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360 CS Exhaust By-Pass

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

  1. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    several people have pinged me about the CS exhaust - I did give my car a thorough cavity examination today - I realized that my assumption that the by-pass mechanism would work like the Modena was wrong - it works like in the Enzo - it completely by-passes the silencer when open, i.e. it is a straight through connection from cat to inner exhaust pipe - if closed the valve pushes the flow up through the silencer and out through the outer exhaust pipe - see picture attached - unfortunately I could not find an angle to show the T connection

    regarding blocking the by-pass open – I wasn’t interested before but now I have to try that …

    regarding the Tubi exhaust for the CS - I hope that they only tune the silencer to a lower frequency to please customers - it would be a shame to remove the by-pass mechanism as they do with the Modena version

    regarding straight (test) pipes - I can not imagine what that will sound like - we already have 120 db in stock configuration ….
     
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  3. loungedog

    loungedog Formula Junior

    Nov 6, 2003
    286
    New Market, Ontario
    Thomas:

    regarding straight (test) pipes - imagine the weight you could save and the flames that you would shoot through every high rmp gear change :) ;)
     
  4. 720

    720 F1 Rookie

    Jul 14, 2003
    2,623
    So. Cal and No. Utah
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    Rick
    thanks thomas. a picture is worth a thousand words :) given your explanation would it be correct to conclude that the US stradale has the same exhaust sound as the euro stradale...at least when the bypass valve is open and the silencer portion of the system is not used?
     
  5. dan360

    dan360 F1 Rookie

    Feb 18, 2003
    2,669
    Boston
    Thanks - awesome !

    Apparently tubi are about to announce the details of their CS system. I met the two guys that run Tubi US @ Lime Rock last summer during the challenge weekend. They're complete car nuts, so I hope they've come up with something interesting. At least now I know the right questions to ask!
     
  6. spyderman

    spyderman Formula 3

    Nov 4, 2003
    1,473
    Toronto - Canada
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    Spyderman
    How does your car sound at 1000 rpm, like the stock 360 Modena?
     
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  8. manu

    manu Formula Junior

    Feb 20, 2002
    981
    London, UK
    Full Name:
    Manu
    We have just taken delivery of the GT Exhaust from Tubi Style for the Stradale - it will be fitted to the customers CS when it arrives early next month.

    1. It is the lightest system we've EVER handled for the 360.
    2. The Muffler is TINY - under 1/2 the size of OE CS muffler.
    3. Just looking at it you can see it is effectively direct exit (no need for bypass valves now).
    4. The muffler inlet and exit pipes are quite a bit larger than OE CS exhaust.
    5. In the interest of weight saving there is one exit tip per side (like the Challenge cars) finished with a straight-cut lip (like OE CS pipes). (this can be changed).
    6. Unlike the "stock" Tubi, it has rapid "clamp-on" fitment for the end tips.
    7. It's a "roadified" version of the system Tubi build for Michelloto's GT race cars.

    Overall, it's clear it's built for three things : power, lightness and a tonal quality to approximate to the 360 GT cars. (not challenge cars).

    Enjoy.
     
  9. spyderman

    spyderman Formula 3

    Nov 4, 2003
    1,473
    Toronto - Canada
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    Spyderman
    Any pictures of the exhaust?
     
  10. manu

    manu Formula Junior

    Feb 20, 2002
    981
    London, UK
    Full Name:
    Manu
    I'm working on it - ****ING digital cameras.
     
  11. Brian C. Stradale

    Brian C. Stradale F1 Rookie
    Lifetime Rossa

    Mar 17, 2002
    3,603
    Dallas, TX, USA
    Please, oh please:

    1) Dyno before and after.
    2) Record the audio of the dyno runs before and after.
    3) Weigh each exhaust while they are off the car.

    Each of those will be very interesting for several reasons,
    including future comparisons to US cars.

    Thanks!
     
