Hmmm. Seems to be a perfect time for another plenum group-buy...

Bump ^^^

Well Fasteddie it doesn't look like group buy time to me. I see what the arguments are about 1999 has said show us the data and all that was said was come see our data. Never any data shown. Since I am a scientist this is always suspect. Still, I see the merits of the plenum and see that it would possibly provide some high RPM power. I doubt if I would ever notice the difference between 20 hp at 6000 RPM since that is rarely seen in my car (it's a daily driver and not a race car). Still over my years I have added items like this because that is part of what I do, modify for fun. If I spent $1k for a part you better believe I would think it was worth it. BTW, I just added the afterhours exhaust and if I had the money I would buy the plenum. I don't care if it really works, I think it should work?

Good post Chuck- I really think it comes down to "YMMV", it seems for the most part that the plenum adds some decent gains and is a good product, but there are those who have not had any luck. I took the time (and spent my own $$$) to dyno my 997 at an indy shop with and without plenum. I also have the AH exhaust (:Dwoo hoo!!!:D), and the combination of plenum + AH exhaust + KN intake really put some bejeezus of pep into my pcar. I'll post the thread link w/ dyno charts etc in a few.. The plenum did indeed give me some gains, so as far as my personal experience goes it works.

How's your AH?? Has it burned in yet?

Here is my thread with plenum dyno results etc, hope it helps-
https://www.6speedonline.com/forums/997/149100-rss-plenum-gains-verified-my-997-dyno-results.html

Summary of it all is, I netted 26 TQ / 28 HP gain by adding the plenum and AH pipes. The plenum was responsible for 15 TQ / 17 HP of the gains.
At retail price for both parts, I suppose it would cost about $1950 (not including installation labor) to get 26 TQ / 28 HP gain (and simply bad-ass exhaust sound :D)

Remember- "YMMV!" - my pcar was bone stock before the mods, with exception of the KN intake (i already had that installed).

Hey Porsch3, your review was one of the reasons I went with the AH exhaust. Don't know if it has burned in as I have hardly had time to use the car. Spent all day yesterday trying to get rid of the hood and tail oxidation using Griots garage machine polish. Also, this was one Brian had about 10 dyno runs on so it was previously used. I am surprised at how loud it is on start up. My wife will probably complain when I go back to work after the holidays and leave the house at 4:30. Kids will probably wake up. It settles down after that initial rush. Actually I have barely had the car out of the garage after I put them in. Should be interesting

What is YMMV!?

Hey Chuck- "YMMV" = "Your Mileage May Vary" :D

So yeah the pipes you picked up should still be about new, usually takes about 200 miles to burn in fully. Sound gets a bit mellower after burn in. I leave for my office very early in the a.m. and after a year (AH on my 996 and now on my 997) not one complaint from neighbors. I don't think that they are that loud overall (unless you are WOT), but comparative to stock mufflers they are loud. My neighbor's new Ford truck is louder at startup than my 997 w/ AH. So I guess it's just relative.
Cold start will be louder since the idle RPM is higher and the cats are cold.

Anyway, I hope you get to go for a drive and enjoy. These pipes put a big grin on my face every day. Yes my sweetie hates them too.. they are not "wife friendly". That's why I got her a CTT, the 997 is M-I-N-E :D :D

Well Porsch3 just drove them about 2 hours yesterday and I've got to say, "wow, good and bad". I liked the sound when I wanted to get onto it but I got a massive drone when starting out in second gear. I had a passenger yesterday and we had to talk loudly to each other just to hear. Mine is a 2000 C2 tip coupe by the way. After I dropped him off I had fun with it but I am not sure if I can take this in my daily driver. Now I see why the PSE was such a good deal, off and on when you want it. Hopefully, it will "mellow" out some more or I may have to take them off.

Let them burn in, they will mellow out. Keep in mind there will always be a resonance hump around 2600 rpm, or when lugging the engine. My 02 996 was a tip also, it just PAINED me that the tip always starts out in 2nd gear.. I only drove that car in manual mode with forced 1st gear starts. Never left it in auto mode.

