Whoa! Your car may have more than 320 lb ft at the wheels then! I thought your second gear would have been somehwere near what the Viggen's was. (It'll go to about 62 before hitting the 6K rev limiter) If you can do 70-75 in 2nd that'd put the WHEEL torque much higher than I calculated before! Are you sure that wasn't just a momentary surge due to shifting out of first and into second?? If not then you've got a LOT more torque than the dyno was letting on.

Here's the math to back the figures up:

1. Convert any acc to hp: hp = weight x g-force x speed / 550

2. Convert hp at a given RPM to torque: torque = hp x 5250 / rpm

I assumed your car weighed at least 3320 with you in it, if it weighs more you have even MORE torque. I also assumed your 2nd gear went to 72 mph. Feel free to get more accurate figures and put them back into the equation to get more accurate results.

If at 6K rpms you're at 72 mph, then at 40 mph you're at 3,333 rpms.

hp = 3320 x .59 x (40 mph x 1.466 fps/mph) / 550 = 208.8 hp @ 3,333 rpm!

torque = 208.8hp x 5250 / 3333 rpm = 329 lb ft!

Remember, this method is only as accurate as the acc, rpm and speed readings. But if the speed was accurately measured, and if it consistently puts down that kind of g-force this is potentially as accurate as a dyno! Maybe it was just a jolt from the shift out of first? Does your engine rev much past 6K rpms (that could affect the approximated gear ratio).

p.s. Always remember to use the appropriate conversions. g-force and weight cancell out the need to use mass and actual accelleration. But you need to multiply mph by 1.466 to get feet per second. Other than that it's a pretty straight forward calculation to perform.