Cars which are a little less on power tend to have very heavy flywheels for absorbing vibrations. These heavy flywheels are kind of blocking the engine from providing their power to the wheels. That can be felt as a lack of acceleration in midrange.
You might think, dude, upgrading the flywheel when the rest of the car is kinda stockish is a little over the top - and you might be right. But I'd do it again anytime! Revving the engine is so much faster, and when you really put the hammer down you feel the engine being super thankful for the reduced rotating mass.
on the left the superlight flywheel with 3.7kg - on the right the stock flywheel weighing about 9.3kg
If you'd put a car on a dyno before and after replacing the flywheel, you will not see much of a difference. It won't adding power - it just helps accelerating faster.
Replacing the flywheel
When you think about replacing the flywheel at your car, you, of course, need to remove the gearbox. I don't own a car lift, so I picked up some stands designed to use for trucks. They gave me a lot of space under the 86, which made getting the gearbox out of the car much easier.
That's of course not as comfortable as using a car lift, but yeah, I don't own one so, it had to be that way. Always make sure, to drain the transmission fluid before removing the driveshaft or you will take a huge shower! And get yourself some help because the gearbox isn't the most lightweight one.
After replacing the flywheel, the 86 feels so much lighter. It's more playful and likes to rev. You can really feel the the engine being thankful for not having to use its power to rotate the heavy stock flywheel!
The new ZF clutch is able to handle about 500hp and 500Nm of torque. That is of course not necessary at the moment but I thought, if I change the flywheel, I can at the same time upgrade the clutch as well.
So, if you think about replacing your stock flywheel with a super lightweight one, do it. The clutch is, of course, a lot heavier to push, but you'll get used to it. And the flywheel, well, like I said before, IT IS JUST AMAZING!