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My 360 feels like a turbo

Discussion in '360/430' started by raywong, Apr 17, 2010.

  1. raywong

    raywong Formula Junior

    Aug 29, 2004
    661
    Hong Kong
    Full Name:
    Raymond
    Why does my 360 feel like a turbo car? When I floor it from low rpm, I feel a sudden power surge at around 3500 rpm, feels almost like turbo kicking in, it pulls and pulls and subsides a little as it approach redline. I thought NA V8 engine have very flat power curve, but it really feels like a turbo engine to me. Anyone else has the same feeling?
     
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  3. RayJohns

    RayJohns F1 Veteran
    Silver Subscribed Owner

    May 21, 2006
    6,459
    West Coast
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    Ray Johns
    There is a valve in the stock exhaust which opens at 3500. Are you running the stock exhaust? If so, that might be part of the reason.

    The other reason is that the motor doesn't produce all that much HP below around 3000 RPM's, so if you floor it from a low RPM, it will take a second until the motor is spinning enough to produce the power required to really cause the car to accelerate noticeably.

    Ray
     
  4. PAP 348

    PAP 348 Moderator
    Moderator Owner

    Dec 10, 2005
    86,854
    Mount Isa, Australia
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    Pap
    Its a highly tuned machine! :eek::eek:
     
  5. Camdon53

    Camdon53 Formula Junior

    Jul 18, 2006
    507
    Texas, USA
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    Jim
    Actually sounds pretty normal. Besides the exhaust bypass valves, the exhaust cam variators also shift between 3500 and 4000 RPM. That means the engine isn't really breathing freely until around 4000 RPM and up. In that range (i.e., 4000 to 8500 -- much wider range than most engines) the BHP curve is indeed remarkably flat with full power available throughout. The performance available from these normally aspirated Ferrari engines is absolutely amazing considering the ease and convenience also present for street driving.
     
  6. AttilaS

    AttilaS Rookie

    Jan 18, 2009
    5
    I think you mean the torque curve is fairly flat in that range. The hp curve is certainly not flat (it climbs steadily peaking in the ~8k rpm range).
     
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  8. Eric360

    Eric360 Formula 3
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    Jan 11, 2010
    1,347
    San Francisco, CA
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    I've owned 3 different Porsche turbos. And I must say the 360 does not feel like a turbo car to me. While the 360's powerband is from 4000 to 8000 rpm, it doesn't have the "pin you back in the seat" ooomph of a turbo car. Not to say it's not fast, but not the wild, wicked oh my god blast of a turbo car. It's definitely a different sort of way to get going fast. Both are loads of fun.
     
  9. raywong

    raywong Formula Junior

    Aug 29, 2004
    661
    Hong Kong
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    Raymond
    I feel the power between 3500-6500 rpm. I think the stock exhaust system is tuned for mid rpm range power.
     
  10. Derek Trotter

    Derek Trotter Formula 3
    BANNED

    Jul 28, 2007
    1,767
    Cambridge, UK
    Spot on.

    No way does my 360 feel like my 997 Turbo. The 997 generates huge torque around 2000 RPM but is all done by 6500 RPM. The 360 is only just getting into it's stride at 4000 RPM.

    Are you comparing your 360 to a 1980's Saab Turbo?
     
  11. teknikl

    teknikl Karting

    Sep 16, 2009
    62
    Does the engine sound completely change when it feels like the turbo is kicking in?

    If so, this is that exhaust bypass they are talking about... I love to get the car to make that noise!
     
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  13. raywong

    raywong Formula Junior

    Aug 29, 2004
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    Raymond
    No it's not related to the valves. It was the same with or without the valves. (I recently installed the valves back)
     
  14. s14roller

    s14roller Karting

    May 3, 2008
    69
    I'm confused at this statement because every car (including the M3 I daily) will pick up speed more rapidly when you pass ~ 3000 at WOT and taper off close to redline...

    Turbo cars pick up much more exponentially...best thing to experience, would be a big turbo Supra or something...
     
  15. Argento6spd360modena

    Argento6spd360modena Formula Junior

    Nov 20, 2009
    309
    #12 Argento6spd360modena, Apr 21, 2010
    Last edited: Apr 21, 2010
    I have owned many cars in the past. From heavily modified MKIV Supra to Supercharged NSX.

    What the thread starter said is true. 360 does feels a bit laggy from idle to 3500rpm and the sudden rush at around 3500rpm is very noticeable. Of course it can't be compared to modern turbo cars such as 997TT, GT-R, etc.

    The kick from 3500rpm does feel like lesser powerful turbocharged car such as EVO. Definitely a lot more noticeable than VTEC switch point of a S2000. If one looked at the dyno graph you will see two VTEC like spike on most 360 Modena dyno graphs, one at lower rpm, the other at around 6k rpm. It is fun at times, but can be annoying. Thank god it is only from a dead stop. Once the car is rolling, the responds is knife sharp.

    "The power unit features a variable geometry intake system, five-main bearing crankshaft with counter-balanced 180� crank throws, titanium con rods, 5 valves per cylinder (3 intake, 2 exhaust, the latter with variable valve timing for improved performance at high speeds) and a Bosch ME 7.3 electronic engine management system"

    Car feels a little bit more responsive with exhaust valve open at all time. But greatly improved once high flow cats are installed.
     
  16. raywong

    raywong Formula Junior

    Aug 29, 2004
    661
    Hong Kong
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    Raymond
    yes yes, I was going to say Evo, you know what I meant.
     
  17. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    33,606
    Clarksville, Tennessee
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    Terry H Phillips
    Ray- I think you are feeling a combination of things, most mentioned above, ie valves, exhaust VVT, but also including a variable length intake manifold that quickly optimizes for high rpm power. Ferrari used fairly mild cam timing with those elements to give good low end torque and power (for a 3.6 liter engine) and still a big boost at the top end. Dr Jeckyll and Mr Hyde.

    Taz
    Terry Phillips
     

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