Questions about AFM on 1J vvt-i...jus curious

[swapinthedark]

I just completed my 1J vvt-i swap into an R32 gts-t and while trying to button everything up, we ran into an interesting problem. The car ran "ok", but Idled low and would not rev out all the way under load. It would just get really weak like it had the timing all pulled away after 4000rpms...

We traced wires, we looked for leaks, we checked cam timing, we tinkered with all the plugs..... nothing.


The car was running with an open AFM that had no filter or anything in front of it(ran a few nissans around the block before with no filter on the maf with no probs...weird) and THAT was the problem. We put a "cone" type filter on there and WHAM, it ran great and has been wonderful ever since.






My question is do I need to add more piping before that filter or should a cone filter banded right to the inlet of the AFM be fine?? I have heard stories of a peice of pipe being needed to eleminate turbulent air or some stuff.


Do any of you fellas have your filter strapped right to the AFM? Anyone ever heard of a peice of pipe after the filter helping the car run better???

I know this sounds a little silly, but I figure if the filter made such a big difference, maybe there is more improvement to be had.....

[Kedderz]

factory setups on the 7m and 1g's i own are airbox->afm
The airbox or pod in your case is directly bolted onto the afm, this is as toyota designed. Theres no harm in what you have done.

[neal]

Aren't all 1j MAP sensored.

[jimmmayyy]

is it a hotwire type MAF?? if it then yes, turbulent air can upset them.

[wilbo666]

Aren't all 1j MAP sensored.

No.

VTTi 1jzgte (and 2jzgte VVTi) run an AFM and a MAP sensor...

Cheers
Wilbo

[swapinthedark]

Thanks, it is not a hot wire like a nissan though...it is the weird kind with the huge bullet in it like some US mazdas and a buncha fords have.

My nissans would idle funny with no filter, but once the air was moving they didnt seem to care...This thing was all kinds of screwy filterless.

I think yall are right that a filter is enough, but I will be dynoing soon,,, I am gonna make a 6" or so pipe to go after the filter and try it on the dyno with and without just so I can report back here if there is a difference.

[CrUZida]

Billzilla found the same thing with his BEAMS 3SGE.
http://www.billzilla.org/AE863SGE.htm

No good


The Fix!!

["Z" UTE]

Same sort of thing on an 7M-GTE MZ20, all sorts of unusual operating symptoms. replaced pod filter with stock air box and all was good.

The local rally team had TRD in Japan do some testing on the various air filters they were considering using. Pod filter was the worst, and the Toyota panel filter was the best for airflow. Subaru came to the same conclusion.

cheers Chuck.

[JP]

I use a spun alloy podram with 6" K&N filter on the front of my 1j vvti MAF. Mine doesn't run too bad with no filter on it though.
http://users.tpg.com.au/adsl0uxv/goonintake.jpg

[mumblezzz]

Same here. Got a filthy k&n pod clamped straight to the AFM no problems. Never run it without though. Although I have started the car without the AFM plugged in.