How come running my 80 ta and shifting manually at 5000 rpm or so it went 1.6 seconds faster on average then when I let the car shift itself in drive..it seemed like it was shifting at 3500 or so.I have read in new mag this month that 455 pontiac of similar year to mine ,mine is 400 I think from 77 to 78 car put out hp peak at only 3500 rpm.so you think since I was shifting past 5000 that I was way beyond the hp peak and car should have run slower... a bit confused here guys.I guess I will also have to try manually shifting car at 3500 or so and see what times it gets..I also supposed since I don't really know what the past owner did to the car maybe it has cam that gives more power into the 5000 range.

 

What kind of gears do you have? If you have short gears, and you shift high, you aren't in the high RPM range for very long so when you shift to the next gear you are gonna be right in your powerband. The previous owner could have also done some stuff to it to give it more topend. Also, your exhaust might have freed up enough backpressure to give it more topend, and your carb might be tuned for that too. It's hard to tell.

 

Not sure what gears I got in the back and not sure what the former owner had done to the engine..It sure don't seem to have much bottom end so makes me think the gears are 3.08 or 2 something.I had an 400 ta in 78 and it had lots of bottom with the 3.23s I think it had or mabye it was 3.42...Its not a big deal just curious about this stuff..I am going to try a few runs at like 3500 and see what I get.