Transmission Controller Questions (Page 1/2)
Reborn756 MAR 18, 08:42 PM
Howdy folks! Just checking in on what standalone Transmission controllers you are using for 4t65s or 4t80 transmissions. Been reading a few older posts here in the forums and just wanted to see if products have changed over the past couple years.

Looking for one that will automatically control the transmission while still allowing me to use a factory type gear selector.

Car will be getting a special, purpose built SBC. So an option that will totally replace the ECU would be doubly awesome. I see that FAST for example makes a setup that can control everything: their EFI, Trans, etc, but it only mentions 4L, not 4T compatibility.

Engine will be getting a performance EFI setup of some type. Not set on an EFI so if there's a system that requires a specific EFI be used, that's just fine.

Thanks in advance for any help!

------------------
- Darryl

tampalinc MAR 18, 08:45 PM
I have been wondering if any of the newer Holly computers could control the engine and trans.
Reborn756 MAR 18, 08:50 PM
Holly setup especially would be great, both Scott with AFR (the head company) and our local and highly respected machinst (Phil Miller) have said the Sniper setup is what they would use on this engine.

------------------
- Darryl

Trinten MAR 20, 09:55 PM
Hi Darryl,

I just replied in your other thread on transmission controllers. If you go the 4T80 route, and you upgrade your SBC to "think" it's an LS (digital distributor, coil packs, etc), there are stock flashes out there (even stock flashes from turbo equipped vehicles) that came with LS/4L80 combos for the 0411 PCM. The 4L80 has the same solenoid pattern as the 4T80, so there shouldn't be any issues there.

If you find you need a stand alone controller, I'd recommend FAST TCU, though I think that is a lot of personal preference.
Reborn756 MAR 20, 10:21 PM
Thanks for the reply Trinten!

Will a FAST work with the 4t80? Because I'm definitely not opposed to using the FAST tcu, since I can run their fuel injection and have everything communicate easily.

I'd prefer to stay away from the digital ignition route. I can toss together an extraordinary HEI setup, but I don't know the first thing about the digital setups and what will run this engine smoothly. Unless you tell me there's some weight savings to be had by converting to digital, in which case I'll be all over it (got a very particular build planned and it's all about weight savings)

------------------
- Darryl

Trinten MAR 20, 10:27 PM
Yes, the FAST will "think" it's an 4L80 as well. The FAST unit seems to have a lot of flexibility.

Here is the unit I have for my 4T80.
https://www.fuelairspark.co...e-4l65e-4l80e-3.html

They also make different units that will control the 4T65e, including a less expensive option. I think FAST recently got a new parent company (recent being in the last year or so), so their email support hasn't been great, but if you give them a call and say "I have an SBC using a standard distributor, bolted up to <insert your final choice of transmission>, which controller will work best to let me program shift points, and what input would it need from the engine / <ECU you wind up using>?" And they'll cover it all with you.
Reborn756 MAR 20, 10:41 PM
Fascinating stuff. While the 4t80 defeats the entire premise of my engine build, it may well be the only viable option I have. I will definitely be calling Brandon's shop tomorrow to get the skinny on the 4T80. I am very interested to see what modifications would be required to fit an SBC vs the LS4, if it would even be possible

------------------
- Darryl

Trinten MAR 20, 11:13 PM
It is possible to bolt them together!

I had it bolted up to my SBC. We switched over to an LS4 before we got around to solving for the starter. That is going to be an issue. Only mod we had to make to the SBC was cutting off a piece from the starter pad mounting area. So once you do that... you're committed. lol

Here's where we were at that time with that (again, before the LS4 change): https://www.fiero.nl/forum/.../000142-11.html#p415

It will require a modified version of the common "adapter" to account for bell housing to engine mismatch.

The other possible issue will be the engine cradle. While plenty of people have done the NorthStar/4T80 swap on a modified Fiero cradle, the SBC *seems* to be a longer platform. At best you might have to notch and reinforce your frame rails on both sides. At worse, you may have to do a Coil-over swap so you can notch the strut towers, too. At nightmare, you might have to do a custom cradle (Which is what we went up going with).
V8Steve MAR 21, 11:05 AM
Reborn,
Just passing on my own experience with aftermarket Holley EFI. My 2nd rebuild on the car began in 2015 with a custom SBC (dyno'd 427 HP, 355 CI) built for this car. The sump even has special baffles inside to stop oil from washing up the back side.

Because the 1st generation, ZZ4, had BigStuff Pro SEFI, I naturally stayed with EFI. This time it was Holley HP, professionally installed and dyno tuned. I even had custom matched injectors. It all cost a great deal of $ and I eventually removed the entire EFI system.

1) The Holley billet distributors kept failing at over $425/ea. Depending on who answered the phone that day at Holley, they were unrepairable or repairable. When the 2nd one failed beside the road, that was the last straw for me.
2) We could never determine without a lot of effort why it would suddenly "skip" at random.
3) Experts at Holley as well as the installer offered comments about "stray" signals in the engine bay.

I was spending more time troubleshooting, test driving with data logging than actually enjoying the car. Furthermore, the multiple distributor failures kept me close to home, not knowing when and where I'd get stuck again. I'd become proficient with making adjustments, reading datalogs, etc. but the Holley HP and HP support was unreliable and expensive.

After the 2nd failure, I put on an AED 750 double pumper and never looked back. Yeah, the EFI controlled the cam and driveability better (When it actually ran) but anybody can fix a simple 4BBL and distributor issue anywhere any time.

Just my 2 cents. Think again about over engineering and getting caught up in manufacturer plug and play claims. Keep it simple and enjoy the car.

[This message has been edited by V8Steve (edited 03-21-2023).]

Reborn756 MAR 21, 01:48 PM
Thanks Steve! What trans are you using to hold that mighty 427HP?