After a lot of track time this season I notice that my control system seems to stick in twin mode when I think it should be switching back to single mode. I know that there is some time delay and rpm range where it will stay in twin mode after switchover, but mine is extream, if I rev past switchover (4500 rpm) and switch gears, it stays in twin mode, even if the rpm drop below 4500, even below 3500?? stays in twin mode.... only after a long sustained non boost run or a very low rpm drop, will it release to single mode.

Any suggestions ono how to fix this, it is killing my track times cuz i sit in twin lag half the time :-(

 

I have the same problem I can tell by the exhaust note. It has to be the TCA. Maybe with age it or the flapper starts sticking.

 

hmm, possible the TCA....when I get a chance I'll have to do some diagnostics on it and make sure its not sticking ... how many miles on your car, im at 40K