Okay so you throw on a downpipe, a new/modified air intake and you are probalby ok. When does the line get crossed, new cat back, new intake pipes, single turbo...... Is it better to just upgrade your ecu and let the pieces fall into place? Given that most can not afford to spend thousands in one shot what makes sense? For me putting the downpipe on was a purely logical decision to do first. Should most new owners opt to trade out the ecu first to avoid the pitfalls of mods that the engine can not handle? Last one to ponder is that if you expect to drive the car in a normal fashion - not racing - what ecu makes the most sense?

 

Just keep it to 10 PSI if you want longevity. Use a boost controller.

If you plan on going single or running any more boost than the stock levels pick up an aftermarket ECU.

 

midpipe is one thing that draws line.. with a midpipe you will get boost spike and probably pop your motor.

 

The stock ecu supplies enough fuel at 10 psi to run any mods short of a single turbo. However, the timing might be too advanced for all the bolt-ons (for best longevity).

To run over 10 psi, you need an aftermarket ecu. Period.

FWIW, I am running an intake, SMIC, downpipe and cat-back on the stock ecu (with a boost controller to restrict boost to 10 psi). Absolutely no problems so far. Who knows though. I might get a slightly off tank of gas and the more advanced timing of the stock ecu may cause detonation. It hasn't so far.

 

Midpipes I am pretty sure are kinda a off limits mod until you get a ecu.

 

Try this web site lots of good info:http://www.newwave.net/~flanham/wlan.../3modrule.html

Also if you are thinking of running a midpipe with a downpipe and a cat back you WILL need to upgrade your fuel system.