MAXBORE unit 75 to 78mm.
I have two 05 coupes a SRT and manual NA, both with the single CAI. Last year I got a 75 mm TB to upgrade the NA but decided to send it to MAXBORE and have it modified. He fluted and bored it out to 78mm, it looks nice. The plan was put it on the SRT and use the stock 75 on the NA. I put it on the SRT and the car ran terrible, I had read that the computer needs time to adjust but after driving around the parking lot it still would barely run. I pulled it off and went back to the stock 75 mm TB. The car still ran terribly until the codes were reset.
So I have this 78mm TB and I am thinking that the stock engine can not pull enough air for it to work, but maybe a modified engine with the smaller pulley that moves more air might work. So would someone with a moded SRT like to try it and see if it produces more power and works with the higher power engines. I plan on putting on a smaller SC pulley in the future but right now just doing suspension work, so would be willing to send this for someone to try and if it works then swap for a stock 75 to put on the NA. If it still not working right maybe it is the electrical pat of the TB that is not working.
When you change your throttle body to a larger one you should force the computer to relearn by doing this:
Turn the Key to the "on" position (the position right before you start your engine)
Press and hold your gas pedal down for 5-10 seconds
Turn Key to "off" position (don't remove the key) and then release the gas pedal.
than wait at least 2, if not 3 minutes, for the system to reset.
If done correctly you will hear some clicks coming form the throttle body as it relearns and adjusts. And of course if you are at the maximum threshhold (due to your other mods) of your current ecu calibration then a re-tune is required. I do this upgrade on my slk32s all the time along with turned down (74mm to 69mm) sc pulley and high flow filters, and never had to retune, computer is able to adjust for the difference, although we do that just to accomodate better performance and more hp. and we always do the throttle body reset/relearn procedure, so the ecu knows its gonna get different readings.