VersaTune User Forum

Hello everyone, I have bough my Mazda with both catalyst converters tanks empty and now I am running high load tune.
I wanted to ask if I will encounter any problems or downsides, because on tune description it says that stock downpipe is required?

A catless downpipe will have less backpressure and the turbocharger will spin up faster. As a result it may overshoot the boost targets. The ECU will correct that eventually, but you might see boost spikes on turbo spoolup.

Also, that faster spool maybe problematic without upgrade fuel pump internals because there will be moments when the fuelling system simply can-t keep up with the fuel demand. So you should also consider that.