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  13. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    >1. It is the lightest system we've EVER handled for the 360.
    >4. The muffler inlet and exit pipes are quite a bit larger than OE CS exhaust.

    !!! excellent

    >3. Just looking at it you can see it is effectively direct exit (no need for bypass valves now).

    need a picture - considering the flow of the exaust gas I can not imagine how to improve the CS installation other than to cut the by-pass valve out - so I am wondering
     
  14. manu

    manu Formula Junior

    Feb 20, 2002
    981
    London, UK
    Full Name:
    Manu


    Everyone knows that the CS sounds LOUD but it's not a "pretty" sound.
    The CS does NOT for example sound like an F1 car or a high-pitched howling F50/F355 etc. That's because of the muffler bypass operated by the valve at certain rpm (depending on the "mode" the driver engages).

    When the valve opens the exhaust is completely straight so although this is great for power and volume you cannot engineer any quality into the noise it's making because there is no muffler. (the only way to alter the tone with a completely straight system is if you change the length of the exhaust itself).

    Having said that CS owners don't want to lose power OR lose volume. So the muffler Tubi have put in (which MUST ALSO be functional at high rpm to give you a nice noise) is the smallest thing I've ever seen. It's more like a resonation chamber than muffler and moreover the inlet and exit pipes are larger than stock allowing for improved flow rate.

    The layout of the system itself is as follows.
    The right engine bank inlet from the cat is fed to the tiny silencer and crosses over to the left side exit and vice versa.

    In the two different stock scenarios - here's how the Tubi would be better:

    1.At low rpm with valve closed:
    a) The OE CS system is channeling flow through it's restrictive muffler completely silencing the car - crappy flow.
    b) Tubi - No valve here - exhust flow is being channelled through the PUNY near direct-exit muffler - as a result it's giving better flow conseequently noisier too!

    2.At high rpm with valve open:
    a)The OE system is channeling flow through the the muffler bypass channel. You're getting maximum flow, max volume but an uncontrolled harsh noise.
    B) Tubi - once again - no valve here - the Tubi is still passing exhaust flow through it's direct exit muffler. The key thing is - because it's more of resonation chamber than a muffler and the diameter of the inlet/exit pipes are larger you are losing NO FLOW over the stock - (likelihood is getting better flow that stock but will await dyno results). But now you're getting a MUCH nicer sound.

    A tricky conundrum solved.

    Bear in mind - the differences in all these flow rates/backpressure etc are ALWAYS marginal - do you even care?
    Hmmm,... Net result is you'll get a MUCH lighter exhaust which sounds a ****eload better.

    I PROMISE to have videos....
     
  15. amenasce

    amenasce Two Time F1 World Champ
    Silver Subscribed

    Oct 17, 2001
    28,371
    Paris / Chicago
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    Andrew Menasce
    anyone heard both the euro and us Stradales ?

    i still fear the US wont sound as good ( as Loud for Manu ;) ) ...
     
  16. rjklein

    rjklein Karting

    Nov 3, 2003
    124
    Can the CS tubi be used for a standard 360 with test pipes?

    Oh please say yes
     
  17. rscholl

    rscholl Formula Junior

    Dec 4, 2003
    296
    Houston,TX
    Do the test pipes (silenced or straight) replace the cats or are they separate?
     
  18. manu

    manu Formula Junior

    Feb 20, 2002
    981
    London, UK
    Full Name:
    Manu

    I do believe so...
    But believe me - the GT Tubi system is CRAZY - perfect for the CS owners (because they're coming from a really loud car) but too much for "normal" 360 owners.
    Tubi will not be making it, in anything like the stock 360 Tubi numbers. Only MANIAC 360 owners will be swapping out of their normal Tubis I reckon

    IMO, with test pipes, I think the exhaust will be too loud. (even for me -and I like cars to be REALLY REALLY ****ING NOISY).
     
