turbo question

[4g63lover]

When you turbo the Galant where do you relocate the MAF sensor to?? the upper intercooler pipe? or the intake from the turbo where the filter is connected to?

and if its to the intake from the turbo, what if you decide to go open tubo? means no tube and filter after the turbo outlet.

and when equipped with a blow off valve should it go after the MAF sensor or before?

[DryBear]

My routing on the Cold side is as follows:
Filter -> MAS -> turbo -> intercooler -> BOV (recirculated to point after MAS) -> throttle body

[bronxbombr]

How bout a pick there sparky?

[peanotation]

you can't put the maS after the turbo, for the obvious reasons. this is why it's so difficult to get a good tune with a turbo. if you could just slap on the mas right before the throttle body, then it'd be just like the maf and you could call it a day.

people run open turbo, because they are running either speed density, standalone, GM maf, maftpro, etc. they remove the filter and mas for absolutely no restriction for ultimate flow. until your running equal length runner exhaust manifold, external wastegate, blah blah blah don't even worry about running open turbo for now.

the bov is placed post-turbo on one of the charge pipes; the closer to the throttle body the better. it is recirculated back into the intake pipe PRE-turbo but POST-mas. if you decide to vent then that's an entirely different story

[DryBear]

How bout a pick there sparky?

[seth98esT]

Or a 4cyl(Easier on the eyes, not so much of a maze :P)

With stock MAF:


With GM Maf(In the upper intercooler piping before the tb):


The reason you see a lot of Hondas and even the 420a Eclipses run with no filter/pipe is they use a MAP sensor to monitor airflow, airflow temp, barometric pressures, ect and its located on top of the intake manifold. So unless you convert from a MAS type system to an aftermarket blow through MAF like the GM Maf, MAFT Pro with speed density, or a MAP on the intake manifold, you still will need to keep the stock MAS connected to the turbo inlet.

Tadddaaa!

[4g63lover]

Or a 4cyl(Easier on the eyes, not so much of a maze :P)

With stock MAF:


With GM Maf(In the upper intercooler piping before the tb):


The reason you see a lot of Hondas and even the 420a Eclipses run with no filter/pipe is they use a MAP sensor to monitor airflow, airflow temp, barometric pressures, ect and its located on top of the intake manifold. So unless you convert from a MAS type system to an aftermarket blow through MAF like the GM Maf, MAFT Pro with speed density, or a MAP on the intake manifold, you still will need to keep the stock MAS connected to the turbo inlet.

Tadddaaa!

this was my initial idea cuz its the same with the DSM's. i remembered the Eclipses always had the MAF sensor on the turbo inlet after the filter.

I remember for one of my uncles Eclipse after we installed the BOV everytime we let off the throttle and the BOV vents off the car dies. He fixed it but I never knew how he did it. Sorry for the newbie question but what is a GM MAF?

[Jet Black]

this was my initial idea cuz its the same with the DSM's. i remembered the Eclipses always had the MAF sensor on the turbo inlet after the filter.

I remember for one of my uncles Eclipse after we installed the BOV everytime we let off the throttle and the BOV vents off the car dies. He fixed it but I never knew how he did it. Sorry for the newbie question but what is a GM MAF?

Its a diffrent type of air meter. There are three seperate types: Karman Vortex, Hot wire, and Flapper valve type. We use the Karman vortex type sensor which calculates air mass from the number of vortices that are produced. If you look down your intake, you would find a honeycomb in front of the MAS. The honeycomb is what produces the vortices for the sensor to read. The problem with using this type of sensor post-turbo is that the pressurised air interferes with the vortices, which causes the sensor to give bad readings.

A GM MAF on the other hand is a much simpler design. It simply uses a heated wire to determine the airflow. If you knew the temprature of the air, then depending on how much amperage is needed to maintain a set wire temprature, that would tell you how much air was coming in. This type of sensor isn't affected by the pressurized air.

Though I should point out, some SDS folks have had success with using the stock MAS post-charger.

Your friend might have fixed his problem by rerouting the bov back into the intake tract.

[seth98esT]

Its a diffrent type of air meter. There are three seperate types: Karman Vortex, Hot wire, and Flapper valve type. We use the Karman vortex type sensor which calculates air mass from the number of vortices that are produced. If you look down your intake, you would find a honeycomb in front of the MAS. The honeycomb is what produces the vortices for the sensor to read. The problem with using this type of sensor post-turbo is that the pressurised air interferes with the vortices, which causes the sensor to give bad readings.

A GM MAF on the other hand is a much simpler design. It simply uses a heated wire to determine the airflow. If you knew the temprature of the air, then depending on how much amperage is needed to maintain a set wire temprature, that would tell you how much air was coming in. This type of sensor isn't affected by the pressurized air.

Though I should point out, some SDS folks have had success with using the stock MAS post-charger.

Your friend might have fixed his problem by rerouting the bov back into the intake tract.

Yes, he did. Went venting his BOV to the atmosphere aka, not routing it back to the intake pipe on the turbo, he was dumping air back into the atmosphere. Which is fine if you have the GM Maf or a Map sensor that is before the BOV. But how our MAS is before the turbo,it calculates all the air going into the turbo and calculates how much fuel to dump. When dumping the BOV to the atmosphere, the ECU already calculates for fuel including the air the BOV dumps, so you will run pig rich and possibly can cause stalling.

