Modulated 4l65E

[Forum 12]

Hello there, we are contemplating using 4l65e transmission with a vacuum modulator kit , is there anything we should be aware of or need to watch for this modification?

Thankyou.

[overdrive915]

From what I understand you are going to run this trannie in full manual mode

[wait4me]

With vacuum modulator, your are just taking away the computers ability to define Line pressure. It will be a forced value instead based on engine vacuum. Not an ideal way to go or gm would have done it from the begining. The reason why shops do it is because then they know that they dont have to rely on a tuner to set up the pressures correctly.

[Forum 12]

From what I understand you are going to run this trannie in full manual mode
Thanks.
No still auto.

[Forum 12]

With vacuum modulator, your are just taking away the computers ability to define Line pressure. It will be a forced value instead based on engine vacuum. Not an ideal way to go or gm would have done it from the begining. The reason why shops do it is because then they know that they dont have to rely on a tuner to set up the pressures correctly. Yes I have my reservations on this idea but the transmission builder believes its the way to go for a sub 11 sec car.to be sure of max line pressure, he has a load of other reasons too but,its beyond me.


thanks .. F12