Quote:
Originally Posted by Intouch
engine dyno. i guess driveline sucks less power then mentioned above. i believe the car would surely make at least 450hp at the wheels....
otherwise it would not leave the f430 standing. the 430 has 490 hp and f1 gearbox.
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Don't get me wrong, the F430 is a quick car, but there are quite a few Superformance prepped 427Rs and 427IRs that have been to the drag strip to figure HP based on trap speed and weight.
In reality the engine HP is just a number. It's the wheel HP or usable HP that will have the most influence on performance. There is variation. From what I've noticed on and about the forum a 550 HP engine in a Cobra seems to range around 330 to 480 wheel HP depending on carb, tuning, exhaust, fuel delivery and stuff like which 427 from Roush. Some of them produce quite a bit less power than the single plane intake 427R and 427IR. My Roush 427R had 561 corrected engine HP in a Superformance. As dealer prepped it produced a little over 400 corrected wheel HP. After I looked into obvious power restrictions and changed things I ended up with 475 at the wheels. This seems about were a 561HP engine should be.
Actual wheel HP comes out really close to 1/4 mile trap speed if you use a racing calculator. In other words trap speed doesn't lie. It's very consistent if you can shift through the gears.
Time for the 1/4 mile is very dependant on how well you start. Each .1 second variation in 60ft time is about .2 seconds at the end.
Here's a drag race calculator. The trap speed portion is really accurate.
http://www.prosystemsracing.com/calculate.html
The lower the DA, density altitude, the more power an engine will make. Here's a sea level correction calculator with a DA calculator built in. Using this calculator you can compare performance of the same car on diffrent days or two diffrent cars in diffrent locations. It's really cool to compare apples to apples.
http://www.modulardepot.com/density.php
Sea level corrected, a 2550lb race weight Cobra with a real 475HP at the wheels should produce a 1/4 mile trap speed of around 131 to 132 mph and with a 1.7 60ft time should be about a 10.5 or 10.6 ET. With a 1.5 60ft the time would be around 10.3 or 10.4. A 1.9 60ft time would be about a 11.1. Trap speed would remain real consistent unless you totally screwed up the pass.
The pass in the video in my signature is starting from idle and only a 1.7xx 60ft time. I had my normal daily drive Mickey Thompson ET Street drag radials in a 275/60 15 with 20 psi. A 1.7 60ft time isn't all that great.
You can check around to see the Superformance cars with the Superformance headers, Superformance side pipes and 427R or 427IR usually trap about 123 to 126 mph at the drag strip. Plug it into the calculator with average weight with a guy in the car and half tank of gas, 2550lbs and you get the HP. There was a guy that took his Superformance with 427IR to a race day a while back on the forum. The car is just like yours. I looked up the weather data for the day and corrected the data to sea level for his drag race trap speeds. It came out about 380 HP at the wheels.
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