Originally posted by Corse-R
When I modify the timing on a determined engine I guide thru all the timing events via a degree wheel, but on almost all engines that I modified for people or myself are Novarossi based and their exhaust window sticks to the BDC (Bottom Dead Center), it's an easy way to describe it by their height (and thus, their timing too). For all the other events I guide by the degree wheel.
Many times when I mod an engine for someone, he asks/requests me some data regarding their engine. Sometimes by rules enforcement I need to stay under some exhaust port height (4.5mm) that's why many people (and I) sometimes we measure the port exhaust in milimeters.
It's just another tunning oportunity that you have on your car, unfortunately, with the advent of 'In-Line' pipes this adjustment almost ever is eliminated and goes fixed by the lenght that manufacturer wants. So if it's fixed is an adjustment you lose or an oportunity less to mess your engine setup.
After many tests I found that Novarossi In-Line pipe is a quite effective pipe for my kind of tracks, but when I need more bottom-end or mid-rpm I change it to an RB pipe that is quite satisfactory to me.
Like I said previously Isn't such a matter of how is modified the engine, there are many other places on your car to search for power (Tip: polish and port the manifold where connects to your engine, many times there's a restriction there).
About the pipes-what is the reason to put TUNED PIPE on the car if the lentgh of that pipe tunned for 36 '0000 rpm, but your car can't go that fast because of other reasons? You don't need that pipe at all. For my understanding car-engine it is one close loop system, which has to tuned together! If manufacturers don't make the pipe for your desired lentgh-make it yourself! But you will bring your RPM and torq on the range where you want to! Otherwise no need to polish manifold, take restrictions-any way your resonce tuning will not take effect at all. Just waist of valuable time! The tunned pipe means-lenght of the pipe in sound waive equal with sound waive of friquency from your engine. If they are not equal-no resonance, no effect!!!!!! Very simple, isn't it? Don't relay on pipes manufacturers! They make what bring profit for them! Play with pipe's lenthg by yourself!