R33 Gtst Afm Compatible With R32 Gtst (rb20det)?

[wilch]

Hi guys,

I have a spare AFM from my s2 R33 gtst, just wondering if I can use this on an R32 gtst RB20det engine?

thanks...

[paulr33]

it is not compatible

[wilch]

bummer, I thought they looked a little different.

Thanks paul

[RB30-POWER]

Unless your prepared or know how to change the plug/connector, then no, they aren't directly compatible.

RB25 Series 2 has a 3 pin plug, whilst RB25 Series 1/RB20 AFM has a 4 pin plug. (extra earth)

[Craved]

so basically it is possible to use if you re wire it in and re-map the ECU to use it, similar to a Z32 on rb20..

where as a S1 AFM would be direct plug in replacement, but would still need a re-mapped ecu ??

[RB30-POWER]

No need to remap, they both have the same 0-5V output per same gm/air sec entering engine.

Re-wire to suit and its apples

You only need to remap if you change to a Z32/Q45 AFM as these read less Volts per gm/air entering engine.

Edited March 17, 2006 by RB30-POWER

[Craved]

if they run the sam voltages, there isn't really any reason to upgrade then is there..

there shouldn't be any difference in them at all as they are both 80mm..??

but i swear i read somewhere that the rb20 items cant handle as much power as a rb25 item.

[Cubes]

Craved, the r33 s1 and r32 afm's are most definitely the same.

From observations the R33 and R32 PowerFC airflow curves do vary slightly.

It appear the r33 airflow curve returns a higher load/airflow for a given afm voltage. SO possibly this is where you may see r33's making the same power as r32's on the same afm voltage.

I'm not completely sure what directly affects the airflow curve, maybe engine efficiency.. I have no idea.

The rb20/25 afm's have different airflow curves in the s13/s14 pfc's also.. Go figure.. I have no idea why.

[Craved]

so theoretically if the R33 afm shows the same voltage for a higher air flow through it, that would mean that if you swapped the AFM's the RB20 would run leaner without changing anything.

doesn't sound nice if i have read what you said correctly Joel.

[Cubes]

No...

The airflow curves are located within the ecu. So the physical afm, there is ZERO difference.

All ECU's contain different airflow curves for a given afm.

So the same afm on different ecu's will return a slightly different load value. As previously said I am not sure why the airflow curves are different UNLESS it has some thing to do with engine efficiency. No idea.

I shouldn't have gone so in depth, only confuses.

I've had both afm's on the dyno on my R32 RB20DET many years ago. There was no difference. Exactly 100% the same afr ratios.

[wilch]

hmmm, so afr's are still the same, and all I need to do is rewire?

Now that I can do.

If/when I do it, I'll post up some pics.

(If engine blows up, I will come looking for cubes and kill him... )

[T04GTR]

off topic, but who does photos of wsid street meeets?

[Cubes]

I need to make it clear.

I ran the R33 S1 AFM. Not the Series 2 pink sticker. So I have no idea if its output voltage is different.

[T04GTR]

apart from the plug being entirly differant. 3 pin instead of 6 or somthing

[Craved]

hahaha

in depth is cool Joel, we dont learn otherwise

dave .. 4pin = s1 and r32 ; 3 pin =s2

[RB30-POWER]

if they run the sam voltages, there isn't really any reason to upgrade then is there..

I wasn't under the impression the guy was looking to upgrade, more so just replace a faulty AFM with another he had lieing around.

[Craved]

hehe i hadn't spoken to wil about why he was doing it, i sort of hijacked it a little to see if there is an other reason to change them over for power gains.. while still getting his question answered

this is only since i was under the impression that the rb20 afm was only good for about 200rwkw, then rb25 was 250ish rwkw then 300+ for the z32 ..

[predator]

there'd be no difference between the r32 one and the series1 afm, as they are the same unit.. the only difference is the s2 one as per above.

where they actually run out of resolution and effectively the power they can make may be different because of the different head flow between the rb20 and rb25 heads. Thats why people probably come to the conclusion they make different power, therefore they are different.. no the afm is the same, the engines are different

[Craved]

makes sense Gordon.. cheers

[wilch]

yessum, looking to replace a faulty one with my old one.

Thanks for the help guys!