Allgemein / Workshop

GT86 HKS V2 Supercharger | Looking Back after 2 Years

Since You’re already here reading this, i assume the 86 or ZN6 platform is no stranger to You.
Ever since Toyota launched the GT86 back in 2012, i knew that it would make for a really great platform to build upon – lightweight, RWD and a locking diff.
So back in 2016, i finally managed to get my hands on a stock 2015 GT86 with just one previous owner, which was the dealership itself.
First little things then were a set of wheels and some small styling additions, like splitters and side skirts.

Introducing my 86

I really enjoyed the nimbleness and pure driving feel of the ZN6 right from the get-go. It’s just a really good drivers car from factory and actually doesn’t need much to get really impressive driving experiences from it. Not gonna lie, a really enjoyable sports car in this price range for a long time!

However – after driving it on stock power for about 2 and a half years, i got that tickling feel in the back of my mind that it would be even more perfect if it just had a little more “oomph”.
So, i started looking into options…

Choosing the right setup for Your driving needs

After some research, it quickly appeared to be the best thing to go down the supercharged route –
at that point of time, there was not really a possibility for me to get a turbocharger fitted with approval of the TUV, and many people recommended a tuner located not too far from where I live that had specialized in upgrading and tuning the 86s with the FA20 motor.
Supercharging would also retain the linear power delivery of the naturally aspirated boxer engine. Turned out that they also had a close partnership with HKS Japan, which i really appreciated as HKS is known as one of the top-notch tuners from Japan. So after a couple of mails and phone calls with GP Performance in Ayl, the decision was made and we arranged the date.

When I arrived at GP Performance’s workshop, the guys didn’t hesitate for long and quickly got down to work. A quick check up on the general state of the car, and then the games began – starting with the disassembly of the whole front end of the car.

It didn’t take long, and the complete front side of the engine was freed up and the space prepared for what was about to come in – You’ll see that in detail in a minute.
I really was fascinated by the super routined work they did on the whole job – definitely could tell that mine wasn’t the first one to get that kit fitted 😀

They also let me have a peek inside the rest of their shop, where i could spot quite a large volume of stocked kits that they had ready to get fitted which i didn’t think that there would be so many of ’em!
There were many other HKS branded auxiliary parts like air filters etc. to be found as well.

Some other customers also had their cars in for work – like for example this mean aero-kitted 86.
This one was also equipped with a supercharger kit but also had the engine already built, including new headers and high flow cats, and was tuned to a much higher spec making just short over 400 hp.

Laying out the kit & starting the build

After having a chat with the owner of the black beauty shown above, i returned to the actual build process going on on my car. The guys already were unpacking and sorting the parts of the kit.
That’s when i finally got to see the “heart” of the kit, where all the fun is coming from –
the actual supercharger.

So to give You some further detail on the kit, its based around a belt-driven centrifugal supercharger which works like a turbo but just isn’t driven by exhaust gases but a belt. The advantage of this setup is that You get practically no lag and have a really linear torque curve, since the engine doesn’t need to build up exhaust gas volume at low RPMs to spin the compressor.
On the flip side, the system is a bit less “efficient” – also when it comes to fuel consumption – since the engine itself has to drive the compressor by belt, no matter what RPM or throttle duty You’re at.
So keep that in mind when contemplating a similar setup ; )

To keep the whole system reliable also under some more heavy usage, a nice front mount intercooler and an additional oil cooler are part of the kit. To be able to use the oil cooler, the fog lights that were sitting on the left and right down corners of the bumper had to be removed though – a tradeoff i can live with since the car is only driven during summer.
Also to be mentioned is that i already had a Milltek cat-back exhaust system on the car,
which has a larger pipe diameter and forms a further advantage for making power with this setup.

A little while later and after some spark-shooting sheet metal modification, the whole kit was fitted and pretty much ready to be filled up with fluids. Next step: final assembly and dyno tuning!

The cool thing at this point is, from the outside You can’t really tell that the car is quite heavily modified already – only if You get down and peek through the front grille You could barely spot the fresh alloy intercooler and piping.

Finishing touches – tuning and mapping

Then, it was dyno time! On the first baseline run, we had some issues due to a clogged or dirty MAF sensor. Patrick, who’s not only the boss of GP Performance but also their master tuner in chief, generously donated me the MAF from his very own 86 – because he wanted to be sure that it was working properly and there were no riks left. Something I really appreciated! That’s truly good customer service!

After a few first runs on the dyno, the numbers that were put out weren’t enough to make the guys content. So without further ado, they went in and pulled the restrictor plate from the supercharger,
put it into a milling machine and widened the opening to gain some more airflow. Done that, plate back in and back on the dyno!

After all this stuff was sorted, we came to the final tuning and the guys worked out all the maps and values in the ECU. With the new MAF and the slightly bigger restrictor, everything went perfectly fine and we were able to achieve some pretty good results with the little 4-cylinder boxer : )

In the end, we made about 280 hp on the wheels and 330 Nm of torque – which turned out to be quite the perfect amount for the 86 chassis (at least in my opinion).
In addition, i now had 4 different maps to choose from, depending on fuel quality available and road or track use. When Pat took my for a test drive afterwards, i couldn’t believe i was sitting in the same car as before! It was a real mind-blowing experience for me, especially since i did not upgrade a car of my own to that extent before!

Looking back after two years of driving supercharged

So – let’s jump forward by about two years to present day. Here’s my conclusion:
As I mentioned at the beginning of this post, the driving characteristics of the 86 already impressed me in its stock form. It’s just a really well balanced, light and nimble sports coupe that – once You got to know it better – fits right like a glove.
Regardless, the 200 hp the car comes with from factory quickly feel a bit slow. As much as You gap any more powerful hatchback or sedan in the twisties, when it comes to straight line acceleration pretty much every performance FWD hot hatch would leave me behind.
Finally, with the supercharger installed, the car felt like it has risen to a whole another level – whilst still maintaining it’s linear power delivery and balanced character!
Sure, the upgrade doesn’t come in cheap – but believe me: taking into account what these 86s are going for used nowadays, and then adding the kit on top, You really get a package in performance and driving pleasure that hardly can be found in this price range. I was driving local mountain roads and easily hanging on to cars like Porsche Caymans and others that cost about triple the amount!

After all, i have now been driving the car on this setup for about two years and i can truly say that the upgrade was worth every penny. It just makes the car so much more enjoyable and also driving gets even more exciting as the car now really challenges You as a driver!
The execution of the build and tune by GP Performance was also flawless – i never had even one single issue, no codes, no check engine light flashing at me. I drove the car in Italy at almost 40 degrees Celsius, as well as in the Austrian Alps at glacier heights. The car always performed perfectly. And maybe the best thing – it now likes to do skids even more than back when it was still stock ; )

So, what do You think of the 86 in general and the route i chose for it to go?
Feel free to shoot us a message on our Instagram ; )

And always remember: a skillful driver has the dead bugs on his side window. 😀

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