dead on with ds - there's a little noise on each one but they seem to average the same by eye . Also wired into the stock map while I'm waiting for my 3 bar to arrive. There is a big, double row connector directly above the kick panel where the ecm sits. Open the glove box, empty it out, release the catch on the left and let it open all the way. Reach in and to the right and there's the connector. The light green wire on pin A on the longer of the two plugs is the MAP signal, headed towards the factory boost gauge. Lift the ears and unplug that plug (unplugging the other one gave me more slack which made connecting things easier but you don't have to), lift the little ears on the sides that lets the cover flip open to expose the wire ends of all the pins, slide a small pick or hex key in beside the pin from the non-wire side -)) to depress the little ear and the pin slides right out. I wrapped wire around the crimp and just stuffed it back in for now; it seemed to fit snugly and I wire tied the two wires together for strain relief. You could easily solder the new wire to the exposed part of the green wire if you want. Snap it all back together and run the new wire to the aux input and you're in business.

I have about a 0.13 V offset in the grounds at the LM1 power/cigarette lighter and the tps gnd at the ecm connector but I just used a custom calibration for that channel to make the lm1 and ds agree at 0.40 and 4.68 and a couple of points that I checked in between were right on. I'll calibrate the 3 bar map sensor with a gauge and tire pump when I get it. Also, I guess if I'm ever going to wire the lm1 in permanently so I don't have to remember to turn it on each time, I should do that now since I'm sure that will change the offset. I did notice that my inverter for my laptop puts out maybe 0.2 V worth of noise onto the tps signal when it is turned on. I have it plugged into a Y along with the LM1, in the cig lighter; don't really know what to do except ignore the noise or run the laptop off of the battery if I want max accuracy. It also shifted the map but didn't seem to move the rpm.

 

[Intercooler]

So is the WB worth it compared to an EGT?

 

[ijames]

No one else has answered so I will, even though I've never used an egt, Jesse. I do think that logging an entire pass at 10-12 frames a second has to be better than just seeing the peak egt, since you can check your afr vs. rpm calibration and your spoolup/launch afr. Both would be great, but if I had just one it would be (and is) the wbo2. List price-wise, I'm at $349 for the lm1, $99 for the rpm-aux cable, $80 or so for the 3 bar map, and $10 for a stainless steel bung since I didn't want to weld a mild steel bung onto my SS THDP, for a total of $538 vs. what, $200 for a single channel digital egt with maximum recall and probe. I think the plx500 is about the same price, and I'm not including the $70 or so for a replacement sensor from where I dropped a suitcase onto my first sensor loading my car up to come home from Bowling Green, sigh .

 

[S10xGN]

Well, I got the RPM Converter for X-Mas!

Trouble is, on my first pass, it showed me at a peak of 6650! I didn't try any calibrations other than the 2,000 RPM live cal. Is there a better way?

Carl, why do you have yours setup at 3x?

So far, I've got:

• [1] RPM's
• [2] TPS
• [3] MAP (3 BAR)

It all works, but the RPM's are off a little (I hope!)

 

[ijames]

The 3x means three pulses per revolution. That's what the crank sensor gives, and what an inductive pickup would see with our waste spark system.