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🔧 Technical Turbo LS4 with 4T80-E build.

Trinten

Regular
TCG Premium
Aug 7, 2018
433
895
North Carolina
Hi All,

I signed up here after finding an epic thread discussing the 4T65E and the 4T80E.

I currently have a F23 manual mated to my SBC (running a 0411 pcm), there is a 1" adapter plate to allow this. I have the car apart for upgrades, and want to switch to an automatic, namely the 4T80E.

I found a source for the transmission, controller, and torque converter, but I am not sure about the flexplate.

The transmission guys I talked to said the adapter plate would influence the flexplate, and I've had my current setup for so long I don't remember what size the flywheel is or the toothcount (I reached out to the guy who last did some major work on my car to see if he remembers - I figured this info would be useful).

It'll be a rear-wheel setup. I want to make sure I can solve for the flexplate before I spend all the money on the other components, (or face selling them at a loss). Even if there's information I can't get until I have the transmission, as long as I know there is a person/shop that can make the flexplate once I have that info, I'll start buying the components.

Any thoughts/suggestions?
 

Trinten

Regular
TCG Premium
Aug 7, 2018
433
895
North Carolina
Oh, I did learn tonight that my current flywheel has a 142 tooth ring gear, which is the same tooth count as the the 4T60, 4T65 & 4T80 transmissions.

My engine is internally balanced. So is it possible to get a flexplate from a 3800 (or northstar GM that had the 4T80), and have it drilled/balanced to bolt up to the SBC?

I think at that point the biggest concern is the thickness of the flexplate, to compensate for any adapter plate? Or can I use spacers to move the flex plate the right distance from the engine? (or, as seen at about 8:30 into this video, he says they can use washers to connect the flex plate to the torque converter if there is too much gap - https://www.youtube.com/watch?v=lrqANOa_k3w ).

And of course I need to make sure the diameter of the flex plate clears the block and the bellhousing, though I think if I'm using a flexplate that goes with that transmission, that shouldn't be a concern?
 

Trinten

Regular
TCG Premium
Aug 7, 2018
433
895
North Carolina
Hey Rich,

Thanks, yes! I have been part of the Fiero community for a number of years. The trick here is that none of them have used the 4T80. The most common is the 4T65. So I'm in some uncharted territory right now.

I might buy the stock 4T80 flex plate, just so I have something to check clearances around the SBC block. I've emailed TCI and asked them if they'd be able to make me a flexplate with the right pattern for the SBC, telling them it'll likely have a 1" adapter plate between the trans bellhousing and engine (my F23 manual has the same bolt pattern as the 4T80, and I figured I can reuse the same adapter plate).

Fingers crossed.
 

Trinten

Regular
TCG Premium
Aug 7, 2018
433
895
North Carolina
Hey Rich,

That might be the final solution, I'll see what TCI says (hopefully they email me back).
To Triple Edge's credit, I found out today that Dave took the time to call V8 Archie (the company I originally got my engine/trans adapter plate from years ago) and they said they might have a solution, so I've reached out to them, too.

I'm super impressed at Dave's customer service with this project - and I really appreciate the responsiveness and ideas you guys have been giving me, too. :)
 

Thirdgen89GTA

Aka "That Focus RS Guy"
TCG Premium
Sep 19, 2010
19,297
15,654
Rockford
Real Name
Bill

Trinten

Regular
TCG Premium
Aug 7, 2018
433
895
North Carolina
So I have some good news! Meziere will make the flexplate for me! They make billet SBC and billet 3800 flexplates (so they are familiar with the right bolt pattern and tooth count).

They want me to send them my flywheel so they can make sure they get everything spot on. And the cost of having them design it was very reasonable!

So I had another question around this, I'm running the 0411 PCM, and was originally going to buy a stand alone transmission controller, but someone told me that I could setup the 0411 to control this transmission, but I would need a baseline of the transmission parameters from a car that came equipped with this transmission.

I'm using HP Tuners. Does this sound right/possible? It would save me about a thousand bucks if it's possible.
 

Mr_Roboto

Doing the jobs nobody wants to
TCG Premium
Feb 4, 2012
25,669
30,557
Nashotah, Wisconsin (AKA not Illinois)
So I have some good news! Meziere will make the flexplate for me! They make billet SBC and billet 3800 flexplates (so they are familiar with the right bolt pattern and tooth count).

