Way to get around the MAF and have 2 airfilters

[bradc]

As everyone knows the stock MAF makes it impossible to have 2 air filters that each go to a turbo because all the incoming air has to go through it. I'm quite keen to get all the tubing done before I get an ECU, but then the intake would have to be redone to get the 2 air filters, each hooked up straight to a turbo.

I don't want to have that small tube coming from the MAF to the front turbo at all because it is just so small.

Then an idea suddenly occured to me, why does the MAF need to be just after the air filter? Why couldn't it be after the intercooler, just before the throttle body?

This way the MAF is in a straight piece of pipe that can easily be ripped out when I change ECU's, and the turbos don't have any restriction on their intake side. The MAF is also closer to the throttle body which should mean that the air it is sensing is not delayed at all, whereas I would imagine that in the standard setup there is a bit of a delay from when the air is measured in the MAF to when it actually enters the throttle body.

Thoughts? Would the MAF be screwed up by the heated air coming in to it after the intercooler? That is the only problem I can think of.

[psbarham]

would it be able to cope with the presure ? normally it works on negative pressure , whereas if it is mounted after the turbos it is in a positive pressure area

[AllBeItMine]

no - wont work after the turbos. its called a MAF for a reason. Mass Air FLOW. not Mass Air Pressure.

[bradc]

ahh ok, worth a shot anyway

[bradc]

thinking about it some more then, how does the ECU cope with a change in the ambient air pressure?

[Kenneth]

it has a barometric adjustment signal that comes from the MAF. not sure exactly how it goes about it, but it is used to adjust the mixture.


I have an idea which I want to try. Just need some time and a couple of MAFs (need 3 in total for the testing and calibration)

It goes like this:
Calibrate the 3 MAF sensors so they show the same (or as close as possible) frequency at various air flows.

Install all 3 MAF sensors. 1 in the original location, the other 2 split off eithier before or after.
Work out the relationship between the frequencies on the split MAF sensors to the original.
Apply the relationship to the signals (ie: add both together) and send to the ECU

you then run dual intake with 1 MAF sensor on each intake.

I have most of the gear to do this, I just need a couple of MAF sensors for initial testing.

[bradc]

Ask You See if he has his MAF sensor still from his ECU work, and when I get an ECU I'll be keen to give you mine as well (after I get the mag wheel to you!)

[Kenneth]

Ask You See if he has his MAF sensor still from his ECU work, and when I get an ECU I'll be keen to give you mine as well (after I get the mag wheel to you!)

Ill have to wait and see what is happening with my car, then ill get back to you.

[ako]

The stock AFM / MAF isn't a restriction at anything under 500hp. The evo boys have proved this over and over.

Just make new piping after it Its not exactly hard work.

The one big thing to remember is that the ECU will ALWAYS be holding you back. Rhys (-legnumvr4- ) made up new pipework, put on an intercooler, and the exhaust work... That alone has limited his car to around 10 - 11 psi before the fuel cut comes in.

Do the ECU FIRST - you'd be amazed what these things can do once you take away the factory safeguards.

One other idea - go to a MAP ECU, its a NZ made device. It lets you run AFM - less (or go open turbo inlets for the most flow possible), and sends a signal to your ECU that it can understand. It also doubles as an AFC, so you kill two birds with one stone, just costs a bit less than a full ECU.

[bradc]

The main reason I want to do it is so that I can have proper 2 or 2.25" piping from the air filter to the turbo, the current pipe is very small and restrictive as Rhys knows.

If you are changing the ECU, then I figure you might as well take full advantage of it.

[You See]

Ask You See if he has his MAF sensor still from his ECU work, and when I get an ECU I'll be keen to give you mine as well (after I get the mag wheel to you!)

Don't think I've still got it....most of the crap was trashed. I'll see what I can salvage.

[ako]

The main reason I want to do it is so that I can have proper 2 or 2.25" piping from the air filter to the turbo, the current pipe is very small and restrictive as Rhys knows.

If you are changing the ECU, then I figure you might as well take full advantage of it.

Yeah, you can still quite happily do that with the MAF still in place. Just get a Y pipe after it.... No need to stuff round with wiring or anything, just make the pipes.

[bradc]

It would be quite difficult though. I think that putting the MAF where the battery is would be an ok option, have the air filter down in the front bumper somewhere.

[zentac]

what you need to do is convert to a MAP and do away with the MAF all together.

[AllBeItMine]

he's going to get an aftermarket ECU and that will run off MAP anyway.

[jaimz]

Brad,
Be careful putting your filters too far down in the engine bay. You don't want water splashing up into them when it's raining...

[bradc]

I will get an ECU anyway, but this is just a concept that might help out.

Jaimz, I've thought about that, remember the water still needs to go all the way up to the engine bay anyway, what does it matter if the water goes up a tube, then gets to the airfilter, or the other way around?

[Kenneth]

I will get an ECU anyway, but this is just a concept that might help out.

Jaimz, I've thought about that, remember the water still needs to go all the way up to the engine bay anyway, what does it matter if the water goes up a tube, then gets to the airfilter, or the other way around?

If you get enough water into your cylinders your engine will hydraulic. goodbye engine. I don't know what it would do to your turbos, but it cant be good!

If your intake is low and you go over a large puddle of water, you can immerse the intake in water. im not even sure if you need to immerse it to hydraulic.

anyway, hopefully you get the gist. imagine trying to compress a cylinder full of water... even half full

[Louis]

Once the engine is running it is sucking air in, you hit a puddle and it sucks the water up the pipe straight into the engine, (bad news).
Anyhoo! Don't Skylines run with two air filters, and two maf sensors, one to each turbo?, (back three and front three, straight six engine). I know a guy who uses two 350z maf sensors on his skyline engine.

[Kenneth]

yeah, at least the GTRs do. When I was in England, the guy I was staying with was repairing a R34 GTR Vspec...