Well, from my basic understanding of hi-performance engines, exhaust tubes can be tuned as follows:
smaller primary tubes help in the areas of low-end torque, but tend to somewhat restrict high-end flow. The reverse is also true: larger tubes aid in high-rpm/gas volume flow, but might hold back low-end torque. So in the 2000-5000 rpm range, you might drop 5% with the large tubes. Above 5k, larger tubes might give back 5-10%. Again, these numbers are just speculation, as you would have to do a dyno test and get the charts. >From previous messages, we can see that this seems to be true of the GTS, FZR's etc., where the GTS has smaller primary tubes and the other bikes the large 34.5 mm tubes. My gut feeling is that going to a non-cat 34mm system might yield another 10% power increase, assuming the computer can compensate. EFI systems with an oxigen sensor can usually compensate for intake/exhaust system changes up to about 20% of flow with no modifications. My preference as this point would be larger tubes. -----Original Message----- From: Derek Baylor [mailto:[EMAIL PROTECTED]] Sent: Wednesday, July 10, 2002 6:32 PM To: [EMAIL PROTECTED] Subject: aftermarket exhausts Here's a question for anyone in the know about fitting aftermarket exhausts to the GTS. I'm interested in in completing my Renegade system by buying the downpipes and collector (I already have their muffler). If I open up my exhaust that much--by having removed the restrictive stock muffler and ditching the cat. con. altogether--might I risk drastically changing the power characteristics of my bike? I suspect I'll pick up some top-end oompf, but will I sacrifice mid-range grunt, or risk making the choppy throttle response even worse? Can the GTS injection system keep up, or will I be running dangerously lean all time? Anyone out there have a full aftermarket system and can speak to the changes, or at least have some strong theoretical knowledge to share? Thanks. -Derek The information contained in this e-mail including any attachments may constitute Corvis Corporation Proprietary Information that is subject to Non-Disclosure Agreement and cannot be disclosed to any other party without the express consent of Corvis Corporation. If you are neither the intended recipient of this e-mail nor responsible for delivering this e-mail to the intended recipient, note that any dissemination, distribution, copying, or retention of this e-mail is prohibited. If you believe you have received this e-mail in error, we request that you notify the sender by return e-mail and then delete this e-mail and any return e-mail immediately.
