Turbo BS Thread

I depends exactly what year Tacoma you have for the IAT sensor. I think the early 95-97 (not exactly sure on the years so don't quote me on that) had the sensor in the air filter box separate from the MAF. Then later on they switched it to being in the MAF.

Some will argue that the MAF will not be able to compensate for boost since it is not a MAP sensor, however, some people forget that it is a Mass Air Flow Sensor vs an Air Flow Meter (AFM). It's not ideal for boost since it has a flow limit, but to me it makes sense to measure the air after it's been pressurized rather than before when deciding how much fuel to add.

Clay, you could also look at installing a GM temp sensor in your IC pipe if you wanted to read IAT only post turbo. IDK what exactly you would need make that work with your set up.

 

Well..thought that was the point of the FIC6. It'll do the boost measurement for you.

Plus i mean, look at every supercharger setup.

 

Maybe I'm wrong but from what I gather using pre and the MAF see's exactly how much air is going in period. Post - the MAF only see's air velocity and temp but not pressure so you can be anywhere from 0 - max boost at any MAF reading. Since the FIC tunes on MAP but the stock ECU tunes on MAF you basically have the ECU adjusting fuel trims at it's load cells (in MAF) based on the fuel it's getting from the FIC (on MAP) so it's never stable.

 

You just need to make sure you know the limits of your MAF. How many g/s is can read, before you have surpassed its duty cycle. Otherwise you need to upgrade to a wider range MAF, or go to a MAP.

 

this is how i see it....




granted...i don't have any of this on my rig..so no much help haha

 

I don't understand what you are saying. MAP and MAF measure different variables but are not completely independent. The MAF doesn't "see" boost, sure, but it does see the increased air flow caused by the extra pressure.

The big issue with a MAF and turbo is they can cause the ECU to measure air flow that isn’t actually going into the cylinders. When you charge the pipes but then suddenly lift the gas pedal and close the TB, that charged air has to go somewhere. It either flows back over the MAF or flow out of the BOV. Unfortunately your MAF/ECU logic can’t discern this. Any air flow, regardless of direction, will cause a voltage signal to go from the MAF to the ECU causing the ECU to add fuel accordingly. Your engine goes way rich and may even stall.

If you cap the MAF voltage you can limit how rich the ECU goes when the MAF reads extra air flow and controls how rich you run. It’s not perfect but works.

MAF mounted pre turbo also tends to help but even that isn’t perfect. You will need a properly configured recirculated BOV to maximize the benefit but even then you will still get extra unwanted air flow readings.

Bottom line, for a turbo, the best answer is either no MAF or a standalone ECU that can properly compensate and correct the readings between a MAF and MAP sensor.

 

Megasquirt 3 it is

 

I agree with this, especially the last part about MAP being the idea way to tune for boost.
The part I don't get is if the MAF is after the BOV, then the amount of metered air being discharged is going to be very minimal compared to if one is running a pre turbo MAF. With my set up, my truck has never stalled or been close to stalling when the TB closes. Granted, though, I am not using a piggyback to tune, i'm still currently on the stock ecu for now. I don't know how the FIC or MAPECU would change this.

Exactly what I'm in the middle of doing

 

Oh really? Nice!

I know they make a PNP kit for my year be the way id go for sure.

 

Is your MAF close to the TB? You only double measure the extra air between the TB and MAF. Generally you want it as close to the TB as possible for this reason with the BOV mounted pre MAF.

 

My MAF is basically right on top of the Valve cover before the piping makes a 180* turn into the TB.

Really? I hadn't seen which years they doing the PNP for. Do you have a link for that?
I'm using a URD PNP harness to make it PNP-ish.

 

Yea i mean its for 95-97 tacomas with the 5vzfe. They have a PNP connector, you still have to assemble the ECU(soldering, easy) and even have a base map.

https://www.diyautotune.com/product/diypnp-nippon-denso-76pin-unassembled-kit/

https://www.diyautotune.com/support...ion/application-docs/1995-1997-toyota-tacoma/

Cheaper then an AEM FIC6 too..well..close anyways. haha

If i had just gone turbo instead of this god damn blower, this is what i'd be running.

 

Thats about where mine is and I've had no issues either. When the BOV opens, you will measure the charged air in that small curved section. It won't be much so you won't go too rich. If you move the BOV to between the TB and MAF, when the BOV opens, all the extra air in the charge pipe starting from the turbo will be measured and you will go much richer. Stalling is pretty rare but I think someone here had issues with his truck stalling after a power pull.

 

Sell it. Or SuperTurbo charge it!

 

I'll follow whoever does it for a 5vzfe and provides wiring

 

That's pretty awesome! They even give you the jumper configuration and ignition settings. I like that IAT sensor kit to get rid of the MAF altogether.

 

Hmm.. Mine sure doesn't. It reads the exact same regardless of boost.

 

The thought has crossed my mind for compounding them...

Remember that crazy modified 1st gen supercharger on here a while back that was setup for an intercooler?? That would have been ideal for a twin charge setup.

But id really really wanna build the block before that haha

Yea super slick kit! MAP all the way. Plus the Megasquirt is packed full of stuff..boost control..launch control..

Ideal no doubt.

 

All of us I believe are post turbo on MAF.....

@GioGuitarDude is the only one I know running preturbo and he prefers it this way.....

 

I think he's post MAF now, I remember him mentioning it when he installed the AEM meth injection... But I can't remember exactly