Jump to content
SAU Community

Recommended Posts

It is not "better" and "more tunable".

Air flow meters measure the load directly. They are therefore actually a better way to measure load. They do have a few problems though, particularly with big turbo cars. These being a few age/reliability/dirtiness issues but mainly reversion from poor turbo intake design/execution. Particularly poor design/execution of the BOV return.

MAP sensors do not measure load directly. You need air temperature and a few other things (including engine speed) to work out what the load is from manifold vacuum. You also need to have a "model" of the engine's volumetric efficiency. In reality no-one has that model so MAP sensored ECUs are tuned using the engine as the model - ie you just add and subtract fuel to get the mixture right. That might sound trivial and normal, but in reality, if you then change something about the engine (say a freer flowing exhaust or something else that affects the VE of the engine) then you actually change the relationship between manifold vacuum and load, and hence the tuning changes. Might not be much, might be bad. This is why famously you couldn't just put bigger cams into many MAP sensored engines without them cracking the shits at you. You can do it with an AFM engine and it will probably still need a tune to get it really nice, but it will still get the fuelling pretty much right without much help.

So the choice between MAP and AFM for PFC tuning on Nissans is really one of taste and capability and what your plans for further mods might entail.

  • Like 1

gtr jet what would you suggest?

I'm only going with pfc because they're proven and the price suits me, I'm not willing to go all out on a haltech or anything like that, way too expensive for the power I'm chasing.

That's some good information GTSBoy, I'll keep it in mind, I'm really not sure what direction to take my car yet...

I was going to say a Haltech but they are a little on the pricey side. I run a PFC and it does what I need but if I had the money I'd upgrade.

If money is an issue then just stick with a normal PFC and grab a Z32 AFM.

AFM gives a 0-5v reading to the Ecu based on airflow (duh)

The z32 gives better resolution for higher airflow. The factory r33 Afms hit a 5v wall at around 220rwkw worth of airflow. The z32s go much higher, around 550 crank hp according to nistune

Where did you get the 400rwkw number from?

Is it a track car? because if its mainly street driven, you'd be better off running a little less power to make it more driveable

The D-Jetro makes it easier to setup intake pipes, run no/atmo bov etc. But as GTSBoy has said, the MAP sensor calculates airflow, where as a MAF actually measures airflow.

I'd suggest looking into a Link or Vipec. They will end up costing more then the Power FC but offer far more features and options for tuning. Keep in mind that this will mean you will have to change to MAP sensor (although not that bad, they have an inbuilt MAP sensor to get you started) and its suggested that you install an air temp sensor as well, which means you will need to fit it into the intake manifold or a cooler pipe near the throttle body. These arent major issues but worth noting. There will also be a small amount of wiring involved, but nothing to complicated

EDIT: The adaptronic as mentioned above I have heard some good things about, but having never used one I can't give any more advice then that

Edited by 89CAL

To put things in perspective.

D Jetro is worth say $1000? What's it gonna cost to pull the intake off, drill cylinder 3 and 4 runners for the MAP sensors positions and put it all back together. Let's call it $3-400.

L Jetro. Cost of ecu itself is $700 second hand. IF you need Nismo AFM's, let's call that $500 second hand or $700 new.

That's $1,400 either way

A Link G4 would be something around the $1,800 zone. No drilling, far more advanced ecu, can support things like ethanol sensors if you need it later on. (Never say never)

All of a sudden the old dinosaur FC isn't such "value for money" anymore.

  • Like 1

the power fc is fine...but the cons with the powerfc is that it doesn't have on board logging....but you have the handy controller which allows making changes without laptop, they are easy for tuners to tune.

...

just think about what your end goal with your car is....what GTSboy said is spot on...the MAFless ecu's take more time to tune properly as you have to do corrections that a MAF system will automatically do for you....

FWIW i started learning with a Powerfc and now i kinda wish i had a Link G4....hindsight is 20/20 if you can be patient and save the money then a link or equivalent that allows retention of MAF would be the way to go IMO.

I didn't realise 400rwkw was a lot, guess they're only 2.5ltrs, I've just come from the world of xr6t's where a reliable 400rwkw is less than 5k away lol.

I still have much to learn about skylines.

I might look into the link g4, ethanol is another thing I've put into the future and being able to run a flex sensor would be good.

Thanks for all the info guys.

  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Latest Posts

    • Even with no BOV you will have issues unless the MAF is a hot film type like the R35 which has some design features to deal with reversion. Hot wire MAFs are very sensitive.
    • So i just change the (whatever is inside ma original MAF and slide the R34 MAF (it is gonna fit right in? ) and somewhere on the hot side a BoV...i presume that would be vented to the atmo? I just "trying" to understand...maybe my mechanic would know this   I would not mind(even prefer) to run stock BoV cuz it is way more than fine but i do not have that and only pipeing what is left is oem J pipe ... I will be running Blitz fmic(to fit oem one side style) and i gonna need custom pipes cuz i do not have rest of those pipes and hoses... But i am want standalone ECU. Only choice i have atm is Nistune...but that is not gonna cut it right?I dont know what Nistune can and cant do... I know you guys know Link and Haltech...but whatabout ECUmaster? I know guys in here run those but i literally do not know about that and do not know differences... Just know to take whatever "my" tuner can work on.  
    • Is that the blue one rpm?  
    • Update 2: Today I'm f**king pissed. Some of you probably saw my thread that I opened shortly after joining this forum, "urgently need expert/experienced opinion", in which I discussed the possibility of a porous RB26 engine block which I also found hard to believe. Currently both turbos are out since the shitty braided line that was installed by whoever fitted the GT28 turbos leaked oil onto the exhaust. Today while working on the cam covers to put new gaskets and half moons in, I cleaned the side of the engine block with brake cleaner. Some time later I saw that it was still glistening with oil or coolant so I dried that off. But it was wet again shortly after. Verdict: I'm royally screwed. What you can see here (hopefully, despite shit resolution), circled in red, is a crack above the turbo oil feed. Extent is a few cm long and basically goes from #3 cylinder wall to #4 cylinder wall. It slowly lets coolant through, even without any pressure behind it. I am absolutely dumbfounded as to how this crack even formed, especially since it isn't along the cylinder as it usually is but rather a horizontal crack. Probably a few cm in length. Not sure on how to deal with this issue right now. Most likely, the only true fix is a new engine block, and even a relatively well done temporary fix requires at least a full engine teardown. Neither of those really fit my timetable right now, the car has been in my buddy's garage long enough as it is. I'm open to suggestions, but I'll be looking into ordering a new 05U block soon so I have one ready for the coming year, or whenever the current block inevitably fails fully. (Most likely once the crack reaches one of the frost plugs) I think it'd be a waste of money and time to rebuild the engine with this block. Oh and I found a rust hole on the side pocket of the trunk, which someone covered up with sealant goop, a piece of number plate and bodywork filler. Fun times. So far for every issue we fix we just find a new one that is arguably worse.
    • I have not found this no. I put one back on a couple days ago with no drama. I agree they are tight, but no need to remove anything. 
×
×
  • Create New...