maf and throttle body diameter

[Homeboy981]

Here's my version of the Cold Air Intake system.

This is Stage1 - using factory air tubing with MAF in factory location and HUGE air filter!


Large Conical Air Filter - it is 6"X11"...


MI Stage1 uses the mesh "screen" from Factory airbox...


You can see the Air Filter peeking through the Factory Side Intake...


This picture is hard to see but a lot has changed from the Stage1 configuration….

1). The MAF housing has been moved to 1" before the Throttle Body
2). Using a Honeycomb Filter to straighten airflow.
3). Using larger diameter silicone tubing - 4" to 3.25".
4). Although it looks rough on the outside, the inside diameter is SMOOTH.
5). Computer has adapted and I am getting SAME GAS mileage as i did BEFORE change, i.e., 22 city and 26 highway - under not-so-gentle acceleration. Average is 350 miles out of a tank.

LOVE the extra power, especially over 4200 RPM. It flies over to the redline now, instead of loping along to the redline.

Getting a Cat Back exhaust system today so we'll let you know how much she feels after "setting the engine FREE"! Love the car now with more power!

Would highly recommend. It DOES take time to get the intake right. If you need designing yours….PM me for details.

Thanks to everyone who helped!

The Downside: I need new tires now!

[shadrach74]

Originally Posted by Homeboy981

Computer has adapted and I am getting SAME GAS mileage as i did BEFORE change, i.e., 22 city and 26 highway - under not-so-gentle acceleration. Average is 350 miles out of a tank.

Wow, I've never gotten mileage like that... Granted, I have a heavy foot...but the best I've done on a tank is 19.5mpg.

[Speedster986]

See my current thread "Typical MPG for a Boxster" under "Performance and Technical Chat".

The strange part of it all... I conducted the upgrade to satisfy by thirst for more HP and ultimately ended up with a "win win" situation!

Since the upgrade in November 2012, increase in performance (NO CEL) has truly been remarkable. My stock 2003 2.7L pulls extremely hard to red-line, improved throttle response & Porsche note enhanced.

Next on my list of modifications for my STOCK 03 2.7L will be to increase the size of the stock 'T' shaped plenum, TB (68mm to 74mm), air tube from the MAF, which will further UNCORK this engine.

Trust me... where I live 91 Octane fuel can average over $4.65 per gallon (soon to be $5.00), so any improvement in engine performance & efficiency is a huge plus in my book.

Typical mileage: 20 to 23 City 35 to 37 HWY (results from 3 months of monitoring via Porsche's on board computer).

Comments Welcomed!

[Speedster986]

Homeboy-

Now that your mods have running for a couple of months now... how are things running, newly realized issues or concerns?

Can you provide me with a 'final parts list' for this setup.

I'm currently modifying my 2003 2.7L Boxster, so I'm very interested in your design, especially the new MAF location (near TB).

Thanks!