Crown

Board: Porsche - 911 - 997 Language: English Region: Worldwide Share/Save/Bookmark Close

Forum - Thread


    Shorter gear ratios option for 997 GT3???

    On the current italian issue of Autocar there is the test of 997 gt3.speaking about the gearbox they wrote that the gear's ratios are too much long and also porsche noted it because now offers a set of shorter gear ratios.
    It's an exclusive option or what????
    with closer gears I suppose also acceleration times are different (better)

    Re: Shorter gear ratios option for 997 GT3???

    GT3's have always had the option (after purchase) of changing the individual gear ratios as well as the ring & pinion gears. It is very expensive, but makes a huge difference wherever top speed or quiet high-speed cruising are not required (especially good on any track with top speeds under 150mph)

    Re: Shorter gear ratios option for 997 GT3???

    Gears are the most useful and noticable "horsepower" you can buy for your car.

    Very few of us need a car that is geared for 190+mph and putting in lower gears so that you actually pull a top speed of around 165 mhp in 6th (as opposed to in 5th like many 6 speed cars) would absolutley transform a GT3.

    Looking at the gear charts 1st is good for 50mph, 2nd 84mph, 3rd 116mph, 4th 148, 5th 180 and theoretically 6th could do 207mph. 6th is an overdrive at 0.92:1

    Putting a Cup Car/RSR Ring & Pinion (8/32 aka 4:1 versus the stock 3.44:1) would make for a much faster car in all conditions (except top speed, but it would get up to its top speed of 178 much faster...)

    In fact, I would say that this is the fastest, easiest and maybe one of the cheapest ways to make your GT3 significantly faster (especially seat of the pants faster).

    Doing that would mean that in 6th cruising on the highway at 80mph you would be at around 3800 rpm in 6th.

    Re: Shorter gear ratios option for 997 GT3???

    Mithras is right and I would go on to say that beyond R&P change, changing the individual gear ratios to be lower and closer together is an even bigger improvement.

    Just changing the R&P will improve acceleration, but it does not change the rpm drops on upshifts. Creating a custom gearset with closer ratios allows the engine to make more power more of the time - a huge benefit and it won't make 1st gear too low to be usable as an R&P change can sometimes do on its own...

    Re: Shorter gear ratios option for 997 GT3???

    so how much would it cost?

    Re: Shorter gear ratios option for 997 GT3???

    Quote:
    PandaMan said:
    so how much would it cost?


    I can't remember exactly, but, with labor, in the neighborhood of $5k for just R&P, maybe $7k for a new gearset (change top 4 gears) and around $12k for both. Just a ballpark...

    Of course, while you're in there, you might as well upgrade the LSD to a Porsche Motorsports or Guard Transmission unit, which are both signifantly better than stock...

    Re: Shorter gear ratios option for 997 GT3???

    I don't have the gear charts in front of me, but with stock gears and the Cup/RSR R&P you're looking at a top speed of about 42mph in 1st, so you still have usable gears.

    Changing the R&P does in essence make all of your gears shorter and closer but not to the degree or correctness that changing each of them out does. But at some point you begin to split hairs...

    The big difference is with the stock gears and R&P you have between 32-37mph between each gear. With the Cup/RSR R&P you have about 25 mph between each gear.

    Really what you want is when you hit redline and shift it takes the rpm's in the next gear down to the beginning of the peak power curve. That's how a little engine with the right gears can WALK away from a big nhp car with gears made for economy.

    Re: Shorter gear ratios option for 997 GT3???

    Quote:
    Mithras said:Changing the R&P does in essence make all of your gears shorter and closer but not to the degree or correctness that changing each of them out does. But at some point you begin to split hairs...


    No, unless you change individual ratios they will not be closer (just lower with lower R&P). You will still have identical rev drops between gears as you do stock. I was confused about this until I used a software program to draw some graphs - I can send you one if you're curious...

     
    Edit

    Forum

    Board Subject Last post Rating Views Replies
    Porsche Sticky The moment I've been waiting for... 10/25/21 12:29 AM
    Pilot
     
     
     
     
     
    480242 1291
    Porsche Sticky OFFICIAL: New Porsche 911 Turbo S (2020) 10/18/21 10:58 PM
    Leawood911
    174796 1150
    Porsche Sticky Welcome to Rennteam: Cars and Coffee... (photos) 10/14/21 6:25 PM
    bluelines
    68539 382
    Porsche Sticky SUN'S LAST RUN TO WILSON, WY - 991 C2S CAB LIFE, END OF AN ERA (Part II) 10/27/21 10:36 AM
    RCA
    61998 647
    Porsche Sticky ROAD TEST: New 992 Carrera 4S 3/3/21 10:57 PM
    Wonderbar
    47877 336
    Porsche Sticky Porsche Taycan Turbo S - Short Review 10/27/21 10:37 AM
    Leawood911
    47446 450
    Porsche Sticky Porsche extends the Taycan model range (Taycan 2WD) 2/1/21 12:42 PM
    Leawood911
    13081 29
    Porsche Cayman GT4 10/5/21 7:04 PM
    Topspeed
    470957 3587
    Porsche OFFICIAL: 911 GT2 RS (2017) 9/28/21 3:25 AM
    WhoopsyM
    387888 3507
    McLaren McLaren on a winning streak 10/20/21 6:01 PM
    Topspeed
    383280 3919
    Porsche OFFICIAL: 991.2 GT3 RS (2018) 4/28/21 12:26 PM
    W8MM
    349496 3252
    Porsche OFFICIAL: 911 R (2016) 10/8/21 11:41 AM
    xpto
    319151 2647
    Porsche 992 GT3 10/22/21 10:59 AM
    reginos
    271117 3051
    Porsche OFFICIAL: The new Porsche 992 – a design icon and high-tech sports car 9/29/21 1:59 AM
    watt
    252982 1587
    Porsche OFFICIAL: New Panamera (2016) 2/11/21 9:22 AM
    Itsme
    168656 1379
    Lambo Lamborghini Huracan and variants 4/9/21 4:32 PM
    Topspeed
    119107 1225
    Porsche Donor vehicle for Singer Vehicle Design 9/22/21 1:28 AM
    Leawood911
    103416 749
    Porsche Welcome to the new Taycan Forum! 10/9/21 1:11 PM
    CGX car nut
    94429 1231
    McLaren F1 7/10/21 7:43 AM
    BiTurbo
    82866 209
    Lambo Aventador and SV 8/27/21 2:33 PM
    Topspeed
    72873 698
    AMG AMG GT R 7/8/21 3:07 PM
    CGX car nut
    72666 824
    Porsche Nürburgring - Tesla vs. Taycan 11/23/20 6:10 PM
    Topspeed
    51473 596
    Others Tesla 2 the new thread 10/26/21 11:17 PM
    Leawood911
    49640 1221
    Others Bugatti Chiron 10/16/21 4:53 PM
    crayphile
    43120 486
    Ferrari Ferrari 812 Superfast 6/24/21 6:30 PM
    Porker
    40590 531
    Porsche Olive 991.2 GT3 Clubsport 1/1/21 7:58 PM
    throt
    39451 615
    BMW M BMW M2 Rumors 7/7/21 8:38 PM
    Jim_in_Iowa
    30797 394
    Ferrari 488 Replacement 4/17/21 8:28 PM
    Rossi
    27736 370
    Motor Sp. [2021] Formula 1 10/25/21 8:03 PM
    WhoopsyM
    27429 785
    Porsche GT4RS 10/26/21 7:33 PM
    WhoopsyM
    27297 434
    256 items found, displaying 1 to 30.