Nistune Forums

i have a s13 ka24de 5301 mt fed. 74mm borg warner s372 w/1.00 turbine housing; 3" piping charge side and 3" cold side. 4" intercooler core. tonsil style blow through ford racing lightning airflow meter. im seeing 5.0 + volts 15-16psi boost. is their an alternative in the tuning, or is most cost efective way to redo piping 4" or get phx airflow meter.

Thats normal considering.

The last lighning MAF I ran up here was 90mm/3.5" id.

Whats the cheapest way to fix it. Please no comments only solutions. Matt maybe.

I just run the HPX MAF. easier, and dont need to deal with shit.

that guy wrote:Whats the cheapest way to fix it. Please no comments only solutions. Matt maybe.

opt 1. put it in a 90mm tube (obvious option to start with)
opt 2. pull it apart and replace the reference resistor pack, very time consuming. (technical, requiring flow bench)
opt 3. setup it up as draw through, the way ford has it setup in the pickup. (missing link)
opt 4. use a Maf extender (like MAFia, expense, adds another point of failure)

It sounds like it's *almost* got enough capacity but is running close to the line. In reality this isn't the end of the world anyway. The Nissan ECU's deal amazingly well with maxxed out AFMs. Sure, not ideal but hardly a major problem. I see it all the time.

The system measures to 5.12V too, so you still have 0.12V to go. This doesn't sound like a lot but these things are hugely non-linear. So 0.1V at that end of the scale is actually worth quite a bit. If it was pegged at 4000 rpm then yeah, you have a problem. But I'm assuming the 5V you're seeing is the maximum you can get at any RPM?

How much higher were you intending to go with boost?

Idea: I'm kinda wondering why we couldn't just run a simple resistor voltage divider in cases like this. Just take say a 10Kohm and 1Kohm resistor in series connected between AFM output and AFM return. This would effectively divide your output voltage by 1/11. So your voltage would be down by approx 10% across the range. For about 50 cents. I've never done this but hey, worth a try...

PL

thank all you guys especially pl. Sorry for being blunt, but im just an asshole in general. i've currently run 22.2 lbs on the set up. shooting eventually for 40 lbs. was'nt monitoring data at this boost. did you look at logged data? The resistor option any specifics on retuning or would i just trial and error maf translation decrease value across scale till nominal.

sorry PL just saw the 10% part.

I suspect you'd need to do some tuning in the VQ map itself with the resistor option. If the resistor option works then I guess there's no reason why you couldn't go further and use a 10K/2K divider to get t down to 80%. Dunno how far you could go with this...

If you're going to increase boost substantially then you may be best off fitting the sensing element into a bigger tube or go HPX. Looks like that turbo is gonna move some serious air.

How do the Ford MAFs compare to Z32? I know Z32 are only 72mm but they really do measure some decent power. I've never used a Ford MAF - they're not terribly common in Oz.

PL

With regards to the HPX they have a lot higher measuring capacity. I've just received mine this week and looking to fit it in a blow through setup on the R31 this weekend and see how my updated calibration curve (3" tube) works out

Following this there will be dyno work required to check AFRs etc are stable with this map so will be a week or two before I can post results of this

Matt And PL you guys are knowledeable, wise and experienced thanks for the information. I did further research on the voltage divider setup on a link. guess it's common for ford guys to max out the sensor and gives me further hope in making big power with an mass air flow meter system.
Im probably gonna try both ideas and get back to you. I do'nt like to post on forums much because typing does'nt make money or power and i can't stand useless small talk, but im proud to saw this forum does'nt cater to much of the later and I am honered to run Nistune and support all this communitys effort. i trying to get my nissan into the 5.9 sec zone in the 1/8 mile ive gone 6.5 w/ old setup 60-1 on 112 leaded.

that guy wrote:i have a s13 ka24de 5301 mt fed. 74mm borg warner s372 w/1.00 turbine housing; 3" piping charge side and 3" cold side. 4" intercooler core. tonsil style blow through ford racing lightning airflow meter. im seeing 5.0 + volts 15-16psi boost. is their an alternative in the tuning, or is most cost efective way to redo piping 4" or get phx airflow meter.

Wow mine maxed over 16psi of boost but I have mine in a 2.75" intercooler pipe. I thought that a 3" pipe would have made it flow more like the Z32.

We'll try to get Matt's on the dyno ASAP and see how the HPX sensor goes.

PL

Hopes for the best, I might just have to change sensors. Is the HPX just from the 05+ mustangs? or is a modified maf sensor?

As far as I know they are a custom sensor. Not a modified OEM sensor.

PL