General Supercharger Thread

@TurboKits.com was working on some device of sorts to solve the MAF voltage issue that it sounded like they may offer for sale. I don’t really know the details though. Perhaps Jesse can give details.

There may be ways around it via tuning, I know DAP had found a way around it when I had the stock intake with the 80mm pulley. That said I don’t think it’s technically the right way, and I did get occasional P0101 codes. Otherwise I think the only proper way to solve it is to get a larger MAF tube and scale for it. I was at 4.97v with the 80mm on the magnuson intake (I also used air straightening honeycomb before the MAF which may have made it read higher.) I’m sure I’m hitting the ceiling now with the 77.5. Being remote tuned though I think I was tuned way excessively rich though, so if anything it’s probably better AFRs now.

 

Ah, I'll peruse through his posts to see what he's mentioned so far. Thanks.

 

This is my understanding:

If the MAF voltage hits the limit you're kind of SOL. If the MAF flow rate value hits its limit, that is different and can be adjusted for. The voltage is mechanically derived from the sensor which is why it can't be adjusted in the software. The sensor deflects so far from airflow and that's 5V either way since you pegged the deflection it can read. The resulting airflow measurement also has a cap, but that's software driven so by changing other variables like injector constant you can keep the airflow value inside the software limits.

MAF voltage limit -> bigger intake
MAF flow limit -> adjust IC and MAF table

With that said, if you just tickle either of those at the high end I wouldn't sweat it. Worst case you get a CEL that does nothing when you're WOT at 6000rpm. As long as the voltage doesn't max earlier since then you don't have MAF data for the higher rpms since it can't read anything then.

 

I wonder if the 3URFE ECU can support two MAF sensors like some of the Lexus V8 engines do? Perhaps another reason to chase that direct injection swap?

 

All-righty, that makes sense. I think that I'm also remembering it being mentioned (possibly by SNS) that when the flow limit is reached (512g/s) that the ECU simply uses the last known values for anything greater. That sound right? I'm not as concerned with maxing the airflow as I am with maxing the fuel, that seems more hazardous, so I'll start by boost referencing the FPR. I have these couple of weeks free to focus on it, so that's where my mind will be. Everything seems to be kosher up until the very maximum, so like you said, it's not something to loose sleep over as it's not typically how I drive; I'm not drag racing spending all my time at WOT.

 

@Wynnded Is this where SNS talks about it?

The basic process for determining air mass is:

1. Reference current MAF sensor voltage
2. Look up base mass airflow for current MAF voltage from Engine -> Airflow -> General -> MAF Calibration -> Airflow vs. Voltage
3. Look up base mass airflow correction for engine RPM and throttle angle from Engine -> Airflow -> General -> MAF Correction -> Base
4. Look up IAT mass airflow correction for Intake Air Temp and base mass airflow from Engine -> Airflow -> General -> MAF Correction -> IAT
5. Calculate final, corrected mass airflow by multiplying the lookup values:
   Final Mass Airflow = Base Mass Airflow * Base Mass Airflow Correction * IAT Mass Airflow Correction

• During large transients, the PCM models airmass instead of taking values directly from the MAF. If you log MAF and Absolute Load during a large throttle transient, you'll note that Absolute Load does not track perfectly with MAF under those conditions.
• MAF Voltage is limited to 5V, Mass Airflow is limited to 512 g/s. Above 5V, a larger intake is required to bring the sensor into range. Above 512 g/s the tune will need to be scaled to bring the air mass back into range.

 

I can't collect my pink slip from the ditch!

 

This looks to be what I'm remembering...

 

The coil arrived and is obviously different, so a little research leads to the following… For the newer generations of engines, Toyota has moved the goods up and out of the spark plug tube, it’s no longer a stick or pencil type unit, but a top mount coil. This move is for an increase in durability due the coil being able to run cooler. The engine literature also mentions these are a high energy type, but do they produce more of what we need? I suspect they might. While not listed as a Dynamic Force Series Engine, the 8ARFTS was a transitional engine that uses much of the newer DFS technologies. Just as with the run to higher performing spark plugs to prevent misfires, perhaps too with the coils?

