Turbo BS Thread

But MAF voltage only changes with air flow. The graph you posted was very clear.

The recirc BOV can't defy physics. What keeps the pressurized air from escaping? Unless the vacuum on the cold side is equal to the pressure on the hot side, when that BOV opens and the pressurized air normalizes across the cold and hot side, there will still be extra pressure that needs to be vented. You can't have xPSI of air just runing in circles when there is an obvious and easy escape for the pressure right out the air filter.

Yes the engine is still pulling in air through the IAC valve but that won't make up for the extra pressure after a WOT pull and sudden TB shut.

Look at your MAF voltage, that spike can't be air flowing into your charge pipes as the air flow to your engine is only amounted to the tiny flow of air through the IAC represented by the MAF's 1.4V. It has to be flowing the other way; basic principles of physics necessitates it!

 

Negative sir. That pressure adds. As well as the continued air intruduced to the space between the TB blade and the compressor. As the compressor is still spinning of its own, and the exhaust gases. Thus you have a pressure spike. Which pushes on the conpressor as well as everything associated with that involved process.

 

I can't prove that air escaped from my maf, but a small pressure spike across the maf can happen. Kinda like a 2 stroke pipe.

That spike looks like when I misfire too. I had a spark plug that went out of gap.

 

A guy acutally mapped it and it was only 1 additional PSI when the TB closed after a full power pull.

I can't find it now but it was posted in an epic BOV/No BOV discussion thread on the MR2 forums. It's what convinced me.

 

So when you boost to x psi then that air is released through the BOV to the cold side of the turbo, where does it go? 8 PSI of air isn't going to circulate through your charge pipe and out the BOV again, and agian, and again, until the idle engine eats it up. It'll rush out the air filter in a quick discharch. Depending on how much air rushes out - how violently the extra pressure is expelled - your MAF voltage will shock the ECU into dumping a crap ton of fuel into an idling engine causing it stall.

Either way, the proof is in the pudding. Jason's truck stalls despite the "recirculation". I doubt its a vacuum leak or he will have other issues. I bet when he gets a stiffer spring it will run a lot better, recirculated or not.

 

Your right !! when I rev the engine from the engine compartment I can hear what sounds like air coming out of the air filter but maybe if the bov is adjusted tighter and slower it will be ok

 

If its tighter, it will release the air slower so you won't get as much of a shock to the system. You will still go rich but it won't be so sudden and shouldn't cause the truck to stall.

But make sure you listen for turbo flutter; that means its too stiff.

 

Outsourced to a different company. They do their tube manifolds and did the one you saw a pic of

 

Have they done a 1GR intake manifolds?

 

I dont think so, but they make some badass parts on some record setting cars. They are huge in the honda FWD world

I took the name of the shop out of my comment in case it wasn't supposed to be released just yet. Those who saw the company named, you're lucky and you didn't hear it from me

 

I feel like this thread has lacked a bit of bs today so....

 

Our BS is just on topic BS

 

Oh, and.....


That looks tasty

 

That doesnt even make since brah haha but ill let it slide



















This time

 

Just a load of BS in the long run...

 

I also spell "sense" "since" but meh

 

That air is going to get sucked back up by the turbo inlet and charged until the turbo slows down. Just like I have attached. Air at throttle closed will just transfer through control volume 1 and control volume 2. MAF sensor is going to see it as a massive slow down like my line graph. That slow down is how much air is getting past the throttle body.

It going to take a lot of air out of a 1" diameter BOV to push back out the intake when you have a turbo spinning at 60k rpms with a ~50mm inducer.

To throw out all my theory and contradict myself, Jason does have a pretty small intake tube between the turbo and air filter. Make for the possibility of a pissed off maf sensor.

My log uses an intake of a 24" long intake at 3" diameter. Plus my bov tube faces towards the front of the turbo instead of a 90* elbow

Who else needs a beer today this evening?

 

This whole deal is entertaing

 

I'd love a beer...

I get what you are saying and its correct to some degree but we're talking a lot of air that has to go somewhere. The second your take your foot off the accelerator, that turbo is going to spin down a lot. It doesn't have a lot of momentum and certainly won't have the energy to build boost with a closed TB (yes, some air is flowing through the IAC) and a good bit of the charged air will go back out of the air filter. If the air behaved as you are saying, there will be almost no air flow at all over the MAF which will create another issue; you will run way too lean.

If you bypass the MAF with the recirc tube and make sure the BOV doesn't bleed off all the charged air at once, as the air is vented, some will flow back towards the turbo (remember there will be an initial vacuum) but as long as the pressure behind the turbo is drawn down slowly, the blades won't be able to flow air back into the charged pipes. This means that most of the charged air will flow out of the air filter without flowing over the MAF. Any back flow of air over the MAF will actually help from going too lean as you are still idling.

Either way, I still like how I have my MAF post turbo, right next to my TB. I also think that MAF's + Turbos suck unless you have a proper ECU.

 

I like how we all bring great stuff to this like, tor has built more 1gr than most toyota factory workers, and mrcrown is gonna have like 250 hp per cylinder when its all said and done and is more or less the the tor of the 2.7 2nd genners, and madtaco has computery stuff on lock, jstan is the new guy that everyone tell him what he is doin wrong, brice is the teenager that somehow is hanging tough with everyone (prodigy of sorts i suppose) i feel like st andrew has been at least in the process of turboing a 3vz longer than anyone else and clay started this thread so that counts for somethin haha. Boostek something somethin is the guy that i can never remember his actually name ao i just type or say boost and add random letters, plus he is the ms3 guy. Josh is the long travel purple yellow green truck, James is the guy from Hawaii and im the cute one... Pretty much a perfect team we have here (greenco ,also have a little trouble with his name same as boosturgagle but i start with "gree", and ur the iso intercooler guy haha) sorry if i missed anybody but there are begining to be about as many as i can keep up with....



Btw did @GioGuitarDude ever get tagged in here? He is the guy that ran a line of starter fluid he duct taped to his gear shift to add fuel when he was in boost before he could upgrade fuel systems