best way to tune for nitrous....

[phat_ridegt]

im only going to be spraying out of the hole, to spool the turbo....im using a zex dry kit, with a 55 shot.....

for now im going to stick to gasoline, but i plan to switch to e85.....


i would estimate ill be spraying for the first 60' (less than 2 seconds)

ive sprayed a couple times with it on my current tune...it doesnt knock, but it comes up to about 12.4afr, id like it to be in the mid-low 11's while spraying. the car stays pretty solid at 11.8-12.0 on just motor....


i was thinking of just adjusting the maf down low, because thats the only time ill be flowing less than 9500k or so......


EDIT: im working with a PT for now, until I buy the credit for HP

ideas? mike?

Click to read more...

 

[Eagle]

12.4 is BAD on the spray. I'd imagine depending on much boost you're running while spraying, that you'd want to be in the mid 11's at most.

This is why wet shots are your friend!

 

[phat_ridegt]

yah im running low boost right now (less than 15), and i wont be running over 10psi while spraying...

im working on a tune as we speak....going to try to just bump the maf up looking at a scan from earlier in the year....im gonna retard the timing 3* in lower RPM's, and and add 10% to the maf table between 6-9400k

now i am out to re-position the nozzle and get this thing ready to race!

 

[02BlueGT]

yah im running low boost right now (less than 15), and i wont be running over 10psi while spraying...

im working on a tune as we speak....going to try to just bump the maf up looking at a scan from earlier in the year....im gonna retard the timing 3* in lower RPM's, and and add 10% to the maf table between 6-9400k

now i am out to re-position the nozzle and get this thing ready to race!

Or, you could have PE enable from 1%TP on up, and change the addvsRPMvstime table to add your desired fuel at low RPM's, that way you're not sitting at -10+ LTFT when you step on the pedal

 

[phat_ridegt]

im only spraying at WOT though, not at 1%tps.....i'll be well into PE (assuming 28%) before leaving the line....

unless i raised PE enable to 80% so i could use the PE-time-rpm table.....

hmm

 

[02BlueGT]

im only spraying at WOT though, not at 1%tps.....i'll be well into PE (assuming 28%) before leaving the line....

unless i raised PE enable to 80% so i could use the PE-time-rpm table.....

hmm

I mean set it to 1%, that table is the min enable %... So you're in PE the whole time, that way you can run a correct MAF table, and actually have the PCM add fuel where you want it

 

[10sec]

Easiest way to setup a dry shot is scaling the IFR table in the 100KPA (not sure about pt) cell since that's the one referenced for WOT or anything above 100kpa. I would scale it 12% (to run richer) for your setup as it is now if you were to go that route. Scaling the maf works just fine as well but doesn't look pretty since it's like a jagged edge from where you're on the throttle and when you're not. Dry shots are a PITA for sure but not impossible to mess with. Do you have a scan the shows the only time you spray is under 9500k? If you know this for a fact and can shut the juice off before it hits over 9500k then adjusting the maf is the way to go, it'll just look funky when graphed. I would still stick with adding 12% to that area and go from there. My guess is your wide band will read 11.6 after the adjustment which is good if you're only spraying for 2 seconds. If you plan on taking the spray down the whole track you want to be in the low 11's to be safe. FWIW my 11.8 pass last season was 11.2:1 all the way down the track. The next pass was 11.9:1 and i melted a plug haha.

P.S. bring extra plugs

 

[ktraver97ss]

This is why wet shots are your friend!

You would love a wet shot wouldnt ya, sick bastard.

:gtfo2:

 

[Eagle]

You know it!

 

[phat_ridegt]

in my application with a turbo, a wet shot is not ideal because it greatly increases the risk of a nitrous/fuel backfire....a dry shot is perfect for spooling a turbo :boost: lol