Jiver67

A question for you guys concerning shift RPM and manual transmissions:

Assuming you know the RPM where your engine makes peak HP, what is the optimal shift RPM above this point to keep the engine at it's HP peak after the shift? The old drag racer's rule of thumb states that you should shift at an RPM ~10% above peak HP. For example, if your engine makes peak HP at 6000 RPM, you would want to shift at 6600 RPM to keep the engine at it's HP peak after the shift. This rule assumes that you lose about 10% RPM during the shift. Is this accurate or exagerated? I know that many guys with automatic transmissions shift 200 to 300 RPM higher than peak HP for the same reason.

Any input would be appreciated.

slow trap

iTrader: (22)

i alway's thought it was around 400-500 rpms past peak hp.that is where i usually try to shift at but the best way to find out is at the strip.

speedfreak440

iTrader: (9)

It is totally dependent on how well your engine "hangs on" after peak. ie: if it hits peak then falls like a rock then you want to shift pretty freakin close to peak. If it hits peak then just kinda stays around that general area then don't shift till it starts to fall hard or till you are right at the rev-limiter.

Ace$nyper

iTrader: (8)

You really need a dnyo chart to gauge where to shift best.

Stock/bolt ons m6 with 3:42s I feel 6K is a good # to use.

Jiver67

Thanks all for your replies! This gives me some information to chew on.

98TADRIVER

iTrader: (36)

i agree !