The difference in tracks...

[Jay 02 TA ws6]

Originally posted by Injuneer
The thing that seems most out of place to me is your stock 109.0 and "with-a-lid-MAF ends" 109.98.

I agree completely. Especially when that 109.98 run was on a hot, humid day.

To run 109.98 MPH with a 3,600# car, you would need to be making about 380flywheelHP..... sounds like something is "off".

So, with 345 rwhp... wouldn't that mean a 109 trap is now too low?

Additionally, a car that could run a 109.98 should be running well into the 12's. If you were using 100% of that available 380HP, you could be running as fast as 12.32. Assuming a 90% HP utilization (reasonable for something that is well driven, but isn't a "track" car), it should have run 12.7.... but running a 13.4@109.98 means you were only using about 75% of the available HP.

:bangshead: I KNOW! That's what is so frustrating! lol...

Would you still say it should be an easy 12 second car - even on street tires? I ran 13.1 @ 109 on KDW 275/40/17s while making 345 rwhp. My 60' was 2.1

At the second track, the 105 seems oddly low.... that corresponds to about 326HP. The fact that your ET also suffered would indicate that there was a loss of power... maybe from weather conditions or altitude.

That was due to the bent pushrods, which I got fixed
After getting them fixed was when I dyno'ed 345 and 360... and after that was when I went 13.1 @ 109.

[fastTa]

Jay put 345HP to the tire. That is in excess of 400 flywheel HP so the 109.88 is actually a tad low.

SBC and LT1 powered cars seem to be fairly consistent with the traditional formulas used to asuume ET, MPH and HP from givens like weight, ET, and WHP.

However LS1's dont obey these formulas near as well. In the vast majority of cases the LS1 will outperform what the traditional math will presume to show.

For example, there is a Combination Motorsports employee who was making right at 450 RWHP and had a racewweight of 3510 lbs. According to the accepted standard formula of ET from HP (1/4 mile) = (WEIGHT / HP)^.333 * 5.825, he thoretically should have been running an 11.54. However he was clicking off 10.80's consistently on the Las Vegas Motor Speedway.

I don't like to use theoretical math to assume what the LS1's will do at the track because it is in most cases far off. The track will always be the best tool of measuring performance.