[Saul54]

If your bike is a US spec SC77, you should take this opportunity to get the Exhaust Servo error code flashed out of your ECU as well as remove the top speed limiter and throttle restrictions that restrict the bikes power.

The slip-on is going to result in a small loss of power in the low to mid range and when coupled with the stock ECUs existing restrictions will actually make th ebike a little slower overall.

But it will sounds as cool as hell

 

[Saul54]

So if you get a slip on exhaust and a ECU flash, will you still lose low to mid range power over the stock exhaust?

Over a stock exhaust tuned bike?
Yes.

 

[Saul54]

Stock exhaust with factory tuned, off the show room floor.

Odd comparison.

Stock US bike is restricted.
A tuned slip-on US bike is not restricted.

But a slip-on tuned US bike will lose low end compared to a stock exhaust tuned US bike.
The exhaust servo is not only a noise management tool, it provides back pressure at lower revs.

Personally I would not even go for a slip on, I would just tune a stock exhaust bike, then a future date go full tuned length header exhaust system and get sound and over power curve change.

But that's just me yeah

 

[Saul54]

The fueling has nothing to do with the loss of low end. The loss off low end is due to the loss of the exhaust servo.

 

[Saul54]

About 6500rpm. And no doubt its double duty is to keep the noise down in the lower revs, but it has the added advantage of acting like a tuned length valve - I bet all the bike OEMs claim that's why they install them, but is was probably easier to install them as a general catch all for noise and an added bonus of low end performance.

I suppose the ideal setup might be a full Ti system with an exhaust flapper to offer the best of all the worlds.

And the loss of power is not crushing by any means, but some people do notice a bit of a hole in the power lower down and others that just rip through the mid range could not care any less about the 'drop in mid range'.

 

[Saul54]

Extra noise always feels faster so it can be a budget seat of the pants power up lol

 

[Saul54]

Back in 1993 I bought my first superbike, a 1992 Yamaha FZR1000.

It had an EXUP valve (exhaust ultimate power valve) for the exact same back pressure reason you mentioned.

Bit surprised Honda is using 24 year old tech but it still works.

Everyone had to wait for Yamaha’s patent to expire.