Scangauge II + boost reading

[Lonicus]

Heya guys,

Hope this is the right section.

Just plugged in a new Scangauge II and on a 80klm drive with the gauge set to PSI and MAP the numbers were a bit scary. Max pressure shown was 30+ and I didn't see it go below 13.8, even when stopped and at idle.

I set the gauge to BST to see if that gave more acceptable figures but it showed -1.4 at idle, so I didn't think was going to work.

I don't have a manual boost gauge connected up just yet, waiting on a couple of parts.

So, is my car over boosting to hell or does the gauge take some time to calibrate itself to the car?

Cheers

[Maxhead]

Heya guys,

Hope this is the right section.

Just plugged in a new Scangauge II and on a 80klm drive with the gauge set to PSI and MAP the numbers were a bit scary. Max pressure shown was 30+ and I didn't see it go below 13.8, even when stopped and at idle.

I set the gauge to BST to see if that gave more acceptable figures but it showed -1.4 at idle, so I didn't think was going to work.

I don't have a manual boost gauge connected up just yet, waiting on a couple of parts.

So, is my car over boosting to hell or does the gauge take some time to calibrate itself to the car?

Cheers

I think you need to calibrate it to your altitude. MAP will show your boost plus around 14.7psi so 30 sounds about right. I cant remember how to calibrate it but you should find it in your instructions.

[Lonicus]

Brilliant, thanks mate.

Didn't see it in the destructions, will go have another read through.

[Drew]

I didn't know it showed boost. I use MAP, a bugger adding 14.whatever but getting used to it.

While towing it rarely went over 29 and usually sat at around 28 which would be around 14psi boost.

Let us know when you get the boost reading.

[Drew]

Thanks for the heads up Nisshead, page 17 of the manual.... Sweet

[Lonicus]

I think you need to calibrate it to your altitude. MAP will show your boost plus around 14.7psi so 30 sounds about right. I cant remember how to calibrate it but you should find it in your instructions.

Doesn't look like there's any adjustment for the MAP/Boost readings in the gauge itself. Basically we just need to see what the MAP reading is with the key on and engine off and then subtract that from the MAP numbers.

So, in Bathurst, at an altitude of near 900 metres the gauge shows a MAP 13.1. I guess as I get closer to sea level that number will get closer to 14.7.

Just went for a run with the gauge set to Boost and the numbers seem pretty good, maxed out at just a tad over 16 psi under full acceleration.

[Maxhead]

From memory you had to change the last 4 digits of the MTH setting in the xGauge for BST.

I remember I had to adjust that setting for my 600mt altitude..... Unless the new firmware is different to the older ones. Mine was a scangauge II as well.

Lets try google...lol

[Maxhead]

Look! what have we found here. I hope this helps mate. I know it worked on mine

http://scangauge.com.au/wp-content/uploads/2011/08/Ample-Outdoors-X-Gauge-Turbo-Boost.pdf

[Lonicus]

Lol thanks mate. Obviously a better Googler than me :)

Reading through that at the end it says to name the new setting BST which happens to be the name of the Boost display which is standard in the Scangauge now. So I wonder if the latest edition of firmware has a boost setting that yours doesn't?

[Maxhead]

Lol thanks mate. Obviously a better Googler than me :)

Reading through that at the end it says to name the new setting BST which happens to be the name of the Boost display which is standard in the Scangauge now. So I wonder if the latest edition of firmware has a boost setting that yours doesn't?

I think you'll find they now include it as standard with the latest firmware but you should be able to make changes to the BST gauge still. Give it a shot ...lol

[Lonicus]

There's always the reset button lol

[Lonicus]

Followed the instruction sheet and set the code for a pressure of 13.1, which is what was showing on the MAP readout prior to starting the engine.

Went for a quick run with the factory pre-set BST display and the new modified display showing side by side. The new display read a constant 0.2-0.3 PSI higher than the factory BST readout. According to the chart I should have adjust to 13.3 or 13.4 given the altitude of Bathurst, that would have seen both readouts showing the same boost.

Max boost spiked at around 16PSI.

Thanks for the find Nisshead, at least we know the factory BST seems to be pretty accurate.

Cheers

[happygu]

Great stuff Lonicus. Now i know who to ask for help.....

[Lonicus]

Great stuff Lonicus. Now i know who to ask for help.....

lol yep that would be Nisshead :)

[the evil twin]

Followed the instruction sheet and set the code for a pressure of 13.1, which is what was showing on the MAP readout prior to starting the engine.

Went for a quick run with the factory pre-set BST display and the new modified display showing side by side. The new display read a constant 0.2-0.3 PSI higher than the factory BST readout. According to the chart I should have adjust to 13.3 or 13.4 given the altitude of Bathurst, that would have seen both readouts showing the same boost.

Max boost spiked at around 16PSI.

Thanks for the find Nisshead, at least we know the factory BST seems to be pretty accurate.

Cheers

The figure you put in to change from MAP to Boost is only an average as the actual local air pressure at Bathurst will be different each day as the weather and seasons changes. So if you compare the readings to an external boost gauge it will be different each time unless you jag two days with the same barometric pressure.

The reason being MAP is 'absolute' pressure IE above absolute zero but a Boost gauge reads 'gauge' pressure (PSIG) where ambient air pressure is zero.

All that is happening with the X gauge program is that you are telling the Scangauge to deduct a fixed pressure from whatever the MAP sensor is sending to the ECU... saves the brain having to do the calcs

If you drive from Bathurst to Sydney 'Boost' will underread as you climb up thru the mountains the overread as you descend into Sydney but the MAP will always be a true pressure