Crown

Board: Porsche Language: English Region: Worldwide Share/Save/Bookmark Close

Forum - Thread


    Question

    To some this might be stupid question but I will give it a shot. What are the differences between VarioCam and VarioCam Plus? Can a car use both VarioRam and VarioCam technology together? When were these technologies implemented in Porsche production cars?

    Re: Question

    VarioCam first appeared on the 968 and varies the angle of the intake cam between two extremes by moving the slack of the chain between the intake and exhaust camshafts.
    VarioCam Plus first appeared on the 996TT (I think) and varies the angle of the intake cam continuously/infinitely (not just two angles) with a hydraulically operated helical screw thing on the end of the camshaft. On the GT3 VarioCam Plus varies intake camshaft over (a larger) 45 degrees of crankshaft rotation.
    VarioCam and VarioRam can co-exist and are controlled by the ECU.

    Re: Question

    Quote:
    To some this might be stupid question but I will give it a shot. What are the differences between VarioCam and VarioCam Plus? Can a car use both VarioRam and VarioCam technology together? When were these technologies implemented in Porsche production cars?



    Porsche offers VarioCam Plus on all models throughout the range. Camshaft adjustment on the intake side (VarioCam) is supplemented in this case by valve lift control also on the intake side (Plus). Featured for the first time on the 911 Turbo, this new system is able to optimise output and performance, on the one hand, while at the same time reducing fuel consumption and exhaust emissions, and improving running smoothness and refinement, on the other.

    The valve adjustment system is made up of switching cup tappets on the intake side of the engine operated by an electrohydraulic 3/2-way switching valve. With two different cam contours on the intake camshaft, the engine always runs on the appropriate lift curve, with the cams switching from one to the other. To be specific, the cup tappets are made up of two interacting tappet elements locked one against the other with the help of a bolt. This creates a direct link, first, between the inner tappet and the small cam, and, second, between the outer tappet and the large cam. A hydraulic compensation unit for valve play is integrated in all cases in the tappet's force flow line.

    For all practical purposes VarioCam Plus means two engine concepts in one. As long as the engine is idling, valve lift is controlled by the small cams to a maximum limit of 3.6 millimetres and valve timing is optimised to keep any valve overlap on the engine to a minimum. The small valve lift serves to reduce friction, significantly increases the charge motion thanks to the very short opening times, and reduces emissions from any previous combustion within the combustion chambers. A further advantage is the considerable reduction in fuel consumption and emissions by up to 10 per cent, together with a much higher standard of idling quality. Under part load, in turn, the engine should preferably run with internal recirculation of exhaust gases in order to minimise any throttle effect and to reduce fuel consumption accordingly. To achieve this goal, valve lift is shifted to a large overlap area, that is a long period for drawing in exhaust gases. Under full load, finally, superior torque and output are ensured by a highly efficient gas charge cycle with minimum losses, on the one hand, and an uncompromising cam contour, on the other, with 11 millimetres maximum valve lift and suitably adjusted opening and closing times during the valve cycle. VarioCam Plus also helps before you set out, for example, by considerably improving the engine's starting characteristics when cool and by reducing emissions through the suitable adjustment of VarioCam Plus while the engine is warming up.

    Both of the two VarioCam Plus systems (camshaft adjustment and valve lift control) are masterminded by Motronic ME7.8 designed especially for these particular requirements and offering a high standard of operating and computing capacity. This is indeed important, since the factors required for controlling VarioCam Plus are, in particular, engine speed, gas pedal position, engine oil and coolant temperature, as well as recognition of the gear currently in mesh. The driver's commands in terms of engine power or torque are compared with control maps within the system, the Motronic control unit then deciding within milliseconds how VarioCam Plus should respond.

    Also have a look at the picture.

    Any more questions?

    Re: Question

    I thank you both for explaining the differences and details about the technologies.

