[ScottSpeed21]

So there is no way to have vta on a EVO. Without messing with maf?

VTA is fine, don't listen to those people.

What spring are you running now? I have the same thing, Tial 50mm VTA. You'll want a -9psi spring. -12 is way too stiff and the valve won't even open at full boost...you'll get some crazy off throttle surge.

You're getting a little surge (fluttering) because the BOV is staying closed, like it's supposed to, and your turbo is basically spooling too fast at part throttle, flowing more air than the engine can take in. Either adjust your right foot, or adjust your MIVEC and wastegate duty cycles a little so it doesn't spool so fast at part throttle.

There will always be part throttle situations with high load/low rpm when you can't avoid that light surge, but you can minimize it by tweaking the above mentioned tables.

 

[ScottSpeed21]

I call them like I see them. I don't have enough disposable income to not follow the advice of certified, tried and tested professionals.

You DO know that recirculating subjects the upper side of the plunger to a vacuum and makes it easier for the BOV to release, Right?

Please just stop this nonsense...

Have you tried and tested it yourself? Because I have...

You DO know that there is absolutely no amount of vacuum in the intake tube with that ginormous open hole we call the air filter, Right?

please do not give out false information's. VTA and the stock EVo MAF set up doesn't work right.

You need to get rid of the MAF to have the VTA bov set up work right .

I dont know who is this guy, but you can ask all respectable tuners and engine builders. They all say the same. I tried the VTA Once in the 4G63T engine and once in the 4B11T. wont work right,.
Now i have VTA , but i have no MAF anymore.


Rob

Zero false information here.

Been there, done that...tried and tested on my own car...it works perfectly, absolutely fine.

In case you were wondering how I know: http://www.evoxforums.com/forums/showpost.php?p=965102&postcount=34

 

[ScottSpeed21]

from some tuners for you ( there is a difference between a MAF and the MAP sensor... )

I'm quite aware of the differences between a MAF sensor and a MAP sensor. So you do know that our cars have both sensors as a stock setup, correct?

Post that in the other VTA threads. Nobody else is posting logs, just videos that don't prove anything.

Well wait a minute...you were the one saying that it goes rich when you're on the throttle...

Now you're changing your story and going with the off throttle rich condition argument? The video absolutely proves that VTA doesn't peg the AFRs rich when you make a pull, which was your original argument...which really never made sense to begin with since the BOV is sealed shut when you're on the throttle.

Is a line across a graph going to show you something completely opposite of what the actual gauge is showing you? Probably not, but my apologies for not getting you a squiggly line...I don't carry my computer and Tactrix cable around with me everywhere I go.

And I'm not really sure what I'm looking at in that log graph...it looks like a big jagged line with one point picked out labeled 10.3 AFR. It doesn't tell me what else is happening with the AFRs throughout the whole graph, it doesn't show how the pull was made...the throttle position is all over the place... and it doesn't tell me what a recirculated valve will do in that exact same situation.

I helped a friend tune his car when he was still learning what all the tables do. He has a recirculated valve. There were several times you could sit there and watch the gauge running 11's, and then he'd let off to shift and it would take a quick stab into the low 10's before getting back on the throttle. So again, showing me one point when a VTA hit 10.3 off throttle isn't proving much...

I'm an open minded guy, and if it was a clear cut WOT, shift, WOT, shift, etc. and it showed AFRs going stupid rich compared to a recirculated valve on an identical pull, then absolutely I'll agree with you 100%. But a few squiggly lines with with no way to read them tells me nothing. The video shows RPM and AFRs, and you can clearly tell it's a WOT pull to redline...and I also posted a part throttle video before, with the gauge immediately swinging more lean during shifts instead of rich...not sure how you can get much more clear than that...

Forgive me, but I'm not the kind of guy that sits here and listens to everyone else and takes it as gospel. If I want to know if something works, I'll go figure it out myself. Just because I don't get paid to tune cars, doesn't mean I don't know how, or how everything works.

