TRD/ Magnuson 4.0 Supercharger Tips, Tricks, and Mods

It's probably true especially when the handful of people participating in this thread are doing things no one has ever done on trucks like ours.

Based on the work I've seen guys do to their cars in my Nissan car Club, the only way to absolutely guarantee a horsepower goal is to increase octane as high as possible.

 

Exactly. Like E85 would be the answer but that requires a whole different set of rules and attempting to find an E85 station in my general trip county area is a challenge to say the least.

 

Hey guys I need to make a PSA regarding the hesitation many of you are experiencing during take off. I'm getting a lot of feedback and concern with this (rightfully so!). So I want to take a moment to address the issue in public forum so all can see and I don't have to type essentially the same message to a number of folks.

So to start. I was first made aware of this issue with a N/A truck that I tuned some time ago. The truck was a 2007 Auto with a good number of miles and clearly had been enjoyed over the years. Not beat up, but a well used truck of that vintage. The truck had some underlying issues after a engine replacement with a re-manufactured unit. After the owner put in a bunch of work he was able to resolve the initial issues, but a hesitation just off idle when attempting to accelerate was then noticed. Our troubleshooting steps led us to reflash the OE Calibration and retest. The truck continued to experience the symptoms. Reviewing the logs showed that all pertinent engine parameters were "normal" with the exception for ignition timing. There was a large "dip" in timing. I made the connection after some head scratching that the timing values observed during this dip are oddly specific and matched up to the map that is used when the truck is at idle (there is a separate ignition map that is used during idle versus the base ignition table).

As a test, I modified specific parts of the idle ignition map to more closely emulate the ignition timing commanded for the RPMs/Loads that are encompass the take off and where the stumble/hesitation occurs. The feedback was positive! Modifying the idle ignition map made a marked improvement I was told.

From memory, the next official case of this was from @12TRDTacoma. This time with this S/C 2012. Similar symptoms, logs showed the same thing. So I sent Roberto a test file with the same modification to the idle table. He also reported an improvement.

To date, I've been made aware of this happening on Stock N/A, Stock S/C, Tuned N/A and S/C trucks, as well as UCON equipped trucks.

My initial reaction to this issue was a mechanical/electrical issue perhaps a wheel speed sensor or one of the DSS sensors. My thought was the ECU was not sensing/seeing the initial forward movement and reverting back to the idle map after the initial throttle application. I'm not yet ruling this out as a possibility, but given the breadth of cases this is currently a viable theory, but I am starting to wonder if their is not something else at play here.

Here's some screenshots to highlight this phenomenon:

Below is a snapshot of what is happening when this hesitation/stumble/bog/etc occurs. This screenshot will show you some of the general parameters at play. If your attention isn't drawn to the dip in the ignition timing (Spark), this is why the truck experiences (insert above verb here). Lets look closer at that in the next image.


To start with the ignition, lets familiarize ourselves with the Base Ignition map. (Disclosure: do not run this table. This was a specifically modified table that was specifically setup to combat specific mechanical issues that are not relevant to this discussion. It's being posted in its entirety for the sake of transparency). This map is generally speaking, the ignition advance your truck will run at a given RPM and Load.


Up next is the Idle map. Their are (4) specific maps related to Park/Neutral vs Drive/Reverse and A/C ON and A/C OFF. I'm making the assumption here Roberto had the A/C on But this is the map for the trucking being in gear with the A/C on.


Now lets take a quick dive back into the datalog.. In this image, we'll take a closer look at timing at the exact instant in the screenshot above. I'm going to share a little about how the ECU derives what value to use and how it gets from A-Z.


Base Timing: Reported value of 26.4. This is derived directly from the base table. You may not see this value exclusively in the base table, but if you interpolate the cells, you'll find this to be the value or close to it. Keeping in mind that the ECT/IAT corections are applied to the base table and then it is checked against "Max Limit" value and then...that value is then reported here as "Base Timing".

BaseFinal WO: Reported value of 12.4. This is essentially the ignition advance value (without knock correction) that is sent to arbitration.

Base Final: Reported value of 14.7. This is the final base timing, including knock correction that is sent to arbitration.

Knock Correction: Reported value of 0.0. This one is a little misleading. This PID reports both knock correction that is applied, as well as torque management correction. BaseFinal WO + Knock Correction = Base Final (In this case you can see it is clearly off.)

Spark: Reported value of 8.0. This is the final ignition advance value as delivered to the engine.

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Now lets work this through.

Base Timing - 26.4
Base Final WO - 12.4

This is where the two timing maps above come into play. The base value (+IAT/ECT and Max Limit check) has the idle map subtracted, leaving us with a 12.4 value minus knock correction.

Knock Correction - 0.0
Base Final - 14.7

With zero knock correction, Base Final WO should equal Base Final. Yet we don't.. We have a difference of +2.3deg. I cannot account for where this additional advance is coming from. Moving on..

Spark - 8.0

Spark should equal Base Final, however in this instance it's not. We've got an error of -6.7deg of timing present here. This advance (or retard rather) cannot be accounted for either.

As observed in the detailed view of the timing advance view, you can see typical/normal behavior following the hesitation event. Observe how all the values essentially line up/overlap? This is typical/normal behavior. The expected correction for idle condition is to be expected when observing the timing in this view, however under the conditions present when at take-off, this is not to be expected. To compound this problem their is additional timing being added and pulled throughout the spark calculation process that cannot be accounted for with the tools available. My initial statements that the problem is with the truck thinking it's at idle are still relevant, but I now see that the picture is a bit bigger in scope and not as simple as I initially thought.