They want me to send them my flywheel so they can make sure they get everything spot on. And the cost of having them design it was very reasonable!

So I had another question around this, I'm running the 0411 PCM, and was originally going to buy a stand alone transmission controller, but someone told me that I could setup the 0411 to control this transmission, but I would need a baseline of the transmission parameters from a car that came equipped with this transmission.

I'm using HP Tuners. Does this sound right/possible? It would save me about a thousand bucks if it's possible.

https://sites.google.com/site/sloppywiki/everything-ls/cheap-stand-alone-trans-controller

Usually Denmah seems pretty spot on.
 

Trinten

Regular
TCG Premium
Aug 7, 2018
433
895
North Carolina
Yes, that's it exactly. I've had the 0411 managing the engine (and feeding the instruments/idiot lights) for about 4 years.

What you are asking is exactly what I'm wondering about, and trying to find someone who has that chunk of code. I know there are guys here that run the 4T80E, but not sure how many have HP Tuners. I was hoping someone could email me the file or point me to where I could find it.

I tried google, but have only found leads on making this PCM work with a Northstar engine, and still no code yet, just feasibility discussions.
 

Trinten

Regular
TCG Premium
Aug 7, 2018
433
895
North Carolina
So I got a great update!

The recommendation was pretty solid. They suggested I get the ATSG manuals for the 4L60 and 4L80, and see which one has the closest solenoid pin-outs to the 4T80. Change the wires and then upload the tables for 4L## I lifted the pin-outs from. This will let me use my 0411 PCM to manage the transmission as well as the engine!

Also split the engine and my manual transmission today, and pulled my flywheel. Going to send it off to Meziere (hopefully tomorrow) so they can take the measurements they need and crank out my flex plate!

Thanks guys for helping me out with the ideas and pointers to the right resources.
 

Trinten

Regular
TCG Premium
Aug 7, 2018
433
895
North Carolina
Hey JFrost,

Thanks! I will once it's successful. Which I really hope it will be after all the cash going into it. lol So if you're on some of the other Fiero boards (guessing by your signature), keep an eye out there. As we go I'll take a lot of pics and notes, and we'll do a mega-series of posts detailing things.

I hope it'll be ready sometime in the spring.

Related note. Meziere called me today, they finished the technical drawing and send it to me to review, so I got it to Dave to review.
 

Mr_Roboto

Doing the jobs nobody wants to
TCG Premium
Feb 4, 2012
25,669
30,557
Nashotah, Wisconsin (AKA not Illinois)
So I got a great update!

The recommendation was pretty solid. They suggested I get the ATSG manuals for the 4L60 and 4L80, and see which one has the closest solenoid pin-outs to the 4T80. Change the wires and then upload the tables for 4L## I lifted the pin-outs from. This will let me use my 0411 PCM to manage the transmission as well as the engine!

Also split the engine and my manual transmission today, and pulled my flywheel. Going to send it off to Meziere (hopefully tomorrow) so they can take the measurements they need and crank out my flex plate!

Thanks guys for helping me out with the ideas and pointers to the right resources.

Megasquirt Support Forum (MSEXTRA) • MShift on Microsquirt (View topic)

This is for the Megashift/Microsquirt control of the trans, but the last post is what's interesting. Based on what they're saying you'd probably want to segment swap with 4L80E code then adjust the pressure from there. Swapping in the later force motor (with a different frequency) to the early 4L80Es is a common enough upgrade if memory serves correctly so it's probably something I'd see if it fit in your trans.

The ATSG books tend to be a good resource and worth having.
 

Jfrost

TCG Elite Member
Dec 19, 2011
2,189
440
Brookfield
Hey JFrost,

Thanks! I will once it's successful. Which I really hope it will be after all the cash going into it. lol So if you're on some of the other Fiero boards (guessing by your signature), keep an eye out there. As we go I'll take a lot of pics and notes, and we'll do a mega-series of posts detailing things.

I hope it'll be ready sometime in the spring.

Related note. Meziere called me today, they finished the technical drawing and send it to me to review, so I got it to Dave to review.

I’m on PFF often but don’t post much, I’ll keep an eye out there.
 

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