Tuning Thoery..., Muffler, timing, engines, fuel pressure..... Options

[soulshadow]

I was tuning the celica yesterday and I found some pretty intresting facts.
I have a Magna flow exhaust with a 4" opening, without the silencer it is very loud, but when vvt kiks in from the 4age 20V. You can feel the torque, however with a silencer on the torque'y feel is not there anymore when vvt kiks. Nontheless, response is much far greater with the silencer vs a wide open exhaust.

So, in my theory muffler does matter and it does effect performance. Im thinking about buying one of those mufflers with an adjustable silencer where you can move it to certain decibals and perhaps I can tune it for a faster response with better torque.

Adjusting timing when VVT kiks is a really hard one to adjust, because its never at 0 TDC, its either advanced or retarded.

Any suggestions.