They physically bolt in place of the stock coil, and the wire harness plug snaps right on. The harness connector is a much more durable type, and supports the wires leading into coil with a loom. Now to find out if they are truly compatible.

New type.

Old type.

 

I love that Toyota makes things that can (theoretically/potentially) be used in multiple models. Some of the Tundra/Sequoia/Land Cruiser mechanicals/electricals. Now potentials like this.

 

Yes, Toyota does very well parts sharing between models.

Sometime it’s the little things, like the two piece connector that captures, supports, and protects the coil wire harness. Tell me this won’t look cleaner while doing an actual job…

 

In regards to fueling, something else to keep in mind is the tune may not command 100% injector duty cycle without some adjustments. If you have PE maxed out at 1.5 and look at the datalog and the duty cycle is at 80%, you need to rescale the MAF/IC so it will command 100% duty cycle. An injector constant of .09 with 1.5 PE might be 80% duty cycle, if you change that to a IC of .11 (telling it it has a smaller injector, so because of that will open the injector longer to try and get the same perceived fuel flow) now you'll be at 100% duty cycle at 1.5 PE, and because you adjusted the IC you then need to adjust the MAF flow down by the same amount so it thinks there's less air so commands less fuel, but with the larger IC ends up being the same result AFR.

My point being, your truck leaning out may not be because the injectors are maxed but because the tune won't command them all the way open, and without the datalog showing the duty cycle, if you just keep increasing PE based on your AFR gauge that might not utilize everything possible.

 

I'm realizing that it's a lot like this:



...But I understand it more and more every time you and I discuss it, and I appreciate that.

My IC is 0.1, anything lower and it struggles to hit stoichiometric at idle with the TRD Airflow v. Voltage map, which I think I've mentioned to you SNS pushed to try to maintain some semblance of, and my PE is 1.2 so there'd be room there. Actually, if I could get my wideband to cooperate and logged, I might even be able to lower that a smidge. I think that if I were to lower the IC and thusly increase the Airflow table to hit stoich, I might hit the 5V barrier earlier; am I getting this right? Oh, you know what, for a little trial and error, I enabled the COT, I wonder if that could be eating up some of the injector flow capability during PE resulting in the high Inj DC percentages. What's your thought on that?

It pains me to just sit here today though, I wish I could get out and try some things, but so many of the roads are closed here today with all the travelers sliding off the road with the snowfall.

 

I'll preface this as always in case someone new is reading this by saying I'm not a professional tuner, and some of these points below may not be entirely correct but in my experience work totally fine in this simplistic view. For instance Silver17 said DAP did stuff to fix the 5V limit issues he had, I'm not disagreeing that's possible, but that's beyond my scope of experience and following the below has always worked for me and at this point numerous others.

------

The IC is somewhat arbitrary. The combination of IC and MAF and fuel trims should hit stoichiometric everywhere, if your fuel trims are zero then your IC and MAF relationship is correct. I start with the TRD values, but I may deviate a ton from those and that's fine. If the MAF flow hits the max, and fuel trims are zero, then just scale IC and MAF together to get MAF flow back within bounds. None of that should change being able to hit stoichiometric. If you have issues hitting stoichiometric, I would interpret that to mean your fuel trims are maxed out.

The 5V barrier is a relationship with the intake and nothing else. You can't tweak things to make it hit 5V earlier or later because it's purely based on mechanical deflection of the sensor. The sensor hitting it's hard stop is 5V, nothing about the tune changes where the hard stop is because that's just a matter of air hitting the sensor and bending it over.

