Tial BOV flutter.
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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.
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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
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
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hm... i sense some sarcasm here and high horse at a same time... :clap:
But still very hollow...:yay:
one last quote's from me here to leave the discussion ...
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"CBRD:
ive found that some cars are more sensitive than others.
we run a tial 50mm on our 05 MR with the utec and 35R, and have had no stalling problems at idle.... also with a turbonetics raptor valve before...
if you adjust the bov, you can get the car to run "well" or "decent" but obviously as stated, MAF should be recirculated.
cheers
cb"
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"ETS:
I wouldn't recommend it. We have had customers have good luck with the 50/50 setup, but the straight VTA seems to always have a problem. I wouldn't recommend it unless running speed density.
Thanks,
Michael"
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"Malibujack:
No drawthrough equipped MAF car will run correctly with a VTA Blowoff valve, you will have to recirculate it.. There is no fix for it other than removng it or recirculating it.. Even those who claim not to have problems are in reality deluded, their car still has problems, only they don't understand what they are."
"I run a blowthrough MAF, it removed a very problematic stock MAF, and being able to VTA is a side effect of the coversion as the ford MAF sensor is integrated into my intercooler pipe AFTER the BOV.
I still run a stock ECU, and still have stock drivability, so it has very little to do with tricking the ECU or anything like that.
However doing this conversion just so you can VTA is a COLLOSSAL waste of money and time, as the stock MAF is capable of pretty decent numbers.
I have clearly had some issues with my MAF early on, and was probably one of the first, if not the first to have successfully used on on a USDM Evo. \
So Cliff Notes:
1) If you run a speed density setup (either using a MAFTPRO or a standalone EMS) or blowthrough MAF conversion where the sensor is AFTER the BOV, then you can VTA with no Ill effects.
2) Doing this conversion is expensive, and probably not a wise thing to invest in unless you need it
3) VTA on a stock MAF results in performance and drivability problems.. PERIOD, you can adjust a BOV to stay closed at idle and it won't stall at idle.. But if you vent at very low throttle, it will stall, it will shift rich, and potentially cause other issues. Those who think their not actually somehow hurting their car's drivability or performance by doing that are deluded."
good read :
http://forums.evolutionm.net/evo-en...-mass-air-conversion-vta-100-no-problems.html
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Originally Posted by BakaUnchi
Lets clear up some MASSIVE mis conceptions here.
VTA BOV on MAF cars WILL affect the tune / Car
Bov's are not just open when you let off the throttle from WOT
Bov's are open quite a bit while cruising, and in part throttle situations.
Bov's Tend to open @ idle quite a bit
Any time you are venting metered air out of a maf system the car will try to compensate just like if you had a boost leak . @idle it will open and mess with fuel trims and idle quality. At Cruise it will do the same thing.
Subarus have fuel trims and the LAST of the 4 affects WOT fueling directly
Bov's make the car think it is rich (cause the air went bye bye) so the ECU says time to lean out that area. It leans it out whatever % it feels and continues to do so until it feels the afr in that area is ok. This area is typically highway cruise speed/airflow.
A bov VTA can cause up to 15% NEGATIVE fuel trims so now your WOT Fueling is -15% and that + WOT in just about any TUNED/Stock car will blow it the **** up. It may take a week or 3 to get that bad but i can tell you it WILL. Some BOV are better than others about it some are not.
This is FACT not fiction, i have seen it on hundreds of Subarus and Evos and other cars. Anyone who tells you differently has no idea how it works. The OEM's use maf for reliability and the ability to drive in massively changing environments without a retune. The cars ECU's are DESIGNED to have a Recirculated valve. Unless you swap to SD or pull some trickery and know how to prevent WOT fueling changes please please please for the love of god KEEP YOUR BOV RECIRC
This has been a PSA from Jon"
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This comes Form UK,:
"quote "There are a number of issues to consider when using a VTA or blanking off the OE recirc valve.
VTA (and recirc) DV's come in a range of opening pressure settings. Whether high or low pressure, with a VTA there can be issues.
1 - Overfueling due to excessive venting to atmosphere
2 - Stalling the turbo
3 - MAF revertions and System volume
4 - Repressurisation time
5 - High pressure damage
Looking at the issues one at a time,
1 - Overfueling due to excessive venting to atmosphere
If you run a standard pressure vent to atmosphere dump valve (BOV, VTA, Atmo DV) with a mass air flow monitoring ECU such as the OE Subaru, then you can have problems when the DV opens under cruise conditions. The DV allows air to escape from the system during the high vacuum conditions during cruise, The reason for this is the signal side of the DV is subject to vacuum and the flow side is subject to slight boost pressure (the difference across the throttle valve) If this exceeds the spring pressure then the valve starts to vent.
This airflow has been monitored by the ECU and fuel is added accordingly, the result is too much fuel for the air being consumed by the engine.
