Flushed with success from my intake mod, I decided to take the minimal financial risk of investing in the "ebay" headers. I have no desire to mess w cats, a louder exhaust, or modded ecu. I added the headers to a otherwise stock exhaust system (no pse) hoping for the usually advertised mild midrange boast and better (different) sound. I expected little or no real world difference since it would seem that it is the muffler that is the main source of back pressure. First let me say the work on these things is great. I have no idea whose design this is but the execution at the price leaves you wondering what is going on. As for the results...well another story. The bottom end feels "soft" as in less torque. It feels as if the useful horsepower range has been bumped up to the 5500+ rpm range. The car will no longer break traction in 1st from 3000rpm roll. Acceleration at top of 3rd and 4th is scary fast but less than useful. The sound has more rasp to it above 4000 or so. Has anyone else added headers to an otherwise stock system with the same or different results? Any input here would be appreciated Gerry

 

what does this have to do with the plenum ?

 

You didnt say what car you put these headers on S or NON S.The primaries on the ebay headers are small and they dont lineup well with the tubes.I have them sitting in my garage and probably will never install them.

 

Have done that mod myself initially, I don't understand your complaint. You have actually gotten more power in the upper range which is where those headers will help.
Couple of questions;
Do you really need to break the wheels loose at 3,000 RPM?
That being said you probably do lose a little down low to gain on top.

Did you notice an improvement in Throttle response? I did.

My car a coupe had a nasty almost subsonic drone or resonance at highway speeds in 6th gear? It went away after I added the headers. Have you noticed an improvement in this area.

I think the best recommendation I can make would be to go with after market ECU software. Softronic seems to be the flavor of the day. I went with APR. The advantage of the APR and probably the others is it will bring your torque curve down. Mine power kicks in at around 3,000 and doesn't stop, with no hesitation like before at approx 4,500 and then the car takes off.

Bottom line your explanation was pretty much how my car felt with the same mods.

I wanted more.

You can see were I am at now with my signature below. The only difference I took the AWE Muffler off and put the Stock back on to quiet things down a little. Kept the AWE Cats and Headers. They make a big difference.

 

Car is an S Lon. Tech felt fitment was good but I can't say.

 

Inability to break wheels loose was my attempt to define the difference between header/stock not a complaint Glad we agree subjectively. If there is a complaint here it is that, as I noted, the car may have had more usable horsepower/torque for "normal" driving before adding the headers. Thanks for the suggestions. Still digesting the possibilities.

 

An ECU flash is the surest way to regain your mid-range you are now missing. Common complaint, which is the reason it's very common to do all three mods, intake-exhaust-ECU. They work great together.

 

The 3.6 exhaust is probably as good as the the E-bay. The E-bay vs stock on my 3.8 I found the Primaries to be the same diameter on both but the collector on the E-bay is about 6MM bigger and the E-bay looks like it has better Flow then the stock 3.8. The Stock 3.6 997 header looks just like the X-51 header but I don't know the dimensional differences. The AWE header's primary and collector are all bigger than the E-bay or stock and the Primaries are of equal length. The better design of the 4 mentioned.

 

Plenum and headers were my attempt to "fix" what it appeared Porsche had not done right. In the case of the headers, they may have it right for daily "drivability". I'm reluctant to flash, but it may be that or replace the cast iron. Thanks. Gerry

 

I'm sure the AWE piece is better but this was an experiment on my part. If it had gone differently I would have "upgraded" at some point. As it stands I am not so sure it is the direction I want to take. I applaud your commitment however

 

Your next investment should be in a better set of tires. Your back tires should not lose traction at all from 3000 rpm.

 

Gerry,

Keep in mind part of the Porsche X-51 option is a Porsche reflash. Other than that it is plumbing changes and a slight re-work of the head. I personally think I have achieved the cost effective x-51 option. It may actually be better, but I would have a hard time justifying that statement at this point. (cost Effective in that I bought the exhaust system used and everything else was on bought at sale prices).

My car has a lot of mid range.

David

 

12000 miles on my Pirellis and it's cold in NY. You of course are quite right.

 

X51 is a nice engine but I am sure it is reachable on a horsepower basis. On a $ cost per horsepower basis, it reigns supreme. It is the midrange that makes or breaks an engine unless you spend a lot of time at hyper speed on the track. I was down at Barbers by you for a weekend with Porsche (That track gave me motionsickness For the most part I enjoy 2nd & 3rd gears on the on/off ramps by my home. I will consider the ecu. Enjoy Gerry

 

Barber's is pretty neat. I was fortunate enough to be a passenger their for a couple of laps in APR modified 997TT driven by a race driver. Hope to attend the school this year.

I used to be able to spin my used Pirelli's too.