Go Back   986 Forum - The Community for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

 
 
LinkBack Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 12-12-2017, 05:36 AM   #13
Motorist & Coffee Drinker
 
78F350's Avatar
 
Join Date: Jul 2014
Location: Oklahoma
Posts: 3,941
Garage
A bit of a side discussion... In very simple terms a resonator (that extra appendage looks like an extra resonator) increases the volume of air in the intake tube without making it flow farther. In doing so it acts as a buffer for the vacuum.
In more precise language:
https://itstillruns.com/air-intake-resonator-do-12156112.html

Deeper still is the discussion of intake runner length. A few years ago I was swapping an SUV engine into a small car and noted the SUV had a much longer intake. In simple terms, length mainly effects where the torque peaks in the power curve. Longer tubes make the torque peak sooner:
https://mechanics.stackexchange.com/questions/25236/how-does-intake-manifold-runner-length-effect-the-power-curve-of-a-car

Then there's the 2000 and later M96 engines with the cross tube and resonance flap that can spread the torque peak across a wider range:
Quote:
Originally Posted by 78F350 View Post
...
Quoted from: http://press.porsche.com/archive/products/press_kits/press_kits_2001/PDF/Boxster_in_Depth.pdf

"The Boxster inherits its twin-resonance air induction system from the 911
Carrera. The system acts as a “resonance supercharger,” allowing the engine
to draw from higher velocity airflow at certain engine speeds. A crossover pipe
connects the individual air collector/resonance chambers for each cylinder bank.
A flap in the pipe remains closed from idle to about 3,100 rpm. When it opens,
each cylinder bank can draw from airflow “excited” by the resonance created by
alternating induction between all six cylinders. In essence, “dual resonance”
creates two induction paths for each cylinder. Below 3,000 rpm, the cylinders
draw air from a “short” path. From 3,000 rpm to about 5,100 rpm – when the
resonance flap opens – the cylinders draw from a long intake path, which
boosts torque. Above 5,100 rpm, the flap again closes to allow the cylinders
to draw intake air from a shorter intake path to boost horsepower at higher
engine speeds."
__________________
I am not an attorney, mechanic, or member of the clergy. Following any advice given in my posts is done at your own peril.

Last edited by 78F350; 12-12-2017 at 05:38 AM.
78F350 is offline   Reply With Quote
 


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 01:05 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page