PDA

View Full Version : 4L80E adapter for Pontiac....



Jagarang
07-14-2005, 04:57 AM
Well....caveat number 16,678,859 when building a Pontiac!

I'm looking to install a 2002 4L80E to the back of my 1971 455 Pontiac motor. I have researched a bit and I believe that the TH400 adapters are the same, but would like collect opinions and suggestions from my PT family regarding the highest quality unit, and any installation issues I might encounter!

I found thess adapters...
http://www.transmissionadapters.com/late_bpoc.htm

Coan Racing..
Coan Racing (http://www.coanracing.com/PDFS/InstallInstructions/COA-980073.pdf)

On a side note, I just read that I'll need a different tail section to work with my mechanical speedo??

There's yet another problem you'll encounter when retrofitting one of these sleek puppies into your non-computer controlled car. The speedo. These transmissions were designed to ONLY work with an electronic speedo. So, you have two choices: convert to an electronic speedometer (apparently over $800 according to CC) or you can get an extension housing for the 4L80E from Art Carr (part No. 17925 - $395) which allows the use of conventional TH-400 speedo gears and cable. Carr also has performance 4L80E converters available

Any help on this idea is also needed.

This is getting complicated!

What about transmisssion tunnel modifications? Frank says the 4L80E bellhousing looks significantly chunkier than either the TH-2004R or TH-400 that were previously destined for the car.

Thanks in advance guys!

derekf
07-14-2005, 06:15 AM
Abbott Tach makes a product that drives mechanical speedos from the electronic tranny signal:

http://www.abbott-tach.com/cablex.htm

Price is just shy of 300.

I don't have any first-hand knowledge of how well it works, but a Google search finds a few reviews on it.

Jagarang
07-15-2005, 06:11 AM
Thanks Ralph. I'll call them to clarify a few questions I have regarding their product.

I should mention that I'm using a factory hood tach and indash speedo and full factory gauge package. The Abbott part seems geared toward late model aftermarket gauges, but that's one of the things I need to talk to them about.

Steve Chryssos
07-15-2005, 09:13 AM
No. I don't think you want to swap out that tailshaft. Unless I'm missing something about this TH400 tailshaft conversion, you need that VSS sensor to run your transmission controller as well as your speedo. The TCU gets tailshaft speed from the VSS and calculates that speed in conjunction with final gear ratio and tire diameter to arrive at driven wheel speed..

What do you have for a speedo? An electromechanical converter is the way to go. Or just get an electric speedo.

Jagarang
07-15-2005, 09:38 AM
I have a full factory 1969 Pontiac Firebird Rally gauge package. They are all original except for a complete restoration.
I need to figure out how to drive my factory tach and speedo with your "Shrifter" and a tanny controller from an aftermarket source(of your recommendation/prefference hopefully).
Frank may call you in the near future if he hasn't allready. We just recieved my console and dash back from fabrication and are ready to begin installation soon. We have an LCD shift indicator mounted in the console which we will need to incorporated into the system to indicate gear selection. It is of the same type and make as most of the aftermarket LCD shift indicators.
I believe Frank would also like to pick your brain regarding tunnel mods needed to install the 4L80E in the first gen. F-Body.

What are your thoughts?

Thanks

Steve Chryssos
07-15-2005, 10:30 AM
Yeah Frank and I went back and forth on tunnel mods today. Clearance should not be a problem other than in trans cooler line area (pass side of trans tunnel).
The TCU definitely needs tailshaft speed to function properly, so unless this tail swap has dual functions (mechanical and VSS sensor) you will want to go with a converter. I have a customer who raves about the abbott unit.
I'll get with Frank and zero in on the right controller for your application. Is your car NA or blown?

EFI69Cam
07-15-2005, 10:41 AM
The abbott box is what you want. You hook up power, vss then attach the speedo cable to the back of your stock speedometer.

TCI sells this product also.

This is what I use in my 69 Camaro with my electronic output only t56.

Jagarang
07-15-2005, 10:52 AM
Sweeet. Good info guys.

Steve you've got PM.

OHCbird
07-28-2005, 06:29 PM
I have the TCI version on my 4L80E-equipped 68 Camaro. We had to massage the trans tunnel a bit, but nothing that would scare ya or make you say 'not for me'. I did it backwards, though- there is a shop in CA that will convert your stock speedo to electronic (2K or 4K ppm IIRC). Something like Speedotech, etc... I'll get on my old confuser to see if I have the link.