11th Gen Honda Civic Turbocharger Design Blog Pt 1. - Started From The Bottom
Well, here it is, our OEM breakdown of the 2022+ Honda Civic 1.5L factory-supplied turbocharger.
If you have been following our method of approach for a while then you know that when we do part 1 type design blogs and talk about an OEM setup of a particular part then the odds are pretty good it’s because we’re working on a aftermarket upgrade of said part.
So, if you are reading this and thinking “OH MY GOSH” they are going to make a drop-in turbo upgrade turbo for the 11th gen Civic, well then you would be right :)
Now, we can’t put the carriage before the horse. We know that you guys are excited to slap on some horsepower to your FE1 Civic, but regardless of how pumped we are, the process remains the same. As the title states, we start from the bottom and work our way up. To know where we’re going we need to know where we are beginning.
So, let's take a look at the OEM turbocharger that comes in your new Honda Civic. We’ll also take a look at how this unit stacks up against the 10th Gen version.
Before you dive in, if you have not already read our Turbocharger 101 tech blog then check it out so you can get familiar with some of the lingo you will see in this series of blogs.
The 2022+ Honda Civic EX, Touring, and Si models carry on in the 11th Generation with a factory turbocharged 1.5L engine. While the displacement and overall design layout remain the same, there are some noticeable and key differences.
We’ll list a few here and for more details check out this Motortrend article. The engine code on the outgoing 10th gen Si was L15B7 and on the new 2022 Si, it is L15CA. With that engine change comes the reintroduction of VTEC for the new model. However, this VTEC is only for MPG and emissions purposes so don’t get too excited. Another big change was the OEM turbocharger. The 2016-2021 Honda Civic came with a TD-025 MHI turbocharger.
For the new Civic Honda did away with that and now uses a 64A-F4 turbo from IHI. MHI to IHI, similar in acronym, but are two very different manufacturers. In fact, the turbo and engine in your 11th gen Civic are basically borrowed from the 10th gen Accord with the 1.5T engine.
Put them side by side and you’ll see that both are similar sized, both have electronic WGA, both are water-cooled, and both house the main AFR sensor in the turbine housing. This is where the similarities stop.
Starting at the turbine housing, the 11th gen unit is a twin-scroll design versus a single-scroll like the outgoing model.
A twin scroll is advantageous in that it performs better at low to medium engine speeds which correlates to good torque delivery. They also make better use of exhaust gas pulses and inlet energy which makes for a more efficient design. This is a feature you’ll want to see in an upgraded version.
Moving to the compressor side of things, you can see some more big changes compared to the outgoing model. The bypass valve and compressor outlet are on the compressor cover itself rather than being a part of the turbo inlet pipe. This layout mimics that of the Civic Type R FK8 turbocharger and 10th gen Accord turbo. This we prefer because it means the design for an aftermarket turbo inlet pipe is much simpler.
Does that mean we are making a turbo inlet pipe too? I think you guys know the answer to that already…
This also means that removing and installing the turbocharger is easier since you don’t have a clunky TIP with valves and outlets on it that you need to maneuver around. Also, the 11th gens have an extra 4-5” inches of space from the turbo to the back of the radiator. Might not sound like much but believe us, that extra space is so nice when working on the car.
Moving onto the CHRA, the heart of our turbocharger, things are similar, but the new IHI unit is bigger in all the right places. The numbers break down like so:
The IHI 11th-gen unit is overall an upgrade over the 10th-gen, but not by a large margin. It's still not a big turbo by any means. It’s great for factory power levels and performs well with a tune and some ethanol thrown at it.
However, just like the MHI did on the CivicX, this turbo is going to run out of steam and when it does, we will have the upgrade you’ll be after.
Be on the lookout for part 2 of our design blog as we take a deeper dive into our goals for the 27WON 11th Gen turbocharger upgrade
-Vincent