I've been given a gift a 4L80E trans from a 99 Suburban w/ < 20,000 miles on it. Jet Performance wants an unbelievable $1,400.00 for a stand alone computer for it. Does anyone know of another company offering an operating system for this trans?

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Try some of the big name race tranny builders. Some are listed in National Dragster. A lot of them sell street transmissions too

The 4LE80 trans is a HD version from 3/4 ton trucks and I think they are the only ones that have anything for this tranny.

There's an article in Jan 2000 Chevy High Performance on trannys but they have very little to say about this one.

Go to the technical reference section of this site and see what is there (yes, I wrote it and it's not totally finished). The big thing is that you have to read the "E" notes!!!

What isn't included is that according to Sallee Chevrolet, chevy is working on a "stand-alone" conversion computer and loom. Hopefully it's less money than what Jet wants.

I believe that the Jet computer isn't programable, and an even more costly option would be to go with the Accel programable computer. As if you wanted to spend even more money.



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Wes. Vann
Technical Reference section
Gold Member #5

I just talked to a friend who is a "chip burner" and asked about what I just read on this thread.

He says "early '90s diesels used a stand alone unit for the 4L80E, and that NAPA sells rebuilt units for about a buck and a half. Aftermarket wiring harness Companys make up wiring harness kits for them as well."

It sounds like it's worth doing some research. I'd probably check salvage yards for the diesel harness since it was a stand alone unit.

Just for my own personal info, which functions of the transmission does the computer control? If it's nothing more than the lockup and kick-down, it would seem to me that you would be able to use switches to control those functions just as the 700R4's did. I've seen alot of computer controlled equipment in my profession, and the computers have ultimately only switched control voltages for relays and solenoids. De-computerization seems like a simple enough solution. Am I wrong?

The computer tells the transmission when to shift according to the signal from the speed sensor (so I'm told
When I had a blown fuse on my Suburban, the transmission wouldn't shift, no speedometer and naturally no cruise control.
I wonder how you would connect the speedometer
http://www.chevelles.com/forum/confused.gif


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Dean Call
Team Gold member #3
A.C.E.S. # 00235
N.C.O.A. # 4350
Mid America Chevelle Club (http://macc.chevelles.net) #001
chevelles.net (http://chevelles.net)

That's a good question, Dean. Maybe replacing the valve body would be an option. Does the tranny still have the manual shift control, or does the shifter also communicate with the computer?

Well once again I guess I'm one of the few that has had the pleasure of working on one of these beasts... The computer controls all functions of the transmission. From line pressure to shift points to lock up. Everything is controlled by solemoids. I truly don't see a way to get rid of the electronics. BTW problems with these transmissions can be a royal pain to track down, also rather expensive. Just my observation of what I have seen.

J.J. Fig

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MCC member #256
http://www.clark.net/pub/chevelle/mcc.htm

Look into the diesel tranny computer, if I remember right it is the '94 or '95 on up 3/4 and 1 ton unit that you need to pick up from your friendly salvage operator.

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"Bomber" '67 El Camino
Beater comes back to life
350/TH350 14.90 @ 93mph!

Greybeard, you mentioned that the chevy unit from a diesel was a stand alone unit. I wasn't aware of that, can you find anymore info on that? I've got a '67 chevelle and a '85 K20 Diesel. Both would do well with a 4L80E but the JET computer units are way out of line. But they are programmable to give you whatever shift points etc. you want.

I suspect that the only units that would work would be '90 to '93. In '94 chevy went with an electronically controlled injection pump. Prior to that it was still mechanical.

Any info you or your friend has would be appreciated.

Oh, and also the diesels will have a lower rpm shift point programmed in, about 3000rpm. So that would still need to be adjusted.

[This message has been edited by fastburn (edited 02-18-2000).]

You are not the first one to do this. I swear the info is out their. I know that Art Carr sells 4L80s, I was looking at them for my car. Give them a call and see what they say. Then post it here.

Fastburn,

It was the 90-93 units my friend mentioned. I'll do some research on this on see what can be done about the shift points. He does some amazing things with chips, so maybe he's got the answer to this.

Hi all, I just got off the phone with Richard at Art Carr. Good guy, sounded honest, and he knew his stuff. Picked up my Canadian "eh" real quick too!

Anyways, their conversion computer, standalone is about $790. It does not come with a vehicle speed sensor. So you'd need that too which is about $395. The tranny itself is $2499. Torque converter around $300. All in all, a little less than JET.

Whether or not you can get the factory GM one from the wreckers and bolt it up, I don't know. But it sounds like either way you go, you'll be spending alot of bucks. If you got the 4L80E for free, its probably worth it. Richard felt that for most of our applications the 4L80E was overkill.

We talked about the upgrades they do to their 700R4's. Sounds like they build 'em better than JET. They say they'll take upwards of 450hp. Apparently they have some drag cars running over 550hp with them and doing fine. Tranny, complete with a converter is around $2400.

He's sending me some detailed info on the build up they do to the 700R4. If anyone is interested in this you can post here or email me direct.



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'67 Chevelle, 388cid
'85 K20 6.2L Diesel

I have an FP Performance 4L80E Controller and harness on a car where I work. Honestly don't know the cost, but whatever it is a great unit. It is a stand-alone unit. However, any ECU you use requires an rpm and throttle position input. You have to run a TPS. FP has an adapter to adapt a tps to a carb I think.
The FP unit allow complete tuning of shift points, downshift speeds, line pressure, tc lockup, everything. On a performance car I think this is a must. With an oem ECU you are stuck with the factory programming.

By the way, that trans is great. I have it on a 570hp big block and it takes it without a problem.

[This message has been edited by Doug F. (edited 02-19-2000).]