3.5 Bar MAP sensor vs 1 Bar sensor

Discuss which Sensors work best with these ECUs and share how you are using inputs and outputs
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VR6Turbo
Posts: 329
Joined: Wed Mar 17, 2010 9:24 am
ECU Model: S80 Pro
Firmware Version: 62

3.5 Bar MAP sensor vs 1 Bar sensor

Post by VR6Turbo »

I've gone back to a normally aspirated engine with a map sensor. I'm using the same Kavlico 3.5 bar MAP sensor that was on my turbo engine and it seems to work fine with DTA's standard pressure compensation map applied.

I say runs OK, but I have a niggling doubt it could be better with a 1 bar sensor.
I know you would get more resolution in the sensor scaling page, but does that really matter? I'm not so familiar with mapping n'asp engines.

Just trying to keep costs down :)
stevieturbo
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Re: 3.5 Bar MAP sensor vs 1 Bar sensor

Post by stevieturbo »

I doubt it will make any difference you'll notice.

Maybe if something seemed odd, check for stable voltages from the sensor. Worst case it may fluctuate a bit more.
But as they work perfectly fine on a boosted engine, they'll work perfectly fine on a n/a

Is it a temp change or permanent ?
VR6Turbo
Posts: 329
Joined: Wed Mar 17, 2010 9:24 am
ECU Model: S80 Pro
Firmware Version: 62

Re: 3.5 Bar MAP sensor vs 1 Bar sensor

Post by VR6Turbo »

Yeah permanent. I've gone back to n'asp tuning. High hp turbo motoring just crippled me at the pumps every month :?

The KPA reading does fluctuate a little at idle actually, but not a huge amount.

It's odd readings I'm getting that make me wonder. Such as 6KPA at over-run, 20KPA at very light throttle on motorway and mid 30s KPA for idle. I'm used to seeing much higher numbers than that (off boost).

This motor is DBW though and when the plate is closed, it's REALLY closed. Which may explain the high vaccum I guess.

I might try a 1 bar anyway tbh as it's makes more sense for n'asp really.....
stevieturbo
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Joined: Tue Aug 02, 2011 12:08 pm
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Re: 3.5 Bar MAP sensor vs 1 Bar sensor

Post by stevieturbo »

readings dont sound that odd really. Id expect a mild cammed engine to pull 30-40kpa at idle.

Why not just get a mityvac or similar and test the map sensor readings ?

Where is the signal line taken from ? It always needs to be from a central plenum or intake pulses can affect the stability of readings. Damping the line can also be needed sometimes. Filtering may achieve a similar result, although Ive never used much filtering.
VR6Turbo
Posts: 329
Joined: Wed Mar 17, 2010 9:24 am
ECU Model: S80 Pro
Firmware Version: 62

Re: 3.5 Bar MAP sensor vs 1 Bar sensor

Post by VR6Turbo »

Good idea on the Mityvac, I'll look into that.

Here is the MAP sensor and it's manifold connection. It's right at the back of the plenum well away from the runners, so I figured that would give a stable enough feed.

Image
stevieturbo
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Joined: Tue Aug 02, 2011 12:08 pm
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Re: 3.5 Bar MAP sensor vs 1 Bar sensor

Post by stevieturbo »

Looks like a decent enough position
VR6Turbo
Posts: 329
Joined: Wed Mar 17, 2010 9:24 am
ECU Model: S80 Pro
Firmware Version: 62

Re: 3.5 Bar MAP sensor vs 1 Bar sensor

Post by VR6Turbo »

Cheers Stevie. Got the Mityvac this morning. Nice bit of kit 8-)
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