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2015 GTS Rules are now available


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FB discussion:

"Maybe I'm blind, but for 2015 how many dyno runs are we required to do and which run do we use for the official number?"


Scott Good's response:

"It's the same as always. Three runs, use the one with the highest peak horsepower number."


New question:

When plugging in "maximum horsepower", do I use the data from the export file, or what the screen shows? There's a small difference, it has to do with the peak horsepower not falling on a 100rpm interval. With that said, there's also a difference for maximum horsepower when choosing 100rpm or 500rpm intervals for the export file.


I would assume the maximum hp number for the run will be what you are judged on vs the max on the export file.


can you post a picture of the differences in numbers please

I would assume so too, but it seems like some of the more basic dyno requirements have slipped out of the rulebook over the years, or maybe I just missed them.


No photo, but to give an idea of what I was dealing with:


GTS2 car showed 213.34 on the graph:

the export data(x.1k rpm) showed 212.59, a difference of 6 lbs.

the export data(x.5k rpm) showed 212.31, a difference of 8 lbs


GTS3 car showed 282.50 on the graph:

the export data(x.1k rpm) showed 282.09, a difference of 3 lbs.

the export data(x.5kr rpm) showed 277.76, a difference of 30lbs


GTS4/unrestricted car showed 327.14 on the graph:

the export data(x.1k rpm) showed 325.18, a difference of 8 lbs.

the export data(x.5k rpm) showed 316.18, a difference of 47lbs.


Another issue I came across is a calculation came up with an average of 211.4HP, and a minimum weight of 3066lbs, however 211.4x14.5=3065.3. Surely it has to do with the number of significant digits.


Small, but these issues need to be worked out and the difference between the peak of the graph vs the export data can make quite a big difference and should be noted in the rulebook.


Side rant: de-tuning a car for multiple GTS classes with the same target weight just got a whole lot more complicated.

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The maximum horsepower number you use should be the actual maximum. The same number we have used in the past...the one that shows up along with the basic information in the legend of your print-out. If you're going strictly from the data, use 100 RPM increments and take the highest value shown.

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The current version of the calculator is free-standing (meaning you can calculate your weight but not save the results), but we plan to replace it as quickly as possible with a version which allows you to upload your dyno sheets and/or dyno data files for a more permanent record. We are investigating the idea of also making the calculator available as a mobile application.

Checking in.... It's been 3+ months, so any updates on the upload tool or mobile app? Or do we all have to manually enter numbers?

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