360 CS Exhaust By-Pass | Page 3 | FerrariChat

360 CS Exhaust By-Pass

Discussion in '360/430' started by thomas_b, Jan 6, 2004.

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  1. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    Luckily your flow of arguments is not 100% correct. You can not oversize the piping of an exhaust. Velocity of the exhaust gas helps to empty the combustion chamber. Pipes that are oversized, including no pipes at all, would reduce exhaust gas velocity (and you would suffer in the mid-rpm range).

    A proper design of an exhaust spec’s the pipes just large enough to get good flow at the same time keeping up velocity to aid in emptying exhaust gas. (Velocity creates gas movement inertia creates vacuum etc.)

    The best bet is to start with 100 cell larger cats and go from there – I tried to convince the http://www.europipe.be folks to do the same for the CS as they have done for the GT3 - unfortunately they want to focus on P cars – however they did give me good feedback

    I can se that F would not touch the air intake and exhaust dimensions simply for cost reasons. All that stuff has to be certified etc. and would create a complete new SKU – keeping headers, pre-cat and main cat makes a lot of sense to me - I assume most of the 9HP static gain are in the little stunt they pulled with the CS silencer by-pass

    F has changed the CS intake manifold, cylinder heads, crankcase however.

    Anyhow my conclusion is that there is something to be gained by optimizing the air intake and exhaust systems and I want to get it – not there yet

    I agree with your reasoning about heat problem
     
  2. bumboola

    bumboola Formula Junior

    Mar 7, 2003
    625
    Thomas, count me in on second silencer if you can find a company to do it, hopefully in titanium.

    I just want to add how appreciative I am also of your sharing of Stradale information on this board. Thanks.

    Paul
     
  3. spyderman

    spyderman Formula 3

    Nov 4, 2003
    1,594
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    Spyderman
    If it works....re sound, weight and HP gains...I am in as well!! I hope I am not asking to much :)
     
  4. Brian C. Stradale

    Brian C. Stradale F1 Rookie
    Lifetime Rossa

    Mar 17, 2002
    3,612
    Dallas, TX, USA
    That's an encouraging counter-argument!

    If the 9HP came from the by-pass, then why'd they do the latter three modifications?


    And, to chime in with others' support for your efforts... I think you know that you and I share almost identical goals with our Stradales... if you come up with a replacement silencer that is lighter and still gives adequate silencing, then I'm all for it. If it gives low-end power boost or improved sound, then that's just gravy.

    On the latter note, since the silencer is only at low rpms, we aren't talking higher flow as much as ideal backpressure for low-end torque, right? And sound-wise, that low-end full-bodied growl, without getting loud or too resonant.

    Similarly, based on your end-pipe weight measurements, if you can provide the rest of the exhaust piping with slightly larger diameter (or even same), but weighs half as much, saving another 10-20 pounds of weight, I'll be all over it. Pulling 30-40 pounds of dead weight off the car is very appealing.


    If you look into that route, I would think an intriguing option would be to use an insulated design... much like the round insulated ducting often used in commercial buildings... the tube walls are metal on the inside, high-R thermal insulation, and then metal on the outside... really channel that heat through and on out the back.

    The primary issue, I think, in any effort at keeping the heat in the exhaust until the outlet is that it will put extra burden on the cats... the cats need to be designed to handle a lot of heat flowing through them...

    So, we want a bigger, (pulling number from air) 5-10% higher flow cat that can handle (pulling number from air) 25% more heat... and we want that in a package that weighs less than the existing cats. :D I'm in! ;)

    Brian
     
  5. Brian C. Stradale

    Brian C. Stradale F1 Rookie
    Lifetime Rossa

    Mar 17, 2002
    3,612
    Dallas, TX, USA
    Maybe another thing we need to do is relocate the by-pass valve to before the cats, rather than after them. ;)

    Hmmm... at what RPM are the emissions tests done? Hopefully normal mode doesn't trigger by-pass until above that. ;)
     
  6. Victory

    Victory Formula Junior

    Jan 28, 2004
    412
    Keep the posts coming guys. I'm reading this with great interest, though I can't contribute anything on the subject. However my Stradale is coming this March and if by changing the exhaust system will enable me to get that extra bhp, I'm keen. :)
     
  7. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    >>>If the 9HP came from the by-pass, then why'd they do the latter three modifications?

    :) that is the reason I put the disclaimer there - until we understand the HP mess it seems to be all idle speculation

    >>If you look into that route, I would think an intriguing option would be to use an insulated design...

    Ceramic coating inside and outside is the way to go - usually done for headers so I am not sure what the impact is more towards the end of the exhaust - nevertheless this can be done easily and it looks very good too

    Maybe someone has done it and can jump in with details as well as recommend a company

    Not sure if Titanium can be coated too – thanks Paul (bumboola) for bringing titanium in – I was happy with stainless steel until you brought TI up – no I have one more thing to look into – anyhow good tip :)
     
  8. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    One of the first things that can be attacked is to make the muffler lighter. I believe 15lb is achievable with a straight-through design wrapped in a Carbon-fiber housing.
    See attached picture for my dream design. I want keep the CS piping and by-pass valve maybe re-done in Titanium with slightly increased tube size. No changes to the location and pipes of the muffler connection.

