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      06-04-2013, 06:05 PM   #1
JStang
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Cobb OTS E30 Log - Overboost??

I have been running the Cobb OTS E30 map since my LPFP is dropping slightly below 50 during a pull with my PTF E45 map. I plan on upgrading the LPFP in the near future and will either opt for the inline Walbro or hopefully a drop in replacement becomes available soon.

The first thing I noticed is that I am hitting 19.38 PSI boost which is about 1 psi higher than my E45 map is hitting. This seems high, no?

I also see that the TPS Act. drops from 80.98 to 68.11 from 3,770 to 4,113 RPM's then begins to climb back to 80.98. Is this an overboost causing the TPS to drop?

Also, there are timing corrections which could be due to the high IAT's (Hot, humid Florida day). Because of the Florida summers, I am trying to run E85 as much as possible because of the cooling effects it offers.

I am getting better at reading logs but I am still not 100% comfortable so if any of you log reading gurus could chime in it would be appreciated.
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      06-04-2013, 06:14 PM   #2
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From the tuning guide (F1 in Accesstuner):

To Adjust/Monitor WGDC performance:
Add “Boost Setpoint Factor” and “MAF Req. (WGDC)” to your logging. These are the axes for the “WGDC (base)” table that we will be adjusting. If needed remove other unused monitors from your logs to make room. Once these monitors are added, collect a log where throttle closures can be seen.
Next step will be to open AccessTUNER and adjust the WGDC (Base) table in the affected area. You should have the required data in the logs to make these changes. The X axis for the table is “MAF Req. (WGDC)” and the y axis is “Boost Setpoint Factor”. Now, look in your logs and find where Actual Load surpasses Load Requested. Once you find the problem area, look at the corresponding values for the X and Y axis on the “WGDC(Base)” table and that's where you'll be making your changes. Find the cell that matches, and highlight adjacent cells as well (the DME will "blend" several cells to get final values). You're going to want to lower the values in the problem area to correct throttle areas, or raise them to correct under-boost/under-load. Make small
incremental changes to the base table then re-flash and re-log.


I recommend multiplying the trouble area by 0.9 as this is usually a good start. If you need more help, shoot me a PM or email and I'll help you get going. If you're seeing timing corrections on multiple cylinders, you can always pull a little timing out of the map in the trouble area. Just be sure to look at where you switch between the spool and main timing table so you you know which one to modify.

- Josh
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      06-04-2013, 07:13 PM   #3
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What Josh just said, also there is a thread entitled "correcting boost overshoots in ATR" that will walk you through it.
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