Fuel Rail Pressure vs Intake Manifold pressure - Here is the skinny

[sleeoffroad]

0 as in the value on the display was 0, I don't know any other way to convey this. I took it as being off line since it didn't look like a voltage value, just a 0.

The accuracy of the air flow aside, the O2 sensors where definitely displaying a voltage well beyond the rpm point when the stock MAF was in place. And the voltage was within the expected range.

Rick, not sure what you are trying to say with these two statements. They seem to contradict one another.

 

[sleeoffroad]

Well, I think that I came to this after-party "fashionably late" . Christo you are welcome to post the logs if you would want although I remember you were wanting calculated load as one of the variables and I don't think that any of the logs I sent to you took load into consideration. I know I have some Stock MAF and LT MAF runs with those on them as well as with airflow on them. Might be better to find those first and post apples to apples.

What I would really like is a log with thorttle position, load, MAF VOLTAGE and O2 Sensor voltage.

Again, I want to emphasize that with the LT MAF the rig never read the 0's as with the Stock MAF; IOW I was never able to find the "saturation point" as I called it commonly even when it was reading 36.6 lbs air (off of my memory here so several grains of salt are recommended ) at 99% calculated load and over almost 5K rpms.

Shaun, the real issue is that you read a number that said 36 but you don't know if that is right, wrong or even close to the actual amount of air flowing. The issues are that anything derived from that number will also be different and that can explain the trim values. As they say in science, garbage in, garbage out. Not referring to the housing or sensor, but readings from it.

So in short, you could be tricking the ECU by supplying a different air flow number and in your case you have positive effects from it.

I also again want to emphasize that when we were running the stock MAF and saw the 0's we assumed that was open loop operation and it closely correlated with what was obviously open loop on my wideband.

Not sure what you are saying here. You can not see open loop on the wideband. I have actually asked the autoenginuity people to add the closed loop/open loop flag as a parameter than you can log. They said they will look into it, but has not come back to me again.

It wasn't until we swamped to the LT MAF that I realized I was in open loop on my wideband but the MAF was still reading strong.

Again, changing the MAF readings, changes load calculations and points were you go from open to closed loop. So yes those will change.

Whether it is saturation of the Stock MAF or something else, one thing that is completely clear to me is that I couldn't find that point through LT's MAF. The calibration concern is a whole other worry and I cannot conclude anything on that without testing on some sophisticated equipment. Anyways again with the LT MAF there was no "saturation point" and there was no leaning past the point of 10.8 AFR at prolonged periods of WOT. That to me and to Rick was an amazing achievement considering that the Stock MAF the rig was reading 0's at around 60% load, getting stinkin rich and all the other things it definitely does do in terms of the shiftpoints etc.

Yes, the signal going to the ECU had changed and the effect helped you, however the correct way to do it is to know the calibration of the sensor in comparison to stock and how you are changing the airflow as reported to the ECU. Not just monitoring fuel trim and hoping everything is OK. Add to that changing the fuel pressure as I have shown, and now you do not know what is causing the FT changes.

You can do me a favor and unhook your fuel pressure reference with the stock MAF and let me know if your wideband readings also change.

All it took was one little look at the tests that you did (and thanks again for that truly) to see the relationship with the Fuel Pressure Regulator and boost and vacuum and the reference to Intake Manifold but as I've stated time and time again we still have many more questions to answer. Still, as you told me time and time again, the wideband has wisdom and so does scanner technology to a proper point and I can say with complete certainty that we never found the true "saturation point" or a truly troubling "lean point" with Ricks MAF. Is this the end of our equation, no clearly not, so, let's keep learning ... I love it all.

Wideband is a good tool to make sure you are not screwing up your motor. As for scanner. One has to be very carefull that you actually read sensor responses in their native form and not the calculated values that are based on a couple of sensor inputs, some of which you have changed.

The calibration of the sensor is really important to know what you are doing. Rick can send the sensor and housing together with a stock one to the company I listed and get some response curves. Cheap and easily done. That would show the data and could even show that the sensor is close to correct.

 

[turbocruiser]

What I would really like is a log with thorttle position, load, MAF VOLTAGE and O2 Sensor voltage.