So pretty much just recirculate the BOV back to the intake and you will be ok. In both pictures I posted the cars are both venting to the atmosphere.

Heres a stock MAF which has a recirculated BOV:

[4g63lover]

Yes, he did. Went venting his BOV to the atmosphere aka, not routing it back to the intake pipe on the turbo, he was dumping air back into the atmosphere. Which is fine if you have the GM Maf or a Map sensor that is before the BOV. But how our MAS is before the turbo,it calculates all the air going into the turbo and calculates how much fuel to dump. When dumping the BOV to the atmosphere, the ECU already calculates for fuel including the air the BOV dumps, so you will run pig rich and possibly can cause stalling.

So pretty much just recirculate the BOV back to the intake and you will be ok. In both pictures I posted the cars are both venting to the atmosphere.

Heres a stock MAF which has a recirculated BOV:

so thats what the use of that little tube sticking out of the intake was for. cool. If the BOV was aftermarket let's say, HKS or Greddy can you recirculate those?

[seth98esT]

Not on the stock MAS, same principle no matter the BOV. Its still letting out air that has already been calculated into the fuel trims, without that extra air, you will be running too much fuel and too rich.

[4g63lover]

Not on the stock MAS, same principle no matter the BOV. Its still letting out air that has already been calculated into the fuel trims, without that extra air, you will be running too much fuel and too rich.

So basically the best option would be to convert to MAP sensor right? or GM MAF. how hard is that to install and will i need to rewire anything?

[seth98esT]

GM Maf isnt hard, they make a translator so you can hook it up to the stock ECU.

www.maftpro.com

[4-G-rim]

Jigz..what are you aiming for? Do you just want the loud venting BOV sound? I clicked on this topic too late to suggest what I wanted to suggest and input since already the others have done so.

Venting to the atomosphere is going to hurt your cars performance. You don't want to sacrafice that for a "sound". Running pig rich between shifts (off throttle) , poor turbo spool up are among the things that will happen.

MAFT is probably you best and cheaper alternative compared to a standalone to vent to the atomosphere with the benefit of proven tuning device.

[peanotation]

since it sounds like you're more into the show off part of turbo rather than the performance, you can vent if you bump your idle to 2,000rpm or so. i've driven dozens of 2g gst/gsx that are venting, and they all idle at ~2,000rpms to prevent stalling. it's not proper, and it's not the correct way it should be running, but a lot of guys seem to think it's worth the super high idle just to vent. i recirculated back into the intake tube with my greddy type S and it was still plenty loud. i loved blowing it off next to bitches on their phone in traffic and watching them almost drop their phone when they freak out. with your idle so high, the engine still stalls slightly, the rpms will drop to about 900 or so, but they'll come back up to 2,000 when the ecu recognizes the engine is about to stall. you can get away with it at 1,500 but i think you'll stall every once in a while. i tried to get by at 1,500 but i got some stalls here and there

[4g63lover]

no no no, you guys got me all wrong. I'm looking for performance. I could care less, about the sound the BOV will make just looking into what would be a best set-up for a N/A-turbo conversion. Im swapping the head and turbo the Galant when I get my funds up again. Basically I'm doing my research. I've never turned an N/A car to turbo before so I was just researching the differences and what I have to do. My initial idea was that the MAF goes into the intake before the turbo. I never thought venting to the atmosphere was bad for your car. All the cars Ive worked on are DSM's with the MAF before the turbo so I'm assuming theyre all recirculated. I'm aiming more on performance and power than show. I was planing on running a standalone ECU when I go turbo just because it lets me tune the car myself. I'm gonna be doing most of the work along with a couple of friends. So I'm mostly researching the best options and best set-up for more power. Is there any differences if I convert to GM MAF or use the stock MAF? or can I use maybe an MAF on the EVO?? and I was also planning to upgrade to a GT42R in the future so I was exploring the choice of going open turbo which pushed me to wonder what MAF I will use IF I went open turbo. since theres no intake pipe and filter. but I don't think I will go open turbo anymore. I'm prolly sound like im just babbling. It all makes sense in my head I just cant put it in words. So imma let you guys tell me what would be the best set-up. GM MAF, MAP, or stock MAF? and oh yeah what's MAFT (another newbie question, jeeze I didnt know there were so many different types)

[seth98esT]

Come on man! From my knowledge,theres nobody sells a map conversion. The GM MAF will help out with spool time and it is by far les restrictive then the stock MAF. Pretty much anything stock on your car now can be upgraded to better parts. STock is never best.

[4g63lover]

ok, GM MAF, need to recirculate BOV or not? and is it good for the performance of my motor or not?

[seth98esT]

Read man! Less restrictve = more airflow = more power. If you look at the pictures I posted first, theres one of a GM Maf. Its between the BOV and the TB. So it measures air AFTER the BOV and calculates fuel at that point so you can vent. It doesnt matter at the BOV is after the GM Maf.

[4g63lover]

that's interesting. I got a choice to make. Now I'm off to make more money. Thx for the info guys.