TRD/ Magnuson 4.0 Supercharger Tips, Tricks, and Mods

In other words, keep it floored and you won’t blow up from knock??

 

@JustDSM might be able to share some insight on this. He had to dial mine back a touch in timing. As I was too close to the knock zone.

 

I don’t agree with that at all.

Based off what you’re telling me about your observations, and from what I’ve seen him post, his method for fuel control (at least on 2nd gens) is by adjusting tables that modify or add too the main fuel table.

I prefer adjusting the main table(s), which will provide you with instantaneous enrichment exactly where you set it.

It doesn’t take any measurable amount of time for the Ecu to calculate that stuff.

 

It won't knock/ ping if your timing parameters are set to what they need to be based upon pulley size. Lol.

But if you want to floor it everywhere than by all means don't let me stop you. Boost on brother!

 

TRD flash stock does not go into open loop until after 70% throttle. With HP Tuners, you can adjust what percent you want it to do it. Mine is set at 55%.

 

I think that is around what mine is set to now also.

Of course that is after you turn off Catalyst Overtemperature Protection mode.

 

I have my cat over temp turned on and set the enable temp super low so it’s always active and that table is always used for fueling.

 

Interesting. I had no idea that table was adjustable, but I never looked at that.

 

My cat over temp protection is off and my power enrichment/open loop is set to come on at 32%. I think gearing must play a role here. At 50+% open loop enable would put me at 8+ boost before it kicked in. Even now I can make 6 pounds before it kicks in.

 

The short version is if I'm accelerating at 25-50% throttle, it'll sit at stoic and then go rich after a few seconds or certain RPM. So how I drive it is I'll give it light throttle at 0-2psi until it goes rich, then dig into the throttle for more power. That's how it behaves.

I also have the automatic transmission, if that matters.

 

It doesn't have to be that way. It is possible to tune it so you don't have to drive it a specific way properly fuel it.

 

I'm going to make some inquiries with Chris and see if there isn't some way to get PE enabled based on load in addition to throttle angle. I think this would be the saving grace for the S/C crowd. You could keep your throttle based enrichment point at a reasonable setting but get additional fueling when boost comes on at low throttle angles..

Now that Rev-Hang is out of the way I've got to give him something else to work on..

 

Yeah that would amazing. I have only seen a low of 14.3 AT most when throttling it before PE engagement and if there can be some additional fueling to at least put you in the lower 13s that would be amazing.

 

Has there been any discussion about load calculation tables? It would be nice to see how the ECU is calculating load percentages.

Seems like for different pulley sizes the calculations need to be different since, say on a smaller pulley there is more boost, earlier. Not sure if that makes sense (it does in my head!)

 

If you want to read up on Load Calculation:
SAE International SAE J1979 / ISO 15031-5


Absolute Load = [air mass (g / intake stroke)] / [1.184 (g / intake stroke) *
cylinder displacement in liters]

Derivation:

- air mass (g / intake stroke) = [total engine air mass (g/sec)] /
[rpm (revs/min)* (1 min / 60 sec) * (1/2 # of cylinders (strokes / rev)]

- Absolute Load = [air mass (g)/intake stroke] / [maximum air mass (g)/intake
stroke at WOT@STP at 100% volumetric efficiency] * 100%.

Where:

- STP = Standard Temperature and Pressure = 25 °C, 29.92 in Hg (101.3 kPa BARO
- WOT = wide open throttle

The quantity (maximum air mass (g)/intake stroke at WOT@STP at 100% volumetric efficiency) is a constant for a given cylinder swept volume. The constant is 1.184 (g/liter 3) * cylinder displacement (liter 3/intake stroke) based on air density at STP.

Characteristics of Absolute Load are (Generic):

- Ranges from 0 to approximately 0.95 for naturally aspirated engines, 0 – 4 for boosted engines
- Linearly correlated with engine indicated and brake torque,
- Often used to schedule spark and EGR rates,
- Peak value of LOAD_ABS correlates with volumetric efficiency at WOT.
- Indicates the pumping efficiency of the engine for diagnostic purposes.

Another thing to keep in mind, Boost is more or less meaningless in terms of our ECU and it's calculation. It's all done based off airflow. If we were using a speed density setup like an aftermarket ECU (Haltech) we'd be controlling fueling based off manifold pressure (boost), but our Mass Airflow based system, does not look at, use, or consider anything related to boost.

It really doesn't care if you're at 10psi or 1. It's fueling based off the measured mass of airflow entering the engine. And remember, just because the pressure is higher, doesn't always mean more air is flowing into the engine.

 

Makes perfect sense now.

 

In otherwords, it's just not defined by a table

 

I just needed an excuse to post cat gifs. Thanks for the explanation!

 

I just sent Chris an email about the load based PE enable. I have a feeling there's not.. But I wouldn't be doing my part if I didn't try!