Hello, I was wondering, how to get a better gas flow through the exhaust manifold without installing tuning parts. I do want the engine bay look original. Then I notecid that some daihatsu's have in some years different exhaust manifolds on the 1.3 engines. I also saw they use the same manifolds for 1.3 en 1.5 engines. Since I use the 1.5L engine in my copen with original 1.3L manifold, I want to improve flow by installing a YRV/Sirion 1.3L exhaust manifold. But i would like someone with more knowledge to confirm that the swat would be an improvement. I've added two pictures to show the difference. Any thoughts?