I am finally getting the AWE cats and headers put on the car this Thursday. I had the AWE exhaust, EVO intake, and GIAC flash installed a couple of months ago. One thing I noticed when I got the car back after those mods was that the car didn't feel as fast as when I dropped it off - disappointed to say the least...However, a couple hundred miles later, I noticed a major difference in performance and 'feel'...I could not be happier with those mods now - always puts a big smile on my face at WOT, especially the sound coming from the exhaust...

Question is - should I expect to go through that same 'break in' period with the cats and headers before I see a difference? Also, do you think I will notice a change with these new mods considering the ones that I already had done to the car?

Your thoughts are appreciated...

 

No break in...why would you need to break in exhaust parts? There are no moving parts to break in.

 

For the first 100 or so miles you should experience adaption...after that the car should rip.

Dave

 

With the exact same parts as you describe, my 997S pulled 321 rwhp on AWE's Mustang dyno. Didn't have it tested stock, but a representative number is 295 rwhp.

As far as "break in" of the exhaust, there is no reason I am aware of that this would occurr, but mine sounded better after about a hundred miles of use and felt stronger.

 

wow nice numbers.

 

I got the cats and headers finally installed and all I can say is...WOW!


I wasn't expecting much from it as I've been reading a lot of debates on the issue here as to whether or not these will bump up the power or not. I definitely feel a difference from before, especially at mid-range rpm's...and the sound is just incredible...I find myself listening to the stereo less and less...

New favorite past time - WOT thru tunnels with the windows down...

 

lol, I'm right there with you mcl. tunnels and overpasses sound awesome.

 

There certainly is break-in with mufflers. Borla quoted me something like 500 miles for the M3. Might not be any moving parts, but there is sound deadening material in there that must get settled and the sound certainly did change with time.

AWE headers, cats, and mufflers really do sound wonderful, don't they. 4k to 7k is wonderful mechanical music - let her rip!

 

Mechanical music indeed...It really enhances the driving experience-don't think I could go back to driving a stock 997S now...

Next mod looks like it will be a plenum from RSS...Think I might place the order today as I found out that it won't affect the warranty (my primary concern with this mod)...

What do you guys think I can expect from the addition of the plenum< considering the other mods I've done already?

As always, your thoughts are appreciated...

 

Expectations from new mods?

Not much, really. I don't even know who they are, to be honest. But they've gotta be better than Todd and Scott . . .

 

I think there was a before and after dyno run with the plenum added to a 997S with headers, cats, mufflers and reprograming in the latest issue of European Car. About an 11 rwhp gain as I recall. I have one on my supercharged 997S and I think its added a bit in the mid to high rpm range. No confirmation with a dyno though. Immediately after installing it I was convinced I had a boost leak because it felt really flat in the midrange. After a period of "aclimatization", it does feel stronger and was a good bit faster than a dynoed 400 rwhp tt on the track from third gear on, for what that's worth. The intake sound is a bit more agressive as well.

 

Absolutely. I have all this too (except Fabspeed). Isn't it crazy to run up the pipes of a turbo that is hitting redline so hard that it puffed on shifting? So cool.