Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Plex Knock Monitor on 2000-2005 STI

General Tuning Discussion

Forum Posts



Tech Articles

Discuss all things tuning in this section. News, products, problems and results. 

= Resolved threads


Hey guys,

For anyone thats set their plex knock monitor up on a 2000-2005 year Subaru STI, a couple questions:

1.) Where is the best spot to mount the plex knock sensor?

2.) What bore diameter did you select?

3.) Does 1st harmonic give best results or 2nd harmonic?

4.) Which audio filter gives the best result?

Thanks in advance!

Anyone ??

1: the "best" place would be where the factory knock sensor is located - the second best place is where you can attach it to the engine (head, intake manifold, block somewhere)

2: google says the bore diameter of the engine (2002 sti) is 92mm (https://www.carfolio.com/subaru-impreza-wrx-sti-97163) theres some other good specs on this page for the engine and chassis (frontal area etc for those desktop dyno programs)

3: test and see - make the engine knock at low load and rpm so the monitor will "see" knock and then decide if you use 1st or 2nd harmonic - depends on the engine, the sensor and the monitor used

4: the one you can "see" the knock clearest with (see 3)

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?