i am planning on adding an intake and 4-2-1 headers for my mirage. how much power is gained. i have herd at least 15 hp, and i have also herd like 8. so i want to know the gain. i am going to take my car to the track to test it out now, so see the ET, and after the mods. also going to a dyno after bolt ons are done. but i would like to know a rough idea of how much power is gained.

 

I gained, 6hp at the wheels and that includes a CAI and a full exhaust, (yes it was an auto), but if all you're gonna have is the 4-2-1 headers, you should have much less, around 3-5hp

 

OH wait, you have a mirage, I'm sorry I missed that, I just saw 4-2-1 and HP, and I answered, well forget everything I said, I don't want to be quoted on a motor I do not know... but one thing is for certain, do not believe what you hear or what people tell you, unless they have dynoed that same modification in the same manner as you will... find a MIRAGE board/forum and you will get more answers there

 

i already have a full 2 1/4 catback system, and i am going to add 4-2-1 headers, 50mm TB, a stage one cam, air intake system. so i was told by a mirage performance guy that i should get about 15-20 after i add that.

 

Sorry to burst your bubble but add ons while they do give you the promised increases it happens at different parts of the power band, hence it doesn't all add up to one big hp increase. One part may boost low end power but not help top end, another will gain on top not on the bottom, some like exhaust systems can actually hurt bottom end but gain on top ( hence the throttle body is needed to counter the torque loss from an exhaust system some times ) . Both me and Bat lord have dynoed our cars with tons of mods and the promised single huge gain was not there, but we saw each part make gains in different places. AS a famous Korean shop owner ( Cheuk ) once said, " it's the numbers under the curve that count " . That and some parts while they make gains on their own, don't when mixed with other parts ( sad but true, cough cough under drive pulleys, but it didn't hurt anything either ). So while the car may perform like it has 20 hp more, a real dyno may only say 10-15. BTW ask BAT how much it took to get either of our auto rides to get 20 hp more on a dyno, I have an intake, 58mm throttle body, Partially ported manifold, 4-2-1 headers and 2.5" exhaust, cam, underdrive pulley, fuel pump, fuel regulator, milled fuel rail and all that gave me exactly 23 hp more on a 2.0 L motor. ( believe it or not 1 hp was from just changing BACK to factory plugs but facing the open electrode part to the exhuast side in each cylinder ).