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Speciale Sound Crisis

Discussion in '458 Italia/488/F8' started by clar, Oct 28, 2014.

  1. 720

    720 F1 Rookie

    Jul 14, 2003
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    #326 720, Nov 5, 2015
    Last edited: Nov 5, 2015
    Hi. It's still pretty quiet at idle and low RPMs. I should have installed one of those exhaust bypass valve controllers :) but when the exhaust valves do open it's perfect...IMHO :)

     
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  3. dustman

    dustman F1 Veteran
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    Jun 12, 2007
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    Rick, All you changed are the cats?
    My Speciale needs love.
     
  4. spyderman

    spyderman Formula 3

    Nov 4, 2003
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    I'm interested in doing the same...200 cell cats or bye pass pipes with mini cats sounds like the best plan of attack.
     
  5. 720

    720 F1 Rookie

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    Yes, 200 cell cats only. I originally planned on keeping the OEM cats (they are 800 cell) and replacing the back box with a Frequency Intelligence Ultimate Race exhaust. I contacted Frequency Intelligence and asked for their opinion on this setup. They said the exhaust sound would be improved, but they recommend straight pipes and their back box. That setup is definitely the ultimate exhaust sound, but for me it is too extreme since I primarily drive in town (I don't track my cars).

    But then I read a post by fchat guy Chrixxx who tried several different combinations of cats and back boxes. He ultimately concluded that 100 cell cats and the OEM back box was an ideal setup for him...much more aggressive, but still reasonably suitable for civilized society :) I decided to try this (but I opted for Capristo 200 cell cats), and the results were exactly what I was hoping for. If I ever decide that I want to go to the next step then I would replace my OEM back box with a Frequency Intelligence Ultimate Race exhaust. I bet this would be just a couple clicks away from the insane sound of straight pipes and Frequency Intelligence exhaust!


     
  6. abdulla.alhajri

    abdulla.alhajri Karting

    Jul 16, 2015
    106
    +1
     
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  8. RichardCH

    RichardCH F1 Rookie
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  9. Challenge64

    Challenge64 F1 Veteran
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    So stock exhaust and muffler? Replacing cats only? I would have never thought of this.

    What's the functional difference between 200 & 800 cell cats other than noise?
     
  10. 720

    720 F1 Rookie

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    Hi Ron,

    Your Speciale looks completely awesome BTW.

    Yes, I just replaced the OEM cats with Capristo 200 cell cats (with their heat blankets and O2 simulators...apparently avoids the check engine light issue..so far no check engine light).

    I'm not an expert on cats, but I found this with a Google search.

    "Catalytic Converter (CAT) is made of many little cells where are deposited high value metals which will take care of oxidizing the gazes that were not fully oxidized in the engine. A 400 CELL Cat means there are 400 of these cells per square inch. As this number goes down, the amount of physical cells decreases therefore generating fewer constraints for the exhaust flows. The good compromise is often to use 200 CELL cats (typically 400cell is what is used by car manufacturers). If we go too low in CELL value, the oxidation process is not well performed, and a check engine light will pop up."

    Cats with fewer cells also provide less back pressure compared to cats with higher number of cells. Lower back pressure reduces torque at lower RPMs a little bit...and unless you drive on a race track all day long most of us like a lot of torque at lower revs. That said, my butt dyno could not detect ANY change in the torque characteristics over the entire rev range. I've talked to others with Speciales that changed cats and they confirmed that they did not notice any difference in low end torque.

    Bottom line is changing cats is relatively harmless, but has a big impact on exhaust sound :)

    One other thing. I'm not sure if the car will pass smog tests with 200 cell cats. In California (I forget the rules), but at some point as the car gets older we have to get a smog test. If it doesn't pass then I'll swap my 200 cell cats back to my OEM cats to pass the test and then I'll swap back to my 200 cell cats. Not the most convenient way to run a railroad, but it's worth the occasional hassle and expense to enjoy the vastly improved sound :)



     
  11. F12Berlinetta

    F12Berlinetta Karting

    Apr 7, 2012
    119
    My head is spinning. I adore the sound of my Speciale revving up off the line. Tomatos Tamatos, I guess. While I have total respect for those who may want a little more noise, I can't help but consider if perhaps a classic American car with a snarling 427 and Weber carburetors might have been a better purchase for less than $80K. A guy drove by in my gym parking lot yesterday in a late 60s Mustang that gurgled so loud and deep that car alarms were triggered for 100 meters all around.
     
