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      10-31-2009, 07:03 PM   #1
slipstream
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Stock Rear Section with Akra Mid-pipe Dyno & Vid

I just had the Akrapovic mid-section (X-pipe and high-flow cats) installed with the stock rear section. EF1 Motorsports in Signal Hill, CA, did the install, with Chasen from Dynotech handling the dyno pulls before and after. [Thanks, guys!]

I didn't get the image from the "After" dyno runs, yet, so I apologize for the minor tease. I will post those as soon as I receive them. Experts feel free to chime in about the "Before" traces.

UPDATE: I've added the "After" dyno runs and the comparison plot. The modification netted me 14.5 HP and 12.1 lb-ft of torque.

I'm still deciding on what rear section to get, so the car has not been tuned to fully take advantage of the new installation.

The car now has a racier (not ricey-er) sound at higher throttle openings, but there is no drone that I can hear at any RPM or throttle opening. It just sounds a little more aggressive overall, both inside and out. My memory of the full Akra system was of a quieter sound than this setup overall, which is a bit of a surprise. Anyone out there have just the Akra axle-back that thinks it is quieter than stock?

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Last edited by slipstream; 11-11-2009 at 11:27 PM.
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      10-31-2009, 09:43 PM   #2
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probably just the video, but sounds louder than stock for sure... and ricier (not racier..) :/
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      10-31-2009, 10:04 PM   #3
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Do you have to cut anything OEM to install it, and will this trigger a CEL?
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      10-31-2009, 10:31 PM   #4
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Sounds like you need the slip-on to finish the sound
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      10-31-2009, 10:49 PM   #5
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Numbers look great bud, especially given how low-reading that dyno is .
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      10-31-2009, 10:52 PM   #6
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Quote:
Originally Posted by smmmurf View Post
Do you have to cut anything OEM to install it, and will this trigger a CEL?
Nope. It bolts right on. I'm not sure you can buy it yet with the adapters. I bought the Akra parts from forum member Trier who had it paired with the AA Signature.

I am keeping the stock pipes in case I have trouble with smog 3 years from now. I haven't gotten the CEL yet, but I'm sure it will happen sooner or later. Akrapovic is supposed to be working on a fix.
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      11-01-2009, 01:02 AM   #7
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How much power/torque gain?
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      11-01-2009, 01:28 AM   #8
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I don't want to misspeak on the numbers, so I'm waiting until I get the other dyno graphs. It wasn't earth-shattering with no tune. Like I said, sorry to tease, but I thought they had sent me both sets of plots. I will post as soon as I have the graph.
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      11-01-2009, 06:06 AM   #9
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Quote:
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Sounds like you need the slip-on to finish the sound
I would agree - And the system is engineered to work together
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      11-01-2009, 07:28 AM   #10
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Quote:
Originally Posted by slipstream View Post
Nope. It bolts right on. I'm not sure you can buy it yet with the adapters. I bought the Akra parts from forum member Trier who had it paired with the AA Signature.

I am keeping the stock pipes in case I have trouble with smog 3 years from now. I haven't gotten the CEL yet, but I'm sure it will happen sooner or later. Akrapovic is supposed to be working on a fix.
I have been waiting for some time so I could pull the trigger and get one as well.
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      11-01-2009, 07:29 AM   #11
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First things first!

Quote:
Originally Posted by Moxie View Post
I would agree - And the system is engineered to work together
First I want to congradulate slipstream on his amazing X-pipe and review!

Second I think Akrapovic X-pipe is the highest quality product money can buy!

Third Engineered to work together maybe? The rear section is TUV approved which means quiet and somewhat restrictive. Not much more sound when installed with stock x-pipe.

Fourth I had this setup mated to an Active Autowerke rear section which was mean and agressive; I felt alot more power in the midrange compared to Akra rear section and alot better sound.

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      11-01-2009, 11:30 AM   #12
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Quote:
Originally Posted by Trier Germany View Post
First I want to congradulate slipstream on his amazing X-pipe and review!

Second I think Akrapovic X-pipe is the highest quality product money can buy!

Third Engineered to work together maybe? The rear section is TUV approved which means quiet and somewhat restrictive. Not much more sound when installed with stock x-pipe.

Fourth I had this setup mated to an Active Autowerke rear section which was mean and agressive; I felt alot more power in the midrange compared to Akra rear section and alot better sound.