Also, I have no disrespect for anyone here, especially Clipse and some of these other guys who have produced some awesome tunes...as far as I'm concerned this is a friendly debate...

...with maybe a few smart ass comments thrown in...my bad..

 

[ScottSpeed21]

I completely understand how this all works...MAF sensor metering air, releasing that metered air through the BOV...I get it.

Almost every other MAF turbo car has that problem.

But...

We also have the MAP sensor, which is the speed density portion of our ECU. The MAP sensor looks at the pressure and temperature of the air to calculate the mass of air flow into the engine. So there's 2 sensors telling the engine how much air is coming in. Tephra has already shown that the engine load follows whichever sensor, MAF or MAP, is reporting the lower load at any given time.

Let's get back with Mr. Joe Rice...he sounds like a cool dude...

Mr. Joe Rice is again making boost with his right foot, MAF sensor is puttin' out some good data for fuel calculations, but the MAP sensor is also seeing absolute pressure (atmospheric + positive boost pressure) inside the manifold, cross referencing that with it's temperature and how fast the engine is turning (RPM) and calculating the mass of air entering the engine, which again, goes into the fuel calculations.

Now our buddy Joe jumps off the gas pedal and the throttle slaps shut, BOV opens and vents some air with that distinctive sound that you either hate or love.

MAF says "I already told the ECU that X amount of air was coming, so send the fuel for X"

MAP says "Hang on, the throttle just slammed shut, and I'm seeing all kinds of vacuum, which means we don't need all that fuel if no air is getting past the closed throttle plate, so I'm telling the ECU to send less fuel"

Now, both sensors send a voltage signal to the ECU. In simple terms, the higher the voltage, the more air that sensor is reporting to the ECU. The more air, the higher the load.

So when the throttle slaps closed and pulls a huge vacuum on the MAP sensor, the voltage is going to immediately drop very low, while the MAF voltage won't drop quite as fast since there is still a bit of air passing through as the turbo spools down.

Less voltage = less load...and we already know the engine load calculated by the ECU follows the lower reported load of the two sensors, in this case, the MAP.

What does all this mean? It means it doesn't matter where you vent your BOV, because when you jump off the throttle and the BOV opens, yes you're venting MAF metered air, but at that point the ECU is fueling the engine off the MAP sensor, meaning that MAF metered air is irrelevant. You're going to run the same off throttle AFR regardless of where the BOV spits out its air.

I have personally seen AFRs during a shift dip a bit rich sometimes, as well as swing leaner with both VTA and recirculated valves. It all depends on how the car is being driven and the situation at hand.

 

[ScottSpeed21]

I might just be an idiot and missed this somewhere along the way, but why does it flutter at half throttle?

Like I said earlier...because the BOV is staying closed, like it's supposed to...the flutter you hear is light compressor surge, and it really doesn't have anything to do with the BOV. The turbo is spooling so fast even at part throttle that it's trying to flow more air than the engine can take. All that air backs up through the turbo and you get your fluttering surge.

 

[ScottSpeed21]

MAF is a primary sensor in this case, what the ECU reads and follows. That is why the VTA cars with stock set up has an issue being bucking and so on so forth. The all well know issues.( the last 10+ years in the EVo world).
I think at this point we start going in circles , with nothing really proven me wrong So i will let it be.

Cheers Rob

as people say , "the little knowledge is the most dangerous", which probably apply's for me too in this case. LOL

See, that's what everyone can't seem to understand here...both MAF and MAP sensors are used together. It's not like the MAF sensor controls the entire engine, and Mitsubishi engineers were kind enough to provide us with a MAP sensor from the factory, just so we can log boost...

They're both there...MAF and MAP...they both send the ECU voltage signals...they both calculate the mass of air entering the engine...the ECU uses both to calculate load. I don't know why everyone refuses to believe that, but that's how it works...it's not a matter of opinion, it's a cold hard fact...you can't really argue with that.