Shaun, the real issue is that you read a number that said 36 but you don't know if that is right, wrong or even close to the actual amount of air flowing. The issues are that anything derived from that number will also be different and that can explain the trim values. As they say in science, garbage in, garbage out. Not referring to the housing or sensor, but readings from it. So in short, you could be tricking the ECU by supplying a different air flow number and in your case you have positive effects from it.



Not sure what you are saying here. You can not see open loop on the wideband. I have actually asked the autoenginuity people to add the closed loop/open loop flag as a parameter than you can log. They said they will look into it, but has not come back to me again.



Again, changing the MAF readings, changes load calculations and points were you go from open to closed loop. So yes those will change.



Yes, the signal going to the ECU had changed and the effect helped you, however the correct way to do it is to know the calibration of the sensor in comparison to stock and how you are changing the airflow as reported to the ECU. Not just monitoring fuel trim and hoping everything is OK. Add to that changing the fuel pressure as I have shown, and now you do not know what is causing the FT changes.

You can do me a favor and unhook your fuel pressure reference with the stock MAF and let me know if your wideband readings also change.



Wideband is a good tool to make sure you are not screwing up your motor. As for scanner. One has to be very carefull that you actually read sensor responses in their native form and not the calculated values that are based on a couple of sensor inputs, some of which you have changed.

The calibration of the sensor is really important to know what you are doing. Rick can send the sensor and housing together with a stock one to the company I listed and get some response curves. Cheap and easily done. That would show the data and could even show that the sensor is close to correct.

Sheesh, I gotta finger out how to have that mult-quote-magic you got going on. Short of that I'll try and answer 1, 2, 3 etc. referencing the first quote, second and so on.

1. I can take logs with whatever you want and will happily send them.

2. I absolutely agree and have always absolutely agreed that we don't know that the 36.6 or whatever it was is really exactly 36.6. I've always acknowledged that possibility and never argued otherwise AFAIR. What I have always asked though of those who stated its off is "how much off", that is all on that one issue but again I absolutely agree and have always absolutely agreed. I still say "how much off" but it all honesty and humility, that's Rick's to answer and I wish he would especially if he can send to some company for low $. It really is an obligation of development if you ask me.

3. It's actually incredibly easy to see open loop operation with the wideband. You even can completely correlate it with the formula the ECU uses to utilize open loop. Time after time it takes same range of rpm, same level of load, same range of throttle position percentage, etc. Regardless of whether AE works on the flag thing, it is incredibly easy to see open loop operation. I don't know how to argue this but basically closed loop equals 14.7 AFR +/- up to .5 or so AFR and open loop equals what happens when open loop operation activates based on rpm, load, throttle, etc it is an instant transition to 12.8, 12.6, 12.4 all the way to 10.8 or 10.0 that is the wideband showing open loop operation. I've tried to trick the ECU with slowly increasing rpms, slowly increasing load, slowly increasing throttle position percentage and it isn't practically possible. I also used other scanners with settings that include the flag and it is exactly the same thing. So, the wideband has wisdom enough to show the open loop operation.

4. If you remember I stated that with the LT MAF the rig seemed to stay in closed loop a little bit longer so I'm saying I agree about the MAF possibly changing that. If that is the case then airflow is part of the ECU's equation. I stated long time ago this might be the case too. So no argument about this from me.

5. Again I agree that monitoring FT short term or long term FT isn't the way to assure that all's well. So no argument about this from me on this one either.

6. Don't wanna do that; some super smart guy named Christo convinced me to leave the reference connected!

7. Agreed. See answer 2 above.

8. Again, agreed, see answer 2 above.

Hope this all makes much sense. And again I love that we're all working towards this overall understanding of fueling our rigs. very very .

 

[landtank]

Rick, not sure what you are trying to say with these two statements. They seem to contradict one another.

Sorry about that. The O2 sensors were displaying an acceptable voltage with my MAF well beyond the point where they displayed a 0 with the stock MAF.

If I may suggest, considering you're a vendor and have more resources than a hobbyist such as myself, you might buy one of these that is on sale in the for sale section and do some testing yourself.

That way you could post up your own data and not continuously do nothing more than scrutinize ours.

 

[turbocruiser]

Sorry about that. The O2 sensors were displaying an acceptable voltage with my MAF well beyond the point where they displayed a 0 with the stock MAF.

