the length of the crank would also be a factor. There are so many things to consider. Just rev it until it stops making tourqe (pulling) after that its just reving.

My 1275 A+ Rover engine's max bhp at the wheels is around 4200 ish (on the dyno it peaked at 120km/4200rpm) is it worth going higher than this or is that when I should start changing gears?
I normally take it up to 4500-5500rpm

Another question to solve an argument;
Is it better to change at max hp or at the red line for faster driving?

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Respect mine and I'll respect yours.

sometimes its ok to go a little higher so that once you let the clutch out in the next gear the engine revs dont drop too far down, thus keeping to in the power band.

what he said ^^^^

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Here am I sitting in my tin can far above the Moon
Planet Earth is blue and there's nothing I can do...



“A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.” - Jeremy Clarkson

It may be easier to see it
This is from a spreadsheet that I use to guesstimate what diff and gear ratios will work best. I think the power curve was copied from a 998 dyno sheet that was put up here somewhere



Basically you would want to change gears just after the lines cross over so that the rev drop during the gear change evens out. I think they say each gear change costs about a second...

WOW 18 1/2 HP that's crazy power :lol:

So it's better to change at max power then...good, that's what I thought.

_________________
Respect mine and I'll respect yours.

No not at max power, but where the lines cross over
so first to second change is at the intersection of the blue and red line or just over 50 km/hr...

[Edit] Maybe this one shows it better;

[Edit]