Are these cheap headers any good?
Let’s start by giving a very short answer: YES.
These are definitely the cheapest way to increase horsepower on your NA 6 Cylinders. Removing the very restrictive oem exhaust manifolds proved to gain instant power. You can feel it, it’s there, no need to do a remap to take advantage out of these, even though it could gain you even more horsepowers.
Before you ask, these headers are referred as “Ebay” headers, but of course, these are not manifactured by Ebay. Usually these are shipped out from US and you can see there are 2 variants: one that fits M54B22, M54B25, M54B30, the other that fits M52B20, M52B25, M52B28 and I believe also M52TUB20, M52TUB25, M52TUB28. So the only difference, as far as I know, is just the lenght of where these mates to the mid pipe flange.
What’s the fitment like?
Removing stock exhaust manifolds is a little bit of a pain. You need different length rachet extension, joints, wrench and so on! Also, as you can see from the picture, I had to remove right engine mount bracket…
As you can see from the above picture the fitment is not perfect. This is reported by ever user and a lot of people also stated that forcing the flanges to come into contact using longer bolts + nut on the other side causes no problems over time. (I suggest to use Steel or stainless steel bolts + nut and a split-lock washer on each side to avoid loosening over time due to vibrations; just avoid zinc coated bolts as they turn bad with heat).
Strenching midpipe out of position, in my mind, could cause premature wear on rubber exhaust hangers. That’s why I decided, while removing mid resonators, to modify the exhaust and mate the flange surfaces without any stretch, making the midpipe longer.
While you are in there, with the headers off, you can consider to remove Secondary air pump system which is useless now. To do so, on ebay you find a small plate which mates to the head opening close to the headers. You will save some weight and of course the engine bay will look cleaner.
Sound got better, some exhaust pop began to show, acceleration improved, engine bay looks better too. That’s definitely the cheapest and best performance mod to do. At this point consider to get a ecu remap to gain a little bit more Hp and throttle responce and also, you can induce exhaust pops without frying catalytic converters now!
If you want to invest more money on headers, consider to buy branded ones, which could net you a better fitment and MAYBE a little more gain BUT, IMHO, I don’t think the branded one are worth the extra money.
Thanks for reading!