Afm Dilemma

[Sydneykid]

hey gary

can you get us the serial # from this 400rwkw Q45

and also a photo if the label?

i think there could be two types of Q45's going around, one is poo and maxes around 250rwkw and the other is OK and goes past 400kw

I don't have that particular Q45 AFM any more, but the current one (just about to go on) is supposed to be the same;

The label is yellow

22680 6IU00 A36-000 P60

1903F

JECS Made in Japan

The R33GTST's rebuilt RB25DET is going in tomorrow, then next week we start on the RB31DET into R32GTST, that's where this Q45 AFM is going. So I will have definitive results for this particular AFM in a few weeks.

There is another variable I have found, that maybe has an effect. It would appear that the R33GTST S2 (and onwards) alternator/voltage regulator runs at 14.2 volts, compared to 13.8 volts for the R33GTST S1, R33GTR S1 and all R32's. I need to test the output/input voltage from the ECU to see if that 0.4 volt difference has an effect on the AFM voltage.

Cheers

Gary

[paulr33]

thanks - let us know

ive had a few guys come to me using the q45 on mid size gt30+ setups and they max around 260kw

it hits the ceiling pretty quickly in the rpm range, like around 4500rpm so its not a std Q45 ceiling that i would expect

[paulr33]

ive got a q45 afm at home will check the serial # and post it up

[hungry6]

Thanks for the confirmation of serial numbers on the Q45 AFM, They've been sitting here for ages, and I have maxed out Z32, so these will go in knowingly they will produce the goods.

I'm abit happier today than yesterday now.

[R31Nismoid]

Yeah Gary - that info was pinched about 2 years ago, in which time you actually updated the info at that point... but the older info was used (which was as good as was had at that time)

[Jmaac]

Go MAP. Get a greddy pressure sensor or something

[Sydneykid]

Go MAP. Get a greddy pressure sensor or something

Worse driveability, poorer response, less accurate A/F ratios and ignition timing............why would I?

Cheers

Gary

[Guilt-Toy]

im going through the Q45 AFM debarcle as well at the moment. Mine goes down to line 16 on 9psi!!! on 24psi its well and truley on the last load point

Is there anything i can do to help sort this crap out ?

I got 363rwkw but it was well and truley maxed out, does the Q45 go to 5.2 volts or 5 volt?

Cheers

[Rezlo]

Ive been threw this, Z32 maxed at 330wkw, Q45 maxed at 350wkw odd (used every Q45 part number as i had access to, use a lot of them), went round and round on what to do, including taking a Z32 or Q45 and cutting the sensor out of it and mounting it into my 100mm intake with a 45mm lexan tube around the bar to stop turbulance and cross flow, a few people are in the proccess of doing this.,

Eventualy I sold my used RB25 PFC on ebay and got a new R33 GTR D-jetro with sensors and everything and it cost me all of $60us difference (got to love how discontinued items rocket in value),

I had to upgrade my fuel system for the new motor so I just got low imp 1000cc top feed injectors with a greddy rail while I was at it.

MAF problems sorted/aborted and no more idle stall with the dual atmospheric bov's YAY

Edited February 15, 2008 by Rezlo

[R34NRG]

is that possible with the R34 GTT? i alwyas wanted to get rid of the stupid afms but was under the impression i coudlnt unless i got a haltec or some other ecu.....can i use a R34 GTR D Jetro?!??!?!?

[Sydneykid]

im going through the Q45 AFM debarcle as well at the moment. Mine goes down to line 16 on 9psi!!! on 24psi its well and truley on the last load point

At what RPM?

Is there anything i can do to help sort this crap out ?

What AFM ramp table are you using?

I can get to 20 on zero boost by changing the ramp table

I got 363rwkw but it was well and truley maxed out, does the Q45 go to 5.2 volts or 5 volt?

5.2 volts

Cheers

Gary

[Rezlo]

I dont know about yours, but Rb25 swap to GTR is fairly simple, injectors, a few wires to add on and obviously the apexi map/temp harness bits and your in business,

The reason I didnt go haltec or autronic was the shear simplicity to do small corrections on the fly with the pfc as well as being able to monitor knock, voltages ectr, here in South Africa our fuel is unpredictable, one can see imidiatly if the knock increases and i can just temp remove a deg or 2 of timing out if need be,

[paulr33]

yeah you can use BNR34 djetro PFC if you like

but youll have to adapt it to the 25t NEO - it will need a few changes and some custom mods to make it work

ask a workshop how much to make it suit 25t NEO

[Sydneykid]

is that possible with the R34 GTT? i alwyas wanted to get rid of the stupid afms but was under the impression i coudlnt unless i got a haltec or some other ecu.....can i use a R34 GTR D Jetro?!??!?!?

Think about it..........set your boost at say 1.5 bar and the MAP sensor is useless, it ALWAYS reads 1.5 bar. So you are tuning off RPM and throttle position. But what if you are at 100% throttle and 1.5 bar? Quite a common occurance wouldn't you say? Then you are tuning against RPM only, that's one dimensional tuning. Compare that to AFM tuning, you have 2 dimensions (AFM voltage and RPM) to tune against. When the AFM voltage maxes out, then you still have RPM to tune against. Which is exactly the same as MAP sensor driven ECU. So tell me where the advantage in going MAP sensor ECU is?

Cheers

Gary

[GeeTR]

Wouldnt it be fair to say though, that when your doing 5650rpm at WOT, 1.5bar boost, that the engine is using the same amount of air, as all the other times, that those attributes were present? ... ish

Edited February 15, 2008 by GeeTR

[RB30-POWER]

answer to this is you want bigger get a 90mm ford lightning maf from the states, there is a guy doing 490hp at the treads at only 4.7v, even if it is american hp (not sure on what dyno was used) its still larger and has more resolution then its nissan counterparts.

[Scooby]

anyone tried using a single AFM on a DETT? engine in question is a 26/30 but only looking for 300rwkw.

cheers

[Rezlo]

if Map was so bad aftermarket and oem would not use them.Yes maf is marginally more accurate, but a correctly tunned map setup will work just as well, usually never even noticible.How many manufactures are moving away from maf and going to map due to reliabitly, packaging ectr, working for an oem and I can't see us moving to map especially with euro 4 emissions if there were not clear advantages that outweigh the tiny bit of accuracy seen on a perfectly clean maf.My biggest love of map vs maf is IAT temps, a most maf cars can not compensate for intercooler efficiency due to most not using iat sensors due to the nature of the maf, map systems have to use iat sensors so it can.

Edited February 15, 2008 by Rezlo

[Turbz_13]

go a haltech!! no AFM's no probs then

[paulr33]

airflow always increase - look at someone's ljetro AFM logs and check the AFM value - it always increses to redline - map will run to the ceiling value of "boost" and stay there

just found this from the apexi documentation;

Source: Apexi Documentation

80m RB25 airflow meter can measure up to approx. 300ps (221kW)

80mm VG30 airflow meter can measure up to approx. 500ps (368kW)

90mm VH41 airflow meter can measure up to approx. 400ps (294kW)

*Output is calculated off of measurable air volume