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  1. #31
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    Quote Originally Posted by FXSlowKroozer View Post
    89 mph is %100 possible with those mods but not at those rpms and temps.Speedos, GPS modules, and Phone apps are not accurate IMO.Use a handheld GPS next time and you will have alot less doubters

    here’s a pic from my personal GP with the same mods minus the RIVA intake grate
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  2. #32
    Team Bilford's Avatar
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    Quote Originally Posted by GreenHulk Jr View Post

    here’s a pic from my personal GP with the same mods minus the RIVA intake grate
    Handheld GPS? Yeah, I got one of those.

  3. #33
    Click avatar for tech links/info K447's Avatar
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    Quote Originally Posted by FXSlowKroozer View Post
    GPS modules, and Phone apps are not accurate IMO.

    Use a handheld GPS
    What GPS modules are you casting doubt upon?

    The CANDooPro GPS speedometer module seems to be quite accurate, as long as the dash display is properly calibrated/matched to the installed module (one time adjustment to show 50mph or 80Kmp/h indicated). And the speed sensing module itself has a clear sky view and external weather/signal conditions are conducive to accurate device operation.

    Handheld GPS accuracy for speed can also vary. Some handheld units are not designed for measuring speed with accuracy, they are intended more for location accuracy.

    Weak GPS signal at the device can compromise speed correctness. This applies to all GPS based speed measuring devices. The GPS unit should have a clear radio signal ‘view’ across a large dome of the sky, unobstructed by human body, wires or metal.

    While many GPS devices will display and record speed numbers to one or more decimal points, there is a degree of uncertainty with all such results. It is not unusual for atmospheric conditions (overcast, or perhaps high dense clouds) to degrade the signal, yet the device will still show speed results to the same decimal point. The number looks ‘precise’ but it is not.

    Testing and comparing GPS units for speed accuracy is difficult, especially as radio signal conditions vary.

    https://www.researchgate.net/publica...g_Environments
    Quote Originally Posted by Accuracy of Speed Measurements using GNSS in Challenging Environments
    … Test results demonstrate that high end, mid-range and low grade GNSS receivers perform differently when measuring speed and caution should be exercised when relying on GNSS speed in challenging environments …

    … not a lot of information is published in terms of how accurate GNSS receivers are when it comes to practical speed measurements in challenging environments. It has become a general consumer expectation that GNSS receivers are always accurate and can be relied upon when measuring speed in any circumstances. Such information is regularly published in newspapers when general consumers tried to use their GPS receivers or loggers to challenge their speeding fines in the court of law with help of speed records obtained from their equipment [1], [2].

    However, little research supports GNSS speed accuracy … where multipath influences the measurement outcome.

    Also, no actual research exists confirming the behavior of GNSS receivers if they have any additional constellations enabled, say GLONASS in addition to GPS …
    … GNSS chipsets or receivers manufacturers are not generally willing to provide evidence of their own testing when it comes to speed accuracy. Usually chipset data sheets contain speed accuracy parameters but it is unclear whether such parameters were tested with GNSS simulators or in static or kinematic modes, including in conditions with multipath. For example, in [13] the datasheet states that an accuracy of velocity determination is 0.1 m/s with a note that this parameter corresponds to good GPS conditions, whereas it is not specified what the good conditions might mean and what happens if bad conditions are applied. In [14] the technical specifications section states that velocity accuracy is 0.01 m/s without specifying when this parameter is guaranteed.

    As a result, such datasheets do not contain any specific conditions when speed records might fall outside the compliance limits and a general user or even more advanced customer may assume that such speed accuracies are always guaranteed. General consumers or even researchers can rely on such datasheets without realizing that the accuracies described might be guaranteed in ideal open sky conditions only …

  4. #34
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    Quote Originally Posted by FXSlowKroozer View Post
    89 mph is %100 possible with those mods but not at those rpms and temps.Speedos, GPS modules, and Phone apps are not accurate IMO.Use a handheld GPS next time and you will have alot less doubters
    He said he runs 8900-9000 rpm at 89 MPH, which is parity or one below. We typically see two MPH below rpm on most modded SVHOs in our group but we are at 1200 ft and 100+ degree heat. So, I don’t see a problem with those speeds and rpm at all.

    Secondly, Jerry and his family are of the highest integrity you will find in this business. They would not come out with false information and risk their reputation.

    This is the same as in competitive drag racing; the people that can’t figure out how to run the numbers always complain instead of trying to improve their program.


  5. #35
    Site Admin Green Hulk's Avatar
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    Quote Originally Posted by FAMT View Post
    same setup on my 2020 GP

    sea level, even colder temps.... turning 9000-9150 rpm and max speed was GPS 86
    You are on the limiter. When running on the limiter you will not achieve your max speed potential. Add some pitch, or increase your limiter

    Quote Originally Posted by FAMT View Post
    yes AGR ATR and running 102 octane Fuel
    Running race gas without increasing timing is actually hurting your performance. If you are going to run 102 octane get some MaptunerX logs and talk to Jesus about making you a custom tune with increased timing. You will be very happy with the results.

  6. #36
    102 octane is not race fuel it is pump gas here in europe.
    yes maybe touch the limiter....

    maybe you testing on a river not a lake so you got stream there

    jesus did some custom maps for me i was logging a lot...

  7. #37
    Site Admin Green Hulk's Avatar
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    Quote Originally Posted by FAMT View Post
    102 octane is not race fuel it is pump gas here in europe.
    yes maybe touch the limiter....

    maybe you testing on a river not a lake so you got stream there

    jesus did some custom maps for me i was logging a lot...
    Ah yes, your 102 RON is about the same as our 93 Octane that we use here in the US, so that's very good!
    If you are seeing 9150 RPM then you are on the limiter.
    We are definitely not running in a river. No current whatsoever where we are testing.

  8. #38
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    Would you not hear it on the limiter?

  9. #39
    Site Admin Green Hulk's Avatar
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    Quote Originally Posted by mittens View Post
    Would you not hear it on the limiter?
    Not at all, it's not an ignition cut like with the older skis. The ECU closes off the throttle when approaching the limiter. Also while we are on this subject, if your ski has a bounce at full throttle it's highly likely it's on the limiter. The ski will bounce as the throttle closes/opens rapidly to keep off the limiter.

  10. #40
    Click avatar for tech links/info K447's Avatar
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    Quote Originally Posted by Green Hulk View Post
    102 RON is about the same as our 93 Octane that we use here in the US...
    The numeric delta between Euro RON and USA octane grading is about five numbers, correct?

    So 102 RON in Europe would be about 97 octane on the US octane rating scale. Rather high grade stuff for ‘pump gas’, even in Europe.

    98 octane in Europe would match ~93 octane in USA.

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