I'm looking into the doing the swap, but I want to retain the computer tuning option I have with the 4L60e. I have searched and all I can find is that you can do this with an LS1 PCM but not an LT1, I find this hard to believe as the 4L80E has been in vehicles back to 95 and computer controlled. Does anyone have a first hand knowlegde of why or how the computer can tell its hooked to a 4L80E instead of a 4L60E? I looked at tyhe wiring diagrams for both and they seem to have pretty much the same layouts, maybe just repin the connector??

I would like to keep the swap reasonably priced, without buying a 600 dollar PCM that does very simple things, maybe I could piggy back the PCM with a early truck PCM that came factory with a 4L80e??

 

I went with Transgo's Full Manual valve body conversion kit. It's $250 and its the cheapest and best way to control the transmission IMO.

-Dustin-

 

I know, but I want computer control just like I have now. I have my 4L60E programmed just like I want now, nice smooth shifts when putting around as neck snapping when WOT. I just like the flexibility of computer control. I might be reduced to a full manual but as a last resort.

 

Then your looking at $600-1000. I did the whole swap with a $650 converter for around $1K.

-Dustin-

 

Man that is cheap for your conversion!!

I think I will try it with the LT1 computer and little rewiring and some ingenuity and see if I can get it to work. I really don't want a full manual, I wanna be able to keep both hands on the wheel

Where did you get your convertor? What stall speed? Lock-up??

 

Precision Industries Vigilante from Tbyrne. 3200rpm Lockup.

-Dustin-

 

Hmm, how do you like it?? I need about a 4500 stall, I'd like to keep lock up too .

I think you have the only LT1 4L80e combo that I have seen. Are the convertors different from the 4L60 to 4L80 or are they the same?

 

I wasnt the first, but I can tell you there arent many LT1 guys who have done it. I've only seen 3-4 ever. One reason is there are ALOT of nay-sayers spewing crap, especially on here, and people listen to them. Probably cause sometimes the nay-sayer is a CamaroZ28 vendor. The LSX guys are all over these 4L80E's, why? Cause they can be built to provide 1000rwhp reliability with overdrive, lockup and not need rebuilt constantly. The 4L80E is one tough trans and the LSX guys are running 9's on the weekend and driving with lockup on the highway to work during the week. You couldnt do that with a TH400, at least not like you can with a 4L80.

I love my Vigilante, I ran one in my 4L60E and it worked great, running one now and I cant say how much I like it. They are different converters, you'll need yours custom made like I did.

-Dustin-

 

Yeah, I would stay with the 4L60E but I will using alot of nitrous and I just don't see it hanging in for more than a pass or two.

Your right with all the nay-sayers though. And no one can tell me why it won't work or why you can't control it with the LT1 Computer, all they say is you need a post 98 OBD2, but GM controlled them somehow with much simplier systems prior to this.

I think I would just find an old truck PCM and use that with a homemade harnees before shelling out 600-1000 for a TCI-Com or simliar. I can tune the older truck stuff with the same t-cat I use now.

 

Are you going to keep the electronic pressure control? I guess you could simplify things if you didn't, but that is a nice control for driveability. Then you have the three solenoids, the lockup, and the pressure and temp signals, and gear select switch to wire up. I would think it could be done, but whether all of the software algorithms are appropriate for fine control of the bigger tranny would be the big question and maybe that could be addressed through tuning. I don't see how it would be all that dissimilar, to be honest with you, but I have no firsthand knowledge of the 80E - I'm just making logical conclusions.

 

Same thing I was thinking, I think the 4l80e has one more speed sensor but I'm not sure if the stock PCM can still shift the tranny with out taking its readings into account. I guess I'll find out

 

what shifter cable will work with the 80 ??

 

I understand where you're coming from, wanting to retain the LT1 PCM control of the transmission! I bracket race and the programmed shift points on my 4L60E make my car very consistent. And, that is one of the "main" reasons I'm bracket racing with the LT1 F-Body.

Also, I’ve had some 4L60E problems with the times I’m running now (1.48 60 fts and 10.80s), primarily the input sprag. I have about 20 people every season tell me, “I need to get a PG or turbo 350/400 with manual valve body for my car." However, when everything is working correctly with my 4L60E, the car is "very competitive" and I win a lot of rounds and occasionally an event!

WD

 

I used the red shifter cable that came with a B&M Megashifter. You will need B&M's TH400/TH350 shift cable plate that bolts to the trans pan to make it work right. It's on their website and Summit/Jegs sells them.

-Dustin-

 

do you no the leagth of cable