EPR on Takeoff

[Hedncld]

Question for Old Smokey???
I was wondering what Epr does on Takeoff as far as the effects of ram air rise.
I fly MD80's and know that EPR decreases (.01 or so) on Takeoff but every book I read says epr should increase? Anyone have a thought on this???
Thanks
PS Dont go nuts with math equations-my brain is small.

[stancioiu]

The effect of ram rise begins at higher speeds. At takeoff, the speed builds up and since epr is the ratio between the pressure at exhaust and the pressure at inlet, is normally that epr decreases.

[Hedncld]

Thanks for the info. I was just alittle confused.