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Engine / Transmission De-Restrict Air Box


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Senior Member
Gazza submitted a new resource:

De-Restrict Air Box (version 1.0) - De-Restrict Air Box

Parts needed
No.20 Torx bit (star shaped) Flat bladed screwdriver. Pair of long nosed pliers New panel filter (k&n,pipercross,etc)

Why do This Mod?
Inside the standard air box there are two pipes that restrict airflow within the box. Removing these Pipes will make the engine more responsive, and may liberate a few BHP in the process – especially When done in conjunction with an aftermarket panel filter and the Vectra C Inlet Pipe mod see other guide on veccy c mod.

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Has any one actually done a before and after on a rolling road to prove this mod??

I only ask as similar mods were suggested on the Opel manta GTE's and when I actually tried it on the rolling road I didn't gain/loose peak power etc but lost a little mid range torque.