According to this dyno sheet when is the best time to shift???

All vehicles are built differently with different mods. Shifting AFTER the peak power point doesn't sound right to me but it's all about seat of the pants feel as you approach or pass the peak power point. If you don't feel like your car is still pulling hard then shift. It's really preference and by feel.

The miles wouldn't concern me. It looks like 4800 to 5k would be about right but it is gonna matter where it drops to rpm wise when you shift. You may benefit from a little more time in the upper rpms even though it is not in the peak HP/TQ area so that it drops to a higher rpm that is in your power band when you shift. If that makes sense.

I'd also be asking what can I do to make it produce over 240hp.

What kind of drag racing are you doing? I am guessing Braket racing. If that's the case, it is more important for you to learn to do it the same every time and pushing the care to the envelope will only serve to narrow any margin of error you have. I remember clearly learning this lesson when I got "sand bagged" by a guy that dialed in some reserve in his ET as he half tracked me when I was, as Scotty would say, "giving her all she's got Cap'n".

Paul Randle said:

here is a pic of the entire sheet but when i dynoed it the guy said not get shift over 4500 cause the motor has 158,000 miles on it lol.

Click to expand...

Your dyno numbers of 238rwhp and 302rwtq are very good considering the modest performance mods.
Edit: I just realised that those are STD correction numbers. SAE numbers are 231rwhp and 293rwtq; still good.

To me it always depended on what gear I was changing to. I almost always ran 1st near 6g even with stock h/c, then started dropping down with each gear change.

90_Red_LX said:

To me it always depended on what gear I was changing to.

Click to expand...

That's correct, which is why one shouldn't take the "hotrodders' rule of thumb" nor the tachometer redline as gospel. It all depends on the shape of the torque curve and the gear ratios.

Paul Randle said:

But can anyone give me a clear answer as to when is the best time to shift according to this dyno sheet?

Click to expand...

I just ran an acceleration simulation using your torque curve and gear ratios. The rpm numbers I came up with are:

1st to 2nd: 5900rpm
2nd to 3rd: 5700rpm
3rd to 4th: 5400rpm

The thing is, the stock tach is junk.. Unless you have a quality aftermarket tach this thread is useless. I have a digital shift light in mine that is accurate to 10 rpms.. I have the shift light set to the optimum rpm in each gear.. Because it would be impossible to see the digital readout on the shift light.

I thought this car had all that GT40 stuff on it? What happened to that?

bullit, where can one get that calculator?

The way I feel about it, the average person won't be consistent enough to benefit from being super accurate on shifting anyway. I always just played it by ear, and by the stock tach even though it's accuracy is, well, not accurate.

I always thought you weren't supposed to lift until you saw Jesus?

RacEoHolic330 said:

I always thought you weren't supposed to lift until you saw Jesus?

Click to expand...

Or (in my case) hold until it starts banging& popping,.....then stand harder on the gas hoping it'll go away.

gearheadboy said:

The miles wouldn't concern me. It looks like 4800 to 5k would be about right but it is gonna matter where it drops to rpm wise when you shift. You may benefit from a little more time in the upper rpms even though it is not in the peak HP/TQ area so that it drops to a higher rpm that is in your power band when you shift. If that makes sense.

Click to expand...

I agree. I'd like to have seen the torque at lower RPM. You want to come into the next gear at nearly peak torque, maybe a few hundred RPM before then. That way as torque starts to fall off the horsepower is coming on.