new setup... blow through MAF

[archaeic_bloke]

hey guys, i was the one who started the thread which got carried away 2 weeks ago called: "MAF Vs. MAP - whats better?" anyways i was at a shop last few days and saw a car which really caught my attention.

k so here's the setup.. 2 low mount turbos.. fed by custom made aluminum tube with apexi filters on each end, a rather, "cold air" intake kit setup... after the turbos the air runs through the intercooler.. then back up into the engine bay.. where it meets ONE 300ZX MAF!... then it goes into the standard intake plenum.

this is all controlled by an oem ecu.. heres the kicker.. its not an RB26 ecu.. its an RB25 ecu! tuned using nistune on dyno!

as far as i can see this is ALL advantage with ZERO drawbacks!

advantages:

- ONE big maf instead of 2 small ones
- RB25 ECU is easy to find and cheap to purchase
- MAF benefits of much smoother tuning, and idle, better mapping resolution,
- no issues with Venting to Atmosphere BOV's
- 100% accurate reading of actual air mass regardless of outdoor temp.
- and due to the positioning of the setup.... no concerns about boost leaks!


i can't think of a single draw back... can you!@?


lemme know..

also if any of you have pics of this setup PLEASE put them up.. im dieing for more details on this.

[derk]

probably the biggest drawback as with any blow through setup.. oil blowby fouling up your maf sensor

[archaeic_bloke]

hrmm... so if you have any oil blow by.. this could be a problem...

but couldnt that be cured by running an oil catch tank?

[linedriver]

couldnt that be cured by running an oil catch tank?

just vent the PCV gases to the atmosphere with the catch can rather then piping it back in

[NismoS-tune]

Atleast you're not in a GTR, otherwise the 1 MAF would quickly be saturated at what, 400hp?

[Skym]

Single 80mm Z32 MAF is rated to around 480hp. A 90mm Ford Lightning MAF is rated to around 700hp. Nistune can run both MAF's.

From what I understand, MAF is a load sensor which helps ECU to select correct load cells on fuel, ignition maps. RPM for fuel, ignition maps is from CAS.

How MAF works -

Air is sucked into intake piping by engine / turbo which cools MAF hotwire. MAF reheats hotwire and measures voltage to reheat hotwire. MAF sends voltage to ECU. ECU converts voltage to load figure for use on fuel, ignition maps via a load vs voltage conversion table.

Only downfall I see is the air in intake piping from turbo to intake manifold being cooler temp wise from intercooler, which cools hotwire more and MAF needs 5.1mv to reheat hotwire or maxes out MAF earlier.

[Brendan]

Only downfall I see is the air in intake piping from turbo to intake manifold being cooler temp wise from intercooler, which cools hotwire more and MAF needs 5.1mv to reheat hotwire or maxes out MAF earlier.

Air coming out of a standard intercooler won't be lower temperature than outside air. The blow through setup will most likely be seeing warmer air than factory, depending where the MAFS and air filters are placed in the factory setup.



A buddy of mine is running a blow through 300ZX MAF setup on his KA-T 240. He loves it, just has to clean the MAF a bit more often and everything is good.

[archaeic_bloke]

skym is on point here! thats exactly what im talking about! one big maf is the way to go,,, and yes this guys dyno sheet read a 430 whp. putting 80mm maf in the pertfect range..

back to the issue of positive pressure versus negative pressure on the maf, i just realized... it doesnt make any difference at all actually, the direction of air flowing over the hot wire is STILL the same direction... wether its sucking through or blowing through doesnt matter at all, think on it.

and as far as IC changing the temps... thats the whjole point of the MAF.. its going to be properly calibrated and calculated regardless of where you put it.. you just need a re-tune of course.

[M13]

Any pic of your set up?

I was contemplating on running my Q45 MAF as a blow through, but couldn't find adequate space to do so nor had the time. I'm running pull through at the moment.



I might just do the Ford Lightning MAF and have it welded into a charge pipe.

[Skym]

Blow through setup on RB20DET with Nistune and Ford Lightning MAF -

http://www.youtube.com/watch?v=z3FSWRsPtL0

Photo of Ford Lightning MAF mounted in intake piping -

http://i137.photobucket.com/albums/q211/Bluerb240/240%20stuff/P1010630.jpg

Wow, sounds awesome.

[linedriver]

http://www.youtube.com/watch?v=z3FSWRsPtL0

did anyone else notice what appeared to be very seasoned accord headlights on this thing?

[linedriver]

thats the whjole point of the MAF.. its going to be properly calibrated and calculated regardless of where you put it.. you just need a re-tune of course.

when you say that it just needs to be retuned, this only applys if anything else is done to the motor right? id like to move my MAF to try this concept out, but i wouldnt be able to tune it though

[Skym]

MAF is normally upgraded when injectors, fuelpump are upgraded due to bigger turbo. But MAF can be upgraded when fuel pressure is raised via bigger fuelpump, adjustable FPR while still running stock turbo at a higher boost level with upgraded intake, exhaust and front mount intercooler, etc.

From what I understand, voltage vs load table that converts voltage from MAF to load figure that engine ECU uses for selecting load cells on igntion, fuel maps needs to be modified and retune of fuel, ignition maps (main, knock maps) to suit.

[linedriver]

MAF is normally upgraded when injectors, fuelpump are upgraded due to bigger turbo. But MAF can be upgraded when fuel pressure is raised via bigger fuelpump, adjustable FPR while still running stock turbo at a higher boost level with upgraded intake, exhaust and front mount intercooler, etc.

From what I understand, voltage vs load table that converts voltage from MAF to load figure that engine ECU uses for selecting load cells on igntion, fuel maps needs to be modified and retune of fuel, ignition maps (main, knock maps) to suit.

but if the only change is just the placement of the MAF, then no tune should be needed though isnt it?

[archaeic_bloke]

well... the point is to remove the TWO maf's... and put one big one... therefore of course you will need to retune.