not in 3rd gear...

 

he would be doing about 140mph with 28" tires in 3rd gear at 7200 rpm

 

It doesn't matter what gear he's in. That's driveshaft RPM not engine RPM. It's the same regardless of transmission gear. With 4.10's and a 28" tall tire that's 146mph. So 3rd gear, 4th gear, whatever that's the fastest he can comfortably go without worry of puking the driveshaft out from under the truck unless he switches to a higher rear gear or a taller tire.

 

Hmmmmm. Ya i dont plan on ever going that fast in my truck without a lot of safety equipment.

 

I don't understand what you're trying to say, brakenit. 3rd gear is 1:1, so engine rpm would be the same as driveshaft rpm.

In 1st and 2nd, engine rpm > driveshaft rpm

4th/OD, engine rpm < driveshaft rpm

 

Actually it does... for 7200 Driveshaft RPMS he would have to be spinning the engine to 17784 in first gear not including the Converter slip

2nd 10584 rpms
3rd 7200
4th 5400

Thats what transmission gear ratios are for




Ive spun my factory 2 peice DS to ~6400 rpms one time.. never again, but it was fun while it lasted. 4800Rpms in 4th with the converter locked.

 

Right, and as I said it doesn't matter what gear he's in, the driveshaft guy gave him the maximum driveshaft rpm. It doesn't matter if the transmission is in 3rd, 4th, 2nd, 5th, or even neutral. You guys are talking about being in 3rd gear, if he's at a standing mile event doing 160 in 4th with the engine at 6000 rpm he's still exceeding the rpm the driveshaft was balanced for because he's going more than 146mph.

 

6000RPMs at the engine, .75 4th gear = 8000driveshaft Rpms..

That would be insane!!!

 

Well i think i can finally call the 4L80 swap complete... I swapped it in last weekend and I just now finished all the driveline angle BS....

Here are some pics.

Truck trying to fly!!!




Finished crossmember



Some pics of the new driveshaft!! Incase anyone is wondering the old Driveshaft weighted 20lbs, the new AL one weighed 17lbs.







The new CircleD flexplate. Incase anyone is wondering the old flexplate weighed 5.5lbs, the new one weighs 7lbs....



Installed



The stock 80 converter vs the new CircleD 3C 3600!!!!



Next i had to extend my existing -6 cooler lines. Turned out pretty good!!

This harbor freight $20 cable cutter slices braided lines with ease and makes a straight cut.





Tools of the trade, Just incase yall don't have a set of the combination AN wrenches, Jegs has a pretty decent price on a set!





AN vice jaws are also i great buy!!



finished product



Everything installed



New crossmember fit like a glove!!!

 

I got some new saddles and bolts when i ordered the driveshaft. For some reason my bolts the heads of them were basically destroyed.. Something must have come in contact with them...



Finsihed product






Results!

I had to shim the rear end some to get the drive line angles in check, but it drives like a dream now!!! the CircleD converter is NICE!!!! It is pretty easy to control, under light throttle you can keep it below 2k but give it some gas and it flashes like a ****!!! The shift extensions with the 80 and that converter are insane!! the RPMs might drop 100-200 RPMs between shifts.... All in all i am extremely happy with the swap, Honestly i really don't know what everyone complains about with the 1st gear. I really like it, 1st gear spins up high as a **** and 2nd is freaking insane, being able to kick down into 2nd at 80 is nuts!!! The shifts are really really quick and they are barely noticeable. 1000x better than the old stock 60 with the shift kit and the level2 performabuilt...