Our 1987 BMW 325is was K-swapped previously, and now we are moving from 2.4L natural aspirated to a super compact 1.5L turbo engine.  

Before we move on, let's talk a bit about the engine.
Honda debuted the L15 Turbo engine in the U.S. in the 2016 Honda Civic ranging from 174 to 205 horsepower.
The 1.5L turbo engines can be found in Civics, CR-V's and Accord models, and needless to say there are plenty out there.  
Some features of the engine include:
-DOHC, dual VTC, direct injection, and a low-inertia single scroll turbo with an electric wastegate.
-Aluminum block with individual reinforced main bearing caps, and cast-in iron cylinder liner for added durability.
-Con rods are lightweight high-strength steel, which are heat-forged.
-Twin oil squirters to keep pistons cool with ion plated rings to help reduce friction.

L series just made sense.  better emissions, better fuel economy while retaining the Honda reliability with a motor that can perform up to the tasks of much larger displacement.  We're in!
After some talks about the project, first step was to get a motor to get a 3D scan and a general idea for mock up.

We opted for the L15B7 out of the Civic Si model. 
We purchased the engine for $2200 delivered.  Non-Si model engines range from $550 to $800 from what we have seen.  
What is the difference?
Si's 10.3:1 compression vs. 10.6:1 to allow for higher boost pressure.  Slightly more aggressive cam profile.
Stock fuel system on ethanol should be able to support up to about 300hp on a RWD setup.

With all that being said, you might ask why are we opting for this engine over the K?
Well, to answer that it's personal preference, however we feel there is a lot of potential locked up in this little package.  First, peak torque is achieved near 2100RPM with a redline at 6500.   turbo lag? None.
These motor are claimed to run very efficient which allows for low coolant temps, which is a plus.

The goal for this build using the L15 motor is to have a fun street car, that can hit the track.
Responsive setup with plenty of torque, and a motor that can handle up to 350hp with some upgrades.