Chineseium Ebay Headers- my report

[Schumi]

So I have a lift and time on my hands so I decided to try a non-name, $130 pair of stainless, cat-less headers from ebay. They were cheap and I was curious so I said screw it. They were here in 2 days and so I threw the car on the lift and went to town.

Firstly- the stock headers are incredibly easy to remove, especially with the lift. After 11 years, nothing was rusty or seized, everything came apart in about 10 minutes.

Now to get these new headers on. Thankfully I was doing all of this in a full machine shop.

They did not fit whatsoever. The exit flanges were a good 1/2-3/4" shorter than where they needed to be to mate up with the secondary pipes, which resulted in me yanking and stretching on a few things to get them mated.

The holes in the flanges to the heads didn't line up with the heads that well, and I had to drill/slot some of them a bit before I could get all six bolts in each head without cross-threading the holes.

The passenger side rubbed against the metal backing to the plastic aero shield under the front of the engine, so I had to massage that bit away from the pipes as to not burn the car to the ground.

3 out of every 6 bolts on each side had zero tool access for assembly- so I had to torque the bolts down with a combination of flexi shafts and odd extensions on the end of the torque wrench.

Finally, after a few hours of work, I go to scren in the O2 bungs. These headers had 2 O2 ports on each side, one forward one on a primary and the secondary one past the collector. Except the one past the collector was rotated down on the pipe too much on either side, so the wires to the sensor BARELY stretched to fit (probably not the best for the wires) and now those two sensors are sticking well low past the engine skid-plate (by about 15-20mm) which is something I must fix by welding some new bungs on (already ordered) before I bottom out on a pothole and rip half my exhaust off.


OK, so now they are on. I fire the car up- mind you, previously I had replaced my stock mufler with set of Borla glasspacks (already a very loud setup) several months ago. With these new catless headers.... Jesus, it's ridiculous.

It really is an orgasmic sound. They develop an awesome higher pitched resonance past 4000 RPM that is reminiscent of a Ferrari 355, and similar to a GT3 Cup car.

Power? Eh. More like a loss of torque down low (the primaries of these aftermarket pipes are WAY too large in diameter- like 2", and they need to be about 1.7") and a small gain in HP past 5,000 RPM. For city driving it may actually be a downgrade. The needle does leap forward with never before seen vigor after 5,000 RPM though, and it pulls hard all the way to redline, no small dropoff like stock. Throttle response has also improved, which is very nice.

The amazing bit- no check engine lights. The placement of the sensors does a good job of fooling the computer, I guess.

Am I going to keep them? For now, yes, they were a ***** to install, and the sound is wonderful albeit attracts way too much attention. There is no sneaking around in this car. And for $130 you really can't complain. Seriously, don't complain. It was a good fun project.

Another bit is they do actually look very, very nice after finally installed. After a few days of use they have started to blue very very nicely, and the stainless is indeed a nice stainless, not chromed mild steel. The merge collector was actually rater nice, and the inside was nicely ground and devoid of any crappy weld spatter.

I do believe it would be best to have the ECU retuned to make use of the massive amount of extra air flow the car now can use- I think I could see far greater benefits from tuning now.

And finally, disclaimer: these modifications were made for track use only as catless headers are illegal in the wonderful state of California.

[Wayne 962]

Yup, I bought a set of those too, just to check them out. Showed them to a prominent LA mechanic who thought they cost $2500! Scary to think what the Chinese can knock out for cheap. Just think of what they can do if they actually paid a little attention to overall quality control!

-Wayne

[ronster]

Thank you for posting this as I've come close to hitting the "Buy" button several times on these headers. I don't have a garage or shop to work in so installation would have to be paid for and from your post I can see I'd have to spend $500 to get a $100 pair of headers installed and the gains would be minimal as I have suspected all along. I can't have a noisy car where I live so that is another minus for me. I recently installed an EVO CAI and love the intake howl at 4K rpm as it reminds me of a F1 car so for now I'll just enjoy that and at some point spend a little more on a set of headers that fit without having to alter them. It would also be kind of you to come back in six months and give your impressions of how they have held up. Thanks again for a great post these are the kinds of things that are most helpful here.

