New to meth spray.. Do i spray more? (datalog no temp drop on 30/70 spray)

[FoMoCoSHO]

I'm running 200ml @ 40 psi nozzle (actually running ~275 psi so it comes out to 500ml a minute). 7.5 minutes of spray per gallon. AJP hasn't chimed in on what he sees in my spray logs so not sure if this is a good amount ... yet.

Hmm care to share the math?  375ml at a default of 275psi?

Also how do you interpret the STFT Llogs?

IIRC when I glanced your LTFT was at 1 and stft was pulling about 10% over the pull

[TopherSho]

175 ml is very close to my 200 ml. I did a real test by seeing how long it takes the pump to suck up 500ml of water, which was 1 minute.

Got it,  so not formula per say but a bench test.   I should likely do this as well.  Pushing fluid through 20' of hose has to have a parasitic impact..

I do think i am getting better results with the 375.. i need to switch to 50% more water and test again after i do a real heat up and run hopefully today if my test road is abandoned.

Ultimately i need to track it.  Track heat with repeated runs is VASTLY different .. i may see better results there than idling on the side of the road up to 150f IAT2 and dashing down the road.

well have to see.... but I am starting to think this *might* have been a incorrect purchase.   I probably should have had Brad add 5 points of global timing and just run E30 on race days ... well see.

[TopherSho]

I'm running 200ml @ 40 psi nozzle (actually running ~275 psi so it comes out to 500ml a minute). 7.5 minutes of spray per gallon. AJP hasn't chimed in on what he sees in my spray logs so not sure if this is a good amount ... yet.

Hmm care to share the math?  375ml at a default of 275psi?

Also how do you interpret the STFT Llogs?

IIRC when I glanced your LTFT was at 1 and stft was pulling about 10% over the pull

So to interpret .. a .9 reading in the STFT is in fact what others call -10 ?  I assumed so but need validation on that understanding.

[TopherSho]

the 375ml nozzle produced much better results. 

Now to drop it 2 pounds for the onset ... then one more test.  After that only the track will determine the true benefit of offsetting PIR's 170f pavement radiating upward in the line up lanes.

Oh yeah love the spark bumping up to 21 and holding in the high rpm range.  Cant wait to test with 15/85 and see if that will go any higher.

[StealBlueSho]

I'm running 200ml @ 40 psi nozzle (actually running ~275 psi so it comes out to 500ml a minute). 7.5 minutes of spray per gallon. AJP hasn't chimed in on what he sees in my spray logs so not sure if this is a good amount ... yet.

Hmm care to share the math?  375ml at a default of 275psi?

Also how do you interpret the STFT Llogs?

IIRC when I glanced your LTFT was at 1 and stft was pulling about 10% over the pull

So to interpret .. a .9 reading in the STFT is in fact what others call -10 ?  I assumed so but need validation on that understanding.

This is correct ... ideally you want your STFT to read 1 in a normal application which Meth is not but understanding how it works will give you an idea of how much meth your are spraying. If you see a reading of .95 then your car is technically pulling 5% fuel to keep the demanded AFR. Which could also be read as -5% depending on the program collecting the data... so .90 would be -10% or pulling 10% fuel to maintain AFR.... and vice versa if you are adding fuel... 1.05 would be adding 5% fuel to maintain AFR and could be interpreted as +5%...

Technically you need to account for the LTFT as well... so you add your LTFT and STFT to get an overall picture of how the car is being fueled...

LTFT of 1.03 and a short term fuel trim of .95 means that your car is technically pulling 2% fuel to achieve demanded AFR...make sense?


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[TopherSho]

This is correct ... ideally you want your STFT to read 1 in a normal application which Meth is not but understanding how it works will give you an idea of how much meth your are spraying. If you see a reading of .95 then your car is technically pulling 5% fuel to keep the demanded AFR. Which could also be read as -5% depending on the program collecting the data... so .90 would be -10% or pulling 10% fuel to maintain AFR.... and vice versa if you are adding fuel... 1.05 would be adding 5% fuel to maintain AFR and could be interpreted as +5%...

Technically you need to account for the LTFT as well... so you add your LTFT and STFT to get an overall picture of how the car is being fueled...

LTFT of 1.03 and a short term fuel trim of .95 means that your car is technically pulling 2% fuel to achieve demanded AFR...make sense?


Sent from my iPhone using Tapatalk

Nice explanation.. thank you! 

[TopherSho]

Spray log #3 for G&G's and comparisons.  this run is still 30/70 WW fluid,  but i turned the screw 1 full turn counterclockwise on the analog boost switch.

if the factory setting is 9-11 psi then i'm now 7-9 .. have to sus-around the logs to see the spray onset in the fuel trims.

initial look is great,  STFT doesn't drop under .9 .. so that's better then the .8 i saw yesterday.  Spark is back again .. it wont hit 22 degrees so i think it is maxed with the current compensation tables and global spark thingamebob..