GSXS1000 Exhaust Valve restrictions
On this page are examples of GSXS1000 Exhaust Valve restrictions from different ECU’s, some from different countries, some form the same. This can only lead me to the conclusion that the exhaust valve is there solely for Noise Restriction tests in different locations.
The GSXS1000 has an ECU controlled Valve placed in the collector before the cat, see here for exhaust details
I chose 4 different ECUs – all from 2015/16 (will do 2017/18 later)
K00 is EU/Australia
K51 is USA/Canada
K61 is Japan
K81 is USA/Canada
All the bikes have the exhaust valve fully open above 6800 rpm but below are very different
As can be seen below in K00 and K51, the exhaust valve is fully open at all rpm below 12% throttle but close down to a minimum of 77% at max throttle at around 5000rpm where many noise tests are done.
With K61 and K81 the exhaust valve does the same at high throttles (i.e 77% at 5000rpm) but also closes completely at 2800 – 5000 rpm at less than 10% throttle
In first gear the map is almost identical to Neutral except for the fact that K61 and K81 have the exhaust valve open 68% from 2000rpm to 6000 rpm and then closed completely from 3% to 13% throttle from 2000 to 6000rpm.
2nd gear is exactly the same as 1st gear
Interestingly 3rd gear is the same on every ECU.
68% open below 6000rpm at below 3% throttle, completely closed from 3 to 13% throttle below 400orpm, then open 60% at 14% throttle falling to 12% open at full throttle up to 5000rpm
4th Gear is similar to 3rd Gear, except the exhaust valve is 100% open at below 3% and 40% open until 13%. K61 is lightly different with higher restrictions at high throttle positions
5th Gear is identical on all ECUs, this time most restrictive at full throttle and very little throttle
Very similar to 5th Gear