    The two pipe sized mufflers would be of the length of the current CS design. They would be on top of each other and the exhaust of the right bank would exit at the left tip and the left bank would exit at the right. I assume width should come in at 6inch versus the 9inch width of the stock exhaust. The carbon housing would be sandwiched between the two metal ends.

    The basic two design of mufflers are: Reactive silencer designs utilize chambers and baffles to attenuate noise associated with air or gas passage (mostly through noise cancellation). Absorptive silencers incorporate sound-deadening materials, fabrics, and compounds to absorb the noise energy of the air or gas flow.

    I believe from playing with the CS muffler that it is a hybrid designs use both reactive and absorptive design elements, combining both gas flow path management and acoustical materials to reduce noise. I assume it is a three chamber design with one for each input and a common output one. The weight of the CS muffler suggests to me that it is filled with fiberglass insulation or steel wool (which also explains why the sound changes after several hundred miles).

    However until I have opened the muffler up this is all speculation.

    A perforated pipe wrapped in fiberglass insulation, which absorbs sound waves, wrapped in carbon fiber housing would be my first choice. Such a design is commonly used in race cars, but it might be too loud.

    Furthermore it is not clear to me how much backpressure the CS needs to keep midrange torque. The race mode cuts out the muffler at around 3000rpm that would indicate that the backpressure created by the muffler is parasitic. This can be validated on the dyno by running it in normal mode up to 5000rpm – I’ll try to do this the next time I am on the dyno.

    What I am looking for is an exhaust guru that can do the design and metal work - Chris (Valence) I know could do a perfect job with the carbon cover

    such a muffler together with a complete carbon air box .... ahh
     
  9. ferrarifixer

    ferrarifixer F1 Veteran
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    Jul 22, 2003
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    I can now see the reason for this discussion.

    We had a track day yesterday here, and the Stradale was THE BIGGEST disappointment, noise wise.

    It looked good, but with 3 360 Challenge sporting rear wings the CS was lost in the crowd.....and the challenge cars can be bought for well under half the price of the CS!

    You could have a nice new 55ML AMG or Similar X5, new enclosed trailer and a used but good 360 Challenge for the price of one CS.....


    It's a no brainer from what I saw.

    Plus, the CS had to be driven carefully, because he wanted to drive it home. The challenge boys went for their lives on slicks and had a ball going 5-10 seconds in 90 faster. (But dont draw me into the "it's all about the driver" debate!)

    By the way, all the Challenge boys also have road Ferrari's anyway!
     
  10. 720

    720 F1 Rookie

    Jul 14, 2003
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    Rick
    did you call your dealer and ask for your deposit back? you were going to buy one, right? why don't the challenge boys buy stradales for their road cars?
     
  11. Aircon

    Aircon Ten Time F1 World Champ
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    Jun 23, 2003
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    In all fairness to the Stradale driver, it was his first time on the track! The sound was very odd, though. Nothing like the video we all saw/heard a few months ago of the car on a race track. Sort of a deep muffled/flat type of sound, I must say. The 355ch and 360ch cars actually sounded a lot better....the the 355ch cars were driven home too!
     
  12. ferrarifixer

    ferrarifixer F1 Veteran
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    Jul 22, 2003
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    yes, not to forget the 355CH. You could have 3 of those for the price of one Stradale!

    720....My point is, that if it's track days that float your boat, then a CS is really the wrong car.

    On the road, you'd want nothing else of course!

    The challenge boys have a number of their own road Ferraris to chose from, and none of them would buy a CS in my opinion.

    I guess it's mostly first time Ferrari owners, or strictly road drivers that would buy one? I coudn't justify the price in my mind (or my wifes), even if I could afford one.

    No, I'll stick to my BB thanks.
     
  13. WCH

    WCH F1 Veteran
    Owner

    Mar 16, 2003
    5,180
    "I guess it's mostly first time Ferrari owners, or strictly road drivers that would buy one?"

    Just sold my 360C, will soon be receiving my CS (stage 90!). One of the principal reasons I sold the 360C was that, though it's a fantastic car, I am more interested in racing than track days, and there just aren't that many places to race the car. Plan to track the CS a few times (4 or 5?) a year, follow this thread with great interest.
     
  14. Brian C. Stradale

    Brian C. Stradale F1 Rookie
    Lifetime Rossa

    Mar 17, 2002
    3,612
    Dallas, TX, USA
    I don't get this logic. Track days are not about winning... the last thing you want is a car that's 5s faster than everybody else... you'll just be held up by traffic all day.

    For track days, here's what I want:

    1) a car that feels great driving on the edge
    2) a car that sounds great driving on the edge
    3) a car that you can drive on the edge without worrying about breaking it
    4) a car that's fun to look at and talk about in the paddock between sessions
    5) a car that can be driven on the track with minimal extra work/fuss
    6) a car that is fun to drive on the road for the 1hour to 6 hours (or more) from house to track

    With the Stradale, from all accounts, I get all of those requirements fulfilled (and typically fulfilled brilliantly).

