BMW 523i E39 header advice. - BMW Forum

Duxter · 05-29-2009, 06:07 AM

Hi, i have an 523i e39 11/1996. I've changed the cat. with a Magnaflow one and also installed two final exhausts. This is the result:

YouTube - 523i E39 Dual Exhaust

Now i'm thinking of buying some ebay headers, actualy this ones: Performance Header BMW E46 99-00, E39 96-00, Z3 96-01:eBay Motors (item 350207638938 end time Jun-02-09 18:30:06 PDT)

What do you think, are they good or they're crap.

Thanks,
Dan

BimmerE39 · 05-29-2009, 04:16 PM

E-bay headers are an interesting trend. I actually just purchased a set myself and they are very legit. I was able to compare them side by side to a set of Supersprint headers and they looked almost identical. I was also able to determine the manufacturer so if I ever have a problem I know who to call. I haven't installed them yet, but in order to do so and pass emissions I need a high flow cat (something like yours) and to reposition the O2 sensors.

IMO anything is better than the headers that come stock. The ones in the E39 look like two pieces of metal crimped together. I think they're worth a shot.

Duxter · 05-29-2009, 04:47 PM

Hi, thanks for posting. Can you give me a link to your headers or a manufacturer. The price is real good (the ones in my post) and they look great. Here in my country a set of nonames costs about 400$. On ebay the actual shippment cost more but i can still get them for less than 200

BimmerE39 · 05-29-2009, 05:03 PM

Mine are made by TopSpeedAuto. They were $200 without shippin on e-bay. Here's the link.

Click Here

Duxter · 05-29-2009, 05:25 PM

They look pretty similar to what i've found

BimmerE39 · 05-29-2009, 05:46 PM

Yeah, there really should not be much of a difference between any of these e-bay headers. More than likely the same manufacturer makes them and I know they are modeled off of something else much more expensive.

When I purchased mine I just wanted to make sure the welds on them looked good, and the bends were smooth. I ended up being pretty surprised by the quality. I'm probably going to ceramic coat them and then have my shop fabricate whatever I need to pass emissions.

Duxter · 05-29-2009, 05:56 PM

Well when i bought the car it had no oxygen sensors, they were canceled because i have no erors on OBC. After changing the exhaust and the cat. my emissions were 3 or 4 times bigger, i had to bribe the guy

Hope it works next year too

Duxter · 01-21-2010, 06:41 PM

Hi, again !

The car has now racing headers, M50 intake swap and dual exhaust.

Cold start, 8min warmup and about 1500-4000max rpm's:

You Tube

nzm · 03-05-2010, 12:17 AM

How did you find the changes in performance before and after your exhausts, cat and headers individually? Which part made the biggest inmprovement and what was the best improvemet? Fuel economy, 0-100kms sprint, top end power?

I am interested as I will eventually be doing the same to mine and this info will come in handy I doubt I'll be doing it all at once, prob bit by bit from muffler to header.

Cheers!

Duxter · 03-05-2010, 05:32 AM

Headers are great but first get rid of the cat and the stock muffer. The M50 intake conversion gives you about 20hp and it's the most worthy upgrade.

nzm · 03-05-2010, 05:43 AM

So u reckon high flow cat back exhaust system with better flowing mufflers at the rear and upgrading to the M50 kit? Wat exhaust system would you recommend and if I were to get a custom in welded with magnaflow
mufflers an high flow cat, would 3"
all the way be sufficient or is that too large? I got a mate who does alot of TIG and MIG welding he could probably make me a custom
exhaust unless there are good ones available easy to purchase somewhere in Melbourne Australia? Am new to euros jap cars I know inside out but euros I don't know hardly anything lol

Duxter · 03-05-2010, 06:40 AM

The 2,5 and 2,8 engines are limited through the 2 original cats., muffer and intake. By removing the cat. and fitting in a high flow muffer you can get the real power of an 2.5 m50 for example. I don't have all the exhaust changer, i modified the resonator and made it dual exhaust like the M5. It is recomended not to remove the resonator because you will lose torque.

nzm · 03-05-2010, 08:21 AM

Yeh I can feel that the motor is definitely being held back. I reckon after modifying the breathing it will be possible to unlock up to 50hp? Or am I dreaming?

Thanks for the advice Duxter, will change the exhaust and post before and after dyno results as we have one in the shop here.
Btw - wat is 200cp+? it's another measurent of power I'm assuming, but haven't seen it before.

Cheers

Duxter · 03-05-2010, 08:38 AM

I didn't dyno tested my car so i estimate somwhere betwen 200-210cp hope for more afte chip tuning

nzm · 03-05-2010, 08:42 AM

What is cp? Over here we use horsepower HP or kilowatt KW haven't seen or heard of CP
before