How much HP will it give to my 2008 sedan
my car has 306 hp now?
i want people that know lots of things about cars to answer this ? thank u

This is a difficult one to answer, which is why you're not getting many.
A good exhaust system will net 10 to 15 hp by itself on a stock motor with about 200-270 hp. However, as more performance parts r installed & the HP count rises, so do the gains from ur exhaust, which is something many people do not realize.

Example: l install a 3.5'' dual exhaust on a 700hp supra or G35, l might realize 25 extra HP. If l install the same exhaust on a 1988 Ford Fiesta, it will likely give me 1-5 hp, & hurt my Tq.

How the part (and any other performance part) will interact with another, & ur custom setup will vary. But with 300+ HP, depending on all the variables, l am going to say with some certainty, that u should get 7-15 extra ponies, depending on the build quality, diameter & flow properties.

Something that totally rocks, & makes for an understated sleeper is an exhaust cutout. You maintain ur normal pitch, & muffler when driving normally, then ''beep'' u hit a button, & the exhaust bypasses the cat & muffler adding at least as many HP as a new exhaust & sounds mean & deep on a 3L & bigger engine. It would rock on a VQ35DE. Check it out.

http://youtube.com/watch?v=QJ-t094ow-g&feature=related
http://youtube.com/watch?v=1uKmhx5INSU
http://youtube.com/watch?v=H5JWkf9EXKM&feature=related

Cheers,
Ryan

The people above me dont know what there talking about at all.
l had a 08 G35 sport & l put a Stainless Steel BORLA Cat-BackSystem & gained 13 HP & 9 foot pounds of torque.
But u should first put fujita is dual intakes on casue u will get better gas mailage & a little performance.
The VQ35HR engine is very easy to get more power from just an intake & an exhaust than the VQ35de engine.
But the VQ35HR engine is way harder to tune than the Vq35de engine.