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  13. 458trofeo

    458trofeo F1 Rookie

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    Not a secret lol these are commonly used to try to avoid CEL's with race cat applications.

    These are also called oxygen sensor extensions on this side of the pond, they just put
    the 02 sensors out of the way of the exhaust stream to avoid CEL's, they work on some
    cars and do not on others; doubt they would work in avoiding CEL's with 100 cel cats.
     
  14. 458trofeo

    458trofeo F1 Rookie

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    That's correct: replacing the restrictive factory cat to a race cat is the one mod which will make the sound much more aggressive: it is literally a before and after thing.

    200 cell is recommended as it is more durable than the 100 cell whose core disintegrates faster and the last thing you want is the cat honeycomb media to come shooting out of the exhaust lol
     
  15. 458trofeo

    458trofeo F1 Rookie

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  16. 458trofeo

    458trofeo F1 Rookie

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    You know what to do to get the love ;)
     
  17. 458trofeo

    458trofeo F1 Rookie

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    You can get the O2 sensor extensions at most race or tuning shops in the US
     
  18. 458trofeo

    458trofeo F1 Rookie

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    No worries the sound at idle with the bypass closed is as quiet as stock:
    200 cell all the way: do it !!! :D But be warned you will want to drive her every
    second of the day after putting these babies on!!
     
  19. 458trofeo

    458trofeo F1 Rookie

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    Words of wisdom :)
     
  20. 458trofeo

    458trofeo F1 Rookie

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    And more wisdom
    xo

    The Speciale's and SA's hyper fast downshifts sound f'ing INSANE with race cats or test pipes!!!! :D :D
     
  21. RichardCH

    RichardCH F1 Rookie
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    So now we have 2 Speciale owners who have solved the issue by simply changing to 100 or 200 cell cats, the way forward ?
     
  22. 458trofeo

    458trofeo F1 Rookie

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    Yes, changing the stock cats to race cats is practically the only mod you need
    to dramatically louden the sound, even if all other parts are left stock.

    However, race cats raise potential CEL and emission issues
    which can be dealt with the various methods in the previous posts.

    best
     
  23. 720

    720 F1 Rookie

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    One benefit of changing the OEM cats to 200 (or 100) cell cats first is there's a pretty good chance that you will be very happy with the significantly improved exhaust sound. Then you're done.

     
  24. Ky1e

    Ky1e Formula 3

    Mar 4, 2011
    1,246
    FL
    when I changed t race cats on my old 360, it reduced the power and torque (noticeably). It sounded louder and better but I couldnt live with the less power so I tossed 'em.
     
  25. 720

    720 F1 Rookie

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    The change to low end torque on a Stradale with high flow cats was very noticeable to me. I was appalled. No way I was going to accept any perceivable change to low end torque on my Speciale. Let me assure you that 200 cell cats on a Speciale do not make any perceivable change to low end torque :)

     
  26. RichardCH

    RichardCH F1 Rookie
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    I guess it depends whether you have virtually no torque in the first place like with a 360, torque is its weakest link. Which make were the cats you used ? not all Cats are the same quality. The Hyperflows I ran on my CS were great
     
  27. rblissjr

    rblissjr Formula Junior

    Apr 11, 2009
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    Robert Bliss
    I guess I'll chime in. All mods made to my car were done to UP the performance. After all it is a track car and mine does it's fair share. The car sits lowere because it was corner balanced by a championship winning GT3, GT2 and Challenge series winning shop. Again in the interest of lap times.

    Yes, I was disappointed with the stock sound of my Speciale but my attitude was that if it was best for the performance I would leave it stock. The new exhaust system has not only increased net HP it has reduced weight. Both performance gains. Oh... Yeah... It sounds fantastic as at least 3 or 4 guys on hear can personally verify.

    Regardless of your state of tune.... Owning a Speciale is truly special.
     
  28. 458trofeo

    458trofeo F1 Rookie

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    High flow cats will not perceivably alter low end torque on any the 458 series cars.
     

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