RomRaider

Crude attempt to model AVCS (Intake only) and how it affects overlap and dynamic compression.
Clicking within the AVCS map will update the graph with the AVCS value so you can see how the cam lobes interact.
The default data came from Wikipedia and the 02 STi service manual. AVCS map from Carberry.

V2: Compare cams. Default data is ej207 vs ej205.

V3: Added Piston Position. Guess that is what valve reliefs are for

Very nice!
Is that the ADM EJ207 motor by some chance?
I'd love a revision where Its clearer for simpletons
(Who aren't familiar with the equations behind the scenes) to plug in the values for their engines on the "Specs" page

I pulled the specs from an 02 STi FSM (I don't know how different the EJ207's are from region to region), as well as the Wikipedia specs page, well within anyone's reach.
Most of the equations and inspirations came from the following sources, hopefully they'll be useful to you:

http://www.popularhotrodding.com/tech/1309_how_to_pick_the_right_camshaft/viewall.html
http://www.team-integra.net/forum/blogs/michaeldelaney/65-compression-ratio-explained-static-dynamic.html
http://www.crankshaftcoalition.com/wiki/Dynamic_compression_ratio
http://cochise.uia.net/pkelley2/DynamicCR.html
http://www.theblowershop.com/upload/Downloads/Effective_Compression.pdf
http://www.xcceleration.com/cr-boost%20101.htm
http://www.epi-eng.com/piston_engine_technology/piston_motion_basics.htm

V2: Compare cams. Default data is ej207 vs ej205.

V3: Added Piston Position. Guess that is what valve reliefs are for

Getting to be a very neat tool!

Wouldn't the port velocity change depending on manifold pressure and/or VE?

Imagine if you could calculate the air stall speed.. You'd be able to get a near perfect AVCS map!
Might be a little out of Excels capabilities lol.

whoops, that shouldn't even be there, that was something I was working on, I don't think the math is even close to being correct...

I would suspect without too much work, this could be altered to show injector timing compared to AVCS
That way you could show graphically how altering the AVCS against the stock injector timing effects spray position relative to valve position

It could end up being a great tool to tweak injector timing to match the factory spray position! It's simple to tell people for added AVCS, remove injector timing by same value (which only works if you use the same MAP and RPM values!

Was actually following that thread and thinking the same thing. I might check it out this weekend...

Ok, need some ideas. I've got the injection start time from the ROM, what I don't have is the ipw. I might have some calculations that I can use to guess a pulse width based on a ton of other stuff, but this is going to get complicated real fast...
Alternately I guess I could provide a table with user supplied values from logging. Then all I need to correlate is the injector closing event in degrees based on rpm.

Before you do that.. Your skills are required On the injection timing thread

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