G-Tech Pro RR newbie

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  • S2central.net
    Retired OG Mod
    • Jul 2003
    • 16590
    • Country: Northern Ireland

    #1

    G-Tech Pro RR newbie

    Had a few trial runs with this new bit of kit from newsh - just about brand new

    Not really interested in brutal launches for 1/4 mile times - specially on public road ya know - not easy, but more so in getting a style of using it for comparative analysis of ECU tweaks and other mods like RS2 airbox and such.

    Tis a well known 'feature' of Motronic ECU that you cant get max boost unless you have max load (ie WOT in a high gear) so I think its going to be tricky using it for runs in 4th... Its a pity all the test runs require a standing start.

    I did three runs tonight. First two were moderate launches with a full blat in 2nd and into 3rd I think. BOth of those came out at 210nwhp (nett wheel hp) - which is curiously accurate for my 280bhp software using the 25% drivetrain loss rule of thumb for quattro. Both these runs stopped (somehow) short of the 1/4 mile mark.

    Did the 3rd run trying a very short shift into 2nd then short again into 4th to get a power/torque run at the higher boost levels in that gear. This run did continue for 1/4 mile but gave a bizarre 320hp result - I know thats impossible at the wheels on my setup. How on earth could I have fooled the thing into that silly number ?

    Trying hard to remember if I reset the unit or did something else stupid.

    Seems like a nice bit of gear, though buttons are a bit unpleasant to use - it was a doddle to setup and get going. Really needs a test track to use it properly... and you could really murder a clutch and brakes if not careful.

    Also doing runs tonight with a development stream of ECU software as well. Need to get back to square one and try be more controlled, but the 1st question is for any experienced G-Tech users who might wish to share how best to get consistent power runs out of it - not balls out ultimate launches for quickest times etc.

    PS - Did one brake test showiing about 230ft from 70 to 0. Could have done a bit better maybe - but thats some baseline figures to be getting on with.

    Paul
    Paul Nugent
    Webmaster http://S2central.net
    Administrator http://S2forum.com

    1994 S2 Coupe ABY - aka Project Lazarus
    2001 A6 allroad 2.5TDi - family tank
    2003 S4 Avant 4.2 V8 - daily burble

    Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

    There are only 10 kinds of people that understand binary - those that do, and those that don't
  • Piu
    S2Forum Hobbyist
    • Jun 2006
    • 16
    • Country: Brazil

    #2
    don't know if it helps, but...

    I have the old Gtech Pro compettition (the prior version of the RR model). I've tested it in the 1/8 drag track in my city and got very consistent numbers in the Gtech elapsed time x timeslips. But in the default rollout of 12 inches, the Gtech time is higher in 0.3s than the timeslip paper. The 60ft is about 0.1 sec higher than the timeslip.
    My 1/8 times with a default ABY S2 sedan are consistent and repetitive 9,1s in a poor track conditions and with 100hp nitrous shot I've dropped it to consistent 8,3s passes.
    A friend said if the rollout setup of Gtech was zeroed, the times are very close to timeslip papers but unfortunattely, my S2 had a minor problem in the engine thats need to be solved before I got the tests performed.

    I have a log made this time and it's show the power added by nitrous very clear and consistently.
    Attached Files

    Comment

    • EspenW
      S2Forum Extremist
      • Apr 2007
      • 1534
      • Country: Norway

      #3
      I always do the testing in 2nd gear, but that is due to low speed limits. 3 or 4th gear runs give the turbo time to spool and thus give higher hp and torque numbers. In addition, lower gears means more power is absorbed by the inertia of the rotating components. Torque numbers suffer more than hp in 2nd, since peak torque happens lower in the rev range.
      I just get rolling in 2nd gear, put give it full throttle and run to redline.
      Remember that the G-tech does not account for air resistance, so losses to drag will be much higher in the higher gears. Approx 10hp is lost to drag at peak power in 2nd, while the same number in 3rd is approx 27hp, and close to 60hp at peak power in 4th.
      Also remember to correct for athmospherical conditions, as these will have great impact:http://www.csgnetwork.com/relhumhpcalc.html
      Some at the wheels hp numbers that I have collected with my Mr. Dyno (The Golf is measured in 3rd, while the others are measured in 2nd, thus giving lower numbers than 3rd or 4th would have yielded)