    With a 355C or 360C, it fails the latter two. I get to drive a tow vehicle pulling a big trailer to the event. Ick. Have to deal with all the extra hassle of trailering it. And then either I need to do my own maintenance, or I have to deal with trailering it to my mechanics for that. Ick.

    So, if I weight those 6 criteria equally, Stradale gets an A+ as a track day car; Challenge cars get a C-.
     
  15. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765

    Car might have not been in "race" mode? Was the sound as loud or louder as the 360ch cars?
     
  16. Aircon

    Aircon Ten Time F1 World Champ
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    You live in the wrong country. My 355CH is registered, driven to and from the track and puts a smile of my face on and off the track whether it's a 5 mins or 5 hour drive! I haven't seen any evidence that a Stradale actually outperforms my car, yet. It proabably will, though.
     
  17. Aircon

    Aircon Ten Time F1 World Champ
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    Not as loud, but you could hear when the by pass valve opened up...so race mode or not, i'm guessing it would have made the same sound, but the valve opens at higher revs?
     
  18. Brian C. Stradale

    Brian C. Stradale F1 Rookie
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    Mar 17, 2002
    3,612
    Dallas, TX, USA
    Cool... if you can drive the Challenge cars on the street, then yes that's a totally different thing...

    I forgot one key requirement for track days usage:
    7) a car with a passenger seat for friend or instructor

    Soo, given you can easily add a passenger seat to a 360C and register it for street use, I would agree... there's essentially no way to justify the price delta for a CS over a 360C... in Australia! Not sure why any CS's would go there. But for much of the rest of the world, the CS is a great track day car!
     
  19. Aircon

    Aircon Ten Time F1 World Champ
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    I didn't say anything about a 360CH! AFAIK they can't be registered anywhere in the world! They don't have air conditioning, either. However, the 355CH has all the road car comforts put back in it (or not removed in the first place) and, at Fiorano at least, laps faster than a 360CS. (tires might come into that though)

    1'25"40 355 Challenge
    1'28"00 360 Challenge Stradale

    Money no object? Weeeelllll.......I guess you'd have to go stradale hey...or an Enzo perhaps? :)
     
  20. Mako99

    Mako99 Formula Junior
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    Dec 29, 2003
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    The 355 Challenge Fiorano time you're quoting was on slicks.
    The 360 CS time you're quoting was on its stock street tires.
     
  21. Aircon

    Aircon Ten Time F1 World Champ
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    I know...that why i mentioned the tires. Did you notice? I also said I've seen no evidence that the Stradale is faster....but maybe it is!
     
  22. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    In my quest for the perfect exhaust I run across http://www.EisenHaus.com

    Titanium exhaust: http://www.eisenhaus.com/gallery/pics/Fer_360_kre_3.jpg

    By-pass valve: http://www.eisenhaus.com/gallery/pics/Fer_360_kre_8.jpg

    Video: http://www.dtmhaus.com/Kreissieg/360_8-20-360-5000rpm.mpg (save to disk first)

    For more information navigate to

    >>Custom Exhausts
    >>>>>Ferrari + F360 + Modena/Spider – Type F1 Race (Titanium)
    + 4x76mm (Kreissieg Type F1)

    Look at pictures and play videos – don’t look at price (not first anyhow)

    Design is a little over the top for me – but it mirrors the CS – look at the by-pass valve in Titanium!!!

    exhaust is made in Japan
     
  23. spyderman

    spyderman Formula 3

    Nov 4, 2003
    1,594
    Toronto - Canada
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    Spyderman
    I am not a big fan of the sound of the exhaust on this video. :(
     
  24. ferrarifixer

    ferrarifixer F1 Veteran
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    Jul 22, 2003
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    The standard 360M, CS and C exhausts all have opposing flow inside the silencers. This causes immense turbulence and inefficiencies.

    The exhaust on my 360C "speciale" is an "x" merge system. One of a few built for the race team. It weighs only 12kg, but we also built an 8kg one that's a bit fragile. The std 360C system inc cats and brackets is 22kg.

    The "speciale" merges below the air box into an "X". At the centre of the X is a large oval hole connecting the two pipes.....so there is minimal restriction. This causes the two banks to self scavenge each other, and create a sound a bit like a 355, but higher. It's not too loud, about 90db. It has two small silencers where the cats were, and two more medium ones over the floor venturi's.

    The down side is heat around the air box. ooodles of nice shiny insulation take care of holding the heat in the exhaust, and also more reflecting off the air box.

    It gives a std 360C WITHOUT CATS another 5 BHP and 8lb ft of torque. So about 12 and 20 over a cat system?
     
  25. wazza

    wazza Formula Junior

    Oct 9, 2003
    614
    I'm not a big fan of the price either !!!!!

    Wazza
     

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