SM_ATL's Carrera S Journal
. It is almost always good to have an off switch - on a spouse, a child, the IRS (seemed timely) and and an exhaust!
#1157
04-15-2013, 08:47 AM
I have not done any modification in a while and had already tried headers and sportcats on my previous 991, so I thought I would study X-pipe center muffler bypasses.
Fabspeed and Agency Power offer products that look pretty similar. Fabspeed is a bit more expensive ($1,595 vs $1,295) and a little more heavy (claims to reduce the car weight by 7.45 lbs vs "about" 20 lbs for Agency Power) but looks better finished -as always with Fabspeed products, they just look perfect-.
Fabspeed Xpipe muffler:
Agency Power Xpipe muffler:
At this point, there is not much to discriminate one product from the other (one seems better finished but is a bit heavier and costly...) and sound clips on the internet are not reliable enough to form an opinion on the acoustic merits of each products.
Both manufacturers have been kind enough to publish dyno curves for their product (with only the Xpipe muffler in place, not sure though if the reference is the standard exhaust or the PSE in both cases). I spent a little bit of time digitizing the power curves:
and looking at the hp improvement at different rpm's
This is where to comparison becomes a little more difficult. I know very well that dyno data has to be taken with a (BIG) grain of salt, but the Agency Power hp gain seems too good to be true around 4,000 rpm. Around 5,000 rpm and above, I would say that there is again no significant difference between the two products.
In both cases, you will not see a very significant peak hp improvement, but the gain you can observe from 3,000 to 6,500 rpm is probably well noticeable when you drive (on average +29 hp for Agency Power, +16 hp for Fabspeed). I know that I should have digitized the torque curve and rather talk about the gain in ft.lbs, but I was too lazy
So what conclusion should I draw:
-$1,300 to $1,600 is not a huge amount of money if the gain (let's say in hp) actually ranges from +16hp to +29hp. This seems in fact to be a good bang for the buck if you compare what you would get from other mods: X51($$$!!! -OK, not the same philosophy and more hp), tune (not available yet, but probably less impact and more potential warranty issues), etc.
-Somehow the Agency Power product seems too good to be true: more than a 50hp gain at 4,000rpm, 12+ lbs lighter and $300 cheaper... I have a tendency to be suspicious when the conclusion, driven by vendor data, seems so obvious
-I am very tempted to give it a try BUT I would lose the on/off functionality of the PSE that I like a lot, especially when I cruise over very long distance and that I have my 991 in 'GT' mode, all soft and cushy and sipping a minimum amount of gas
On the track, there is no doubt that I would be happy with the mod.
I'll sleep on it for a while and maybe contact the vendors to get more direct feedback.
If forum members have had experience with these products (or similar products on 997's or others), please chime in!
Thanks,
Serge
Fabspeed and Agency Power offer products that look pretty similar. Fabspeed is a bit more expensive ($1,595 vs $1,295) and a little more heavy (claims to reduce the car weight by 7.45 lbs vs "about" 20 lbs for Agency Power) but looks better finished -as always with Fabspeed products, they just look perfect-.
Fabspeed Xpipe muffler:
Agency Power Xpipe muffler:
At this point, there is not much to discriminate one product from the other (one seems better finished but is a bit heavier and costly...) and sound clips on the internet are not reliable enough to form an opinion on the acoustic merits of each products.
Both manufacturers have been kind enough to publish dyno curves for their product (with only the Xpipe muffler in place, not sure though if the reference is the standard exhaust or the PSE in both cases). I spent a little bit of time digitizing the power curves:
and looking at the hp improvement at different rpm's
This is where to comparison becomes a little more difficult. I know very well that dyno data has to be taken with a (BIG) grain of salt, but the Agency Power hp gain seems too good to be true around 4,000 rpm. Around 5,000 rpm and above, I would say that there is again no significant difference between the two products.
In both cases, you will not see a very significant peak hp improvement, but the gain you can observe from 3,000 to 6,500 rpm is probably well noticeable when you drive (on average +29 hp for Agency Power, +16 hp for Fabspeed). I know that I should have digitized the torque curve and rather talk about the gain in ft.lbs, but I was too lazy
So what conclusion should I draw:
-$1,300 to $1,600 is not a huge amount of money if the gain (let's say in hp) actually ranges from +16hp to +29hp. This seems in fact to be a good bang for the buck if you compare what you would get from other mods: X51($$$!!! -OK, not the same philosophy and more hp), tune (not available yet, but probably less impact and more potential warranty issues), etc.
