The Build

Current effective hp is somewhere around 255bhp (35% over stock) less some unknown wing drag. This gives me 8.3 whp/lb (46% more hp/weight), and 4 wheels @275 section with (about 10.2" tread width each) gives 45 lbs for every inch of race tire to handle (vs 59lbs/inch stock sport tire, 33% improvement vs stock). Pure guess work comparing to other wings online puts downforce at about 120-180 lbs @60mph or 7-10% of vehicle weight. vs virtually no down force in stock configuration.

Thus in terms of critical physical performance measures vs stock :
  • ~46% better power/weight
  • 33% better tire/weight
  • A7 vs A048 tire rubber compound.
  • possibly 7-10% more normal force at contact with road?
Plus suspension & brake improvements...

Weight below is typical start of event weight. At the end of the 2018 NJ Pro Solo the car weighed in at 1826 vs estimated 1841 starting weight, but was fuel starving badly last 2 runs on left side. The car so far has never starved at Devens since the fuel tank upgrade. Devens has lower grip levels. Therefore the lowest usable weight is probbly 12lbs under typical starting weight on high grip surfaces and 15 lbs. under on lower grip surfaces.

I suspect that previously there may have been some fuel gauge inaccuracy leading to higher weight estimates driving the large change with my no-fuel weight. The present figure is validated against weighing the car with an air-dry for 3 mo gas tank and no soft top which came in at 1786, indicating 1796 before fuel at the end of 2020 season. To understand the markup on the dyno plots below, see the explanatory post

  • 190 whp on dyno dynamics, prob equivalent to 
  • 215whp dynojet which would indicate about 
  • ~250-255 bhp, normally aspirated

No comments: