Anybody know, how this muffler partial bypass modification result for an N/A car ?
Will it make more power or just make more sound ?
Will it make more backfire ? Any effect for the engine if more backfire ?

 

It's called LPMM. Do a search and you'll see that everyone who has done it (including me) LOVE IT!

 

As Paul said, LPMM. No more power, just sounds much better. No backfiring. Similar in theory to OEM Motorsound muffler, except the by-pass pipe is on the outside of the muffler instead of inside. IIRC, the Motorsound internal by-pass is about 1" but, obviously, one can select any size external bypass, the most common is probably 2".

Add a Motorsound airbox cover (keep the stock paper filter) and it'll end up sounding like a Porsche.

 

Jimbo3, the Motorsound airbox cover was installed already with a K&N filter.
Just wishing in trying this mod, but i still think about the adjustable flap control to that mod pipes that i want to add too. (but still don't know where to start).

 

Throw the K&N away and go back to the stock filter. Tons of threads on the topic.

LPMM isn't much louder until you get on the accelerator. If you just want it to be a little louder, go with a 1 1/2" by-pass pipe.

 

It's a great mod. I have done MANY of them, I may have a set you can try...email me directly: fisterd@earthlink.net

 

thanks for the advice jimbo3

FisterD, thank you too for your kind offer, but since i live overseas, far away from Usa, it will easier for me to do the conversion here.