Yamaha FZ-09 Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
58 Posts
Discussion Starter · #1 ·
I like to race 1/4 with my fz-09 .... I just installed a akrapovic carbon exhaust, and I wanted to know...... for win mph, what sprocket I need to change?my best speed on the 1/4 is ... 122.09 mph, by changing the sprocket is what I could gain speed? sprocket and what I should use

thank you
 

·
Registered
Joined
·
62 Posts
You can take a 17 front sprocket. (instead of 16 origin)
Logically you should rise 130.

Or you can change the rear sprocket to a 42 (instead of 45 origin) but it's more expansive.

And in both cases you will read the true speed on your speedometer, whereas now you have a 7% error.
 

·
Registered
Joined
·
2,330 Posts
If you are drag racing the FZ09 you need to eliminate the speedlimiter and to do that you need to have your ECU reflashed.

You have an exhaust so you need a reflash as well or the exhaust is a waste of $ as far as performance goes.

Once you eliminate the speedlimiter you can put a bigger rear sprocket and/or a smaller front sprocket (shorter gearing) to increase your acceleration. In either case your top speed can be increased over stock and how fast you get to that top speed will be increased.

If you just want more top speed, then adding a tooth to the front and/or dropping a few teeth on the rear will increase your top speed but reduce how fast you accelerate.
 
  • Like
Reactions: triplethreat

·
Registered
Joined
·
3,079 Posts
Top speed won't change by much regardless what you do IMO. What you can improve is how fast you get there. Shorter gearing is the way to go. F-1 & R+2 is available if I'm not mistaken. The problem with the 09 is to get out the box and keep the front wheel on the ground. Maybe a custom flash could help at limiting the throttle input in 1-2nd gear so you can just go for it without having to correct the throttle has you go or having a better sensitivity. Quickshifer with that too... If you go short enoughight be good to test 2nd gear take off.
 

·
Registered
Joined
·
315 Posts
Top speed won't change by much regardless what you do IMO. What you can improve is how fast you get there. Shorter gearing is the way to go. F-1 & R+2 is available if I'm not mistaken. The problem with the 09 is to get out the box and keep the front wheel on the ground. Maybe a custom flash could help at limiting the throttle input in 1-2nd gear so you can just go for it without having to correct the throttle has you go or having a better sensitivity. Quickshifer with that too... If you go short enoughight be good to test 2nd gear take off.
The quick shifter is the way to go for sure. Gearing tighter, as you said, will make it even more of a handful off the line. Leaving in second gear with tight gearing, might be fun.

Tighter gearing, also has the distinct possibility of having the bike, simply blow through it's pulling range too quickly (using 1st gear), resulting in a slower time, not quicker.
Been there, done that, on other bikes.

Taller gearing, may tame things down nicely, out of the gate.

Looking forward, to seeing what you come up with, gearing wise.
 

·
Registered
Joined
·
4,444 Posts
My brother use to have a 1/4 mile race car. It wasn't always the top speed that improved his overall 1/4 mile time. Often it was how good you hooked up on your launch off the lights and how fast you got out of the gate. He often beat guys with higher tops speeds because his car launched faster and he was able to control any excessive wheel spin off the line. His top speed was very consistent, it was his timing off the line that really made the difference.

A lot of the good guys he raced with all knew that it didn't matter how much horsepower you had under the hood, if you couldn't get that horsepower to stick to the ground.
 

·
Registered
Joined
·
123 Posts
I'm with the thought that the last thing the FZ09 needs is Lower gearing off the line.

Remove the ECU limits, and add one tooth in the front, and you would have a bike that is less prone to wheelie, and has more to offer on top slightly. (Not that in a 1/4 mile it's going to be all that different, it's about how you can keep the bike hooked up off the line, and the front wheel down where you do not have to back off the throttle significantly.
 
1 - 9 of 9 Posts
Top