Anyone hiting overdrive at the end of the track with the 4l80e? I want to run 4.10 gears and hit 125mph in the 1/4 mile. (I WANT, does not mean I will) but I would like to set up my gearing for it. The 4l80e has a shift kit and rebuilt with red alto clutches and the htrk kit. I think I may have to hit Over drive to hit the estimated 125mph, my RPM would be alittle high in 3rd with a 28 inch tire.

 

Why not switch to a 3.42 rearend ratio. The turbo will like it better also.

 

I guess I am alittle worried about that 1st gear, weight, and 60ft times. I think you are right, maybe the 3.42 would be better. I remember you hit 1.6's with the 3.73's.

 

I agree, the taller gears will load up the turbo better. Don't worry about 1st gear, you'll make up for it half way down the track.

How's it all coming together Brian? When do you think i'll be streetable?

btw, I have a set of 3.42 ring/pinion for front and rear if you need?

 

Its alittle slow thanks for asking. The trans rebuid really slowed me down. Waiting on parts, and trying to figure out all that went wrong in it. I had so many melted parts in there I didn't know what the parts where. I will pm you on the gears to see what you want for them. Thanks

 

Was up Brian? Glad to hear your almost back in action. I would love to see pictures of what you have done. Mr Gibbs is doing quite well whne I drive it both trucks are completely done and admired by most. Good to see you almost back in action.

 

Thanks bro, I am glad that you are doing well with the t56. I think I should have it up and running in two weeks I hope. I am waiting for my buddy to make room in his shop so he could help me do the fabrications. I will take pics of it all and post it when I am done.

 

I have a 3.42 in the rear. Keep in mind I was only launching at 2800 rpms. Once I hit the track again I'm gonna bump it up.

 

Oh, ok. Thanks for the info.

 

The 4L80-E can tollerate a WOT 3-4 shift. There is a set of Raybestos Blue-Plate special clutches available for the 4L80-E fouth pack. Not sure if you've ever seen a 4L80-E overdrive setup, the clutches are so large in diameter you could slide the entire geartrain from a 4L60-E right through the center. Also, the 4L80-E overdrive has its own dedicated planetary and roller clutch - these components are heavy and strong. There are only four clutch discs in the overdrive pack but the large diameter seems to get the job done.
The 3-4 shift in a 4L80-E is softer than the 1-2 and 2-3 shifts. You can compensate by drilling out the feed hole in the separator plate larger. For example, if you have a TransGo shift kit in it, drill hole "A" out the next stage larger than the other two.
I have done countless WOT 3-4 shifts on a 4L80-E with stock type fourth clutches and have never experienced any hesitation or unpredictable behavior.
Best of all, if you do smoke those clutches, replacing them is simple since they're so easy to get to - right after the front pump.