If I may suggest, considering you're a vendor and have more resources than a hobbyist such as myself, you might buy one of these that is on sale in the for sale section and do some testing yourself.

That way you could post up your own data and not continuously do nothing more than scrutinize ours.

Rick, my very fine friend, with the utmost of real respect to you from me, that's sorta harsh man; Christo is simply sticking to the same things that he has been saying for some time now. You've got a great product (housing) now you need to find the right sensor and/or the right inner diameter for that fabulous housing of yours. This is simply the scientific method in action, sticking with it will be well rewarded, anything less won't. Please please please see this strictly for what it is. I know I'm not emotionally attached, but, I think that is an advantage here. We've got a great start let's just finish unfinished business.

 

[landtank]

harsh or not it's the reality of the situation. Both you and me have done our best to prove out this design and ensure that it works properly. I've done testing on multiple trucks both stock, SC'd and turbo'd to the end of my ability.

The bottom line is that Christo states that the design will cause excessive lean conditions that will damage a motor. The first point of business should be to prove that condition exists. Either way, moving on to understanding why things work they way they do and how to adjust for it is secondary.

I've gone as far as I can to ensure a safe mod. All the data that I've gotten back has been positive as far as wideband readings and sniff tests from areas that still require it.

If all that Christo is willing to do is speculate and second guess I really don't see where that will uncover the truth about this mod. It will only add confusion and quite possibly deprive someone from an enjoyable mod for his truck if in deed it is safe to use.

 

[turbocruiser]

harsh or not it's the reality of the situation. Both you and me have done our best to prove out this design and ensure that it works properly. I've done testing on multiple trucks both stock, SC'd and turbo'd to the end of my ability.

The bottom line is that Christo states that the design will cause excessive lean conditions that will damage a motor. The first point of business should be to prove that condition exists. Either way, moving on to understanding why things work they way they do and how to adjust for it is secondary.

I've gone as far as I can to ensure a safe mod. All the data that I've gotten back has been positive as far as wideband readings and sniff tests from areas that still require it.

If all that Christo is willing to do is speculate and second guess I really don't see where that will uncover the truth about this mod. It will only add confusion and quite possibly deprive someone from an enjoyable mod for his truck if in deed it is safe to use.

I understand man, I do definitely understand. I guess I've given Christo the benefit that he's saying the same things all along which include "it might lean things too much" and also that "it might not lean things too much". Keep in mind that without Christo working my wideband install, I wouldn't have had the courage to test the MAF any at all. It was he who told me the wideband had wisdom and that your mod might make my truck run like, what was it he said, "a raped ape" but to do this somewhat scientifically I shouldn't push the performance without the wideband and that I shouldn't rely on OBD-II data to determine things. He even openly offered me the use of his own scanner not to prove that your mod didn't work, but, to prove that it did!

I guess I'm simply saying that Christo totally helped me have the extremely enjoyable experience of your MAF and I guess I'm simply saying that he's acknowledged all along that running a little leaner will push the performance but too lean will push the risk. As I already wrote, I'm not emotionally attached; I totally get off on the scientific pursuit of performance so I'm simply not seeing this the way you would. You have put ten thousand percent more into this terrific mod than I have so please pardon my interference. I'm just saying that I absolutely KNOW your mod makes my rig run better in many many ways, but I'm also interested in identifying all the factors that affect performance and safety. I see this simply as another evolution of understanding, not as an attack, but again I acknowledge I'm emotionally removed enough to see things such way.

I admire the hell out of you and your mod. AFAIK, no one here other than yours truly has "pulled" 8.5psi through this thing transitioning from 6K ft altitude to 14K ft altitude at almost full throttle the whole way while watching wideband readings, scanner readings, temperature readings etc. I can say with complete certainty that this mod rocks but I'd also like to see the "Gen II" or "2.0" or whatever version take things to the next level. Ohh, BTW, whenever that is in the works, please place me as the first person to purchase!!! Your fond friend, Shaun.

