Jump to content
SAU Community

AFM Max Values

tang0

By tang0,
in Engines & Forced Induction

 Share

Recommended Posts

tang0 Proficient

tang0

Posted
Posted

ok, so I know (i think) that the AFM gives an output of between 0 and 5 volts, 5 volts being at the max of its range ... looking at the stats from my consult port logging, I can see that the afm is VERY close to the 5v mark on quite a few occasions ... 4.90 being the top end so far - my injector pulse width being in the 15-17.5ms mark and a duty of between 60 and 85%

so the question is this : What needs upgrading first

fuel pump ?

injectors ?

afm ?

any thoughts anyone ?

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/
Share on other sites
Sydneykid Grand Master

Sydneykid

Posted
Posted
ok, so I know (i think) that the AFM gives an output of between 0 and 5 volts, 5 volts being at the max of its range ... looking at the stats from my consult port logging, I can see that the afm is VERY close to the 5v mark on quite a few occasions ... 4.90 being the top end so far - my injector pulse width being in the 15-17.5ms mark and a duty of between 60 and 85%  

so the question is this : What needs upgrading first  

fuel pump ?

injectors ?

afm ?

any thoughts anyone ?

How many rwkw?

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/#findComment-996947
Share on other sites
tang0 Proficient

tang0

Posted
  • Author
Posted

i have no idea how many rwkw it has now, or what i want to get

to be honest i'm not really interested in looking at what the numbers are, i am more interested in driving it bloody fast (on a private track of course) and also being drivable on a day to day basis - not to be spitting flames at every gear change.

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/#findComment-997552
Share on other sites
Sydneykid Grand Master

Sydneykid

Posted
Posted
i have no idea how many rwkw it has now, or what i want to get

Sorry I can't really help you then. All the components for upgrading are rated and, based on a large number of cars, I have a rule of thumb wherebye I can tell what part is capable of what power. It is pretty stupid to have a 400 rwkw capable fuel pump, 300 rwkw capable injectors and only a 250 rwkw capable turbo. Stupid = wastes time and money and is limited by the weakest link.

i am more interested in driving it bloody fast

To many people a 200 rwkw Skyline is "bloody fast". Others need 400 rwkw to get any jollies at all. Some think anything less than 1,000 bhp is plain whimpy.

I have a personal preference for 2wd drive Skylines to have around 250-270 rwkw, that's enough for a high 11 at ~200 kph. Over that and they get a bit cranky in traffic, tricky in the rain and you get a pretty poor return for your money (lots of $'s per kw). For 4wd Skylines, add another 50 rwkw or so, as the wheelspin problem is covered.

Hope that helps :P

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/#findComment-997684
Share on other sites
  • 2 weeks later...
b2barker Enthusiast

b2barker

Posted
Posted

Tang0 : Mine goes as high as 4.96, with 80% duty (mods exhuast, filter stock boost control).

I have major hesitation issues from 5 to 7k RPM. I think the solution maybe AFM or piggy back with Z32 AFM. I sent you a PM

SydneyKid : Do you know what sort of rwkw you would reach where you would be maxing out the stock R33 AFM? I though it was in the 200kw range, but I would be suprised if mine pulled much more than 150kw atw with only exhaust and filter and stockish boost.

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/#findComment-1013290
Share on other sites
Sydneykid Grand Master

Sydneykid

Posted
Posted
SydneyKid : Do you know what sort of rwkw you would reach where you would be maxing out the stock R33 AFM? I though it was in the 200kw range, but I would be suprised if mine pulled much more than 150kw atw with only exhaust and filter and stockish boost.

Hmmmm, an unusual combination. If the numbers are all as you say, I suspect something is wrong. I haven't seen a R33 GTST go that high in AFM voltage until over 200 rwkw. Maybe try cleaning the AFM (brake clean is the go as it has no residue) and checking it's connector. Then check the voltage with a multimeter, as a few spots in the rpm range, that might help narrow it down. :D

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/#findComment-1013556
Share on other sites
Beer Baron Grand Master

Beer Baron

Posted
Posted
It's about 1.1V at idle. Should it be lower?

You may need to re-ground the MAF. I've heard of this problem cropping up a number of times of GTI-R SR20s. Adding another gounding point to the MAF should help. You will need to identify which wire is the negative earth and then CAREFULLY solder another wire to where it fits on the AFM, then ground the other end to a good ground place on the chassis.

HTH.

Richard

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/#findComment-1013736
Share on other sites
b2barker Enthusiast

b2barker

Posted
Posted

The ground to the AFM is switched off the ECCS relay, and connected to the CAS sensor and the ECU on multiple pins. I am unsure what other things may be affected by wiring another ground in parallel. Personally I would want to disconect the existing ground first. See atached schematic.

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/#findComment-1014651
Share on other sites
tang0 Proficient

tang0

Posted
  • Author
Posted

well, hopefully this can now be solved, I have ordered a PFC from nengun, and am awaiting its arrival ...

