Which exhaust yields the most power?
#32
07-26-2006, 10:07 PM
Originally Posted by Evan@FVD
Stop wishing you had the Race exhaust and just buy mine 
You can pick up my race for $2500 bux and just sell your Export for $2,000 or so! Come on for $500 bux!!!
Evan
You can pick up my race for $2500 bux and just sell your Export for $2,000 or so! Come on for $500 bux!!!Evan
#33
07-26-2006, 10:35 PM
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Join Date: Jun 2005
Location: Gig Harbor, WA
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Originally Posted by GHOSTRIDER-TT
I am very happy with my Fabspeed Supersport GT2 Loud.
Sounds great!
Sounds great!
thanks
#34
07-26-2006, 11:03 PM
Ring the bell...
Originally Posted by Craig
I have never seen a 9ff Variotune, so I cannot comment on it. However, most of the valved/switchable exhausts that I have seen have a common design shortcoming. The valve is half way through the pipe running parallel to the cat/muffler, such that, when the valve is closed, the exhaust flow is permitted to travel down the pipe to the closed valve, thereby creating resistance/turbulence, and when the value is open, the exhaust flow is still split between two open pipes, with some of the exhaust flow traveling through the cat/muffler. IMHO, this design is not optimal in either the open or closed position.
I have never spit fire, and I do not have straight pipes.
Craig
I have never spit fire, and I do not have straight pipes.
Craig
The key to eliminating resonance is knowing exactly what the final path the flow will take. Its a bunch of math really. The reason resonance has been an issue is that too often manufacturers/designers try and make the most power but dont factor harmonic frequencies into their calculations.
If you know anything about music and/or physics you should be able to calculate harmonic frequencies based on the knowledge of the pipe length, it course and the pipe thickness!
Regarding your assesment of the variotune valve function and operation...I hate to inform you that you are incorrect (again).
Without giving away all 9ff's secrets, the valve is nothing like you described. Going back to physics 101, you may remeber that flow travels preferentially down the path of least resistance (just like rivers and global diplomacy)...the valve sits VERY close to the exit point such that when in its closed position, the flow follows the low-resistance circuit; through the muffler.
By the way, 9ff just completed a Variotune for their High HP applications (650HP+) Obviously, at this level of power...heat becomes a real issue!
Joe, should I send this one or the +39HP version over?
Both incidentally are streel legal, with full TÃœV approval.
#35
07-26-2006, 11:41 PM
Originally Posted by ECB
Of course the real superiority that the variotune has over all other "competitors" is its complete and absolute lack of resonance, a weigh savings of 20 lbs, the smooth mellifluous soundtrack , but most of all the advanced technology that allows the selection of either a "loud" setting or the quieter "sport" setting.
The beauty of the system is that unlike the fine Kreis-seg, the 9ff's valves are entirely behind the cats. As such, the only diversion involves the mufflers. The importance of this is that the power delta between open and closed modes is negligible.
Actually maybe what we should do this time is send all the exhausts to germany so that the american brands can attempt TUV certification. Wherein not only must they be proven to work, but also tested for noise and emissions compliance.
By the way, there's a tech test in this months Luxury and Modified Exotics...check it out, and our vids too. My favorite is the first - "rolling thunder".
The beauty of the system is that unlike the fine Kreis-seg, the 9ff's valves are entirely behind the cats. As such, the only diversion involves the mufflers. The importance of this is that the power delta between open and closed modes is negligible.
Actually maybe what we should do this time is send all the exhausts to germany so that the american brands can attempt TUV certification. Wherein not only must they be proven to work, but also tested for noise and emissions compliance.
By the way, there's a tech test in this months Luxury and Modified Exotics...check it out, and our vids too. My favorite is the first - "rolling thunder".
Last edited by ebaker; 07-26-2006 at 11:45 PM.
#36
07-28-2006, 01:06 PM
Registered User
Join Date: May 2006
Location: Pompano Beach, Florida
Posts: 204
Rep Power: 27
Just to clarify a few things...
https://www.6speedonline.com/forums/...501#post662501
Regards,
Your FVD Team!
https://www.6speedonline.com/forums/...501#post662501
Regards,
Your FVD Team!
#37
07-28-2006, 03:51 PM
Originally Posted by Erik@Cargraphic
Which manufacturers were not brave enough to show? I know for a fact had cargraphic been made aware of such a shoot-out we would have surely participated.
For the record, we have dyno tested Fabspeed 996TT mufflers and our mufflers back to back on client cars and found little difference in power, although the Fabspeed did its work with *a lot* more noise volume.
#41
11-08-2006, 03:48 PM
Originally Posted by Craig
The exhaust that did well in the IA test was a Fabspeed Loud, not quiet (I think the Quiet uses a chamber muffler -- I am not sure about this). The reason the Fabspeed Loud did well is because it used (and may still use) a straight through muffler, as opposed to a restrictive chamber muffler (that is also why the Fabspeed Loud is louder than other exhausts). Unfortunately, the Fabspeed Loud uses relatively small 2.5 inch piping. IMHO, 2.5 inch piping is far too restrcive for higher HP applications. Thats why I had a custom exhaust made. I wanted to use straight through mufflers, similar to the Fabspeed (although my Burns Stainless straight through mufflers are better), but with larger 3 inch piping to permit greater flow. I also eliminated the cats for even better flow.
Craig
Craig
I was considering having a Custom Exaust built as well.. My idea was to Do a Staright Thru Muffler and remove the cats, but add 2 resonators in place to keep the noise down.. 3inch piping all the way.....
Last edited by Rambino; 11-08-2006 at 04:02 PM.
#42
11-09-2006, 12:49 AM
Basic Sponsor
This is my custom exhaust... I personally don't give a damn about resonance... I have a pair of GT35rs with TIAL 44 mm Wgs... LOL
__________________
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
#43
11-09-2006, 01:53 AM
Originally Posted by MARKSKI
This is my custom exhaust... I personally don't give a damn about resonance... I have a pair of GT35rs with TIAL 44 mm Wgs... LOL
#44
11-09-2006, 03:53 AM
Basic Sponsor
I know Mike.... they already are at .9 bars....
BTW- Ill be in ALberta on dec. 2nd....
BTW- Ill be in ALberta on dec. 2nd....
__________________
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