 

[landtank]

I understand man, I do definitely understand. I guess I've given Christo the benefit that he's saying the same things all along which include "it might lean things too much" and also that "it might not lean things too much". Keep in mind that without Christo working my wideband install, I wouldn't have had the courage to test the MAF any at all. It was he who told me the wideband had wisdom and that your mod might make my truck run like, what was it he said, "a raped ape" but to do this somewhat scientifically I shouldn't push the performance without the wideband and that I shouldn't rely on OBD-II data to determine things. He even openly offered me the use of his own scanner not to prove that your mod didn't work, but, to prove that it did!

I guess I'm simply saying that Christo totally helped me have the extremely enjoyable experience of your MAF and I guess I'm simply saying that he's acknowledged all along that running a little leaner will push the performance but too lean will push the risk. As I already wrote, I'm not emotionally attached; I totally get off on the scientific pursuit of performance so I'm simply not seeing this the way you would. You have put ten thousand percent more into this terrific mod than I have so please pardon my interference. I'm just saying that I absolutely KNOW your mod makes my rig run better in many many ways, but I'm also interested in identifying all the factors that affect performance and safety. I see this simply as another evolution of understanding, not as an attack, but again I acknowledge I'm emotionally removed enough to see things such way.

I admire the hell out of you and your mod. AFAIK, no one here other than yours truly has "pulled" 8.5psi through this thing transitioning from 6K ft altitude to 14K ft altitude at almost full throttle the whole way while watching wideband readings, scanner readings, temperature readings etc. I can say with complete certainty that this mod rocks but I'd also like to see the "Gen II" or "2.0" or whatever version take things to the next level. Ohh, BTW, whenever that is in the works, please place me as the first person to purchase!!! Your fond friend, Shaun.

thanks for this Shaun, I think it's necessary for everyone to realize that the period of speculation has passed on this. The removing of the vacuum line was a design consideration to ensure that the FT% stay with in the specified limits set by Toyota. To that end it has succeeded.

Now Christo has some reservations about this, that is fine, but from a technical stand point any further changes must be prompted by a repeatable issue with the current design. That is how these things work. You formulate a design as to what will work, test and prove/disprove the design and adapt for the next generation.

Until it is shown that the current design is flawed making random changes because someone doesn't like how things are done is not productive it's actually counter productive. You end up designing in circles or chasing your tail.

That's not saying it can't be improved but it's a big difference between damaging engines and improving performance.

 

[sleeoffroad]

Sorry about that. The O2 sensors were displaying an acceptable voltage with my MAF well beyond the point where they displayed a 0 with the stock MAF.

I would like to see these logs. Since I did not see this at all in the logs that Shaun provided me.

If I may suggest, considering you're a vendor and have more resources than a hobbyist such as myself, you might buy one of these that is on sale in the for sale section and do some testing yourself.

With all due respect, the amount of money you made on these are beyond the hobbyist category.

I have repeatedly asked questions which you choose to ignore. I have stated facts, we were challenged on them so I went ahead and showed the proof.

That way you could post up your own data and not continuously do nothing more than scrutinize ours.

I scrutinize data and post questions on findings and statements you make. If you are not prepared for that or to answer questions then do not promote or make statements on this site for the benefit of selling your mod.

 

[Romer]

Just to show you everyones vehicle is different

I reconnected the vacuum line using standard fuelk hose.

Have run it for a week and over 250 miles city and highway driving with no codes or issues.

Tomroow I am leaving for Moab so it will be really tested pulling a camper over Mtn passes and then wheeling

Seat of the pants doesn't register any real change, so thats good.

Idle is rock solid, but then it always was for me.

 

[Romer]

So after a month later, no issues, no Codes with the vacuum line hooked back up.

Probably 1200 miles since then and towing a trailer up and down mtn passes in the heat and a snow storm. Also a week of wheeling in Moab

Sarah's truck doesn't have a SC so maybe I will hook her vacuum line back up

What I got from Christo's post is the vacuum line concern, and if I have that working then I didn't catch any other concernms from his information, or did I miss something?

 

[mikedamageinc]

So after a month later, no issues, no Codes with the vacuum line hooked back up.

Probably 1200 miles since then and towing a trailer up and down mtn passes in the heat and a snow storm. Also a week of wheeling in Moab

Notice any MPG difference? Any difference power wise?

 

[Romer]

Notice any MPG difference? Any difference power wise?

Most of the miles was wither towing over the mtns or wheeling.

I dont notice any difference with the line hooked back up.