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MAF lbs/min converted to gms/cyl

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Old 02-01-2004, 09:03 PM
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Default MAF lbs/min converted to gms/cyl

I looked all over for this and it looks like I'm the only one that needed/wanted to do this.

Thought I would share it with others in case anyone else wanted it.

Here's what we will use as an example:

RPM = 551
MAF lbs/min = .78

First ... you have to convert the MAF lbs/min into grms/sec
lbs/min * 453.5924 / 60 (.78 * 453.5924 / 60)
This will give you MAF grms/sec which would be 5.8967012

The multiplication of 453.5924 is a constant to convert lbs to grams. The divided by 60 just takes the minutes and turns them into seconds.

Now ... take this number and do the GMS/sec to gms/cyl conversion on it
MAF gms/sec * 15 / rpm (5.8967012 * 15 / 551)
After doing this, you come up with 0.160527256 which is your grms/cyl

This comes in when you are trying to look at your log files which captured MAF lbs/min and trying to see where the timing is at on your spark tables.
Old 02-01-2004, 09:09 PM
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I think I may have found BigTex's X factor when it comes to timing tables too.

In EDIT 1.3 there is a new table labeled 'Fuel Ratio vs RPM modifier' under the Ignition tab.

In PE mode ... the multiplier is set in the RPM table. This ratio vs RPM table has similar numbers in it. At a given line in a log file I was looking at, the table adds 4 degrees of timing. That goes right along with the High Octane Spark table showing 16.4* and my actual 20* on the log. I will look at some more and report back.
Old 02-01-2004, 09:17 PM
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Yup ... goes along with every line I've checked of it being in PE mode.
Old 02-01-2004, 09:34 PM
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Originally Posted by Flyer
I think I may have found BigTex's X factor when it comes to timing tables too.

In EDIT 1.3 there is a new table labeled 'Fuel Ratio vs RPM modifier' under the Ignition tab.

In PE mode ... the multiplier is set in the RPM table. This ratio vs RPM table has similar numbers in it. At a given line in a log file I was looking at, the table adds 4 degrees of timing. That goes right along with the High Octane Spark table showing 16.4* and my actual 20* on the log. I will look at some more and report back.
OK.. whats my problem? I have 1.3 and I can't find that table.
Old 02-01-2004, 09:35 PM
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Good detective work. I'll go look at some of my logs.
Old 02-01-2004, 09:54 PM
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No need for you to convert lb/min to gm/s if you use EFILive. It does it for you. Not down to 7 decimal places though.
Old 02-01-2004, 10:21 PM
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Originally Posted by BenKey
Not down to 7 decimal places though.
LOL ... never know when you will need that 7th decimal place!

I use EFILiveV5, but all my CSV logs only have lbs/min.

Blown .. I'd say your prollyoff the scale with your monster! How much boost are you pushing?

BigTex ... lemmie know if you come up with the same thing I did.


Forgot to mention .. the lines I checked that weren't in PE mode were dead on with what was in the high octane table.
Old 02-01-2004, 10:40 PM
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Originally Posted by Flyer
LOL ... never know when you will need that 7th decimal place!

I use EFILiveV5, but all my CSV logs only have lbs/min.

Blown .. I'd say your prollyoff the scale with your monster! How much boost are you pushing?

BigTex ... lemmie know if you come up with the same thing I did.


Forgot to mention .. the lines I checked that weren't in PE mode were dead on with what was in the high octane table.
I'm pushing 11psi. Seeing 54lb/min.

I'm working on timing right now and fighting the X-factor! Sorry to sound stupid, but what the hell am I missing? I want to see this table.
Its under the ignition tab and its called fuel ratio vs rpm multiplier??? I don't see it what the hell?
Old 02-01-2004, 10:51 PM
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Hey flyer, or anybody, could someone post a screen shot of this table and where you get into it?

I'm thinking I got a bum version of 1.3. I can't find it.
Old 02-01-2004, 11:12 PM
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If you have your files from efilive, go into the saved runs, select the graph display, right click on MAF rate, select edit. From there you will have to choice to display in either imperial(lb/min) or metric(gm/s). You can do this even if the original was saved in lb/min.


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