MUSTANGBRKR02

iTrader: (91)

Well I plan on building a 4l80 for my twin turbo 370 car. I plan on doing Jake Shoe's trans brake with MVB. As far as internals. I was planning to go with the Billet mainshaft and forward hub.

Is the billet intermediate needed?
Does this build sound strong enough for 7-800rwtq?
Anything else I should do to help it live?

Thanks

FLT

iTrader: (1)

Depending on which billet drum with intermediate sprag you go with some machine work might be necessary. There are some nice billet aluminum direct drums out there that use a factory HD sprag. The idea behind this the aluminum drum is lighter than the steel drums and this will take some load off the sprag when it stops the drum. These are usually used in high hp applications and are a good upgrade if you can swing it. With using these you will not have to machine other parts to make it work. So keep this in mind when making your decision.

I would make sure that you get a torque flight 8 snap ring to be used for the intermediate pressure plate. This will help from the snap ring from blowing out. Also you can easily add a clutch to the direct drum by using the forward steels from the 80. Normally I use a self regulating boost valve from sonnax in the pump as well. I hope this helps. Vince

MUSTANGBRKR02

iTrader: (91)

Thanks alot Vince some very good info thanks.

I am still debating the 80 vs 400. As I have the TH400 in my garage that is already built but the OD is so tempting.

slow67

iTrader: (2)

An aluminum drum isn't needed for 750-800 rwtq. I would do a billet input and possibly a billet forward hub (they are pretty cheap).

Heads-Up-Outlaw

Usually a builder recommends a billet drum in the name of safety. Have you ever experienced a transmission explosion at 100+ mph?

What most folks don't realize is that parts are either expensive to buy or expensive to manufacture and if a builder isn't manufacturing the specific component he is probably giving it away at or damned near his cost. The recommendation for upgraded components may not be necessary, but when a guy with Vince's tenureship in the transmission market suggests it, I would listen well and do a little research before settling on a "cheaper" build because it isn't necessary.

It isn't necessary to put a forged crankshaft in an engine when you spray a 200 shot on it, but it is highly recommended. Same theory applies. Ever kicked the rods at over 100 mph? It isn't a fun ride.

slow67

iTrader: (2)

If you drive it correctly (proper 2-3 burnout, don't neutral the trans at speed or let off in 2nd with no front band) you won't have any issues. If you are worried about that get a trans shield/blanket. Besides that, aluminum drums will wear out fast on the street. Aluminum fatigues much more quickly than iron or steel. Also most of the drums that have exploded were 40+ years old. I've seen a 4L80E neutraled after redlining overdrive in a new H2 and it didn't explode.

As far as kicking rods out at over 100mph, a forged crank won't likely stop that. An engine diaper will though (and I can count on one hand the number of street vehicles I've seen with a diaper on it).

MUSTANGBRKR02

iTrader: (91)

Thanks for the replies guys. I will be talking it all over with the builder so we will see.