Report on my exhaust

Md11skipper · 10-27-2009, 02:20 PM #1

Akrapvoic Evolution Race Exhaust System report

akrapovic.com/car-exhaust/products/porsche/model/997-gt3-rs-2009/racing-d3b1cd5d3b/

I finally set the time aside to write a long overdue installation and drive report of my Akrapovic Evolution Race Exhaust System.

First, why did I purchase the Akrapovic Evolution Race system and not another system?

#Price, I got a good deal from FVD to be the launch customer for this system as long as I write a full report and include a video. Shortly after I installed the system, FVD decided not to market this exhaust company anymore (unfortunately because Rhonda, Mark and the rest of the team stand way above most other aftermarket companies, dealing with them was a first class experience)!!!
It took quite a while to get the system manufactured and shipped to the US. The packaging and owners manual including installation manual - DVD, were the first signs of a superb experience with this system.
I fitted the complete system to weigh on my bathroom scale, weight: 31lbs. I did not weight the individual items - parts but can tell you the headers - cats are feather light. After talking to Wolfgang Dietz who is the main distributor in Austria, Switzerland and Germany, I learned besides other information that Akrapovic has access to military grade titanium which explains their confidence in selling systems made out of titanium.
Installation was a lot of fun because taking off each part of the original exhaust reminded me each time of the weight savings I will experience up to 3’ behind the rear wheel axle (savings of about 60lbs). Wolfgang was told from Manthey racing that you can effectively multiply the weight savings by 3 under lateral acceleration. Good to know but most likely of no use for me since I will not race the car. I get off on knowing to have a top system on my car.

#Quality, second to none from what I have seen.
The Porsche GT3 RS was my dream car for quite a long time, I always felt connected with this company ever since I was 18 and saw my first turbo. I felt if I modify my GT3 RS, only the best will be fitted and Akrapovic to this day makes me believe I made a good decision.
When I bought the car used, it came with long tube aftermarket headers and mufflers and I did not like the power delivery that much. When accelerating, I felt a very strong pull in the midrange but it somewhat stagnated in the upper rpm range from 6500 rpm to redline, it was somewhat lagging. After I put on the stock system I could tell the difference in design - stock headers are a lot shorter and the pull was a very even power increase till red line. I like that a lot more for my driving style. When I compared the stock headers with the Akrapovic headers, they seemed to be the same length. Below is a little excerpt from Stef who owns Europipe (another great exhaust system company in Belgium):

“ We used to build race exhausts for years so we are aware of the different power curves that you'll get with different tube lengths and tube diameters. *Basically you'll get more peak hp with short headers and more hp at midrange with long headers. *The Akrapovic headers seem to have about the same tube length as the stock Porsche headers and that is good. *With the long headers you'll get more torque and less peak hp indeed.
The benefit of your 100 cell cats is that your exhaust system will be more free flowing aka having less back pressure. The benefit of the lower back pressure is that you can add more advance ignition timing and more ignition timing results in more power from idle to redline”.

I also noticed on the Akrapovic website the power diagram shows no drop in the midrange. The stock system in comparison has a small drop off in the midrange which I happily confirmed when driving the car after the system was installed.

Back to the installation, it was a perfect fit in every detail, the instruction DVD and manual were first class, every set of crews, nuts and seals was packaged in separate zip lock bags and included special anti freeze paste - very impressive. After I installed the system in my own garage on a kwik lift, I wiped down the whole system with a drenched in WD40 rag as instructed (to eliminate finger prints which would be permanent if burned in) and after the first heat cycle the system turned into to most incredible purple bluish color.

#Driving impressions: Excellent but at first after having driven the car with the too quiet for me stock exhaust, I felt it was way too loud!
A week of driving went by and I got used to it and actually started to really dig it. On several drives with other Porsche enthusiasts, I was told they all wanted to drive right behind me because the sound and my blipping of the throttle was just the best they ever heard. One 60 year old wife of another Porsche owner who usually shuns these drives, said to the dislike of her husband, that this was by far the best drive she has ever been on because of listening to the sound of my car - really!
Power delivery is steadily increasing all the way to redline just the way I like it BUT unfortunately there is a little drone between 1800 and 2800 rpm. Here is another excerpt from Stef - Europipe:

“We've build several prototype central mufflers for the 997 GT3 just like your Akrapovic setup and had plenty of drone too. *Also the sound inside the cabin was loud up to 3000 rpm , quieter between 3000 rpm and 5000 rpm and again somewhat louder up to redline. *Not good. *The total lenght of the main exhaust pipes is too short , hence the drone”.

