First single & dual channel A/F runs with LM-2

Sean,

You wrote:

"The aux box and several other Innovate products have thermocouple inputs on them . . isn't measuring exhaust gas temperature one of the ways you look for optimum a/f ratio besides dyno? I wanted to play with this but figured a thermocouple on the outside of the header wouldn't be accurate enough . . .thoughts?"

What type of tc's do the inovate products accept, type-K (chromel-alumel), type-T (copper-constantan), other?

If you want to use a tc on the exterior surface of the headers I can offer some advice.

Simply wrapping the tc around the outside is not very good as the junction needs to be in intimate contact for accurate and repeatable readings. The best way is to weld it on. Second choices would to put it under a band clamp and tighten it down or bond it on with a very high temperature adhesive. Muffler sealant is not good for header mounting but I did find an adhesive/sealant for headers that as I recall was good to 2000 F. This would probably work ok provided the surface were prepared appropriately.

I would recommed placement of the tc's away from the head interface, maybe on the order of 4-inches if possible, as heat will be bled off to the cooler head.

One would expect temperatures cooler than the exhaust gas temperatures. One would also expect the signal to lag the gas temperature in response, because of pipe mass (thermal capacitance) and the headers will be giving off heat to the surroundings. Comparisons between pipe temperatures should be good provided they are placed equidistant from the head and the loca,l external air flows are similar.

Bill

 

I was just on the LM2 forum on Innovates site.

They have a new display that is easier to see. You can get the one you have upgraded for $15 if you send it in. Even if you just got yours a few weeks ago it probably has the old display.

The are coming out with an 18ft extension cable. You can't use the one for the LM1.

Lots of people are having the same problem I was having with the RPM. They are suggesting putting a pot in to reduce the voltage from the MSD as well as other things to try. Sounds like they still don't have a great handle on the problem.

 

There's a pretty good hill by me where I can hold WOT for like 30 seconds . . .

Bill they are T thermocouples if I'm remembering correctly . . Omega has one that screws in 1/8" pipe . . it's got a little tip about 1/8" diameter that extends into the stream and they're only like $35.

Thanks for the info guys . . could do what Bill said and compare with the Omega TC and see if I have to go to that trouble to tweek individual cylinders.

Sean

 

Russ,

I don't disagree with anything you said regarding egt tracking. I guess the efficacy of measuring pipe temperatures depends on what one wants to use the information for.

Pipe temperature will track egt but be some what less in temperature during operation. It will also lag egt temperature changes by a noticeable amount and will tend to average out transient temperature changes.

What one would be looking for would be differences in pipe temperature, but if you are only looking at 2-inputs, the data may not be really useful. On the other hand, if one could monitor all 8-tubes, this could be really useful for trouble shooting purposes.

One instance where this technique might be particularly useful is during and after startup from cold. I know that on my car, there are probably 2-cylinders that take a minute to warm up before they fire reliably. Presumably, the tubes to these cylinders would be cooler during the warm up process. This technique should easily pinpoint the miss behaving cylinders. One could then adjust the idle mixture, maybe richen the bit and try the start up again, when cold.

During normal operation, again monitoring of tube temperature might be helpful to confirm balance or missfiring. If some tubes are cooler than others, it could be they are not really pulling their weight, so to speak.

As far as setting mixure based upon egt, I don't this see this technique being particularly useful. On an aircraft, under cruise conditions, where you are measuring egt under steady state condition, would one tune for max egt?

Sean,

We buy all our tc wire from Omega and I suspect that's also where we buy our immersion probes from too.

Bill

 

I've got a good laser pyrometer already . . . I just like understanding as much as I can about . . . well . .. everything

 

thanks for the info and thoughts . . EGT might show some cylinder inbalance to dial in individual injectors instead of trying to put an o2 sensor in each header pipe which won't fit in the factory hole.

I guess my pyromoter might tell me this but I just luv graphs with lots of data . . . actually come to think of it I don't think it measures over 1000 degress . . bummer

cheers

 

Did you ever get the Lm-2 to read RPM or analog inputs steady? One cure is to get the SSI4 from Innovate. Attached is the RPM data from my LM2 and the SSI4. The SSI4 is an accy for the LM-2 that plugs into thier MTS chain. The purple line is RPM from the ssi4 and the gold is the LM2 RPM input. The signal was from a function generator on a bench not installed in a car. I'll have more data later next week from a car but you can see my LM2 would not even read the cleanest pulses I could put into it no less the tach signal from an MSD. PM me for more info.
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Generally 50F lean of peak EGT.

