So, I know this question comes up from time to time, but I figured I'd hear it from the master-class tuners on 2strokeworld. I hear a lot about Stage I, II, III, and sometimes even IV. But, those numbers must mean methods of complexity and work performed in some aspect right?
What are the goals of the stages, and the what do they usually accomplish?
I kind of just have 3.
STG 1 is a mild build with stock or smaller range carbs like 30's on a RD. more torque under the peak power.
STG 2 is more maxed out with more aggressive power, bigger carbs up to 34's, keeping them still reliable with forged pistons with a higher HP
output, more expensive parts to buy to support sustained higher RPM's.
Then a full race with much narrower powerband but more HP with much more aggressive porting, intake system, custom made chambers and using 36-38mm carbs, race lightweight magneto ignition, setup in a stripped race chassis.
Chuck
Stages just give us reference points that both the tuner and the owner can relate to while deciding whats best for the owner. When someone asks about porting I say I've got 4 stages:
Stage1 To me is what Yamaha would have liked to have done if they could go back and update these cylinders while still retaining the stock ex port height they designed it with (well within .5mm for cleanup). Unlike many tuners that don't do much on their Stage 1 I believe a Stage 1 should really be a full port job. (I don't do buff and fluff meaning I don't believe in just making your ports shiney and handing your cylinders back to you..)
Stage2: Is Mild Street Porting
Stage3: Is hot street porting (This would be just below Roadrace porting)
Stage4: Is Roadrace porting.
Additional options you have are:
If the cylinders have ex bleed ports to plug these and weld them up (this is worth 1.39hp per cylinder)
To weld-up stock ex gasket area
To open up the intakes for larger reedcages
Dragrace/Landspeed/All out porting is a subject all to itself.
You run across guys every once in a while that will say they don't use "stages" or that "they tailor their porting to the customers specific needs" but we all do that.. every tuner that's done A LOT of performance builds has their goto specs they've developed that they know work well for 3-4 or even 5 "levels" of performance and then we just tailor in between those for guys that want a little more or a little less of this or that. Ed