What is the optimal RPM to shift a 5 speed bolt on modded NA 4.6 for best ET? I always wind to 6k but saw on dyno charts the rwhp starts dropping after 5k!

 

run it to red until you know otherwise. i wouldn't wind it out past that though (6k's not too bad i don't suppose, but i wouldn't do it real super often...i mean they put the redline there for a reason). i think of it this way...use every gear as long as possible...even if you don't make power past 5k, it's always easier to wind out a lower gear, not to mention the higher you rev it, the higher rpm it puts you in next gear.

 

Go to the track and try different shift points. Alot of cars like to be shifted early on the 1-2 upshift try 5500rpm on the 1-2 and then 5800 for the rest( by the time you make the shift the engine will see about 6000rpm). I really don't think you will hurt it by going to 6000rpm, but if the power drops off sharply after 5000rpm you need to get it in the next gear so the engine stays in its powerband.

 

my cobra cuts off at 7200 ..but shift around 6800..

 

Best times with a 99+ with gears but still stock cams is 6k shift to 2nd, 6k shift to 3rd, 5800 shift to 4th. Peak power is at around 5200 but the power curve stays relatively flat and its better to be at 5800 making descent power than at 3500 making nowhere near as much. Its not necessarily where you make the most power, its staying in the best power curve.

 

Nothing more to be said.

 

Thanks, makes a lot of sense.

 

Max power comes on at 5250 RPM in stock form....So try to shift as close a possible to that... I know it's hard trying to race and make every shift at the perfect RPM....so just make shift when the indicator screams past 5000 and you should be ok...What RPM do you lauch that Vert at?

 

I launch about 3k since I got the Drs they spin one turn and hook hard.