Best case - You just waste fuel but who cares when you get that 'pschhhht' you've always wanted
Worst case - You cause bore wash, increase oil consumption and reduce engine life.
2 - Stalling the turbo
The term turbo stall refers to stalling the airflow across the compressor blades, not physically stalling the rotor (common misconception)
This is a case of what happens if you don't use any DV or use a valve with too strong a spring.
When you lift off the throttle on full boost, the compressed air has no where to go and blasts back across the blades giving that (lovely ) sharp 'cacho' or WRC chirp as some call it. Very taxing for the turbo, all this backwards flow.
Best case - Runs forever (TD series generally tougher than VF series)
Worst case - Shatters compressor wheel or thrust bearing fails
3 - MAF revertions and system volume
This is not such an issue with a TMIC but when FMIC's are used the system volume is so large that when the throttle is brought back from power (boost) to cruise, if a strong spring DV is used (strong enough to eliminate issue 1 ) then you can get a sudden pulse of pressurised air back out of the MAF, this is measured as an airflow (the meter can't differentiate) and the engine overfuels giving a hicup/jolt
Best case - Slightly jerky drive as you come off throttle
Worst case - Very jerky !
4 - Repressurisation time
This is where the stiff spring DV or running without DV scores a point. The system holds more pressure between gearshifts as the DV isn't venting it. Boost recovery in the next gear is improved (slightly)
Best case - Improved response after a gearshift
Worst case - Issues 2 and 3 above.
5 - High pressure damage
If you use no DV or a high pressure DV spring then when the turbo is spinning at high speed and the throttle valve is snapped shut, there is a pressure pulse in the system
which can be high enough to damage the intercooler etc.
Best case - At boost below 1.5 bar you will probably be ok
Worst case - Bigger turbo's/ higher boost may pop hoses off or 'balloon' the intercooler core.
Options ?
A light pressure recirc valve (just like std) overcomes all of the above issues but sounds a bit boring
Sequential dump valve. At light pressure it recircs, at high pressure lift off it still goes Pssshhht
You pays your money, you takes your chances.
Andy" end quote"
aaaaand we can go on and on... LOL
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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...
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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
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
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Oh by the way you didn't show Any evidence yet, besides I say so , and useless video.
If you will show some hard evidence over what the leading evo and race tuners have, then you are talking. But you will still lacking is proving your theory since it was not put into test yet.
You see even dyno tunes can fail in racing when you put them in use. Ask me how I know...
If you will show some hard evidence over what the leading evo and race tuners have, then you are talking. But you will still lacking is proving your theory since it was not put into test yet.
You see even dyno tunes can fail in racing when you put them in use. Ask me how I know...
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Scott, can you post a link to that graph tephra did up showing maf/map using the lower of the two?
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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...
Absolutely
http://forums.evolutionm.net/ecuflash/580764-how-load-calculated.html
And here's Tephras graph from that thread...
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What that map has to do with the VTA discussion here?
Tephra mades changes in the ECU etc. ( he is very good with that), so other people use his maps for different reasons.
This thread/case for the car wouldnt go to LIMP mode with VTA, and you can use that for your X, if you want to run a car without warning codes and ecu safe modes- actions /like limp mode to save the engine/, since the codes are disabled to have a VTA bov - valve, trhough the ECU tune...
Other words you take out the safety fetures in the ECU, to having a VTA valve run "properly" . It does change the fact is not good for the car? No, only thing it does , the car will not recognize the problem, in my mind.
Since they are not there anymore after the retune , and it was a reason why need it to be taken out in a first place. I am sure you get where i am going with this.
http://www.evoxforums.com/forums/showthread.php?t=18264
press on .
Rob
Tephra mades changes in the ECU etc. ( he is very good with that), so other people use his maps for different reasons.
This thread/case for the car wouldnt go to LIMP mode with VTA, and you can use that for your X, if you want to run a car without warning codes and ecu safe modes- actions /like limp mode to save the engine/, since the codes are disabled to have a VTA bov - valve, trhough the ECU tune...
Other words you take out the safety fetures in the ECU, to having a VTA valve run "properly" . It does change the fact is not good for the car? No, only thing it does , the car will not recognize the problem, in my mind.
Since they are not there anymore after the retune , and it was a reason why need it to be taken out in a first place. I am sure you get where i am going with this.
http://www.evoxforums.com/forums/showthread.php?t=18264
press on .
Rob
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Coolio, thanks man :thumbup:And here's Tephras graph from that thread...
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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
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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 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.
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Yeah absolutely.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
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.
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"...
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Not going to read all of this thread on my phone.
Switch to speed density, get some bolt cutters, and fix your spring. That is if you want to run VTA on your Tial.
Switch to speed density, get some bolt cutters, and fix your spring. That is if you want to run VTA on your Tial.
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