Tephra...ya know, the guy that rips apart ECUs and tells all of us how they work...he has already proven as a fact that the engine will follow the lower load of those two sensors. So in this case, the MAP would be the primary sensor, not the MAF.

I don't care how many quote's are posted, I don't care how many people heard from someone else that it doesn't work, I don't care if it didn't work on Subarus or Evo 8s and 9s or any other MAF car....I don't drive those cars, I drive an Evo 10 with a 4B11T engine with both MAP and MAF sensors. I don't need to hear it from someone else...I've tested it myself, on my own car, and it works perfectly fine, so much so that I've run a VTA setup for 3 straight years and never once has it given me a problem.

I'm supposed to be proven wrong with what people say or what they heard someone else say....but when I show as much hard evidence as I can give, as well as an easily understandable written out explanation of how it works, everyones opinion still apparently overrides any tiny shred of evidence.

If everyone besides me wants to listen to what other people say instead of look at facts and figure things out themselves, be my guest. Ever since people have walked this earth, it's never been the followers that came across anything new...

And if no one else has anything to add, I'll be done here because it seems this is all falling on deaf ears...I haven't taken a dime from anyone to tune or help tune a car, so I must not know anything about anything...

 

[ScottSpeed21]

You would have a more credit in this situation if you have a proven tune and racing history which means your tune and work was put it up for test
Racing teams "not weekend wariors" are the best place to test your product street and occasional track use will NEVER prove a 100% reilability of your tune,period.

Those guys who said a BIG no for MAF with VTA , has countles tuned cars and racing history. With the X too. I do race my X since day one in 2008 early springs. Fact many company's test and tryed they first product on my car...
So you are not exactly talking to someone from your locals.

Those people you say you don't care what they say , they do put down something on the table, and your comment on them more then ignorant.
This attituide will not fly neither in the tuning world or the racing.

I could have post seriuos race tuners opinion on this but would be really useless since most of you never heard of them. They do not tune personal cars. I hope you do understand the difference of they knowlidge in the tuning. About the X. Fact one of them is coming to visit me next month or february, who tunes cars and his OWN racing history is more then stellar. Like won the WRC 2011 rally Catalunia rally grupe N with his own evo. Which he tunes and also he does his own suspension work.
By the way this is the guy who helped and designeds the R4 suspension for the evos for Ralliart...
Now I am sorry if I give them credit over your testing and opinion, wheter is a X or the 4G63T.

There is a hard and long head of you with these attitude.

Be safe

Rob

This has nothing to do with opinion, mine or yours...this has nothing to do with years and years of racing history...this isn't about tunes or whether someone has tuned 1 car or 1000 cars. This isn't about me being ignorant...like I said before, I have no disrespect towards anyone out there.

You want proof out of me, but all you're giving me is "this guy said so" or "that guy said so" and because they've been racing for 20 years, I'm supposed to just listen. I'm pretty sure all those big shops and big name tuners didn't build their names and businesses by just listening to other people.

I don't care what other cars do...this isn't othercarforums.com...Evo 10's have only been in existence for just about 4 years now. Compared to other cars, especially all previous Evos, it's a brand new platform with a brand new engine, so learning about this car started only 4 years ago...everything else is irrelevant.

I understand how engine sensors work...my opinion, your opinion, or anyones opinion isn't going to change how those sensors work. We're only talking about one thing here...MAF and MAP sensors working together. Show me someone that went in depth, on an Evo 10 4B11T, to figure out how the MAF and MAP work together and I'll absoutely listen. Unfortunately, I personally have no way of digging into the ECU like that to see these things, that's when I listen to the guy that did and showed proof...Tephra.

As far as my attitude, I have the best attitude there is toward this kind of thing...the attitude that I'm going to figure it out myself and learn from it. If you tell me one thing, and I see something else with my own eyes, does that mean I should disregard my own experience and believe you? If someone told you before you started racing that you absolutely cannot turn an Evo 10 into a rally car and race it, would you have listened?

