this ought to put the cat amongst the pigeons but what is the general consensus of fitting an induction cone before having the car remapped as opposed to waiting until its remapped before fitting it.....

 

I think the main problem is the MAF sensor giving up, depending on the filter type. Since the ECU measures air mass it should compensate without a problem. Saying that I have read about the early JDM cars leaning out with indution kit's, and I'm sure someone told me that when they fitted an APS cold air feed (mounted in the wing) it leaned out (that was a later model uk classic).

Dave

 

More air = more fuel and you cant really get that "safely" without remapping it. Best to fit it 5 mins before the remap More often than not the early MAFs just give up when induction kits are fitted, its a byproduct of banging the MAF around when fitting it, dirt, moisture etc all upsetting the hot wire. Later models did away with this type I think.

 

Ive just fitted a 300ZX Apexi filter to our MY93 Subaru.

The hot wire system in the air flow meter is pretty much identical to the set up on the 300ZX air flow meters. In fact the whole units near identical, to the extent that Im going to try a Scooby MAF on a 200SX (200s use 300ZX afms as an upgrade).

Anyway, my point is that I, and loads of my customers, are running air filters with the hot wire 300ZX/200SX (which also use a hot wire) air flow meters with no problems whatsoever.

The air flow meter should adjust automatically for any increase in air flow as thats what its ther eto do, thats its job!

I cant get my head round why fitting an induction kit to these cars would cause any sort of issue. Anyone got the reason why its supposed to be detremental?

Ive fitted a Wlabro pump and have a wide band lamba so will check fueling to see if its leaning out but I dont see any reason whatsoever why it should unless people are simply running too much boost and over coming the abilities of the standard injectors or pump??

 

Ran one for 3 months nearly on my 98 before fitting new ECU and remap (was previously mapped by PE for a panel)... 98 MAF is stronger than 99-> .....

I do have an AFR and KL, so best be cautious - BUT, more air=more fuel is what a MAF does .... - providing you don't go too far (or beyond the limit of the fuel system (pump/injectors...)

Just my experience,

Mark

 

Eh?

 

It is the effect of the filter/induction kit on the linearity of the airflow, ie tumble, swirl and non concentric flow.
The hot wire/film is only measuring the flow in the centre of the meter. This has been calibrated within the ECU to match the OE air current flow pattern.

When mapping, it is not abnormal to adjust air flow scaling by +/- 20% at certain flow rates to compensate for an aftermarket induction.

It may well be that this 20% fuel difference is not an issue on the Nissans ? I do however know that in some cases this is enough to melt Subaru pistons.

Andy

 

Aaarrhhhh, that makes more sense.

The 200s are pretty susceptible to det but having said that the S14 afm has the hotwire built right in at the top of the afm, its not in the centre like the Subaru one. The 300ZX is in the centre though and those afms are used on a large number of high power 200s as theyre larger than the S14/S13 items.

Our own S14 was running 368+@wheels with a 300ZX afm and Apexi filter on standard pistons and rods so Id have thought if turbulance was a major det instigating issue then it would have gone pop.

Ill check our fueling, Im about to go for a ragging with a wide band to see what we can get the boost to, fingers crossed it doesnt go pop Im assuming Im going to be limited somewhat with the 98 octane optimax and the original 100ron map but Ill see what happens