  19. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    7,058
    I disagree (respectfully): There is a lot of room (shape-wise) to alter the tone of these engines, starting with the shape, diameter and length of the headers; through the shape of the entrance to the (if any) collector; and the shape of the end of the collector where it becomes an exhaust pipe again.

    For example; a step from header size to collector size sends a wave back up the header of the same shape as arrives, however, a convergent divergent duct from the header tot he collector will broaden and lengthen the shape of the return pulse. This HAS TO change the tone of the exhaust, because it is cahnging the shape of the pressure waves, and pressure waves ARE sound.

    There are those who would love to own a Stradale but never will because of the volume of sound. I think the volume of a stock F355 is barely tollerable for long runs. (And, yes, I have a large stock of ear plugs, but I seriously dislike having to put them iin to drive my cars or ride my motorcycles.) This has something to do with being too close to the stage in too many heavy metal concerts 20 years ago that damaged my hearing.
     
  20. manu

    manu Formula Junior

    Feb 20, 2002
    981
    London, UK
    Full Name:
    Manu
    Mitch - I have no argument - you are exactly right. I was referring to a cat-back change to a system that is already straight and must remain straight.

    What you've said is about headers is spot-on.
     
  21. Brian C. Stradale

    Brian C. Stradale F1 Rookie
    Lifetime Rossa

    Mar 17, 2002
    3,603
    Dallas, TX, USA
    While the Tubi alternative sounds very interesting... I completely disagree with the above statement... from the various videos of the CS, it is not just loud... it is a suhweeeeet sound!

    Again, I disagree. Mitch made one argument. Mine comes from the above opinion... I think Ferrari carefully engineered the sound of the CS... that didn't happen just by luck.

    Finally, since this is a street/track car... and I often mix with non-sportscar-radicals, I really like the silenced/bypassed approach. The Tubi will need to be distinctly better sounding or much lighter to justify the loss of the option to be reasonably quiet. (I doubt seriously we'll see anything on the dyno greater than measurement error.)

    And weights? and dyno numbers? Thanks!!
     
  22. amenasce

    amenasce Two Time F1 World Champ
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    Oct 17, 2001
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    Andrew Menasce

    Wait im confused ,

    The Stradale with the Tubi GT will be quieter than the stock Stradale ?
     
  23. manu

    manu Formula Junior

    Feb 20, 2002
    981
    London, UK
    Full Name:
    Manu
    OOps.. I've just added to the confusion.....

    - The Tubi GT is just as loud as stock CS but sounds nicer- additionally it's louder at low rpm...

    *********************************

    Brian - everyone is entitled to their opinion mate....

    I reckon Ferrari (rightly as far I'm concerned) think CS owners like a lot of volume (in keeping with a visceral car). But I don't think they would have considered how "nice" (tonal quality) all that volume sounds..

    My opinion is like this:
    The 360 (stock) sounds pretty average... a sewing machine whine below 4000rpm followed by a highly artifical bark - savage yes but a "sweet" noise??? hmmm.
    The 360 Challenge - too gravelly - too harsh. YUK.
    The 360 Stradale - LOUD but more of the same.

    I like a howling, high pitched note and *in my opinion* the CS does NOT have it... it's loud sure, but to me not nice... not nice for example like the even the stock F355 which is one of the most musical and glorious sound engines of all time.....


    Interestingly I had a conversation with Ferrari salesmen recently that said the stock Stradale exhaust was fun for a while and then got tiresome... NOT because of volume but because of the frequency.

    110dB of pure BASS (harshness etc) is terrible.
    110dB of howling F355 is bliss..
    If I have a point, that's the one I'm trying to make.

    Err.... :)


    P.S. Agree about the problem with dyno numbers - also agree about eliminating the option of keeping it quiet too (but I think CS owners don't care too much... after all race mode mean valve opens quite early hence noisy too). .. but it is very light and will sound AWESOME.. One thing though Brian - if Ferrari were THAT concerned about the sonic result of their cars you'd would not have a situation where LEGIONS of Ferraris owners switch out to Tubi/Fuchs/ etc etc...
    I'll get some clips up ASAP.
     