Other than my "useless videos" which clearly show AFRs and what we're talking about here, I have no way of getting you the undeniable, irrefutable evidence you're looking for. Let me see your irrefutable proof of what we're talking about...and that doesn't include the opinion of someone else that thinks the same way you do...

Scott, can you post a link to that graph tephra did up showing maf/map using the lower of the two?

Absolutely


http://forums.evolutionm.net/ecuflash/580764-how-load-calculated.html

And here's Tephras graph from that thread...

 

[ScottSpeed21]

Coolio, thanks man :thumbup:

So that top graph is showing the load is inline with MAP calcs? Could you maybe explain what we are looking a little more (still learning :innocent

Yeah absolutely.

If you take look at the top graph, the red line is the load calcluated from the MAP sensor, the green line is from the MAF sensor. If you look closely, you can see the blue line, which is the actual load the ECU uses to calculate fueling. You can see that the blue line follows the MAP line exactly, since it's the lower load of the two. When the MAF load crosses lower than the MAP, the blue line then follows the MAF load exactly.

So like I was saying earlier, the actual load the ECU uses for fuel calculations follows either the MAP or MAF, whichever one is lower. It does not rely only on the MAF like some people think.

The X is a smarte design and using boit maf and map sensor. But the primery is a MAF whic the ecu use for calculate the airflow. This graph if I am right shows how you calculate how they work together in diffenent condition.
I am also not a tuner, so I can be off here.
I talk to couple tuners and they al said the same about the VTA.
And they told me this about the two sensor too.

I still don't know how you can sit here and say "the primery is a MAF whic the ecu use for calculate the airflow". That graph clearly shows that the load calculated by the ECU follows the lower of the two sensors. If the MAF was the "primary" sensor, then the load would only be following the MAF calculation. It's clear as day, in graph form like everyone likes to see. Again, it's a fact...what you think or what I think doesn't matter...that's how it works. If I could log that type of graph and that information myself, I absolutely would and get several logs of different conditions...but I have no way to do that, so this is all we have to go from.

...and you're still saying "I talked to tuners and they said it's bad"...that's even more useless than my "useless videos"...

 

[ScottSpeed21]

I think I said everything already. This is going I circles.
I trust in 10+ year tuning and race toner , so you can say what evet you want. By the wat the older evos used MAP too.
Hm I think this is the end of my end here.
There is nothing more to say here specially if some one that right with that much experience ... LOL

Rob

The only reason it's going in circles is because you keep explaining yourself with "the tuners said so". And besides, it's a BOV..that's all it is...I still don't know why everyone gets so offended by the guys that choose to vent. That's kind of the main reason this all started. People that VTA do so with zero problems, and then everyone else says "Noooo it's bad!"

But that's fine...it was a decent discussion...at least I thought so anyway, even though a couple guys bowed out early. You can keep listening to the guys that "say so" and I'll keep digging into things to figure it out myself :thumbup:

For anyone else that cares or that might be following this, I'll try to get some logs that best shows what we're talking about here in graph form, that way instead of listening to someone say things that they heard from someone else, everyone will have the raw data to look at.

 

[ScottSpeed21]

I tend to think along the lines of Rob here when defaulting to knowledge of proven tuners but at the same time I have respect for anyone willing to do/try things for them selves.

I would deff like to see some data when you get a chance :thumbup: Personally I could give two shits about vta, AMS intake + recerc DV is plenty loud , but this whole MAF / MAP thing is interesting for sure.

I agree with you...when it comes to tried and tested, proven data, I'll listen to anyone out there, especially the big name shops and tuners. I've said it before, I have no disrespect towards anyone, nor do I think I know more than those who have worked to figure things out and brought there findings to the community to share. But if I see something with my own eyes, it's hard for me to believe the exact opposite just because somebody said so and with no data to back it up...that's all I'm sayin...