How much hp has my car gained?

I got a question, just curious, I have a 06 automatic honda accord v4, and I'm wondering about how much hp my car has gained from the mods, I have kn intake, DC sport headers, Megan exhaust system, Megan test pipe. The reason I ask is because I have two friends, one with a g35 03 stick shift 250+ hp and the other with a 04 BMW 3.30ci 225hp, and the BMW, I take him out and the g35 barely beats me, so I'm just curios as to why and how much hp could my car possible have gained, it took my friends and I by surprise what my car has don't sometimes

Probably not much, as those modifications usually don't add much horsepower, even in tandem. One way to find out would be to get your car on a dynamo and test it, but this won't tell you how much you gained unless you did this before the mods as well.

Stock was 166, I'd say you are within 10-15hp of that.

Your car is lighter than your friend's vehicles, so will require less power to keep up.

Your Accord does not have a "V4". It has either a V6 or an I4 engine.

Given that you don't know that V4 engines are found in boats, I highly doubt you gained much. By what you have posted, I bet you have one of those economy K series engines any knowledgeable Honda tuner would ditch for a performance K series or in your case start out with a V6 Accord. On the forums, people are claiming 40 hp gains from basic bolt ons on a performance K series that makes it competitive with an F20C engine. Both the BMW and Infiniti are heavy vehicles. Combined with bad driving, the odds swung over in your favor.