  24. Brian C. Stradale

    Brian C. Stradale F1 Rookie
    Lifetime Rossa

    Mar 17, 2002
    3,603
    Dallas, TX, USA
    Indeed. I like more of a growl than a whine; you prefer that higher pitch whine. Oh, BTW, have you heard the new Porsche Carrera GT... I'll wager you'll LOVE its sound... about as F1-like as I've ever heard in a road car. But me, I prefer the sound of the CS. But we do agree on the sound of the Challenge.

    I disagree. The majority of the customers do not want their car as loud as Tubis make them... Ferrari has to target them... but the overall sound, Tubi or Stock, is primarily driven by Ferrari's engineering, not Tubi's. People going to Tubi's has nothing to do with Ferrari not engineering the sound... it has to do with your first statement quoted above... everyone has their own opinion!
     
  25. rodsky

    rodsky Formula 3

    Mar 24, 2003
    1,601
    Los Angeles
    I for one agree with Manu. The 360CS is loud but it doesn't sound as good to me as say a Porsche Carrera GT. I like the F1 tone of the Carrera GT. The CS sounds good and loud and overall I like it, but I was disappointed with the "tone" of its loudness. I certainly don't think I could "live" with it being that loud every day.
     
  26. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    7,058
    An amasing amount of the noise is associated with the intake system. You could change this back to a 355 style intake (single harmonic) and get the pure howl of that system and lose some of the midrange power of the dual resonance intake the 360 has.

    Perhaps we are looking at modifying thw wrong component of the sound!
     
  27. bumboola

    bumboola Formula Junior

    Mar 7, 2003
    625
    Went to the Detroit auto show today, I think the 612 is a truly beautiful car in person, but it's not aggressive looking, especially with a Stradale w/stripe next to it.

    Anyway, I talked to a FNA representative at length and found out a few things. As for the Europe vs. US sound of the exhaust, he told me that the first batch of cars sent out in Europe had no cats at all, so that accounts for the incredible volume of some of the clips we have heard and the complaints from some magazines. He said all cars built after those have cats, regardless of where they were being shipped to. As for any differences between Europe and US versions now, he didn't believe that there was any difference. He didn't know for sure if the Europe cars had pre-cats or not. As for the US cars being held in customs, he said the first few cars were fitted with taller airbox covers for better flow and either new or recalibrated (can't remember) MAF sensors. It seems that there was a shortage of correct parts when they were built and they sent out the correct parts afterwards. Besides those first few cars, the rest came fitted with the proper (or updated?) parts. He also said cars are sometimes held up in customs for no reason at all, and there were no modifications made to the majority of them. He had no idea that the manuals state 409 hp, reiterated that the cars have 425 and that is a mistake. He didn't know of any significant difference in weight between Europe and US, said the cars has been built as a world car, the same in all markets. I asked him about removing the cats, he said the car would run poorly unless I could re-map the ECU and that it would not compensate enough for the change. I think that covers the main points.

    As for any changes to the 360 in the near future, he said don't believe everything you read. He spoke to Montezelomo at length for the first few days of the show and he told him not to expect a new car for at least 3 years, the car is still selling strongly and they were in no hurry to change it. There was never a mention of modifications to the engine or the car. The local dealer still has a 3 year wait on coupes and a 5 year wait on spiders! My bet is that they replace the Maranello within the next 2 years before they change the 360 at all.
     
  28. dan360

    dan360 F1 Rookie

    Feb 18, 2003
    2,669
    Boston
    Thanks bumboola - sounds like (as is standard with Ferrari) a less than 100% definitive answer. But at least this is v encouraging stuff.

    I assume it was a US stradale there rather than the Euro car that's been doing the rounds?
     

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