Celica Forums General Discussion Engine and Performance racing chip

Does anyone have a racing chip/ecu installed? If so how much of a performace gain is there? My friend had an old maxima and once he put the racing chip in, it was hella fast. The only racing chip i know about for celicas is the JET one

I hear they are just reprogram of original stock ECU chip. You have to send it in and they "reprogram" and send it back to you. Now I have seen article by people saying these people just send the stock chip back, but then I did not do any business with them before.
My buddys cousin had his A4 chip reprogrammed, before reprogram the car ran with turbo at 5p.s.i. after reprogram it is running with 10p.s.i. They also reprogram the fuel curve and raised the redline...

Some people were saying that they didn't see any gains for our celica's with the Jet ECU. It was on NC.org .