Transmission Conversions and Computers

[2nd Time Round]

I have a 4L60E and I've been thinking lately about switching to a 4L80E. As one can imagine the sticking points are the computer and the VSSB and the speed sensor(s) on the new tranny. Assuming it wasn't possible to get all the stuff from the donor vehicle, how hard is it to reprogram the existing computer and VSSB from the 4L60E? What would I need to do the job? Is the VSSB really relevant if I'm not planning to change rear gearing/tire size and I have the proper speed sensor on the new tranny?

One last question: what would be a good company to get a complete rebuild/upgrade kit for the 4L80E?

Thanks for any help.

[totsabe]

The easy way to deal with the trans computer is to add the TCI TCU, transmission controller. It comes with the wiring harness that just plugs into the trans. It also has extremely user friendly software to program the trans. So you just have a extra box under the dash to plug your laptop into to make changes.

You just leave your existing OEM computer in place taking care of the engine and unplug it's connection to the trans. When you go to sell the truck, slip the TCU out and plug the OEM back into it. Keep the TCU for your next truck.

I think the TCU actually pays for itself in longer life for the trans, by simply being able to easily match trans settings to compensate for power add ons in the engine deparment.

It also has the circuits built in for paddle shifting if you ever get the urge to go in that direction.

It is worth looking into.............

[99-2door]

What year and model are we talking about?

[totsabe]

It does'nt matter. The TCU works with all of them.

http://www.tciauto.com/Products/Electronics/

[99-2door]

It does'nt matter. The TCU works with all of them.

http://www.tciauto.com/Products/Electronics/

It does matter, because on the newer trucks you don't need the TCU. The stock computer can be reflashed to work with the 4L80e.

[Justin_Inc]

at 1000 bucks for the TCU, i find it very hard to justify that cost... then again thats just me

[totsabe]

It does matter, because on the newer trucks you don't need the TCU. The stock computer can be reflashed to work with the 4L80e.


I don't doubt that the existing computer can be reflashed. If someone is going from a 4L60 e to a 4L80e, it is generally because the engine is much stronger than stock. In that situation, a TCU will do a much better job of controlling that extra power than the stock computer. Just doing an overall increase in transmission pressure is not the correct answer.

There are also a couple of wiring changes that must be made to go from 60 to 80. I doubt that GM includes the additional wires in a stock wiring harness.

[99-2door]

2 wires you have to run from the 2nd VSS to the computer and you have to swap some around in the trans connector. Not a big deal.

If you are building a hard core race machine, it might be worth the cost, but for anything for the street the stock computer is fine.
I would rather spend the money on EFIlive or HPtuners.

[2nd Time Round]

What year and model are we talking about?


It'll be going in a '95 ecsb truck.

[totsabe]

The HP tuner is OK for OBDII but does not cover the 95 in question. Personally I wouldn't waste the $500 on the Hp tuner. I prefer to have more control than they offer.

But hey, that's the great thing about this country, you can waste money on anything you want.............

Good luck with whatever direction you take.

[2nd Time Round]

Thanks for the help guys. I think that I'm in a gray area with what I plan on doing. I want to put in a nice torquey 383 (approximately 425-450 lb/ft), but I'm not sure that the L60 will last behind it, even with a "proper" build, sun shell, and planetaries.

[Justin_Inc]

I'm in the same boat you are, only i have no computer control, i'm running a 383, soon to be turbocharged, on a Megasqurit ECU, and i'm debating on transmission options. An 80e is the way to go, but I just dont want to go through the hassle.

So i'm going to do a stupid thing and dump some coin in the 700R4 and see just how far i can push it.