I heard your clip you posted of your Akra & AA - It sounded good. Did you ever get any Dynos with the AA rear section compared to the Akra?

Like you mentioned, the Akra slip on is around the same db level as stock to keep it within TUV & I'm thinking one of the best performance oriented exhaust packages you can buy and stay within noise standards, agree? Not sure if there are many others out there that can match the weight reduction & gains. Of course it comes at a price - I'm an Akra fan - Just haven't made the plunge yet. Maybe in the spring after more R&D is done -
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      11-01-2009, 01:56 PM   #13
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Originally Posted by SECRET M View Post
probably just the video, but sounds louder than stock for sure... and ricier (not racier..) :/
Considering all those ricers out there with V8's to compare it too.
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      11-01-2009, 04:07 PM   #14
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I thought Akra didn't sell the x-pipe separately, has that changed?
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      11-01-2009, 05:29 PM   #15
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I guess Krenzer Performance Parts provides just the Akra x-pipe with adapters.

Quote:
Originally Posted by FStop7 View Post
I thought Akra didn't sell the x-pipe separately, has that changed?
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      11-01-2009, 06:22 PM   #16
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Quote:
Originally Posted by SECRET M View Post
probably just the video, but sounds louder than stock for sure... and ricier (not racier..) :/
Maybe u just have shitty speakers...
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      11-01-2009, 07:00 PM   #17
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Quote:
Originally Posted by FStop7 View Post
I thought Akra didn't sell the x-pipe separately, has that changed?
You can now buy the Akrapovic X-pipe separately
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      11-01-2009, 07:51 PM   #18
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Quote:
Originally Posted by M3_WC View Post
Considering all those ricers out there with V8's to compare it too.
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Maybe u just have shitty speakers...
i'm saying he's managed to get his V8 to sound like a coffee can exhaust. get off your high horses; didn't realize you guys would get so butt hurt about some honest feedback.. haha.

if it makes you sensitive guys feel any better, i'll be pairing the exact opposite (Akra Rear + OEM Mid) then pairing it later with an AA Mid or Fabspeed Mid.
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      11-01-2009, 10:04 PM   #19
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This modification was an experiment, and as such, I don't feel offended by negative comments. Exhaust sound is a personal preference. It does sound a little raw and unfinished.

I plan to buy something to replace the stock muffler at some point. From what I've read, the mid-section is where you get the most power gains, so I was curious what kind of results I would get. I expect there are others on the forum who share my curiosity.

It's all good.
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      11-02-2009, 07:02 PM   #20
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The dyno operator was shifting way too early which is what made it sound so bad. The actual pull sounded like a race engine.

I think it's the stock muffler - it's tuned for the OEM midsection. My car sounds a little "off" with the fabspeed resonated xpipe and the stock muffler at low speeds and high load. The thing sounds absolutely amazing at 4k plus though.

I would guess you get similar, but not identical, sound with all the aftermarket xpipes.

Thanks for posting this for the forum!
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      11-02-2009, 10:36 PM   #21
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Quote:
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The dyno operator was shifting way too early which is what made it sound so bad. The actual pull sounded like a race engine.

I think it's the stock muffler - it's tuned for the OEM midsection. My car sounds a little "off" with the fabspeed resonated xpipe and the stock muffler at low speeds and high load. The thing sounds absolutely amazing at 4k plus though.

I would guess you get similar, but not identical, sound with all the aftermarket xpipes.

Thanks for posting this for the forum!
I think you're right about X-pipes sounding similar, although I'm guessing the pipes without resonators all add a few more dBs. Mine also has a nice snarl starting around 4,000 rpm. Unless I'm shifting or on the gas, I hardly notice a difference from stock at lower rpm.
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      11-02-2009, 11:33 PM   #22
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Quote:
Originally Posted by Trier Germany View Post
First I want to congradulate slipstream on his amazing X-pipe and review!

Second I think Akrapovic X-pipe is the highest quality product money can buy!

Third Engineered to work together maybe? The rear section is TUV approved which means quiet and somewhat restrictive. Not much more sound when installed with stock x-pipe.

Fourth I had this setup mated to an Active Autowerke rear section which was mean and agressive; I felt alot more power in the midrange compared to Akra rear section and alot better sound.

That combo sounds GREAT.
How was it in the morning when you're leaving the house? Some get kinda boomy and are very loud at initial start up.
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