MAP Sensor resolution

2012+ US/Canadian Civic Si / 2013+ ILX
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Gernby
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MAP Sensor resolution

Post by Gernby » Fri Mar 13, 2015 7:34 am

I noticed that the stock MAP sensor in my '13 Civic Si appears to be about 1/5th the resolution of the MAP sensor in my S2000, which uses the same MAP sensor. Instead of reading the MAP at an increment of about 2 mBar, it reads at an increment of 10 mBar. Is there anything that can be done to improve this?

I recall that the S2000 would show a low resolution MAP value when I flashed back to the stock calibration, so it seems that the Civic could get the same "fix".
'06 NFR S2000

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Hondata
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Re: MAP Sensor resolution

Post by Hondata » Fri Mar 13, 2015 8:32 pm

Is that with a stock calibration or a FlashPro calibration? The ECU usually only uses 1 kPa resolution for scan tools and datalogging.
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Re: MAP Sensor resolution

Post by Gernby » Sat Mar 14, 2015 7:26 am

It does this with a custom calibration.
'06 NFR S2000

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Re: MAP Sensor resolution

Post by Gernby » Mon Apr 06, 2015 8:45 am

Here is a screenshot showing the difference in MAP resolution between the S2000 and '13 Civic Si. The lack of resolution in the Civic really makes it hard to get a good tune. I basically have to datalog the car at various barometer readings to find "good enough" for fuel and timing, since it's always rounding up or down to the nearest 10 mBar.

I've also attached a datalog.

Image
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ITB 184-150404-211712.fpdl
(224.5 KiB) Downloaded 94 times
'06 NFR S2000

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Re: MAP Sensor resolution

Post by Hondata » Mon Apr 06, 2015 10:43 am

Yes, the 2012-2015 Civic has 1 kPa resolution on the MAP sensor for datalogging.
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Re: MAP Sensor resolution

Post by Gernby » Mon Apr 06, 2015 10:59 am

So, can you fix that? I see that the 8th gen Civic Si has higher resolution, so I'd hope that the new Civic could as well.

Also, it doesn't seem to be just a datalogging thing, since the shape of the AFR actually changes significantly when the barometer goes up or down a bit.
'06 NFR S2000

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Re: MAP Sensor resolution

Post by Hondata » Mon Apr 06, 2015 1:35 pm

It is only for datalogging. I will add it to the list, but there are many more important items to look at first.
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Re: MAP Sensor resolution

Post by Gernby » Mon Apr 20, 2015 2:22 pm

Is there anything I can do to bump this issue higher on the priority list? I know that you guys don't recommend FlashPro or MAP based tuning for ITB setups, but I've developed a new type of MAP block (chambered and valved) that really makes it work very well. However, since the Civic has such low MAP resolution, it's taking me a lot more effort to get it tuned than my S2000 did.

FWIW, I know there are a lot of skeptics out there, but I really believe ITB's will be the next big thing for Honda performance enthusiasts. I'm actually making more power with my '13 Civic Si than I am with my similarly equipped '08 S2000. The gains in VTEC are about 25% over stock. I'm confident the Civic will do the same if I can get better MAP resolution.
'06 NFR S2000

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Re: MAP Sensor resolution

Post by Gernby » Fri Apr 24, 2015 9:53 am

I dynoed the Civic again yesterday after doing some more ITB runner tuning and exhaust cam timing adjustments, and wanted to share the results with you. The dyno plot from my '08 S2000 with the original DBW ITB prototype from URGE Designs, and my original production version of my exhaust system (Gern-Pipe and Dingle muffler) was done a few weeks ago on the same dyno. The motors in both cars are stock with stock injectors, and the exhaust systems have HFC's integrated into the expansion chambers. The Civic still has the OEM muffler.

I'm pleased with the performance I'm getting from the S2000, but I'm blown away by what I'm getting from the Civic!

I've also attached a datalog. Note that Density Altitude was 1852 feet at the time due to low barometric pressure and high humidity.

Image
Image
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DynoJet3.fpdl
(7.65 KiB) Downloaded 96 times
'06 NFR S2000

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