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MAF placement

Posted: Sat Apr 03, 2010 1:03 pm
by Silver03Se
Has anybody done any experimenting with moving the maf into the straight portion of the intake, and jb welding the throttle body nice and smooth? if not, any ideas on why or why not.

Re: MAF placement

Posted: Sat Apr 03, 2010 3:27 pm
by 01bonneSC
What straight portion?

Re: MAF placement

Posted: Sat Apr 03, 2010 5:50 pm
by Silver03Se
the section inbetween the fenderwell and the little turn right before the throttle body. im just curious if any gains made by having a more symetrical throttle body would be worth the effort.

Re: MAF placement

Posted: Sat Apr 03, 2010 8:10 pm
by willwren
The MAF is calibrated for where it is.

Re: MAF placement

Posted: Mon Apr 05, 2010 9:09 pm
by Silver03Se
what would/could be done to calibrate that to either a new position and/or a jbwelded throttle body?

Re: MAF placement

Posted: Mon Apr 05, 2010 9:19 pm
by willwren
The MAF reads the amount of incoming air. If you trick it into thinking there's more, you'll just run rich. Your O2 sensor will correct for it.

The real game here is to INCREASE the amount of incoming air, then let the MAF sensor do it's job. The MAF sensor simply tells the PCM what's coming in, and the PCM uses that data along with the O2 and MAP (MAP for Series 2 only) to determine fueling. Inputs from the IAT and ECT are also used.

So you want to do something to the motor itself to increase flow, not move the sensor. And make sure the incoming air is as cool as possible, and that the IAT is reading the cool air temperature.

Re: MAF placement

Posted: Mon Apr 05, 2010 9:39 pm
by Silver03Se
thats why i brought this up. if the maf were moved into the intake pipe, and the throttle body were made symetrical. would the effort put into making the throttle body a clean funnel shape, porting it a quarter inch, aquiring some larger junkyard throttle plates and putting the die grinder time into making them fit. be worth the increase in flow numbers. and since the maf just *reports* to the ecu. what, if anything would need to be done to the maf calibration. im new to mass air meters,GM in general. i've always tuned with map, egt,wideband, and some rice!

Re: MAF placement

Posted: Mon Apr 05, 2010 10:08 pm
by willwren
Good luck fitting a new throttle plate to a ported TB with a die grinder. Just give that idea up now (trust me). Add more flow to the engine the proper way. A cam or rockers.

Don't fall for the myth that tuning is the way to power. Sure, you can get a little, but tuning is to adjust for REAL changes to the engine itself. Want more flow? Port match your LIM. That's the major restriction on the L36.

Re: MAF placement

Posted: Mon Apr 05, 2010 10:18 pm
by Silver03Se
any benefit from making the UIM breathe better? I have to tear it all apart for the manifold gaskets, and would like to do all this freebie stuff while its tore down. Thinking about the rockers too.

Re: MAF placement

Posted: Mon Apr 05, 2010 10:26 pm
by 00Beast
There really isn't much to port on the UIM. You could try an HVIII insert, but you might have issues with the fuel rail fitting.

Re: MAF placement

Posted: Mon Apr 05, 2010 11:08 pm
by willwren
Port the LIM, leave the TB and UIM alone. The LIM is by FAR the biggest restriction on the motor.

Re: MAF placement

Posted: Tue Apr 06, 2010 7:51 am
by Silver03Se
Thanks