Worth more, RSRBOB, because you have adequately explained why / how the engine SYSTEM works and why messing with one part probably will not improve the target without substantially changing the other 2 parts and spending copious amounts of money. That's certainly one reason why I tend to stick to "stock" as far as the engine system is concerned.
Regards, Henry S. Winokur 94 GTS1000, AMA, MRF, Nationally Certified Riding Instructor Columbia, MD Ride for Kids Task Force West Bethesda, MD USA > -----Original Message----- > From: GTS-1000 Owners List [mailto:[EMAIL PROTECTED]]On Behalf > Of [EMAIL PROTECTED] > Sent: Friday, July 12, 2002 10:31 PM > To: [EMAIL PROTECTED] > Subject: Re: aftermarket exhausts and other tidbits > > > You guys are getting on the right track with the exhaust systems. The > statement that small tubes are for bottom end and large tubes are > for top end > is correct. One other thing you have to keep in mind here.......... an > internal combustion engine is effectively an air pump. Its > efficiency/horsepower is dependant on the volume of air it is capable of > moving. Here is my point, overly simplified. you have three basic > componenants to the engine, for the main purpose of processing air. The > aspiration system, the cylinder head and the exhaust system. > Increasing the > flow in any ONE area may or may not yield a gain in perfomance. > Here is why. > Put numbers to each componenant. Air volume flowing is measured > in cubic feet > per minute. In a perfect world, all componenants would flow > exactly the same > volume of CFM. In the real world, such is not the case. There is always a > bottleneck, so to speak. Example, say your intake flows 150 CFM, your head > flows 100 CFM and your exhaust flows 200 cfm. Increasing the exhaust or > intake flow would yield no increase in performance because of the > bottleneck > at the rate of flow the head has. In performance engine building, > they just > constantly chase the weakest link. Improve head flow above exhaust > capabilities, build a better exhaust. Got the good exhaust now? > Intake wont > keep up, improve the intake. Intake flows more than the head? > More headwork. > On and on. My point to all this is that not only are the exhaust tubes > smaller on the GTS than the FZR, so are the injectors, compared > to the size > of the carburetors on the same year FZR 1000. The reason they > chose smaller > sizes was indeed to boost low end and midrange ( read that > usable) horsepower > for sport touring riding.Smaller tubes increase velocity at lower > speeds but > obviously dont handle the volume. To get the same velocity in > bigger tubes or > carbs/injectors, obviously, you have to be turning more RPMS to obtain > similar efficiency. My other opinion on a company that produces a > perfomance > product dyno'ing it themselves is buyer beware. Dyno's themselves, esp the > less expensive brands, say under $15,000, are quite easily > manipulated to get > favorable readings where you want them. We are cuaght in a bit of a > vulnerable position because we are not going to be seeing any > magazines doing > independant testing of a NEW HEADER for the 1993/94 GTS 1000 > Yamaha. Further, > you can not see what your buddies are using and what works for > them, or what > seems to be the hot pipe at the race track. Within reason, bigger > pipes will > flow more, and if they are all about the same length, it should > work and be > an improvement to some extent for top end horsepower. Whether it > is worth the > money/effort to obtain and install becomes very subjective. > I think all that rattling was my $.03. > RSRBOB >
