T28

[30psi]

How did you work that out?

[ChEsTeR]

With a wide band o2 sensor ecumster piggyback compter wich tell me AFM imput voltage to the ecu and a boost gauge. And i have a volvo 740 IC.

[30psi]

So if it maxes out at such an early stage how do the S13 owners manage 270bhp @ 1.2 bar?

It is worth noting that higher boost will result in higher fuel pressure so to some extent a reasonable fuel ratio can be maintained.

[ChEsTeR]

s13 ovners have 370cc injectors compared to 270cc in the s12's Yesterday i have instaled s13 injectors and remaked the MAF its now 60mm wide not mear stock 45mm. MAF that big will leen out whrew whole ragne of rpm's but will allow me to tune it more precise in the higher boost range.

[30psi]

The s13 uses the same air flow meter and that doesn't max out at 0.7 bar though. Its good for airflow up to 270bhp.

Worth noting that increasing the bore of the afm doesn't create a linear difference, but a logarithmic difference

[ChEsTeR]

S13 and s12 AFM are not the same. Thats all i can say. Can u explain term logarytmic diference?? Im a bit of with higher math.

[30psi]

The pre lambda ones are the same I have used both with no difference.

Pure examples here:

Small afm at idle

1.2v

Large afm at idle

0.8v

Small afm at full throttle

4.8v

Large afm full throttle

2.7v

On the Nissan s12's they have what is know as a VQ map which is a curve. The shape of the curve is difference for different afm's but the VQ map can be transplanted when using say a Z32 afm.

I can't drag up pics from ROM Editor coz I'm at work. If you look at this you can see the different VQ curves for the different afm's.