When [for example] on a ls7 max hp is at 6300rpm why rev up tp 7000.

wouldnt it be better to shift at 6300rpm?

cheers


[simple question but never understood it]

 

This is a question that a lot of people don't understand.You want to shift above your power peak because of what happens when you shift-rpm's drop back way below power peak.You want the best power across that whole rpm range.Shift above peak power and rpm's won't drop down as far and you have more average power across your rpm band.Of course how fast your power drops off after peak would effect how far you want to go too.Hope this helps.

 

Ultimately you want to fall back right where peak torque happens after the shift. Pro Stock have this luxury of selecting specific gears to reach this impossible task for street cars. Street cars can only shift after peak power and hope they fall close to peak power or somewhere that provides the best under the curve power. Street transmission ratios are setup for fuel efficiency, not all out performance.

 

Yep...it is all about where you fall in the RPM band after the shift. I once found a nice tool on the internet that let you put in numbers from your dyno sheet along with your gear ratios, and it would spit out the best RPMs to shift at. Not surprisingly, it was higher than peak power for a stock LS1 engine (at least for my numbers).

 

Ideally you want the shift point rpm horsepower to match the rpm horsepower after the shift. That way you get the most power under the curve. However due to the power curve you may not be able to do that. Follow the above advice for most power under the curve.

 

thank you