In other words the distance from the cat outlets to the rear central muffler is too short to get rid of this drone but on a race system if used for racing, who cares? I use it for street hence I would rather have no drone but I can live with it.

In my case it is only somewhat irritating between 1800 - 2800 rpm. In quiet neighbor hoods, I just keep the rpm below 1800 or quickly get the rpm up above 3000 with no load.

The throttle response is awesome and the 100 cell cats are trouble free, I was first worried that they may not be able to control the CO within the range the ECU dictates but after going to my very supportive dealer, they confirmed with their magic box that the O2 sensors have absolutely no problem controlling the values as needed. I never had a check engine light come on or a rough idling engine.
Right after I got the system installed, I purchased the side mufflers for this system, just in case I either move to Europe with the car or get tired of the race sound. So far they are still laying around gathering dust because I love the sound the way it is right now.
I plan on seeing MAX RPM who is an Evolution motor sports dealer and have my ECU finely tuned to the Akrapovic system on their dyno, date is not yet set. I heard super good reports about Todd Zuccone and feel confident that he will together with MAX RPM dial the system in to perfection.

If I install the side mufflers as seen on the picture below, I will write an update on this site. Till then if you have any questions please let me know either via a response here or via a pm.

Hope I could enlighten some of you folks who were waiting for this write up.
Akrapovic sure made my love affair with the GT3 RS even bigger- what a car!

Link to a youtube recording of my car with the Akrapovic Evolution Race system installed:

http://www.youtube.com/watch?v=fwgM7aRFiEI

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80shilling · 10-27-2009, 03:39 PM #2

GREAT write-up !!! Fantastic pictures and video... Overall one of the best posts on this subject.. Rep given.

Glock Guru · 10-27-2009, 05:03 PM #3

Great write up. Thanks for all the good info and time to post it.

-Troy

GT3Ranger · 10-27-2009, 07:35 PM #4

Do you have pre and post dyno #'s?

Ranger

D-UberCars · 10-28-2009, 09:27 PM #5

Have seen this RS at a MaxRPM function, WOW! Sweet exhaust, especially sweet RS!

GT3Ranger · 10-28-2009, 11:18 PM #6

Hey Md11skipper glad to read you're happy with the system.
A couple questions though.
Reading your write up I do not understand what happened with FVD? What exhaust system did they not go through with or dropped?
Looking at the collectors the design is ?
They have the bung on the cats?
The entire system, headers, tubes, cats, rear center muffler / resonator and tips all weigh 31 lbs?
How does it save 60 lbs? Deleting the OEM side mufflers = 42 lbs.
How much does each header bank w/ cat weigh?
Did you do an ECU tune to compliment the headers / exhaust system?

You stated the RS had aftermarket long tube headers when you bought it. Just currious, which headers were those?

btw the comment about 3 times weight savings with "g force' turns is not valid. The 3x's rule applys to the equation of unsprung weight and rotating mass.

Nice road you have there to do your runs.

Also btw did you do stock and post Akrapovic install dyno's?
You have to dyno.
One final question. Cost of the system. If you like PM me.

Enjoy the system and best of luck.

Ranger

rvhpno80 · 10-28-2009, 11:27 PM #7

wow, excellent footage.... i thought Akrapvoic exhaust were only for Motorcycles, see you learn something new everyday....

Md11skipper · 10-29-2009, 11:16 AM #8

To answer your questions:

#I have not talked with Rhonda (FVD) for a few month now but my last talk with her, she told me that they will not represent Akrapovic after all even though I bought the complete Akrapovic system from them (FVD). They may have changed their business strategy and now represent Akrapovic again, that would be great, my experience with them was superb.
#Sorry, I don't understand these two questions:

Looking at the collectors the design is ?
They have the bung on the cats?

