HP noob. Srt4 questions

[PurplePoweredNeon]

Hey guys, new to hptuners. Previously used diablosport but made the switch for more tunability.

Now I'm under the assumption that tuning injectors starts with the pratio table. But what exactly does pratio mean? I just want to understand what everything is before I attempt to actually adjust anything. I know I'll have a lot more questions but this is where I've started. Thanks

[Scottyb_288]

PRatio is "Pressure Ratio". Its MAP sensor pressure divided by barometric.

[PurplePoweredNeon]

Why does it only go up to 3.0? And is the pratio power enrichment table how injectors are scaled?

[MarkTucker]

3.0 PRatio is alot of boost. (but if you hitting more than 3.0 PRatio, you can raise Ratio axis by clicking on Ratio in the table)
Example: if you have barometric pressure of 100kpa(ambient barometer sensor) and a manifold pressure of 300kpa (MAP sensor), that is 3.0 PRatio (3:1 ratio)

Injector Pulse Width tables, Injector Offset and Min InjPW are your main injector scaling tables.

Power Enrichment is to set your commanded AFR/Lambda.
1/(fa stoich + fa power enrich) = commanded AFR
Example below:
stoich = 0.0696
power enrichment = 0.0154
1 / (0.0696 + 0.0154) = 11.7647 afr

You can also reverse the math, so you can input the afr that you want to command and give you the value you need to input into the power enrichment table to get that commanded afr.
(1 - (11.7647 x 0.0696)) / 0.0696 = 0.0154

[PurplePoweredNeon]

3.0 PRatio is alot of boost. (but if you hitting more than 3.0 PRatio, you can raise Ratio axis by clicking on Ratio in the table)
Example: if you have barometric pressure of 100kpa(ambient barometer sensor) and a manifold pressure of 300kpa (MAP sensor), that is 3.0 PRatio (3:1 ratio)

Injector Pulse Width tables, Injector Offset and Min InjPW are your main injector scaling tables.

Power Enrichment is to set your commanded AFR/Lambda.
1/(fa stoich + fa power enrich) = commanded AFR
Example below:
stoich = 0.0696
power enrichment = 0.0154
1 / (0.0696 + 0.0154) = 11.7647 afr

You can also reverse the math, so you can input the afr that you want to command and give you the value you need to input into the power enrichment table to get that commanded afr.
(1 - (11.7647 x 0.0696)) / 0.0696 = 0.0154

Awesome. Thank you! So what are the VE tables for?

[MarkTucker]

VE Bank 1 is your Main Fueling tables. VE = Volumetric Efficiency

You might want to consider looking into a good tuning guide book or dvd or training class, before diving into this.

So going off your questions, have you ever tuned a vehicle before?

[PurplePoweredNeon]

VE Bank 1 is your Main Fueling tables. VE = Volumetric Efficiency

You might want to consider looking into a good tuning guide book or dvd or training class, before diving into this.

So going off your questions, have you ever tuned a vehicle before?

Not with anything like HP. I've been using a diablosport handheld but that was pretty basic and very user friendly. This is way more advance. Any idea where I can find a guide for dodge ngc tuning? I can only seem to find guides for GM and ford. Thanks

[MarkTucker]

Simply google search dodge ngc tuning guide.

There are tons of threads on this forum on tuning the NGC PCM's.

Just need to read thru all of them to try and understand what each table is and what that table controls.

[PurplePoweredNeon]

So I think I'm starting to get things figured out. But for the injPW, is that info that can only be found from the injector manufacturer without actually having a flow bench?

[PurplePoweredNeon]

also, is there a formula to adjust the throttle Body size if that even needs to be changed? I can't find much on it other then the electronic throttle body's.