tklimes

I'm not sure how the MAF sensor works but it sounds like a good explanation.

It looks like the only was to be sure would be to monitor the Lambda sensor to see if the car is running lean at low revs. If that is the case then it's a trip to a tuner to custom map an ECU I guess.

Tom

john banks

http://www.scoobynet.co.uk/bbs/threa...D=57428&Page=1 might help

My ITG is goo free after a week or two properly installed.

Floyd

iTrader: (9)

A K+N panel filter in the std airbox could be a nice compromise, no goo and better cfm - quiet too.

F

tklimes

This is just my personal experience but:

I have a MY98 5dr, standard appart from PE T75 twin dump down pipe. Last week I fitted a STi induction kit (large K&N filter and aluminium 'bell mouth' trumpet adaptor for fitting to the MAF unit). When I took the standard air box off I found it contained a ITG foam filter but the bottom of the box was covered in green goo (like thick oil).

Anyway, after fitting the induction kit the sound was a bit louder to 3000rpm at wich point it developed a nice muted whooshing noise. Unfortunately, the bottom end torque was substantially reduced. By way of compensation, there was an equivalent increase in top end torque making hitting the rev limiter easier.

As I spend most of my time driving on the road I value low down torwue much more highly then top end increases so I removed the induction kit pending an ECU remap to compensate. I replace it with the standard air box and a Subaru genuine paper air filter which does not seem to allow the turbo to spool up quite as quickly as the ITG filter (but isn't oozing green gunk either!)

A summary of my findings:

1) Fitting an induction kit increases top end performance at the expense of bottom end torque. It may be possible to compensate for this with an ECU upgrade such as Link or Unichip (yet to be confirmed).

2) The sandard air filter is quite restrictive but offers reasonable low down torque whilst strangling the top end quite a lot.

3) An ITG pannel filter may be the best compromise but I am very worried about the green goo that oozes from it and the effect this may have on the MAF sensor.

Tom

[Edited by tklimes - 1/5/2002 7:57:25 AM]

john banks

I need to look under my ITG which has been in about a week. I swapped it with a K&N 57i over Scoobynet. Much quieter with the induction kit off, but possibly similar observations to yourself. Very difficult to say with the different noises on my car. Noisy makes you think it is fast!

Maybe the STi trumpet smooths the airflow too much and the MAF under-reads because of less central turbulence around the sensor due to more laminar flow resulting in lean spots? This was debated in Stephen Done's thread a few months ago in Drivetrain with an APS wing kit. Possibly the smoother pipework makes a contribution also.

[Edited by john banks - 1/5/2002 9:58:50 AM]