4L80E vs boost pressure - data requested

[Eric Deslauriers]

I have a non-lockup TH400 in my MH at the moment and have a 4L80E in my garage to install in it.

Can someone get me some #s on the following please? Nonwastegated would be the best as it matches my setup. BTW, I'm at either 15K or 19.5K pounds, and I was looking for #s loaded, not empty. Also, 700R4s have a much steeper OD, so the #s won't map as well as I want, so let me know if you're NOT talking about a 4L80E plz.

In D, convertor unlocked - PSI boost
In D, convertor locked - PSI boost
In OD, convertor locked - PSI boost

I'm trying to get an idea what my PSI will drop so I can figure out how fast I can safely go. ;)

TIA!!!

[britannic]

Thre's no real set figure for boost, as it depends on factors such as ambient temperature, elevation, grade, IP configuration, timing, air intake/filter set up etc.

The real issue is EGTs; optimized boost and exhaust back pressure will lower EGTs for any given situation, providing the IP is set up and timed correctly and the air intake is modified for maximum performance. Overdrive engaged below 2000rpm with a heavy throttle opening will definitely increase the EGTs - I've had 1000F in locked overdrive (700R4) and 450F downshifted to 3rd on the same grade under WOT.