 

This is a very cool thread, interesting reading.

That's why you need a setup like this :

http://forums.rennlist.com/rennforums/4963551-post1.html

 

Hmmmm. Arent O2 sensors all a bit "off" from one another?

 

I'm sure they are all not perfect but you can try switching them between sides and see if the numbers change. There is also a calibration in air that you do with the Innovate products when they work.

 

I've had an LM-1 for almost 3 years. I'm on my 5th O2 sensor. When I swapped 'em and recalibrated with the LM-1 the data seemed pretty darn consistent.

Bummer to hear they're having so many problems with the LM-2. I have the auxbox with the LM-1 which has a 2 axis accelerometer ... a tweeker's dream . The only thing that's really lame is if the 02 sensor stops working you can't just use the accelerometer, tach, and MAP of the auxbox independently. I've been looking for stand alone data acquisition systems with camera overlays. I was going to build a PC from scratch for capturing camera data but I did a little research and I think vibration would be a major issue with a standard PC with aggressive driving.

Also Innovate might have a stand alone product now that does not require O2 sensor to be working?

Cheers

 

What I was refering to about the O2's being different was the 928 on rennlist posted above. If they are all off some % from each other the greater the indifference from the highest to lowest would be get to be like chasing the wind regarding exact cylinder to cylinder fuel mixture measurment. Sometimes less really is more.

 

The intake manifold on the S4 928 is far from ideal, especially on an engine with a supercharger @ 30psi. The air / fuel difference between the cylinders is as high as 8-9% when all cylinders are measured and tuned with a single O2. The length of the intake runners is far from equal.

The eight O2 sensors with Autronic controlling the spark / fuel helped dial in the system. So even if the range between the multiple O2's were 1-2% it's still better than a single sensor in the X-pipe. The O2's were moved around a few times to rule out any possible issue with a bad or out of range sensor. The "swing" between the different cylinders was consistant.

 

aaaaah ... comparing cylinders ... wonder how much difference we'd see between cylinders on a 308?

I think I recall the front bank running richer than the rear bank with all things being equal so I just left the o2 sensor in the rear bank. I wanted to use my pyrometer to compare cylinders after a long hard pull up a big hill but I think the header will be over 1000 degrees. With a higher temp pyro or thermocouples will I be learning anything?

cheers

 

The pro teams in NASCAR and others will put O2 sensors in all cylinders and tweak the header flow for different cylinders if they can't fix it in the head or have to work with stock looking manifolds. This would be for carburated cars. For EFI cars you would just program that injector to just give a little more fuel.

I would rather have GPS data instead of video. Someone that crewed for me a wristwatch made by Garmin or Magellan and he let me strap it to the rollcage. It drew a perfect track map and automatically did lap times. You could go to any data point on any lap and it would show your speed. Many have asked Innovate to incorporate something like this but they have no interest.

 

Check out www.race-keeper.com or www.traqmate.com Both advertize video with GPS data.

 

Here is some data from the SSI4 hooked to the LM-2. The purple line is the tach from the MSD box and the Black is a TPS(throt pos sensor) that I was holding in place by hand. I didn't have the o2 sensor hooked up but never had a problem with the LM2 O2 sensor readings. Just the tach and analog inputs on the LM2. I only ran the car for a minute or less but you can see the tach signals and TPS signals don't have any of the noise that my LM2 inputs have. If you have an LM2 and want to log anything more than the O2 sensors you need to get an SSI4 and correct cable to get data that looks like this.
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I have the Innovate SSI4 hooked to my LM2 and I am very pleased with the tach and analog inputs on the ssI4. I just ordered a 2 axis accelerometer to hook to the SSI4 analog channels. It should be a very easy install since the SSI4 has a 5v output to drive sensors. Something the LM2 should have but doesn't.

The accelerometer was only $24 so not much to loose and the innovate logworks software already knows how to display the data since they sell a modual with a 2 axis accel built in.
Should be fun to play with. http://www.dimensionengineering.com/DE-ACCM2G.htm