I simply deal in real world results, not just a peice of paper telling me how much power I have. If the tach reads low on rpm and my clutching is the same as before, then I dont have what was sold to me,wether its a aftermarket part or engine work, whatever. The whole case in point here was the guy gained rpm by going back to stock yamaha exhaust.... so he gained power,thats what tachs do they show you gain or loss very simply.
Always alot of spinning of information,just like in politics here with some people to try and "prove" thier product or way. It gets hostile and accusatory when thier paper proof doesnt hold up to infield testing, like pulling more clutch weight, gain in rpm, more speed,etc.
Like the srx stage tuning, back in oct/nov 98 amsnow magazine, written by terry paine. Hmmm, a article written by the owner back then, on thier products, dyno results from the same owner,not a independant facility. The dyno charts tend to NOT show you key peices of information like coolant watertemp,air quality, just what the added on products gain on a base sled. Anybody can produce large numbers on dynos by doing cold runs,and other tricks to artifically add some increase in results.
Going off whats in print, a silencer,cold air kit they report a best run of 145.8hp at 8300rpm,then silncer,coldair,and reeds netted 148.3@8300. They report in the article that porting will give a solid gain of 15hp alone,and thier recorded run with silencer,cold airkit,and vforce reeds,porting got them a run of 157 hp@8500, whoops... thats only 8.7hp gain,not quite the gain printed. This is what I am talking about. Read the magazine article for yourself and make your own conclusions.
I no where said jim isnt any good, theres lots and lots of excellant dyno facilitys in the country, not just in New York. I couldnt agree more that its great to check work on dyno's,its a great tool to tell you if your going the right way while developing something but if it doesnt perform in the field, a dyno queen isnt worth the ink on the paper its printed on when your buddy just beat you with a stocker. Do your own research when looking at aftermarket products,work, see who and what is performing in the field. Make your decision on research,dont always go for the dyno sheet sales,youll not get all youve paid for alot of times!