davidspalding

My Gtech-Pro RR needs information for more accurate performance calculations. One data point it needs is "frontal area." We know the drag coefficient is 0.27, but does anyone know where I can find the front area measurement? Hopefully someone has stumbled across this somewhere.

The other data point it asks for that has me stumped is the "HP loss to wheels (%)," but I suspect that someone with some dyno runs may know this.

TIA!

nbtx

I've never seen the frontal area number ...

All Honda's aerodynamic computer simulation is done in Ohio - Maryville, I think. Maybe somebody from there can chime in. Else try one of the Honda forums.

davidspalding

Have Googled through many, many forums, no joy. I appears that Honda/Acura never disclosed the detail, just the Cd and some text hyping the improved aerodynamics of the 1G TSX.

I'm beginning to wonder if Car And Driver's "est." is actually based on a measurement, not just an interpolation based on prior Accord silhouettes.

davidspalding

I've been using Google to an obscene extent, trying to find definitive numbers. You'd think that with the Acura TSX also the CL9 Accord Euro, SOMEONE would offer accurate numbers.

I found on several sites that the "easiest" way to compute your frontal area is to take a photo from a distance with a telephoto lens, then in Photoshop or Gimp, make a mask of the car's silhouette, convert the image to a pixel to inches dimension, then using the software like CAD software, to compute the "area" of the silhouette. (sigh)

I found measurements of 57.3"x69.4" (HxW, w/o mirrors), and Ecomodder wiki says that ((H/12)*(W/12))*(Cd) = CdA ("drag area"). This gave me a frontal area of 27.62', and a CdA of 7.46. Car and Driver "estimated" a frontal area of 23.5' IIRC, and a drag area of 7.46'. Huh? Using Ecomodder's formula, I get a CdA of 6.35 (pretty damn good). Color me confused.

redpoint

If you find this info out, post it here. I've briefly looked myself but gave up quickly. I'd like to plug all that info in at eccomodder.

davidspalding

CAR AND DRIVER estimated 23.5' and I can't find anything, anywhere else to dispute this, even searching for specs on the CL9 family of Accord Euros (roughly the same body, slight differences in front lower bumper/lip). I've begun to think that C&D's estimate is based on actual measurements, not just a blanket presumption, as the American Accord's published front area is larger.

For the purposes of my Gtech-Pro RR Fanatic's computations, 23.5' and 0.27 is more than sufficient, according to the maker. He said that a "HP loss through the drivetrain" estimate of 15-18% for a sedan is also close enough.