At this point in time I do not have a solution/fix. I know this will be disappointing to many if not all of you, but when this happens on stock vehicles as reported here in this thread some time back I'm thinking the issue is far beyond the control I have with the current software. What I can assure you all, is that if you are running my tune in your truck, regardless of aspiration type or level of modification, there is nothing done in my mapping that would induce this issue. I cannot however rule out that there is some yet undefined/unknown limiter, scalar, table, map, etc that is the culprit, but I cannot pinpoint specifically what is causing this problem.

HPTuners does not offer tuning advice/help/support. They offer tools. The problem now becomes how to illustrate to them that our platform is experiencing something that warrants investigation into the code to see what (if anything) is there that could be the culprit. But generally, their going to need to know where to look and focus their efforts. Simply telling them the truck is hesitating off idle is not going to cut it. That problem is compounded in that their aren't many people pushing to develop this platform so we're going to have to have our ducks in a row to make a legitimate case.

I'll be honest. I do not have the time to head this effort up. I need folks help. I need people interested in committing to the "cause" to help. Very specific and focused datalogging needs take place, and I'd encourage folks to go back to as close to stock as reasonable possible and run stock tunes, datalogging identical sequences on stock tuning so we can compile a dataset that shows we have an issue. If trucks returning to stock calibrations "cures" the problem, that's data we need to know. It would make the case that the increase in airflow/fuel/power that's being made with the custom tuning is potentially triggering some form of torque management.. It's going to be a process to figure out.

I do appreciate everyone's patience and understanding on this. I feel all of your guys frustration/disappointment with this phenomenon. I assure you that it's not something I'm "engineering" into my work

 

@JustDSM , great info and effort. I definitely want to beat this thing, it is beyond a nuisance. Do you know how the VSC/ABS/Yaw sensor interacts with the ECM to pull throttle or timing during an "event"? I've always felt like its something in that system that has been causing these issues.....may not be, but it's easy for me to blame something I don't understand.

 

So just as long as you don’t nail the throttle off the line it won’t likely do this? Not saying that it’s an acceptable condition, just curious if that’s the only place where it happens.

 

For me specifically, it can also happen if accelerating over a crest in the roadway. The engine tries to apply power, but then it surges until I back off the throttle.

 

I know in my 4runner I have never had an issue like this, stock, or X1 for the tuning. On the Tacoma both pre and post hptuner that event happens mostly if I back out of a space go from R to D and give it any amount of gas like a form a traction control and a second or two later it gives the demanded throttle. the wheel can be turned or straight and will still do it. It doesn't do it all the time but let's say outta ten times I can replicate up to 6. I mostly figured it was either an 09 and up deal or a 90l deal.

 

for you, cause made in JPN, a possible bypass would be to unplug the connection at the master cylinder, one of my tricks on track days, so that those systems cannot interfere. It does not harm the vehicle but obviously you would lose the ABS, trac, and stability systems. You could also a kill switch for that but involves more work.

 

Unfortunately I don't have much on that. I'll see if I can find any patents Toyota may have filed on the topic.

 

I did do that as a test a while back......I'm embarrassed to admit that I don't remember the outcome. However I think I remember that it interrupts the ABS, and while all the lights go on, the vehicle is still torque managing via the yaw sensor....

Also no tests for a while, truck is undergoing some surgery while I go LT.....stay tuned.

 

Is this an auto tranny issue or are dudes seeing it with a MT as well?

 

I think you might be right, for me I think it was a combo of steering angle and wheel speed (open diff on corner exit). I think the exacerbation was lessened with stickier tires. I know the system didn't really care if I went into a corner at 100+ but any undulation, while the wheel was turned and demanding power, would magnify the brake pedal input tenfold with or without systems receiving signals.

 

I was also wondering if the 90L also had a hand in that.

 

Ditto. I haven't seen this issue being a MT, but I HAVE noticed a "stumble" when blipping the throttle (i.e. to rev match). @TodayWasTHeDaY have you experienced that?

 

I’m manual, I haven’t experienced anything like this....

 

Thanks for the detailed response! Still learning what all this means but thanks for the effort so far. I am sure its just as frustrating for you as it is for us. Do you think the cam gears were all putting in could be accounting for some of this? I assume you accounted for that in the tune or some folks do not have them still see this issue. My truck did not start doing this until the S/C, Cam gears etc. I wish I had some stock data to help out here.

 

I have to say the return to a larger pulley size and a modified baseline TRD tune cured my issue.

Whether or not it was a software issue or a blower pulley size issue is anyone's guess, but based on the fact the blower pulley was causing fueling issues leads me more inclined to say that the pulley was screwing with things.

I don't know, but my reversion ended up working.

 

I had mentioned before, I’m not MT and not experienced anything like this. Whether or not MT matters and if certain mods do or don’t. Mine are as follows.

MT
2.7 pulley
OV tune (custom tune by Mat for a 2.7 and my respective mods)
No cam gears
DT shorty headers/high flow vibrant cats - JFR 3” y-pipe - URD Mark lll 3” exhaust
AFE Pro dry s CAI
255 fuel pump

These are all the mods that I feel would contribute to such madness. hope this helps

 

I have noticed a stumble on fast acceleration in cold weather that I'm positive was belt slip. Don't notice anything when throttle blipping.

 

unless im missing the symptoms i dont have an issue. my mild yet only complaint is the 4th to 5th random shift flare.