z4 2.5si n52 mods. need help from the knowledgeable members

[nemex12]

hi guys, I have a z4 2.5si which I've been modding like crazy. now it looks almost like I want it too so I'm moving to the power department. I put a k & n filter and some z4m cans and mid section exhaust and it seems the car got a little more power but now I'm considering getting headers but don't know if it would allow too much flow which means less backpressure which in turn may translate into hp losses. I don't care too much for the sound or the emissions as in my country they are not too picky about that, I just want to get as much power as I can from my car. btw I dynoed my car in 184 hp in a local heartbreaker dyno dynamics which should be decent given that I got it with 85 aki pump gas which is awful. please guys help a fellow in his quest for power and share your thoughts

[gas-can]

Honestly I don't think there are many n52 power mods that are worth it. Most of the time, with stuff like filters, you are just emptying your wallet more than you are actually increasing your speed. The exception is forced induction, of course.

Only thing worth mentioning is the N52 3.0 to si swap. This is different since the 3.0i is the factory de-tuned version of the faster si. So simply upping to the 3 stage manifold and the extra code can net about 40hp - that's 40 hp already designed into the engine, just not 'enabled'.

I'm not sure where you are - the profile says Florida but I don't think the US ever saw a n52 2.5Si. If you have the actual 6 cylinder 3.0i (215hp) version, then you could try the swap I mentioned above.

Btw, the backpressure is not important- in fact your engine would like as little of it as possible. It's the exhaust velocity that's important.

Sorry to be the harbinger of pessimism

-gc

[nemex12]

Originally Posted by gas-can

Honestly I don't think there are many n52 power mods that are worth it. Most of the time, with stuff like filters, you are just emptying your wallet more than you are actually increasing your speed. The exception is forced induction, of course.

Only thing worth mentioning is the N52 3.0 to si swap. This is different since the 3.0i is the factory de-tuned version of the faster si. So simply upping to the 3 stage manifold and the extra code can net about 40hp - that's 40 hp already designed into the engine, just not 'enabled'.

I'm not sure where you are - the profile says Florida but I don't think the US ever saw a n52 2.5Si. If you have the actual 6 cylinder 3.0i (215hp) version, then you could try the swap I mentioned above.

Btw, the backpressure is not important- in fact your engine would like as little of it as possible. It's the exhaust velocity that's important.

Sorry to be the harbinger of pessimism

-gc

I have a 2.5si in south america. I made a swap so I'm using the oem xpipe and boxes of a z4m so I'm thinking in buying supersprint headers and maybe a performance x pipe and boxes for the z4m which should give at least 20hp. what do you think bro? any advice? I just wish ESS came out with the kit for the z4 asap