PSE mufflers are completely different type of muffler (it's a stock muffler with a switchable bypass cutout). You'll add back weight and zero performance improvement, for tradeoff of a stock-like quiet ride. AH pipes are for those who want max performance at the tradeoff of some quietness. If you've tried bypass pipes, you'd get a good reference of how quiet the AH pipes are in comparison (much much quieter). If you've tried some other types of performance mufflers, the increased noise difference of AH is marginal. Not a fair comparison to stock mufflers :D

Before upgrading exhaust, it is always good to try and first determine your modification goals. Example, do you want just a tad bit more exhaust sound and primarily use car for putting around town / socializing / family drives with wife and kids? pcar is fast enough as-is? If so, stick with PSE or a very mild aftermarket muffler. Keep in mind that almost every aftermarket muffler will add some resonance vibration into the 996 cabin (interior parts buzz / rattle). The AH pipes are the only one's I've personally used that do not add any vibration- and of course the PSE does not add vibration either.

If your goal is ultimate driving performance and pure sports car fun / car is primarily used as a personal driver and you drive it like you stole it, the AH pipes are the best exhaust pipes one can buy (IMO).

Summary, I went through 3 different exhausts before sticking with the AH because they perfectly fit my style of driving and daily use of the pcar. The AH's delivered in a way on sound / performance that none of the other exhausts I tried could. So, worked out best for me but I had to try a few exhausts to get there.
I'd suggest letting these burn in for a bit and see how they fit your lifestyle / use of the car. You may also want to pick up a set of modified PSE-like stock 996 mufflers (look up Gundo) or a set of mild performance mufflers (try Dan at Vivid). Try them all out, see which one fits you best. After you have changed mufflers the 1st time (and hopefully reversed the two long bolts) it is easy to try out different mufflers / simple DIY.

Hope this helps!

Thanks for the input. I plan on leaving them on for a little while and seeing how I like them. I never tried bypass pipes but was getting close to trying them when I saw these. I appreciate the comments about the other aftermarket mufflers. Which ones did you try? Unfortunately I don't have the budget to keep trying several exhausts and absorbing the cost. I was considering that I might look at other mufflers but I realized that the tiptronic needs a flex sleeve on the inlet to limit vibration. That's the nice thing about the AH exhaust. This is my DD and a lot of times I'm just running back and forth to work. I am a little worried that hearing that lovely wail out back will entice me to run it hard and become a target of the local police. Since I am usually the only one in this car it is only I that have to listen to it. Still driving each way for 1 hour???? I am also considering driving from Texas to Laguna Seca for the Monterey Historics in August (Porsche is the premier make). 1600 miles one way of straight and mostly flat roads!!!

By the way, butt dyno makes me have the impression the car rev's a lot faster. Seems like I barely was into it before having to shift gears

Yeah, the AH really woke up my 996 and 997. If you dyno the car with / without the AH pipes I'll bet you'll see a good HP/TQ gain with the AH. The gains were consistent on my 996 and 997, so no reason to think your pcar is not getting the same benefit :D.

Sound check- I wouldn't sweat it. I live in an area where local PD are very strict and have not had a single prob (Beverly Hills). Heck, my neighbor's deisel truck is louder than my 997.. lol. My friend's Gallardo w /stock exhaust is louder. Most of the ricer cars around here are louder. So, in the scheme of things it is far from the loudest car on the road. Only time you'll attract attention is at WOT hitting between 4-7k rpm, but doing that you take your chances even with stock mufflers.. If you are just cruising light to part throttle your pcar is not much louder at all- That was one of the cool things that stuck me on the AH, they only "wail" when you have your foot in it.

The pipes do definitely beg you to "get on it" a lot more often.. I have always loved the sound of a good motor and to me the AH's really "showcase" the pcar sound perfectly. I'm always finding excuses to go drive somewhere. Some folks prefer the lexus-quiet thing on their cars, I just can't see that working out on a pcar especially with the 6speed. You need to hear the engine to gauge your shifts. I test drove a new '09 997.2 and it was so darn quiet I had no idea what RPM I was at without visibly looking at the tacho. I know, not so important with the tiptronic, but when I had my tip I always drove it in manual mode. To me, the AH's give the perfect level of sound feedback.