     
    Edit

    Forum

    Board Subject Last post Rating Views Replies
    Porsche Sticky SUN'S LAST RUN TO WILSON, WY - 991 C2S CAB LIFE, END OF AN ERA 1/19/18 10:13 PM
    throt
    263655 1687
    Porsche Sticky OFFICIAL: New 991.2 GT3 (2017) 1/21/18 5:31 PM
    Boxster Coupe GTS
    260593 4018
    Porsche Sticky OFFICIAL: 911 GT2 RS (2017) 1/21/18 8:18 PM
    absent
    89759 1374
    Porsche Sticky 992 (Next 911 generation 2019/2020) 1/12/18 7:11 PM
    the-missile
    67527 673
    Porsche Sticky Porsche Mission E - the future of Porsche? 1/3/18 8:32 PM
    CGX car nut
    39875 468
    Porsche Sticky OFFICIAL: New 991.2 Turbo S Exclusive Series (2017) 11/28/17 12:15 AM
    EnglishManInNY
    23926 332
    Porsche Sticky OFFICIAL: New Porsche Carrera T 12/1/17 7:24 PM
    crayphile
    13729 243
    Porsche Sticky OFFICIAL: Porsche 718 GTS models (Oct. 2017) 10/24/17 12:19 PM
    amazon
    7291 19
    Porsche 918 latest news Thread Closed 11/6/17 10:43 AM
    RCA
    548417 5574
    Porsche 991 GT3 RS 1/9/18 1:43 PM
    Kimi
    456625 5816
    Porsche OFFICIAL: 991 Turbo and Turbo S 10/26/17 1:33 PM
    NSXER
    446383 4239
    Porsche OFFICIAL: 2016 Porsche Carrera 911 [991.2] Facelift 3/24/17 12:49 PM
    RCA
    254981 1382
    Porsche OFFICIAL: 911 R (2016) 1/4/18 9:14 PM
    wurlie
    247604 2558
    Porsche 997 GT3 RS 4.0 3/15/17 10:40 PM
    noone1
     
     
     
     
     
    231293 737
    Porsche Cayman GT4 12/30/17 11:07 AM
    Boxster Coupe GTS
    213276 2482
    Porsche 991 GT2 RS (2017) - Rumors, speculations and gossip Thread Closed 7/3/17 2:04 PM
    RCA
    175537 1699
    Porsche The moment I've been waiting for... 11/13/17 2:32 AM
    Pilot
     
     
     
     
     
    165152 874
    Porsche OFFICIAL: New 991.2 Turbo and Turbo S 12/15/17 1:44 PM
    RCA
    164506 1072
    Ferrari 488 GTB/GTS 1/21/18 10:49 AM
    RCA
    141394 1220
    McLaren McLaren on a winning streak 1/8/18 12:32 PM
    rhino
    139016 2855
    Porsche 991.2 GT3 Thread Closed 3/7/17 11:47 AM
    RCA
    125036 1651
    Porsche Boxster Spyder (981) 12/29/17 8:31 AM
    dreamcar
    110809 692
    Porsche OFFICIAL: New Panamera (2016) 1/6/18 10:41 PM
    Wonderbar
    108111 1284
    Others Audi R8 V10 Plus (2016 model) - Review (updated Feb 13th 2017) 1/18/18 11:38 AM
    RCA
    105677 1869
    Ferrari Ferrari F12 Berlinetta / 599 GTO Successor 12/5/17 3:29 PM
    RCA
    87271 765
    Porsche OFFICIAL: 718 Boxster (2016) 10/20/17 11:17 AM
    DaveGordon
    81722 732
    Others VW caught cheating emissions tests 7/10/17 2:36 PM
    RCA
    81485 861
    Porsche 991 GTS 4/3/17 4:27 PM
    bluelines
    68500 247
    Porsche OFFICIAL: Cayenne (958) Facelift 2014 3/2/17 4:22 PM
    RCA
    67179 163
    Porsche OFFICIAL: New 991.2 (facelift) Carrera 4 and Carrera 4S 3/30/17 7:33 PM
    Carlos from SpainM
    60368 131
    371 items found, displaying 1 to 30.