      Audi 80 Avant (2.0E) FWD: 88hp
      My Golf II with heavily tweaked 2L engine: 120hp
      Mini Cooper S: 130hp
      B6 Audi A4 1.8T Quattro: 133hp
      My RS2: 330-350hp
      1995 RS2 on Alcohol (6.8sec 100-200km/h)
      1994 80E Avant
      1986 2L Golf 2 on Alcohol

      Comment

      • S2central.net
        Retired OG Mod
        • Jul 2003
        • 16590
        • Country: Northern Ireland

        #4
        Understood on the drag thing - GTech measure nett hp and use of higher speeds/gears will create more aero losses. I'm not looking for deadly accuracy. Just a good way to do a test run repeatably - then quantify any benefits with upgrades on same method. Thats the hope at least.

        Power runs in 2nd are OK but will never record the higher torque levels seen at WOT in higher gears...

        Just read the manual thoroughly and it seems the test can run up to 4000ft (approx 0.8 mile) as long as you don't lift off. That should provide sufficient runway to get loaded up nicely in 4th for more useful torque measurements.

        Guess I need to try some more runs and practice the art - and try real hard not to a) attract attention or b) destroy my clutch !
        Paul Nugent
        Webmaster http://S2central.net
        Administrator http://S2forum.com

        1994 S2 Coupe ABY - aka Project Lazarus
        2001 A6 allroad 2.5TDi - family tank
        2003 S4 Avant 4.2 V8 - daily burble

        Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

        There are only 10 kinds of people that understand binary - those that do, and those that don't

        Comment

        • Rusty
          Super Moderator
          • Jun 2004
          • 18953
          • Country: United Kingdom

          #5
          I've just got a GTech although it's a bit more archaic (and cheaper) than your unit. Still gives relative HP etc though. I'll do a few runs when I can find the time and space.
          Cheers'en, AndyC
          1994 ABY Coupe - Projekt Alpinweiss

          Comment

          • magarv
            S2Forum Addict
            • Jul 2004
            • 323
            • Home: Norway

            #6
            When doing hp/tourqe measurements I think it is important to NOT launch to hard. You should not launch to easy, and not to hard. Just a firm launch and easy on the clutch/trottle when shifting gears. (I belive the manual state this as well )
            The hard launches/gearshifts can mess up the measurements as I have understood it.

            So I don't think you need to worrie about your clutch
            "Ring addicted"
            8,43 BTG with trafic and roadworks:http://www.youtube.com/watch?v=pYg50Bg2lVQ

            Comment

            • Rusty
              Super Moderator
              • Jun 2004
              • 18953
              • Country: United Kingdom

              #7
              I love doing stnading starts and as I have a nice new clutch I'm happy to give it some abuse :mischeif: Need to look into 0-60 and standing 1/4. Hoping for 5s / 14s or so.
              Cheers'en, AndyC
              1994 ABY Coupe - Projekt Alpinweiss

              Comment

              • Rusty
                Super Moderator
                • Jun 2004
                • 18953
                • Country: United Kingdom

                #8
                I was looking to calculate weight of my standard car. Ballpark figure is 1700Kg (1550Kg car, 50Kg fluids, 100Kg me) which calculates as 3740lbs. I know that previous to the 3B flywheel and HG change I was running 240bhp ATW so I'm going to calibrate the weight to give this figure as it'll be within 5% and then any cahnges can be measured relative to this baseline figure (and I'll set the unit up teh same each time). Looking forward to the DP, sports cat, 7A inlet and possibly chips to see if there's anything more to be gained.
                Cheers'en, AndyC
                1994 ABY Coupe - Projekt Alpinweiss

                Comment

                • S2central.net
                  Retired OG Mod
                  • Jul 2003
                  • 16590
                  • Country: Northern Ireland

                  #9
                  I'm going with 3570lbs which might be hopefully light... Was 1700kg at MOT with me and a fat(ter) lad on board. Thats approx 3528lbs with just me plus another 20kg of pheckin RS6 reps for 3570lbs total.

