Thread: Another pull-through vs blow through

Mass air flow sensors are very sensitive to air flow, so it does matter where you put them. I think the big issue with this setup on blow thru is the maf being used. The stock DE maf is very sensitive to air flow. So sensitive in fact, that nissan put an air-horn in the factory air box in order to smooth out the flow and get more accurate readings. This is another reason why the cars do so well with a pop charger on there as well.

The DE maf is a horrible design, and causes the air flow to neck down to a hole the size of a half-dollar. This causes air to slam into the wall inside the sensor and turn 90 degrees. When it hits the air-flow-stream it has to turn another 90 degrees to go through the MAF. This is causing the maf voltage to become static. You would prob see this on Datascan, As the voltage jumps up and down violently the computer just lets the fuel flow.

Is there anyone running a DE maf blow thru with good results and decent power? Or is everyone else who runs blow thru running the cobra and Z32 maf?

when I moved the cobra maf from draw through to blow through my mixture leaned out a bit, and the maf maxed out faster. I did get gains with no changes other than that. Thread is kinda retarded. The benefits are less issue with open BOV, less issue with leaks in IC piping and better idle. It isn't to make more or less power! If done right, power should really be the same with a more stable and reliable idle/tune.

Brent

I would say otherwise. I bet there is noone here who is running blow thru on the de maf. I don't see that maf working for blow thru setups effectively. I know you're a smart guy coach. Who here has honestly run blow thru on the stock maf?

Sure if airflow problems weren't an issue, the car would have made the same power. Why would the maf affect power at all unless it was a restriction? What I am saying is that the blow thru setup with the DE maf on dallon's car would not be able to be tuned out. There is nothing you can do to fix the static the computer is seeing. I had a similar issue with my lightning maf, but that's another story.

If AFRs stayed the same you would not notice any difference in power. That I can agree with. But can someone chime in here who is currently running blow thru on that particular maf? I bet noone here is getting good results doing it.

i personally am all for the "experiment." my only debate was that it was stated that once the maf was swapped to blow through, the car ran rich. if it ran rich than it would need a new tune to run proper and set a comparing table. untill both setups are both tuned for each setup, the numbers mean nothing to me. now if you had said, and showed slips for proof that each setup was running at an optimal A/F, then we'd have nothing to argue. it has always been to my interest if one setup was "better" than the other. when you show good A/F results on each setup, then we'll see. i dont know about anyone else, but i appreciate the effort!!!

Now it's actually starting to make sense to why this might have low numbers like it does.

The stock DE maf.... and you are completely right, the design of it is terrible for airflow.

So now to all of the people that said that this is BS, who all is running a DE maf for blow through?

^^^That's what I'm saying. I don't see that maf working at all for blow thru. I don't care how much you try to "tune" it out, you are still going to get the same results. One of two things is happening: Either the maf is maxing out, or it is going static. I think it is going static. There is no way to tune it out.

i tried DE maf with blow through, my car ran worse and had less power.

We have one of those stock MAF working as blow thru, on my friends car, with the SAFC on zero (not doing anything) AFR's were at 10:1 on WOT, after working a lil bit on the SAFC we got the AFR's to like high 11's/flat 12's. The car pulls strong as hell now.

So I guess without tuning, the stock MAF indeed makes the AFR's go rich as hell. If you have a stock MAF, an ECU that you cant tune, you should reconsider going from draw thru to blow thru.

hmm...ok, beginning to make sense now. i missed the fine print i guess in that it is stetup with the stock maf. im still confused on why it cannot be tuned. unless it is an untuneable ecu setup. i personally dont think there are many guys running the oem de maf though. but for those that are, this is very informative.

I noticed you edited your comment so I thought I would address the other issues you brought up. There is nothing flawed about the results. They are what they are.