[Schumi]

After two weeks now I must say I am enjoying these headers. The ECU has compensated as much it can I believe, and I have noticed some power increase after I was able to open the car up with some open road. At high speeds the extra top end is noticeable.

The throttle response improvement is also very very welcome.

I had a CEL come on earlier in the week on a long drive- sure enough, it was a cat efficiency code. I cleared it with a code reader and it has not come back. It will eventually, though.

[harryrcb]

Originally Posted by Schumi

After two weeks now I must say I am enjoying these headers. The ECU has compensated as much it can I believe, and I have noticed some power increase after I was able to open the car up with some open road. At high speeds the extra top end is noticeable.

The throttle response improvement is also very very welcome.

I had a CEL come on earlier in the week on a long drive- sure enough, it was a cat efficiency code. I cleared it with a code reader and it has not come back. It will eventually, though.

Hi Schumi. You have probably read some of my older threads on these headers but let me share with you what I did to compensate for any lag you might feel in areas. I had the local muffler shop make up mid pipes out of 2" pipes for $60 and welded flanges on to mate to the headers. world of difference in the mid range. I have now installed about 4 set of header , on other cars and I actually bought the cheaper ones for $ 69 plus shipping 2 of them fit without mods the other 2 just a little adjustment to the mount holes with a dremel. I also ceramic coated one set to keep the engine bay cooler- could not tell you if it helped. Theoretically it's supposed to increase power as it evacuates the gases faster. Anyway try those 2" mid pipes I think you will like them. If you also have a cold air system then I would recommend getting DME tune to maximize the performance of all the aftermarket upgrades. I wound up with 309 FW hp from my 04 S not too bad for the money I spent and nice increase from 255.

[Crispy]

Schumi, Could you or someone explain the O2 sensors again. Without a reprogram and with catless headers, how do the O2 sensors work? And, where are they in the system exactly? C.

[Schumi]

On the stock car, there are 2 sensors on each side of the engine. One is placed at the intersection of the 3 primaries right before the first integrated catalytic converted, and one is located after that primary cat, still on the header. When you remove the header (with the integrated primary cat) both those O2 sensors now do not have a home.

These catless headers have two O2 bungs in each header. One is located on a primary, about halfway between the head and the merge collector. The other is located after the collector. In this way, the first O2 sensor is only reading exhaust gasses from 1 cylinder now, and hte 2nd one is reading from all three.

Originally, the O2 sensors do 2 things: 1 is that the first sensor monitors air/fuel ratios and, to a certain degree, adjusts the engine tune to ensure he car does not run too lean or rich. 2 is that the two sensors on each back are compared against each other- the 1st sensor is compared to the 2nd sensor, and the 2nd sensor is supposed to show a decrease due to the catalytic converter between them. If it doesn't, you get a check engine light, because it thinks the cat is going bad.

I haven't been getting a check engine light, but that is only luck. The car is burning clean enough and the sencond sensor is far enough back that I'm guessing it is within limits still.

Some other brands of catless headers do not have O2 bungs at all because they assume that you flash the ECU to ignore them since, if you're buying catless headers, you're racing it. If that is the case then of course without a flash the CEL would always be on since you would have to simply unplug the sensors. The car however would run fine, and would just simply not perform any fuel trim for aif/fuel - no real performance would be lost when the car was at normal operating pressure and temperature unless there was something else wrong with the car (like an old MAF, vac leak, etc)


I hope my understanding of this is correct, but that is what I've come to know about the system.

[Rockster]

Nice write up!
Can you post up a sound clip?
I'd like to hear what it sounds like.

[Hatzenbach]

did you get rid of all 4 cats all together or do you still have the cats in the pipes closer to the muffler?