LM-1 now $299; a necessary tool?

[berettafan]

My brother in-law informed me that the LM-1 can now be had for $299. I suspect he's hoping i'll buy it (damn VW people always on the mooch ) but i have been giving it some thought because i can't imagine being satisfied with my carbs and NOT knowing what my a/f #'s are. Not that i know wtf to do with this thing but it looks like a fun thing to learn.

But is it necessary? If i drop $299 on this thing will i sleep better at night knowing my carbs are dead nuts perfect?

Thanks in advance-

Erik

[John Z Goriup]

A firend of mine has an LM-1 and swears by it to keep his 2.2 '70 911T sharp. I think it's best to establish a baseline on a dyno first and then use aids like the LM-1 to maintain the state of tune.

John G.

[kenikh]

Ever wanted to tune your MFI pump? I mean really tune it? Like to the tune of making a '72T pump get perfect AFRs on a Mod-S cammed 3 liter? Read on:

http://forums.pelicanparts.com/showthread.php?t=386414

The LM1 was the catalyst to making this a reasonable proposition at home.

[EsGeht]

Isn't it necessary to also get the RPM capability of the LM-2 in order to accurately adjust the A/F across the full range?

[kenikh]

I'd PM Jeff Higgins to be sure.

[ttweed]

Isn't it necessary to also get the RPM capability of the LM-2 in order to accurately adjust the A/F across the full range?

AFAIK, the LM-2 has been delayed in production, and is not yet available. For logging RPM, you just need to add accessories to the LM-1: an inductive clamp pickup for the plug wire and an LMA-2 converter, which adds $130 or so to the price. If you can wait for the LM-2, it might be worth it, since it will have dual channel capacity, from what I've heard, but will be in the $700 range for that capability. It would be really nice for the 911 flat six, though, as you could log and compare both banks of cylinders at once.

From my experience, it is necessary to have these accessories if you don't have someone else to ride along with you and watch the display on the LM-1 while you're doing on-the-road tuning. I did it alone somewhat satisfactorily when tuning an EFI system by hanging the LM-1 on the dash and stealing glances at it, but it's better if you're logging the data and can review it at your computer later with the Logworks software. Adding a TPS or MAP load-sensing trace as well as RPM to the data would be even more helpful. Without these elements, you are left with only A/F over time displayed, and it is difficult to remember what you were doing when, exactly, to interpret the data.

TT

[X-Faktory]

Has anyone used a Gunsen Colortune? Not an LM-1, but appears that it does allow you to view the combustion flame of each cylinder individually. I've heard that motorcycle tuners (multi-carb/ITB) tuners swear by (not at) them.

al

[Davz912/911]

I think you need to see the sparkplug to use one of these (they have a clear
insulator).....kinda tough on a 911...

Cheers
Dave

[X-Faktory]

Comes with a periscope/mirror dealy to see into the cavity. Paul Abbott, who rebuilds Webers (did a great job on mine) mentioned using one of these to adjust/tune Webers. I'm going to try it. I've used a sniffer in the tailpipe and a Lamda sensor/Megasquirt method, but they all give you the average A/F ratio. This method may allow you to observe the individual cylinder A/F ratio (or approved equivalent) at any RPM. Not under load, but....might be a good DIY method until you get the garage dyno installed.

[304065]

Tom, the LM-1 does have a logging function. The RPM converter is a must, otherwise you would just make idle and part-load adustments (hey, that's what the factory did in CMA!) and the rest of the curve would fall where it might.

Adjusting the interal screws is a major leap forward, but not possible without the RPM converter so you can see where the dropouts in the fuel curve are.