Just out of curiosity, I was thinking about removing the STCS (Secondary Throttle Control System) on my 03 Gsxr 1000. Has anyone done this before? If so did you see postive or negative gains. I know its there to regulate air flow at certain speeds so you gain the maxiumum horsepower out of each gear, but if your wide open a lot, does it really make a difference if you keep them on or take them off? Any thoughts?
Leave it.
Bikes need to be tractable.
Leave it unless you have a problem. Again, I am not sure about the new model, but the '01-'02 models occasionally had a problem where the secondary butterflys would quit opening.
You may hear about racers safety wiring the secondary butterflies open. I did this when I had that problem. The only bad part is that it then causes an error code to constantly be on on you dash. This is no big deal except that if you get another error code, you will not know it because it flashes the same FI error for all errors. (unless you hook it up to get the actual FI error number) I then un-safety wired them and just un-screwed and removed the secondary butterflies.
With that being said... I agree with Super Dave. They are there for a reason and you are going to need all the tractability that you can get. I also don't think that you will see any benefits from removing them. Unless the quit working obviously. I would not mess with them unless they cause you a problem.
Cool I figured that, I just wanted a 2nd, 3rd opinion, cool guys thanks
With the Yosh ECU I ran last year on my 03 1000, it disabled the Secondary butterfly and left them wideopen all the time.
I did back to back dyno runs on my model 250 dynojet dyno in a controlled setting within a few minutes of each other, making sure I did several pulls with each ECU to make sure I was getting repeatable results.
The YOSH ECU did produce more power in a desirable manner. I don't have time to post dyno runs till after daytona though.
I would assume, but have not tested with the stock ECU, that you would see similar results wiring the Secondary butterflies open or removing the plates with your stock ECU.
Although, to be sure if you have time, dyno test it.
I did not notice any problems with acceleration or traction out of the corners against any other 1000cc bike I was on track with. But hey, I was on a 1000, it can spin up the tire if you let it.