As far as COTS is concerned, I set the base values to 1 so 99% of the time it doesn't do anything. However, I don't straight up click "disable" because that keeps the other COTS functions active like retard enrichment and stuff. How valuable that is I don't know, but SNS had mentioned doing that because you keep COTS side effects active but effectively turn off the catalytic converter enrichment which throws AFR for a confusing loop. I have disabled COTS entirely before because I was suspicious it was doing things, I've also turned it on and fucked with the base values to try and richen out the fueling even more but both those circumstances were trying to troubleshoot things. In normal form, I set the base multipliers to 1 and leave the other tables.

 

To add a specific example to the above, a week ago @helidave and I were tuning his truck. I started with the TRD MAF and IC values, and got his fuel trims to zero by slightly tweaking some MAF values. However his fueling was off, he was above 11 for AFR even after I maxed out PE to 1.5, but his duty cycle only showed 80%. To fix this, I increased IC by 20% so it'll flow 20% more fuel, reduced the whole MAF table by 20% so it thinks there's 20% less air to cancel out the 20% extra fuel, and then decreased PE by 20%. We are effectively at the exact same point we started at now, except PE is now below the 1.5 max limit, so we have 20% more fuel to add by increasing PE again.

In this case, the TRD values for everything are long gone. Which is even more odd since he has the Magnuson intake and injectors so I thought it would've been a walk in the park since those are known values, but for whatever reason did not work in his case. Now however, he has PE left to play with, the MAF/IC relationship is the same so the fuel trims are happy, and the truck is right at the AFR we want.

Again, maybe my approach is simplistic and wrong, that's why I tell people to try other tuners first. For instance maybe the efficiency tables should be modified also, that's not something I've screwed with but I also haven't seen any need to screw with.

 

The truck runs good, I'm learning a ton about tuning, and if I want to tweak something I'm not locked out of the file. Sounds like a good deal to me

 

https://youtu.be/PF-R5ZaG71I?si=F2_hABiPj7xZmnM-

 

Yes!

I have a suspect bad set of DW650s. Injectors behave really strangely going extremely rich or lean randomly. DW is going to take them back for testing, and replace as a warranty claim.

Meanwhile I'm getting a set from another member on here to test/validate the injectors being my issue before installing a new set of FICs.

 

What's everyone like for air filters? The maggy ships with a

$72 K&N 33-2387 K&N Engine Air Filter: Increase Power & Towing, Washable, Premium, Replacement Air Filter: Compatible with 2007-2019 Toyota/Lexus V8 Truck and SUV (Land Cruiser, Tundra, Sequoia, LX 570), 33-2387

K&N 33-2387. Has anyone noticed an improvement switching to AFE or something else?

 

Improvement in what respect? lol K&N flows good, but doesn't filter so well. I currently use the AFE DryFlow and it does a much better filtering job. I don't think it's restrictive at all, at least not according to my airflow restriction gauge. WIX makes a pretty good air filter too.

 

I've never been super impressed with K&N stuff, so if there's something that's better at keeping crap out of the engine but doesn't hurt performance, im all for it.

 

Wix is the answer. I use them because I work in dustville.

Project Farm says so.

 

I agree. I've been opposed to KN for sometime especially in dusty or sandy desert areas. I'll run afe dry or wix filters.

 

@snivilous thanks for all your simplistic approaches to tuning. When we all have similar setups sometimes it's not all plug and play and requires a different approach. I've been saving your posts on tuning on here and hpt from SlowNStock posts.
Thanks!

 

Does the magnuson airbox use 2013 tundra filters?

 

I found that Napa’s branded filter is just a Wix re-brand without the added cost. I throw a new one in every oil change, as cheap insurance.

Yes

 

Do you notice any performance difference between the afe and wix?

 

It bit subjective but I read a comparison of top filters and the wix/stock paper flows best with good contaminate entrapment.
I was gifted 2 afe dry filters and been using them the past 8 years. Was just thinking of trying paper again...

 

Yes sir! I've been wanting to make a YouTube video of the full break down of how to build the tune, what does what, how to datalog, what to take away from it, etc. It's hard to find all the pieces, let alone in one compact and simple form somewhere.