Dual MAF setup

[naughtika]

hey guys.. im crazy and bored.. so I'll ask here

can this be done?

Run the dual MAF on our car? the way i see it, we'll need to connect them in Parallel to each other..

opinions please

I think GTR runs the same but im not too sure..

 

[lathiat]

You can't just connect them, but, there is a tool for combining MAF inputs around.. I cannot remember where I've seen it might even be an APEXi thing.. but you'll need an active device to combine it.

 

[Scottie]

Wouldn't the idea behind two MAF's be two different readings and not just an average of the two? If that is the case then i am pretty sure you would need an after market ECU.

Wouldn't you prefer to run MAF-less anyway?

 

[lathiat]

Wouldn't the idea behind two MAF's be two different readings and not just an average of the two? If that is the case then i am pretty sure you would need an after market ECU.

Wouldn't you prefer to run MAF-less anyway?

Not necessarily a requirement, generally the main point is to get more air flow by having two, and to allows running two air filters to save the air merge.


You could run the MAFs separately with an aftermarket ecu but not completely necessary.

 

[Kenneth]

The simplest way is to run 1 MAF.

But that wasn't your point was it?

The way to get what you want and still only use 1 MAF is to run 2 inlets, 1 with the MAF, one without. You would need to have the pressure balanced behind the MAF somewhere (either a pipe joining just before the turbos, or further back in the intake. I would have just before the turbos personally) with a cross over tube which would make sure that your MAF doesn't affect the turbo PR balance across the turbos.

You then go and re-scale the Load axis (or the maf size) in the ECU based on the percentage flow increase.

Check the tune and then job done, 1 MAF.

 

[lathiat]

Has that been tested? I'm not sold on the accuracy of that method. Even with your pressure balance.

 

[Kenneth]

Has that been tested? I'm not sold on the accuracy of that method. Even with your pressure balance.

Who is Mr negative today eh?

The MAF uses this exact principle to measure air speed. It has bypass sections and then it has the measuring section. The bypass even has a adjustment screw so you can calibrate the bypass proportion.

I have read MAF bypass being done on other vehicles to work around MAF flow limits.

Search the web.

 

[naughtika]

okie.. my mind just blew up.. english please

 

[Kenneth]

Adding a bypass (extra intake pipe which goes around the MAF) is almost exactly the same as having a big ass MAF pipe. Think 5" pipe with standard MAF reading stuff inside.

The one complication is that you need to ensure the same amount of "suction" is applied to both intake pipes, or you won't be able to calculate what is going through the non-maf intake.

To do that, you either balance the suction at the turbo inlets, or have the turbos feed from a common plenum (essentially what it does as standard)

 

[mookers]

stupid question time.

what is the point of having dual MAFs?

 

[Kenneth]

There actually is none. However it is the logical step up in removing inlet air flow restriction which, inevitably, leads to the MAF becoming the single air entry point.

/edit: well, there isn't a point on our vehicles that is. If the ECU was designed to run with 2, that is a different matter.

stupid question time.

what is the point of having dual MAFs?

 

[jet150]

If your car is a manual you are better off getting rid of the MAF and getting a MAP. The only reason the MAF is still under my hood is so the torque converter works.

 

[Donkay]

If your car is a manual you are better off getting rid of the MAF and getting a MAP. The only reason the MAF is still under my hood is so the torque converter works.

100% whats Rob has mentioned

Why make things complicated? Just do it nissan style, put the maf inline of the intercooler pipe (after after turbos, or near throttle body) thats what id do

If your sceptic about if the maf can do it or not, just buy that inline maf sensor from 3sg for $120? Simple

 

[TME_Steve]

I see a heap of other options.

1. what kenneth said, make the bypass pipe a similar restriction but the tune etc would deal with all that if it wans't perfect anyway, you might just have a weird looking fuel table in some regions
2. run a combination MAF and MAP assuming you're worried about running out of scale but no one has had this problem to my knowledge yet so I wouldn't get too worried about that (and yes the evos do but there is a software fix for that) You could use the MAF down low and then switch to MAP, that way you'd get the driveability of MAF and you could deal with the high end stuff with MAP, then you could go really compliacted and only open up a second path while running MAP etc etc etc this option is complex and only there for people who want to play for no real reason
3. Get a bigger MAF and translate it to suit ours.

Not sure how far the pressure scale goes on our MAF so it may be a problem after the turbos if it can't deal with measuring the 30psi of boost your running to justify this but Don's other one could work

 

[VR4 WRC]

When people were playing with the 6G VR4 engine code, they worked it out to half the MAF code to to able to extend the map to register more airflow to around 450hp. Someone's theory was that you should be able to run a twin setup to get more air into the engine to get more power without going full aftermarket as you were able to half the code.
It was quite a few years ago now so the memory is a bit cloudy.

Scott