so i got an osiris tune in denver on the 1st of september i made 380 whp on 5 psi on a dynojet. it was 100 degrees and 6000 foot elvation my afr was 12.0 at wot...so the next day i drive home to rapid city where the elevation is much lower and was around 65 degrees. my 4th gear pull 7psi on a dynojet was 333 hp with afr below 10. the dyno wouldnt show how low it got because anything below 10 is just super rich...im like wtf...so i go back on the highway and my afr at wot is anywhere from 10.2-10.5...still rich but better..any ideas what this could be? im runnning shell t6 syenthetic oil my tuner said it was good for turbo z's.

 

ya, the load cells were tuned at 5psi and not at 7psi. The 7psi load cells need to be properly tuned. They are obviously too rich and the tuner never took time to adjust them.

why didn't you adjust them when you did the pulls on the dyno?

 

Because it was just 2 pulls for 50 bucks. It was an outside mustang event.

 

oic

so ya, if you are in a different load cell (due to different psi) then it's probably not tuned which is why it's really rich. Better it was set for rich than it actually being lean and causing an issue.

I would just tune it in the higher boost since you are running that now.

 

It's a 7 pound sprIng. We weretrying to make 7lbs of boost but the conditions and elevation would Only allow 5psi to be made. I didn't turn up the boost it's just weather conditions and elevation that allow me to make 7 psi now

 

That doesnt make sense.

Turbos are supposed to good for elevation changes and not letting the engine lose power.

Springs don't care about elevation changes.

 

truth, something else was wrong. 7lbs is 7lbs over atmospheric so it doesn't matter what base atmospheric pressure is since it starts from 0 being the base.

 

ok well heat def makes a difference it was over a hundred

 

heat doesn't change absolute pressure either.

If you are talking barometric pressure then yes but this is absolute which means it references atmospheric pressure as 0. So no matter where you are absolute pressure of 7psi is going to be 7psi above anything around it.

Now, when you say 6000 feet and the gauge reads 7psi that will not be the same actual pressure as sea level with the guage at 7psi BUT you are still going to display 7psi and still will be in 7psi load cell.

all of our gauges and ecus are reading absolute pressure not actual pressure which means it's just the amount of pressure or vacuum above or below the surroundings.

i've been a pilot for 10 years this december. I'm very familiar with pressures and gauge readings. We use actual pressures in planes so we have to set the barometric pressure every time we get into the plane and then frequently have to change pressures as we fly if we move into areas of high or low pressure.

 

that being said, it's a simple fix. Just go get the 7psi load cells tuned and all will be good.

 

the problem is wot afr is at 10.2-10.5 even before 7 psi..i step on the throttle and it is 10.2 from vac to 7 psi

 

list the mods you have for the car

one thing is for sure it needs to have the tune adjusted. Not many issues will cause a rich problem so i don't think something "broke".

 

1/2 motordyne spacer
powerlab turbo kit
GT35R 1.63 housing
tial wastegates and bov
1 step colder ngk irridiium XI plugs
up rev osiris
600cc injectors
walbro fuel pump
oilpan spacer
mishimoto thermostat
mishimoto fan shroud
mishimoto radiator
bc true coilovers
spc camber arms
spc A arms
19" volk gts wheels

 

Found your problem. A/F is directly related to having aftermarket wheels and suspension components.


How are you tuning osiris based of pressure? Shouldnt it be based of the MAF?
Could you of had a leak that caused you gauge to only read 5psi while being tuned that was since fixed and giving you 7psi?

 

Osiris is MAF based so the difference between 5 and 7 psi might not even by 1 cell. MAF does not always move proportionally to boost. I can set my boost controller anywhere from 6 to 10 psi and the cursor barely moves 1 cell to the right. Given that, the A/F is spot on 11.7 at any boost level, mostly thanks to the fuel return system.

But I think the main issue is the climate. You tuned in high altitude, so the MAF saw less air, and the fuel schedule was lower. Move to lower altitude, the MAF sees more air and the cursor moves right into un-tuned areas of your fueling table. Get the tune touched up at lower altitude / higher boost and you should be OK.