Its works great... everyone with an FCON before you has been running that way, that is how the typical install of an FCON goes. Im pretty sure most quality EMS can also emulate the MAF.

As for why not? MAF is a more accurate way to measure airflow, it isnt based on any volumetric efficiency assumptions and can be tuned to damn near perfection without having to hit every cell on the map. Its also nice to have the car run like this when you blow a hose coupler off, rather then damaging a turbo or wasting time thinking of what else might be wrong. I have been contemplating going to dual MAFs with my FCON since I first installed it, ive got the extra sensor in my garage!

 

i thought a simple ecu reflash took care of that?

 

It can I believe but if you have two TB's that open 90-100% then you still have alot more airflow then one TB

 

of course.

with the amount of power people are running on a single TB seems like something you'd do for show (like a shop car )or had lots of extra money laying around.

 

Thus, so as long as you are not pulling more air flow on either side of the intake system than an individual MAF sensor can handle, then you can use the dual MAF's in lieu of a MAP sensor to calibrate your fuel and timing maps, and gain greater accuracy in doing so. Certainly makes sence.

How much air flow can each MAF sensor accurately monitor? Since a single stock MAF sensor can sufficiently monitor enough air flow to exceed 300 hp, with dual MAF sensors you should be able to exceed 600 hp. How much hp per MAF sensor can you run before running into problems?

I think the stock MAF sensors output up to 5V. Thus, the more accurate question is how much airflow corresponds to 5V? Based on the airflow an approximate hp rating can be estimated for a target A/F ratio.

 

i would figure somewhere between 600-700rwhp with the dual stock MAFs pre-turbo but who really knows until you try. You can go a little further by putting the MAF element into a larger diameter tube as well, but I believe that only works for minor increases because it causes wierd readings. But once again, I never did it so I dont really know.

 

So what are we talking about here for a full conversion?

Assuming a TT application:

custom piping from IC to individual TB
2nd TB
2nd MAF
custom piping pre turbo to include both MAFs
custom manifold
Custom MAF wiring
Custom slave TB driver board

I "think" the only real hard part is the custom piping from the IC to the individual TBs.

As Quadcam already posted you can purchase OEM manifolds that will somewhat fit our motor and allow for the two TBs.

TBs and MAFs can be picked up used very reasonably - not sure on new prices. The preturbo piping should be fairly simple considering the turbo already has filters on it that brings the piping away from the motor.

Would you need a custom IC that has two outputs instead of only one, or could you just split the output of the IC and run it to each TB? In the picture it looks like two outputs which would also require a 2nd blow off valve I do believe.

OK, so I see how this is cost prohibitive!

Awesome information Tim!

 

I started thinkking about this mainly due to our intake manifold. I HATE THE DESIGN. it's not the look of it, but the way that nissan implemented it. we have plenty of TB diamter, but that's not the problem.....it is the way that the intake has to feed 2 separate banks of runners. swtiching to a dual TB manifold (using OEM manifolds) could be a reasonably affordable method of delivery a better air path to the cylinders.

 

I believe a OMC TB from Nissan is around $300.

I am still not following how the second TB is wired in to be fully functional rather than a "slave" for the extra volumetric flow.

Tim: What is the volumetric flow characteristics (i.e. at idle, beginning of boost, WOT) of your twin plenum set-up under FI applications?

 

The HR motors intake manifold will not bolt to the VQDE lower plenum so you would have to modify the stock lower intake runners.Hopefully you wont run into a height issue which could lead to having to use a custom hood.Then you would have to use the newer throttlebodies from the HR motor which are not really appearing "used" so those will be expensive from Nissan.Those two TB's are relatively small so at that point I think you are actually better off using one stock VQDE 70mm unit.

They way we did our system is by using the MAF's as blow through.It simplifies everything.We ran two inlets and two outlets on our intercooler to avoid the "plumbing nighmare" and to keep everyhting symetrical and as close to equal length as possible.We also ran a separator on the inlet of the intercooler but no separator on the outlet of the intercooler to keep the airflow balanced pre-throttle from bank to bank and then we went as far including a balance tube in the intake manifold to keep the airflow balanced post-throttle from bank to bank. The wideband show identical mixtures from bank to bank at idle, part throttle and under boost.We had pretty decent dyno gains running low boost pressures.We picked up a good deal of torque from 2800 to 4500 rpms and a big increase in horsepower past 6200 rpms tpo redline.My car is not the ideal test subject because it is still running on the oringnal,untouched,unmodifed stock engine.We have a car in our shop right now that will be running this set-up and 25psi of boost,built motor with some big turbos.That car should be dynoed in Early December.

 

would the GTR manifold bolt on VQ35de !!

 

no.

 

could fit with an adapter plate.........

 

The tb are bigger than the ones on vqhr .. I might try the gtr manifold sine my car at gtm to install there tt kit on my z .

 

How did this work out in the end with the dual throttle body modification? Also could this be done on a supercharged car?

 

Simple solution: buy VHR car.

Not simple solution that costs money to make work right: drop off the car with us for a few months so we can tinker with it. We can figure out what parts will be needed pretty easily and we can make the stock ECU control those parts. We can machine adapters if needed, and we can have PMAS make custom MAFs for this purpose.

 

Well I have been driving my car like this for over a year so it is working well.You wouldnt be able to do this on a supercharged car with our intake manifold.



Tim

 

I would absolutely purchase this module since I am going to be working on twin SC's soon!!! Twin TB, Twin SC V-mount FTMW!!

 

I actually got the parts yesterday to build a controller. Hopefully soon I can play around with it. The idea is to use the same signal that drives the OEM throttle body to control a 2nd TB.