How do I read the Data log?

General Topics for configuring, operating and tuning the Megajolt. Also see the <a href="http://www.autosportlabs.net/MJLJ_V4_Operation_Guide">Operation Guide</a>

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pristic
Posts: 46
Joined: Mon Jul 07, 2008 10:55 pm

How do I read the Data log?

Post by pristic »

Hi Guys,

I tried to find this but cannot...
Can anyone point me to a page where it explains how to read the datalog?

I have the datalog from my run but not sure I am reading it right - ie/ Accel Load, Load, Decel, etc...
I want to work out exactly how much boost its showing and also at what RPM...
Eg, it shows 6320RPM and 200KPa - am I right saying that means 15psi of boost at 6320 RPM?
How do I know where 'boost' starts? eg/ It jumps from 3000ish RPM to 3800rpm...
At 3500rpm showing 56KPa, etc.


Just want to know what all the numbers, etc

Cheers,
Peter

brentp
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Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hi Peter,

Attach a part of your datalog file to this thread and we'll walk you through it.

Regards,
Brent Picasso
CEO and Founder, Autosport Labs
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pristic
Posts: 46
Joined: Mon Jul 07, 2008 10:55 pm

Post by pristic »

Hi Brent,

Thanks mate... attached is the last datalog... on 100% its small - I had to go to 800% to read it properly... also had to add .txt so I could upload it.
Is that what you needed or an image of the MJ screen with the datalog open?

Peter
Attachments
MJLJ_Log_2008-11-02_13.50.14.csv.txt
MJ Output - 15psi 2nd, 3rd - uphill. Just breaking traction in 2nd.
(4.24 KiB) Downloaded 464 times

brentp
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Posts: 6282
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Here's the breakdown of the data columns:

Timestamp - The time for that particular sample
RPM - RPM
Load - Load, in KPA or tps%
Advance - Ignition advance, in degrees
RPM_Accel - the rate RPM is changing, in RPM per sec.
Load_Accel - the rate the load is changing, in Load units per sec.
RPM_Bin - What RPM bin in the ignition map is active
Load_Bin - What Load bin in the ignition map is active
Aux Input - Auxiliary input value
Advance_Correction - The amount of ignition advance correction currently applied.
Mark_Interval - where you marked the datalog while driving "1" shows a mark

"Boost" typically starts when the absolute manifold pressure goes over the current atmospheric pressure, typically around 100-103 KPa.

You are correct in your assumption about correlating RPM and boost. That is the key benefit of datalogging- correlating and comparing the data points over time.

As an example, your datalog shows on the 2nd hard acceleration you went to about 184KPa in about 4.5 seconds from when you started, spanning about 1300 RPMs.

Hope this helps,
Last edited by brentp on Fri Nov 07, 2008 5:25 am, edited 1 time in total.
Brent Picasso
CEO and Founder, Autosport Labs
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pristic
Posts: 46
Joined: Mon Jul 07, 2008 10:55 pm

Post by pristic »

Thanks Brent... appreciate it.

Peter

paulc
Posts: 66
Joined: Thu May 01, 2008 10:49 pm

Post by paulc »

does anyone have an excel spreadsheet already setup that graphs this stuff?

one tab can be the source and the other the graphs?

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