4L80e Orifice Sizing
 

Hello, this is my first post on this forum. Trying to get baseline suggestions for drilling the 2nd-3rd-4th feed holes in the separator plate. Looking for anyone WITH A STALL CONVERTER as this greatly effects shift feel/firmness. Please list your setup with hole sizes. My stock 4L60e with vette servo would chirp 2nd above 50% throttle with crisp 3rd and stock stall. I'd like to duplicate this feel. All street driving. Frequent burnouts through 2nd gear.


Here's the truck setup:

99' 2wd RCLB, n/a 5.3 about 425hp @crank

30 inch tire, 4.10 w/posi


Trans setup:

Internal dual feed, accumulators active, boost valve w/ stock spring (for now), using all waves, Circle D 3000-3200 258mm billet stall.


I understand there is no perfect number and I am sure I will have to resize the holes after testing. Any assistance is greatly appreciated!

Active accumulators with wave plates?
2nd .093
3rd and 4th you can probably just toss the checkball and call it a day...but if you want to keep the checkballs and drill. Go .150 for 3rd and .125 for 4th

I keep 2nd on the smaller side because I assume you have a 34 element sprag still and there's no need ot "chirp tires" going into 2nd...all that will do is accelerate wear and reduce the life of the sprag.

If you want to chirp tires go .110

Good advice above. I will agree with keeping 2nd more conservative. On my last build I did 2/3/4 all 0.120. 2-3 & 3-4 have good firm shifts but 1-2 is harsh, especially at light throttle. Tuning shift pressures didn't help soften it up either.

Yes 34 element sprag. Transmission is still apart. To my basic knowledge, using wave plates (th400 in direct, stock elsewhere) is less harsh on hard parts. I try to lean on the side of reliability so going .093" in 2nd makes sense to me. At my power level I didn't think I would need to delete the accumulators?

I've only ever overhauled 2 4L80e units, both were from 1995. Neither had the wave plate on the intermediate clutch, and I'm pretty sure both had never come apart. One of them had the 34 element sprag, but the other had the standard 16 element sprag (which I did upgrade to the later.)