I got an 07 Si.
and 5th takes me to 131~132 if i redline it
and 6th goes up to 135 then governor kicks in at 135.
Interestingly enough, it climbs prity well in 6th to 135, and governor kicks in at 135 which is exactly right before 6k rpm's which is the stpck vtech point for my 07 Si. therefore I'm curently looking to buy another ecu to have it reprogramed.
(wana keep my stock ecu for waranty isues, i got 75k waranty)
i'm prity sure that if governor could be removed, that 6th gear with another 2k rpm's before redline would definately pull in for good 10-15 aditional mph.
or possibly more. (never bothered actualy calculating mph/rpm by using Si's 6th gear ratio).
In short, I'm sure this car with removed governor, could pull into 150's

(keep in mind, my car is completely stock. not even a filter)
(also keep in mind that i found out that Si's with their stock 17's are slightly lighter then the optinal factory 18's)