Breaking in S4 13B on Base Tune
 

So I've been rebuilding my motor and it's current spec is as follows.

Pineapple racing "large" intake street port
Pineapple racing "EP2A" exhaust port.
Stock injectors
S5 Turbo

Motor is freshly rebuilt with all new seals and everything.

So I planned to install a megasquirt as well (MS3pro) to run this motor and give me more flexibility down the road.

Should I break-in the motor with the megasquirt installed and just use the base tune from aaroncake?

Or should I reinstall the TII S4 ecu (I'd have to find a new s4 TII harness) and break it in with the stock ecu.

My initial inclination was to go with the Megasquirt and just dont attempt any real tuning until the motor has broken in.

I'm not one to really stress over break-in periods. I am typically beating on the new engine the first week it gets started and I've never had an issue.

That said, I would suggest going megasquirt before starting the car. There is a lot of features that will making starting the car for the first time easier on the megasquirt, particularly if the housings weren't in great shape. Having flood-clear is #1. Being able to adjust AFRs to keep it running is #2.

Just plan on spending a good amount of time verifying all the systems in the megasquirt are functioning before attempting to start the car. The Test Mode allows you to check all the outputs before the car ever starts.

Just stay in vacuum and you shouldnt have anyhting to worry about.

Installing the stock ECU, then ripping it out again, sort of doubles the amount of work. I'd say if you are going to go standalone, go standalone from the beginning. Now the potential is that it could introduce more troubleshooting if something doesn't work, but probably not more so than the stock ECU anyway.

As for the break in, the map on my site will start the car. Then I'd suggest once you know the engine runs, lean it out across the board so the ratios are more reasonable (in the 14s) so you aren't hammering fuel into the engine which will cause all sorts of annoyance (stripping oil off the surfaces, contaminating the crankcase, fuming out everyone behind you, wasting fuel, yadda yadda). Once you have about 100 miles on the engine it is usually stable enough that you can do a quick and dirty base tune. You can turn on autotune to the AFR table included with my map and let the ECU rough tune it.

Final tune really won't be worthwhile until it has broken in about 500 miles (depends on the condition of housings, seals) because the engine will be changing so much.

If you are paranoid, just set the boost cut at 2PSI or something. For the first few hundred miles you can also set a rev limit at 4K. Then remove that and gradually increase the RPMs.

As posted above me, I'm not a big fan of excessive breakin. Basically I drive an engine easily for 500 KM then start tuning/beating on it.