#The whole system as installed weighs 31 lbs, I believe the first picture shows my system on a yellow blanket, this is the way I weighed it, turned it vertical and balanced it on a scale with one finger so as not to influence the reading.
#I was told the complete stock exhaust weighs about 90lbs, mine weighs as stated 31lbs, makes a difference of about 60lbs, I did not weigh the individual parts of the Akrapovic or the stock system.
#Wolfgang Dietz from Akrapovic recommended to tune the ECU on a dyno, I will do that within the next three month, I can then write another report and update all of you
#Which headers did the car come with? Sorry, I do not want to disrespect any company hence I do not want to mention manufacturers. Anyway, what works for some does not work for others and I believe different headers for different applications. Possibly short and tight road courses would benefit long tube headers (more torque in the midrange, hence better acceleration out of the tight turns) and fast race courses with high speed turns would benefit short tube headers due to exiting in higher rpms. This is just a guess on my part, I am not an expert whatsoever!
#3x60lbs: I just quoted Wolgang Dietz who runs the Akrapovic race team in Europe, he talked to Manthey and was given this information. I think what Manthey was referring to is the 60lbs times the distance to the rear axle between 2' and 3' will result in an effective weight which is about 3 times as much under lateral acceleration. The scientists could jump in and enlighten us all in this subject.
#I think the system cost is between $10k and $14k depending on the exchange rate and incentives the company will give at the time of order.

I hope to have answered all your questions!

Quote:

Originally Posted by GT3Ranger

Hey Md11skipper glad to read you're happy with the system.
A couple questions though.
Reading your write up I do not understand what happened with FVD? What exhaust system did they not go through with or dropped?
Looking at the collectors the design is ?
They have the bung on the cats?
The entire system, headers, tubes, cats, rear center muffler / resonator and tips all weigh 31 lbs?
How does it save 60 lbs? Deleting the OEM side mufflers = 42 lbs.
How much does each header bank w/ cat weigh?
Did you do an ECU tune to compliment the headers / exhaust system?

You stated the RS had aftermarket long tube headers when you bought it. Just currious, which headers were those?

btw the comment about 3 times weight savings with "g force' turns is not valid. The 3x's rule applys to the equation of unsprung weight and rotating mass.

Nice road you have there to do your runs.

Also btw did you do stock and post Akrapovic install dyno's?
You have to dyno.
One final question. Cost of the system. If you like PM me.

Enjoy the system and best of luck.

Ranger

GT3Ranger · 10-29-2009, 10:36 PM #9

Md11skipper thanks for the response.
I look forward to your dyno results.
I too am not an expert but I am physician(radiologist) with much physics education and the weight claim loss stated is bunk. Whoever said that has no knowledge of unsprung weight and the rotoring mass.
The collector appears unusual. That's what I meant.
btw is this a titanium system?

Beautiful GT3RS, white is my favorite color. I bought orange because that's what was available when I made my move.

Best of luck and dyno the system.

Ranger

my997turbo · 10-29-2009, 11:25 PM #10

Are you at pacific raceways in washington in the video?
It looks very familiar...

mikymu · 10-30-2009, 01:22 AM #11

Very nice write up and love how the exhaust look! I am sure it has that multi-color glow once titanium is pipping hot. 60 lbs of weight saving is fantastic for our rear heavy RS. I was only able to shave off a total of 25 lbs with Euro rear bumper and center muffler bypass. I do have to say $10K- $15K is ..... well, mighty expensive. I got a set of OEM CSL exhaust for my E46 M3 from Germany and it cost around $5K and I thought it was outrageously expensive for a gain of better sound and 25+ hp and torque. I am sure your new exhaust is very loud. Do heat up the 100 cell cats well if you have to smog with it.

Md11skipper · 10-30-2009, 02:35 PM #12

Yes, this system is full titanium, that explains the low weight!

You are correct the youtube movie was filmed at the Pacific Raceway.

I am with you when it comes to cost of the system but the whole hobby is outrageously expensive, it's all passion and feel good. I feel good about this system on my car and I don't regret spending a s... load of money on the GT3 RS hobby.
Actually these 100 cell cats don't give me any problems what soever, hope it stays that way.