-Somehow the Agency Power product seems too good to be true: more than a 50hp gain at 4,000rpm, 12+ lbs lighter and $300 cheaper... I have a tendency to be suspicious when the conclusion, driven by vendor data, seems so obvious
-I am very tempted to give it a try BUT I would lose the on/off functionality of the PSE that I like a lot, especially when I cruise over very long distance and that I have my 991 in 'GT' mode, all soft and cushy and sipping a minimum amount of gas
On the track, there is no doubt that I would be happy with the mod.I'll sleep on it for a while and maybe contact the vendors to get more direct feedback.
If forum members have had experience with these products (or similar products on 997's or others), please chime in!
Thanks,
Serge
#1158
04-16-2013, 03:18 PM
I'm in the same boat right now... looking for a nice x-pipe to increase the sound somewhat and give me a power bump. Personally I prefer build-quality over power gain any day, and from what I've read Agency Power has some quality issues. I think I'd lean more towards fabspeed. I'm really hoping sharwerks is coming out with an x-pipe for the 991 soon.
Here are 2 products that are relatively similar in their design and that are catching my attention:
Supersprint exhaust (under final development)
Scorpion Tuning Exhaust (I like the blue 'burnt' exhaust tips BTW)
Both exhaust should almost sound like straightpipes in loud mode (maybe the Supersprint even more than the Scorpion)
Now some people already complain that the PSE -which I already have- makes too much noise... Is it reasonable to go for something more aggressive
The only real concern would be to be banned from tracks that have more stringent sound limits or during quiet hours. Still, the exhaust could be switched to 'quiet' mode in that case.
The agony of choice
#1159
04-16-2013, 03:26 PM
Registered User
The Akrapovic system I'd installed in my former ZO6 was fantastic: it sounded killer at WOT on the highway (just like an F car).
I'm anxious to hear the system they develop for the 991.
I'm anxious to hear the system they develop for the 991.
#1160
04-16-2013, 03:29 PM
Yep, they certainly are a very reputable company, but their 991 exhaust is kind of a 'black box' (meaning, you can not see what's inside) and is also pricier. Not sure the fact that they use Titanium is really worth the extra $$. Sound clips are already available on their websites.
#1161
04-16-2013, 05:01 PM
Yep, they certainly are a very reputable company, but their 991 exhaust is kind of a 'black box' (meaning, you can not see what's inside) and is also pricier. Not sure the fact that they use Titanium is really worth the extra $$. Sound clips are already available on their websites.
Techart sounds pretty dull, and the sound of the Tubi left me cold as well.
Supersprint one sounds great!
#1162
04-16-2013, 05:09 PM
Yep, they certainly are a very reputable company, but their 991 exhaust is kind of a 'black box' (meaning, you can not see what's inside) and is also pricier. Not sure the fact that they use Titanium is really worth the extra $$. Sound clips are already available on their websites.
The titanium is great, is super light. At least you get a good amount of weight savings.
I have dozens of aftermarket exhaust on my various cars, and I have never seen anything compare to the quality of Akra, and they always sound amazing, no drone. Had it on my M3 last.
I did order it with the wireless valve kit, to fully control the volume.
I do like sounds the PSE makes, but there are just no performance or weight savings with it...so I passed on it.
#1163
04-16-2013, 05:12 PM
#1164
04-19-2013, 07:12 PM
Yep, they certainly are a very reputable company, but their 991 exhaust is kind of a 'black box' (meaning, you can not see what's inside) and is also pricier. Not sure the fact that they use Titanium is really worth the extra $$. Sound clips are already available on their websites.
The welds are typical Akra, meaning they are extremely well done, and its incredibly light.
#1165
04-19-2013, 07:37 PM
Nice, the fit and finish looks as good as always with Akra (saw one on a new F10 M5 recently). It would be great if you could share sound clips when you have it installed! Enjoy it!
#1167
04-19-2013, 07:46 PM
Who said the 911 was a 'glorified Beetle'? I am OK with it, I find even nice that there are some common genes... Try to find some similar heritage in Japanese cars for instance
Last edited by SM_ATL; 04-19-2013 at 07:53 PM.
#1168
04-19-2013, 08:03 PM
They indeed have much in common. My first Porsche (designed car) was a 1967 1300 cc Beatle. It got about the same MPG on the highway as my C2S!