                  @Andy - I'll have a new turbo chip for you soon to get the benefit of cooler air from thy RS2 IC. I've found the temp comp map... Just need to tame it, as I'm seeing 1.7bar at WOT in high gears - just a lil too much oomf !

                  I'll keep banging away on the binary bongos and let you know matey.

                  Oh and I'm running 12" rollout just for the record.

                  Agreed with magarv on the clutch issue - I shouldn't be stressing it, but its hard not to when that red light is flashing and the screen says 'Launch when ready'
                  Paul Nugent
                  Webmaster http://S2central.net
                  Administrator http://S2forum.com

                  1994 S2 Coupe ABY - aka Project Lazarus
                  2001 A6 allroad 2.5TDi - family tank
                  2003 S4 Avant 4.2 V8 - daily burble

                  Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                  There are only 10 kinds of people that understand binary - those that do, and those that don't

                  Comment

                  • Rusty
                    Super Moderator
                    • Jun 2004
                    • 18953
                    • Country: United Kingdom

                    #10
                    There's plenty of midrange there already, I think that it needs a little more up top 1.7 bar sounds like fun too, I think that I'll need the DP and cat on before that's a good plan though (that's the same as the MRC high boost map BTW).

                    I'll report back what weight gives me the expected 240bhp ATW, it will be a little skewed due to the hideous squat that I get off the standard springs. 0-60 will be affected by the squat a bit too so I'll see if I can tune it to what I have manually timed it at. Should be fun. Once I've got a baseline setup then I can compare setups more easily.
                    Cheers'en, AndyC
                    1994 ABY Coupe - Projekt Alpinweiss

                    Comment

                    • EspenW
                      S2Forum Extremist
                      • Apr 2007
                      • 1534
                      • Country: Norway

                      #11
                      For hp measurements the launch can be a soft as you want. Just get started in 1st or 2nd, then shift into the gear you want to use for mesurement and put tha pedal to tha metal
                      1995 RS2 on Alcohol (6.8sec 100-200km/h)
                      1994 80E Avant
                      1986 2L Golf 2 on Alcohol

                      Comment

                      • S2central.net
                        Retired OG Mod
                        • Jul 2003
                        • 16590
                        • Country: Northern Ireland

                        #12
                        Yeah Andy reminds of the other ting - PITCH correction... The default setting is 2 degrees per G on my machine. Now I'm pulling about 0.5g in 2nd gear runs but everyone knows the S2 really lifts its nose when you nail it from low speeds. Surely 2 degrees is too conservative, but I don't yet know how much of deal it makes. Maybe best left alone.
                        Paul Nugent
                        Webmaster http://S2central.net
                        Administrator http://S2forum.com

                        1994 S2 Coupe ABY - aka Project Lazarus
                        2001 A6 allroad 2.5TDi - family tank
                        2003 S4 Avant 4.2 V8 - daily burble

                        Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                        There are only 10 kinds of people that understand binary - those that do, and those that don't

                        Comment

                        • Rusty
                          Super Moderator
                          • Jun 2004
                          • 18953
                          • Country: United Kingdom

                          #13
                          I don't fancy finding 6500rpm in 4th 2nd or 3rd it'll have to be. It's a bit like doing a boost run in 3rd, road-gauge-road-gauge...
                          Cheers'en, AndyC
                          1994 ABY Coupe - Projekt Alpinweiss

                          Comment

                          • magarv
                            S2Forum Addict
                            • Jul 2004
                            • 323
                            • Home: Norway

                            #14
                            Originally posted by EspenW
                            For hp measurements the launch can be a soft as you want. Just get started in 1st or 2nd, then shift into the gear you want to use for mesurement and put tha pedal to tha metal
                            The manual clearly states that you should not launch to soft The most accurat is a firm, but not to hard launch.
                            "Ring addicted"
                            8,43 BTG with trafic and roadworks:http://www.youtube.com/watch?v=pYg50Bg2lVQ

                            Comment

                            • Rusty
                              Super Moderator
                              • Jun 2004
                              • 18953
                              • Country: United Kingdom

                              #15
                              The effect will be less in 3rd for exaple than 1st so perhaps it'll cancel out if you set it for second gear.
                              Cheers'en, AndyC
                              1994 ABY Coupe - Projekt Alpinweiss

                              Comment

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