ok guys, I've tried to fix the exhaust low rpm underpowered issue. So below are the pictures to describe what happened.
as mentioned earlier i've changed my exhaust to the following s-flow setup by adding this double exhaust:
few guys from the waja & lancer club told me that the diameter if the output pipe (marked in red in above picture) has to be equivalent to the diameter of the original exhaust pipe (the 1.6" pipe). So at the exhaust shop today, the guy removed the pipe and replaced then with a smaller diameter pipe. So it's very very small (the mufflers are big but the pipe in the mufflers are very small)
then my friend (from the lancer club) chatted something with the exhaust shop guy (in chinese) then they agreed to changed the current center bullet with a swirling bullet. I know that a swilling bullet is a BIG NO
for a manual car but he (the guy at the exhaust shop) told me to trust him.
This is the original bullet in my previous setup
The internal diameter of this bullet is 1.7"
The shop gave me this swirling bullet with a diameter of 1.6" (free of charge)
As you can see, the exit pipe has been replaced with a smaller pipe.
So, people would say that i've done a wrong setup for the wrong car, adding a swirling bullet with an s-flow exhaust is much suited for auto cars. But the results:
1)It takes almost 4 second to reach from 1.5K rpm to 2.5K rpm
2)Easy acceleration after 3K rpm (100km/h to 150km/h is easy. Stock myvi very hard to reach this without flooring the pedal hard)
1)It takes around 3 second to accelerate from 1.5K rpm to 2.5K rpm. The acceleration is very noticeable.
2)Power after 3K rpm is almost similar to the previous setup
Unfortunately I didn't have the opportunity to test the top speed yet.
As a conclusion, i think that the new setup helped me to get back my lost low end acceleration while maintaining the high end acceleration or maybe it's just in my head....
Feel free to test my car during TT for better clarification.
Btw, no other mods have been done (no crank pulley mod, CAI, open pod etc) just added pivot and UR front strut bar and rear ARB. Rims changed to 15" k-speed rim (192/55/15)