Has anyone besides me using a LM-1 to read A/F?

[cyrus]

Has anyone besides me using a LM-1 to read A/F? If so what do you think?

[Guest the_dj]

I think it's awesome. I have the LM-1 + Aux Box package.

 

Here's a link to the LM-1 for those that don't know what we're talking about.

[rags]

I'm using it with an aux box also.

 

Joe

[RB26powered74zcar]

Has anyone besides me using a LM-1 to read A/F? If so what do you think?

 

:2thumbs:

[jt1]

I bought one, but haven't got the bung welded in the exhaust yet. I'm looking forward to fine tuning my somewhat rich holley.

 

John

[Tim240z]

BTW...as for O2 sensor bungs....I always use the 18mm spark plug anti-foul inserts available from any parts store for about $2 a pair. Just cut the end off with a hacksaw and weld to the exhaust....works great. Used it for the LT1 in the Z and for the L31 in the truck....cheap and available and works perfectly.....

[Jolane]

Tim,

Thanks for the tip, but what is an anti-foul insert? Is that what I should ask for?

Joshua

[Tim240z]

Usually just hanging on the rack, in the "HELP" brand section. They are used for spacing the spark plug outside of the chamber in instances where plugs have fouling problems.

[cyrus]

I think most people have seen my dyno in the 6 cylinder section, Anyway my Lm-1 and the dyno wide band were different. The dyno shows a smooth 13 to on and my LM-1 is from 12 then drops to 10. I do not know who to trust as I am leary of leaning this bad boy out.

[zeeboost]

Cyrus, perhaps you should re-calibrate the unit, or try it with a different o2, and see if that yields different (better, hopefully) results.

 

I also have the LM-1 -- best bang for the buck right now! Plus the customer support is awesome -- it has its own forum with the guy that made the lm-1 answering most of the questions!

[Guest bastaad525]

Cyrus - was the dyno wideband sensor put in bung on the downpipe or was it one of those that they stick in the tailpipe. If it's one of the tailpipe sniffers those can be way off sometimes and I've been told and seen things with my own eyes that say that readings gotten from the tailpipe are not to be too trusted.

 

One of the last dyno's I went to did the tailpipe sniffer and the results were very weird and not at all consistent with results gotten before and after at other dyno places with the O2 installed in the downpipe.

[80LS1T]

Hey Cyrus, if you dont like the LM-1 I'll take it off your hands for a reduced price!

 

 

Guy

[clarkspeed]

I have found the LM-1 to be very repeatable. I tend to recalibrate it frequently. When tuning my programable EFI, I eliminated all the peaks and dips by adjusting fuel values. When the LM-1 shows a dip, it's really there, and it will show up again at the same place most every time unless you correct for it. That's the advantage of a LM-1, you will never see the dips/peaks on the meter, you need the data log to "slow" things down to see it.

 

Of course, I was never really sure if a 12.0 on the LM-1 was really a 12.0. I backed some of my tuning up with a pyrometer just to be safe.

[cyrus]

I went over my data again and found that the LM-1 was very repeatable. I cut and pasted by dyno runs on each other and the same funny pattern for boost, rpm, and AFR showed up again and again! So this thing is repeatable now I just need to figure out the accuracy. And it was a tail sniffer dynojet I am comparing it to. Also I found out that the rpm calibration was off some, it reads 6k at 6.8k. So I need to go to another dyno to verify things.

[Afshin]

Grassroots motorsports mag had done a review of 4 wideband units including the LM-1 and the PLX units (I have one which works great and auto calibrates, which is why I chose the unit). I don't remember all the details, but the good news is that they found ALL of them to work VERY well (when calibrated, if needed). They also tested a narrow band unit which as expected faired very poorly and had very wide variance (non-repeatable) in addition to being inaccurate.

[Guest JAMIE T]

Also, the ones used with dyno's like Dynojet, need to have the filters changed on a regular basis or they will give inaccurate information. That is usually the case after an overly rich tune has just passed through it.

[clarkspeed]

The LM-1 has always seemed accurate to me, like at least within +/- .1 Which seems incredible. I found the LM-1 to be more precise than my computer (SDS). I kept trying to adjust fuel values to that last tenth of a point and either jumped over or under the desired value. That's when I ripped the LM-1 out and declared victory.

 

I have noticed a slight lag at times, like correcting for a quick lean, you may have to add fuel 250RPM before the spike.

 

One time I thought the LM-1 was drifting, I recal'd and got the same values. I ended up blaming the shift on weather and air density that my computer didn't compensate for.

 

Perhaps a gauge R&R on the LM-1?

[clint78z]

I own an Lm-1 and have been fairly pleased with it, you may note a lot of people tend to get bothered when they see a jittery A/F on there tuned car. Most often they blame the unit itself. The resolution on the LM-1 is very fine, this tends to show you the swings in data that you would not see if you didn't have that resolution. I am going to say which one is right or not but I will give you some inside info from myself who works with these type of machines. For example if someone analysed your running form, it looks pretty smooth. If you used a high speed camera, then all of a sudden you can see so many nasty things you can see is wrong. Some you can correct and some you can't.

 

I have dealt with gas analysers at my company for quite a while. They are very touchy units !! The units O2 cells must be calibrated once a year, after that they become inaccurate. With this proceedure they hook it up to a calibrated gas and compare the readings of the O2 cell. Another thing that can screw up readings on a dyno is the desacent. This drys out the gas before it is measured.

 

I would error on the cautious side, an EGT can help a bit too !! I would concentate of keeping the A/F smooth, rather than picking an exact number.

[spork]

On a side note with the lm1 (since so many people have it). Has anyone had prblems with rpms jumping around on the logs? I'm using the the sdsem4-6f and my rpms will will never read correctly no matter how aI callibreate it, and sometimes they like to double themselves. I recently talked to someone else running a trubo dodge that had similar problems with his sds equipped car...and was wondering anyone else has had this problem and been able to fix it?

[cyrus]

I am hitting apex motorsports Tuesday to compare the lm-1 and the dyno wideband.