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X-51 headers & AWE (HJS) Cats on stock mufflers

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Old 02-08-2008, 01:43 PM
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X-51 headers & AWE (HJS) Cats on stock mufflers

Well, another one on the exhaust...
I'm planning to to the X-51 headers along with the AWE 200 cell cats to improve air flow, but with the stock non-PSE mufflers.

I'm not in for to much sound, especially as the local track is very restrictive on the noise side...

Will this setup improve things, or do I have to do the mufflers to get some gains ?

I have always been told that there weren't any HP in the mufflers, but...

Thanks a lot

Cedric

P.S : If anyone has a got idea in finding or making a hoose with venturi effect for the X51 air box (junction hoose from box to throttle body), I'm in, because I think it is the only effective way to really improve the air flow. Just adapting the existing one may create turbulences in the flow, that you really don't want (unless I missed the point, talked with the Porsche motor guy :-)).
 
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Old 02-08-2008, 02:35 PM
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I think you would be happier with the mufflers also. They just sound cleaner than the stock ones and have a flow through design.
 
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Old 02-08-2008, 03:51 PM
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Originally Posted by cid042
Well, another one on the exhaust...
I'm planning to to the X-51 headers along with the AWE 200 cell cats to improve air flow, but with the stock non-PSE mufflers.

I'm not in for to much sound, especially as the local track is very restrictive on the noise side...

Will this setup improve things, or do I have to do the mufflers to get some gains ?

I have always been told that there weren't any HP in the mufflers, but...

Thanks a lot

Cedric

P.S : If anyone has a got idea in finding or making a hoose with venturi effect for the X51 air box (junction hoose from box to throttle body), I'm in, because I think it is the only effective way to really improve the air flow. Just adapting the existing one may create turbulences in the flow, that you really don't want (unless I missed the point, talked with the Porsche motor guy :-)).

I have that exact set up on my car now. Ideally I would like to have the Remus exhaust but this works very well for now. It is definitely louder then stock but not as loud as it was with the AWE muffler. The AWE muffler was not bad and I enjoyed it for the most part but I am planning to use my 911 more as my Daily Driver so I wanted it quieter. I probably gave up a few HP at the top end but I am not complaining. My thoughts on this exhaust are that most of the HP gains are in the Header and Cats. The APR ECU tune makes a very nice improvement too.

As far as the X-51 Airbox I understand what you are saying. I tried to modify my adapter wring to do what you are saying but gave up.

I did add the Modified Throttle Body(which creates a venturi effect) from the Folks That sell the RSS plenum and I think that achieved the best result. On a thread on the Plenum you can see how they modified it. Being that the air is drawn or sucked in I think the balance of the turbulence is minor given the bellows design of the hose between the air box and the TB.
 
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Old 02-08-2008, 03:59 PM
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Go here for a picture of the modified Plenum. If you want a side by side picture of Stock vs Modified. PM with your e-mail or e-mail me at ddodd100@charter.net.
https://www.6speedonline.com/forums/...111315&page=16
 
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Old 02-10-2008, 06:14 AM
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Thanks a lot DNDODD.

Did you find that the modified throttle body added something (in BHP or feel) by itself ?

We will have approx the same engine setup, as I am also adding a plenum.

I will also use C2BS (french company) sparks which are modified NGK ones, know for better efficiency : a few HP and better MPG plus improving pollution (no CELL with Hi-FLow Cats, even tested without cats...). Beside that, I'll try the GDA with is an additive to mix with oil. Those two mods have been tested and approved with before and after dynos by a reputable magazine here (Flat 6).
 
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Old 02-10-2008, 07:59 AM
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"Did you find that the modified throttle body added something (in BHP or feel) by itself ?"

By feel maybe a little bit. But that was one quick 4-5 mile run.

I would be interested to know more about the Plugs and GDA? Do you have any links?
 
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Old 02-10-2008, 09:47 AM
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Here you are, but only in french :-( :
C2BS plugs :
http://www.c2bs-bougies.com/page/bienvenue.htm
Mecatech (GDA) :
http://www.mecatech-lub.com/gest/up/FTD%20101.pdf

Don't hesitate to ask me, if you need a little bit of translation...

Cedric
 
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Old 02-10-2008, 11:50 AM
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No help to me. But let me know of your experience with the plugs. I am curious as to why they haven't caught on in the states yet?
 
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Old 02-10-2008, 12:47 PM
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Well, I don't know... What I know is they are using a patented process and have several happy users in the french forums, as well as the GDA which seems to have proven its efficiency in reducing the engine frictions and therefore reducing the engine temp and noise.

I will tell you when they will be on the car.
 
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Old 02-10-2008, 04:17 PM
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I forgot to say the reason it is no help to me because I can't read or speak French. So I will wait to hear from you.
 
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