VersaTune User Forum

Hi, my name is Darko, 41 years and i am from the Netherlands.

Bought myself a Mazda 3 MPS/Mazdaspeed about 3 years ago in Switzerland. Bought it with no running engine. I am a car mechanic so fixed it and it's running perfect now. Recently replaced the downpipe for a catless one and yesterday purchased the versatuner. Planning to do some more mods but for now i would like to see what a catless dp can do with the right tune.
Can anyone tell me what tune i can use?

Darko

Do you have a gen 1 or gen 2?

Gen 1

Hey Darko! From my experience you can use any of the tunes from the existing database made for a race pipe. I know that in the tune description is stated that the factory DP is required, but since the secondary cat is the most restrictive (and the OEM downpipe is good for well above 300bhp with the right turbo) the wastegate duty settings are pretty much spot on.

Hi Mituc!

Thanks for the reply. I will try one of these tunes within a couple hours. My obd cable will be delivered any minute
Do you know if my check engine light will stay off with one of these tunes? It's on now because of the catless dp. Any ideas how much bhp i can expect minimum?

The check engine light will stay off if you suppress the code from the tune settings: when you flash the tune click on Edit Settings -> in the first/default tab (Special Features) enable smooth shifting, NLS, LC and megaspool for both, switch to "Disabling DTCs" tab -> check the "I have read [...]" box -> Advanced -> and disable 0421 PID. Flash the tune and then you will see if any other code will pop up, and at the next tune flash you can take care of that as well if it's a code that needs to be suppressed because something you removed from the car and not something that you have to address as a defect.

It's hard to predict the power because as I learned over time every car is different: the engines have different wear, the injectors have different wear/clogging state, the piston rings seal a bit differently even if the engine is otherwise ok, the intake valves clogging has also a big role in air intake, the drivetrain losses (gearbox, bearings, sticky brakes) are different, the missing or improperly fitted/positioned panels can generate drag, and so on. With an off-the-shelf (OTS) tune wen can expect anywhere between 250 and 270bhp, up to 280-285 with a high-load version (usually around 260-270, but you never know). And with a custom tune on a setup with fuel pump internals you can reach 300bhp with the exhaust mods you have now (you can, doesn't necessarily mean you will).

If you want I can help you with a virtual dyno sheet. You said you have a 3MPS BK, so please use this dashboard preset:
https://www.dropbox.com/scl/fi/55qyxbqs ... rrg5x&dl=0
load it from your versatuner -> Dashboard -> presets -> import and then click the Load button, log 2 pulls in 3rd (ideally 4th gear if you have a proper road to accelerate up to 160-165kmph), then upload the logs somewhere and I can run them through virtual dyno for you.
To have a clear point of reference you should take two similar logs with versatuner before you even install VT to your car's ECU. this way you will see what your car did before flashing a tune to it and what it does after, with the same modifications.