I don't have the consult plugged in at the moment as was fed up with it sliding around behind the gearstick ... will plug it up at the weekend and see if I can get some logs off it ....

now to read up about the pfc ..

gah

so much to do

so little time

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/#findComment-1014737
Share on other sites
The Mafia Grand Master

The Mafia

Posted
Posted
Hey guys did the re-grounding work ?

I haven't done it yet, but the problem is shitting me off to the max.

I have 1100mv on the powerFC at idle (700rpm) and at 2000rpm in 5th gear on flat highway, its at 2500mv - 2700mv

****en big cough at around 6500rpm gearchange if changed hard..

this is what I am gonig to do, find the earth, chop it off the AFM and wrap it up, and then solder a new earth onto the AFM and ground it somewhere on the motor or the chassis.

Anyone know a good spot?

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/#findComment-1019423
Share on other sites
MM2death Grand Master

MM2death

Posted
Posted

My AFM goes the the max value on the data consult port display all the time when i get up it (5.11). It also says my injectors are in theory going up to 125% duty cycle.

Car is R32 GTS-T with around the 200rwkw mark. On dyno it shows there is still plenty of fuel. Sydneykid you have seen my dyno graph. Any idea on all of this. Car runs great.

Regards,

Scott

Link to comment
https://www.sau.com.au/forums/topic/50002-afm-max-values/#findComment-1022637
Share on other sites

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Borci88
      Borg Warner EFR Series Turbo's V 2.0

      By Borci88 · Posted

      Not a problem at all Lithium, I appreciate your help regardless. I've pulled a small part of a log where the target pressure was 28psi and it spiked to 36.4psi. I've only just begun using Data Log Viewer so if I'm sending this in the wrong format let me know.
    • Lithium
      Borg Warner EFR Series Turbo's V 2.0

      By Lithium · Posted

      Sorry had a bit of a week and haven't had heaps of time to follow this, so apologies if I've missed something - any chance of showing a log with the rpm, turbo speed, MAP, and wgdc all in one view? Definitely an "interesting" problem, and while it's definitely worth noting that there was a similar issue with the twins I'd not completely put all bets on the root cause being the same thing.  Keep an open mind, follow the data.
    • Borci88
      Borg Warner EFR Series Turbo's V 2.0

      By Borci88 · Posted

      I built this engine approximately 12 years ago so my own head (brain) is a little grey on the exact hardware in the RB head, however what I recall is. Stock RB25 NEO TURBO Intake Camshaft HKS 260 degree Exhaust Camshaft (R34 GTR) RB25 NEO Turbo Springs  I ported/removed the exhaust stud humps found in the RB25 head so theres less turbulence but it wasn't ported/polished properly, just a hump removal. I've attached two pictures of the before and after to illustrate.     The ECU gets its boost reference from the nipple on the rear of the head on the intake side, behind the fuel rail. The wastegate gets its boost reference from a nipple on the cooler pipe immediately after the comp cover.  Could a decent pressure drop across the intercooler cause the wastegate to be seeing a higher PSI than what the ECU is seeing, and thus it can't control it accurately and quick enough?   We ran a line to the actuator and watched it open and close using an air compressor, while we didn't have a gauge on the line to see when it was cracking open, it was opening smoothly.  I just removed the gate now and even though the documentation says you need to open it in a vice due to preload (which I did), there wasn't any preload on the cap, which is something we noticed straight out of the box as well when new. This silver cap internally is threaded to the actuator rod that runs out the bottom of the straightgate. Not sure how I'm supposed to get this spring out to be frank.. Potentially but everyone else doesn't appear to have to stop at 500kw because of 6boosts design.  I would, but I think I'm getting to that point where if I'm going to do the head and make another 100kw, then I'm going to need a fancy gearbox and quite a few other things and 10k becomes 20k becomes 30k within a few months. I'm not necessarily sold on the idea just yet that the head is restrictive at 4000rpm (and what.. 300kw?) and yet doesn't seem to be restrictive at 7000rpm when it's making 500kw, however I'm obviously not closing the door on that theory.
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      Yeah - Half the problem is I know this sensor actually goes to 150C.. I'm pretty certain it is min of 11C. So still more data required I suppose. It's really quite hard to get the oil temp to 100+ then immediately pull over and take a reading before the temp drops. Annoyingly I suppose the range I really 'want' is likely 80 -> 120C. TBH the ecu can't really *do* anything with it, and the gauge itself is very visible... ...but you know how it is.
    • The Mafia
      Borg Warner EFR Series Turbo's V 2.0

      By The Mafia · Posted

      My EFR 8474 Black, made 800awhp on a roller dyno. at 25-26psi. E85. Shaft speed was around 106,000rpm 1.01 rear. The rear is maxed.  6 boost Turbosmart 60mm gate 3.5inch exhaust  Head is worked to the shithouse. Bain racing. VCam. 272 exhaust. RB28 - RB26 foundation.  You have an intake issue. Start getting proper data and I mean go back to the simple things.  - Pressure test your intake - Block off the Turbo BOV, you don't need it.  - Test pressure before and after your intercooler If your head is pretty stock, that is your issue. Especially if it is NA.  Take it off and spend $10k on it. 
×
×
  • Create New...