[caf4676]

What would happen if I get a bigger turbo installed but nothing else until later on?

I.e. No tune, larger IC, etc.

[chris719]

Not an expert on this, but pretty sure you're gonna need a tune for the turbo unless you want the car to go into limp mode.

[5.M0NSTER]

Nothing good. You need right air/fuel ratios, boost, fueling and timing to run properly. If you have more compression without the right tune you can hurt your engine components. Bad idea in an EPIC way.

[detroitm2]

As others have said. Bad idea. Go FBO first, then do turbo.

It's a couple grand to go FBO if you do the work yourself. Worth it for the longevity of your vehicle.

[McPurrs]

This is like buying a primed bumper and installing it on your car while you can't afford paint. Don't do it. You need paint in this case (a tune).

[SeanWRT]

Welcome to M2 club.

Hear this - Yes - you would be running just fine with bigger turbo (presumably the hybrid type) and nothing else needed. No CEL, no limp mode, no nothing. And boost/ignition/AFR spot on. Car will be rock solid.

If anything, it will run cooler and more efficient, but spool up time will be longer and torque band will be shifted to upper range a little.

That being said, a tune and the supporting hardware (especially the intercooler) can make bigger turbo really shine where it can.

[5.M0NSTER]

Originally Posted by SeanWRT

Welcome to M2 club.

Hear this - Yes - you would be running just fine with bigger turbo (presumably the hybrid type) and nothing else needed. No CEL, no limp mode, no nothing. And boost/ignition/AFR spot on. Car will be rock solid.

If anything, it will run cooler and more efficient, but spool up time will be longer and torque band will be shifted to upper range a little.

That being said, a tune and the supporting hardware (especially the intercooler) can make bigger turbo really shine where it can.

Hey Sean, so what you're saying is larger hardware has more inertia, takes more time to spool and thus shifts the power band. But without new software to control the boost, even though the hardware is capable of making more boost, the controller would keep boost at current levels. So just the turbo hardware by itself would not lead to a noticeable power increase. Is my thinking correct?

[ZM2]

Related but different question:

When you have a larger turbo, is there really any point in flashing BM3 back to stock when you take the car to the dealer for service?

Seems like if you have an issue they’d just blame it on the hardware, even if the software is “stock”.

[SeanWRT]

5.MONSTER, yes correct.

ZM2, it's very difficult for the dealer to tell hybrid turbo from stock one without taking it off. Meaning, I'd flash back to stock prior to the dealer visit, provided you do have a drivetrain problem.

Damn...In the past 2 years, I installed bigger turbo twice, put 15k miles on them, did 5 hard track days with them. And I have yet to see a single CEL! Talk about N55 reliability and the art of tuning.