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optimum AFR for power
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Author:  nomad [ Wed Oct 10, 2012 8:17 am ]
Post subject:  Re: optimum AFR for power

A word of warning here. When you hook up your RPM converter to your LM-1 the RPMs will not be accurate. Example: it may read 5500 at the shift when you know it was 5900.

That's okay. It's the relationship of the RPM trace to the O2 trace. You'll see where the shifts were and how the carb was working at that point. You'll also see when you came up on the converter and even wheel slip if the RPM spikes at the hit.

I like my data recorder. I don't know anyone who doesn't. But, it's just one tool, not the whole tool box.

Hook it up and see. Even if the season is over there must be some quite roads somewhere where you can make a short whack at it.

Author:  74 firebird461 [ Wed Oct 10, 2012 9:52 am ]
Post subject:  Re: optimum AFR for power

So All I need to do from what i was reading is hook it up to my tach output on my msd digital6 box right? Then plug it into the aux output on the LM1. And when i record it will record the rpms too along with the afr on the graph correct?

Author:  nomad [ Wed Oct 10, 2012 11:06 am ]
Post subject:  Re: optimum AFR for power

Hook the RPM converter to the LM-1. You will need to calibrate it to read the RPM. This can be done manually or there is an automatic option available, too.

The manual is pretty specific about how this is done and it will get you through it. I never had much luck with the automatic option. I think it just didn't play well with my laptop.

Author:  74 firebird461 [ Wed Oct 10, 2012 11:48 am ]
Post subject:  Re: optimum AFR for power

Thanks Bruce, question for you in setting this up manually, which do i select below on chart? I will not be using the clamp so i am guessing the second choice, and 8 cylinders?


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Author:  nomad [ Wed Oct 10, 2012 4:59 pm ]
Post subject:  Re: optimum AFR for power

Pulses per crank rotation. There are 4 pulses per rotation.

Author:  74 firebird461 [ Wed Oct 10, 2012 5:46 pm ]
Post subject:  Re: optimum AFR for power

Bruce
I got it set up and just did a test run with it idling and then revved it a couple of times to 3000 grand just to see if it would work.Here is the graph, Now i need explanations of what i am looking at :). My secondary blades are sticking a tad that is why it spiked to 16-17 when i let off each time, need to look at that too. This aftermarket BLP linkage kit is nice but i think it either binds in the bores, or something, its happened before too took it all out and sanded everything smooth. Nevermind that tho lets just focus on what i am looking at on the graph please,lol..

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Author:  74 firebird461 [ Wed Oct 10, 2012 7:18 pm ]
Post subject:  Re: optimum AFR for power

I played with the graph settings some more and figured it out :)... Got it changed to RPM'S now so i can see the scale and how it goes with the afr. I think I will like this addition \:D/

Author:  Beretta [ Thu Oct 11, 2012 6:18 am ]
Post subject:  Re: optimum AFR for power

Now you need drive shaft and fuel pressure =; =; ..

Author:  74 firebird461 [ Thu Oct 11, 2012 7:03 am ]
Post subject:  Re: optimum AFR for power

Beretta wrote:
Now you need drive shaft and fuel pressure =; =; ..



OH boy! Whats next hiring Austin coil =;

Author:  nomad [ Fri Oct 12, 2012 6:35 pm ]
Post subject:  Re: optimum AFR for power

On that BLP linkage you'll need to work the opening rate a bit. You can go to the Holley web site and download the instructions for the Ultra Dominators. It has detailed instructions on how the BLP linkage is to be adjusted.

Author:  74 firebird461 [ Sat Oct 13, 2012 9:08 am ]
Post subject:  Re: optimum AFR for power

Thanks Bruce, Found it! I have been running it in the second hole and that has worked out nice.

Author:  74 firebird461 [ Sun Oct 14, 2012 7:43 pm ]
Post subject:  Re: optimum AFR for power

Well It was cool today about 50 ,but the bar was terrible at 29.70 mid 40's dew point and high hum. The car ran great with the 94's in it, LOkoking at the logs tho its going lean up by the shift point on both shifts. The fr was right around 12.8-12.9 with that jetting. I tried all kinds of things today. ran my normal setup 94 sqaured with no air filter made two passes then i installed some 21.5 bleeds in the sec only all i had, it didn t like that slowed down, then i put the other bleeds back in the 24's and installed that screen hated that lost almost 1 mph!. so went back to what i started with. By the end of the day it was 27.78, 36 dew point and 60% hum and car would've ran 10.66, but i was racing and was on the brakes :) Take a look at the log and let me know your thoughts.. thanks!

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Author:  nomad [ Mon Oct 15, 2012 7:57 am ]
Post subject:  Re: optimum AFR for power

Nice graph. So, other than it's bit fat over the entire pass what's the problem? 'Cause I'm not seeing one.

Author:  Beretta [ Mon Oct 15, 2012 8:09 am ]
Post subject:  Re: optimum AFR for power

Yep looks fat.......I would try a set square of 91's...

Author:  74 firebird461 [ Mon Oct 15, 2012 8:38 am ]
Post subject:  Re: optimum AFR for power

I guess I don't see what u guys are seeing as far as it being fat? It pretty much is running right around 12.8, 13.0 on that run. So that lean spike up near each shift isn't nothing to worry about? Its up to 13.5 or so on the first and second shift.

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