Guys,

I have a 997 C2 and wanted to improve the sound further. My car currently has a cat-bypass with stock mufflers (which I will do the hack mod) and I was curious if there are any benefits to be had with the X51 headers on a base 997 in terms of sound or power? I found a killer deal on a set and already purchased them but don't let that affect your answer if it was a bad purchase for my car.

Thanks!

 

Will X-51 headers fit a base 997 engine?

 

Yes, there are a few threads saying they will but there isn't as much of a gain relative to S cars as the base cars had a stock design that flows better. I am just trying to figure out if there is a sound difference on a base car or what power increase (if any there is) for my car.

Also, they are listed on sun coast's site for a base 997.1

Has anyone put X51 headers on their base car before?

 

The design of the 3.6 headers is better than the 3.8 headers (look for some pictures and you'll see). The 3.6 headers and x51 headers look the same except the x51 headers have a little larger tubing diameter - I believe the primary tubes of the x51 are 48mm v. 42 mm on the 3.6 headers. They will fit.

 

Any idea what the gains in performance and sound characteristics would be on my car?

 

I replaced the stock headers on my 3.6L C2 with the X51 headers. I also installed 200 cell cats and less restrictive mufflers and exhaust tips. As jhbrennan wrote, the X51 headers have larger diameter pipes that are less restrictive. To realize a performance improvement, you've got to improve the exhaust flow throughout the system. If you've got stock mufflers with narrower piping, then the restrictive mufflers will defeat most of the benefit from the X51 headers. That said, even if you improve the entire exhaust system, to achieve a significant performance improvement you've got to also improve the air intake system (less restrictive air filter, block the resonator, GT3 throttle body, IPD plenum, ...).

.

 

PM Sent

 

What are your thoughts on a car with my mods?
Bypass made out of stock exhaust, fabspeed intake, and a hack mod to the mufflers

Worth installing or not?

 

I got your PM but can't reply until I have more responses.

To answer: Yes, I may be interested but depends on what I find out about how effective they would be on my car.

 

Did you ever install the x51 headers on the 3.6l? What was the outcome?

 

I installed X51 headers on my 2006 C2 along with S mufflers that have a few o9f the baffles cut. I also have the IPD plenum and GT3 throttle body. The intent was to stuff more air into the engine and to provide a better exit flow with the larger muffler pipes. There is a pleasant. sound improvement gained by all this. I am now debating whether to install the Fabspeed X pipe, but have some concerns about passing emissions.
Lyn