New feature: Baro fuel comp table

Post by **calvin** » Thu May 22, 2008 8:59 pm

This will be accessible shortly.

Boosted K20 · Post by **Boosted K20** » Fri May 23, 2008 7:41 am

what does this do?

Post by **calvin** » Fri May 23, 2008 8:15 am

it compensate your fuel when your mbar(PA/BAro) get lower e.g. above sea level Stock code i just exposed it because i read something on EFI101 forum...

relic1 · Post by **relic1** » Fri May 23, 2008 1:27 pm

cool.

all though I'm not so sure how useful it will be to have it listed. I can see it now... 95% of the people will leave it alone, 4.9% should have left it alone, the other .1% will love it.

sewell94 · Post by **sewell94** » Fri May 23, 2008 1:37 pm

I'm glad i'm right at sea level, I'm sure Mr Davis is wil be playing with this in the Blueridge mtns soon

Post by **calvin** » Fri May 23, 2008 3:06 pm

yes most ecu don't even have baro

zeeman · Post by **zeeman** » Sat May 24, 2008 1:41 am

most ecus i see here in canada have baro's in them

MADMAX · Post by **MADMAX** » Sun May 25, 2008 3:10 am

Whats the hardware look like for the barometer input? Does it go to one of the analog mux's? If analog, baro equipped ecus could remove the sensor and have it for another analog input, or a switch, etc. Just something to consider. Also, it looks like pin 9 on the D connector is for an external baro. It goes through a 22K resistor.

HiProfile · Post by **HiProfile** » Mon May 26, 2008 10:19 pm

I think the largish retangular item right behind the external 28-pin EEPROM socket was the baro. The only use I can see for this is people that travel between high and low altatudes - and even at that, mainly those with turbos. With NA cars, the changes between intake/exhaust are nearly directly proportional. But since you are running different compressor PR's at the same boost, and usually see 2-3:1 exhaust PR's, atmos pressure changes more things. But like all things that depend on external variables, you need to tune it with the variables, not guess at it.

JaredKaragen · Post by **JaredKaragen** » Tue May 27, 2008 3:05 am

I waited silently for this one; knowing the road trips to Reno and over mountain ranges for those drives. Good work; But tuning it will have to be something else too...

Adam Hopkins · Post by **Adam Hopkins** » Tue May 27, 2008 10:06 am

It is not just about the higher or lower pressure, Altitude also changes the amount of oxygen in the air. The higher you go the less amount of oxygen.

greasemonkee · Post by **greasemonkee** » Tue May 27, 2008 6:47 pm

Someone help me understand this.

The only difference between the map and the baro sensor is that the baro can read the pressure outside of the throttle plate (and turbo) right? The only variable that would change between the two is the waves within the induction system altering cylinder filling for a particular throttle angle? So instead of having to use 100% TP at 6000 ft. to achieve 800 Mbars of MAP, I can just use 80% TP at sea level to achieve the same MAP. If that isn't the sole purpose of the sensor to begin with, why can't we get by with the stock map sensor alone? Or is it due to exhaust pressure variation as mentioned earlier?

Post by **calvin** » Tue May 27, 2008 7:00 pm

it tells you PA(outside pressure). That tells you how much oxygen to mix with fuel..

Richie2 · Post by **Richie2** » Sun Jun 08, 2008 9:18 am

where excatly you find this table?

Almighty-Si · Post by **Almighty-Si** » Sun Jun 08, 2008 1:20 pm

Could have used this last weekend. Going up the mountains at Deal Gap car was wicked rich at 6000ft. When I got to the top had to pull 5% fuel out of my maps and it still wasn't enough. Forget about EGT's, 14-1500 degrees.