Which transmission 5speed or tweeked automatic (Page 2/3)
theogre MAR 26, 02:02 PM
No-one asked "What Auto is it?" ???

Because if has an unit ends w/ E then more work to eliminate the trans from the engine.

PCM controls both Engine and E auto like 4T60E.

2. No-one asked where etc you drive it.
Example: If drive daily in slow traffic and/or in City... Stick cars can get Very Un Fun and Fast. More so when you replace the clutch every few year or faster.

Fiero and many others use Diaphragm Spring Pressure Plates that break the spring driving like that and hope you can get off the road to wait for a tow.

For Drag Racing and some other types... 2 of same car and engine... Auto beat Stick most cases for normal street cars.
TC Torque Multiplier is a big reason Why.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

olejoedad MAR 26, 02:35 PM
Arthur, thanks for the clarification.

Since you have two Fieros, all the pieces you need are there.
It will be relatively easy to do a cradle swap from the 87 supercharged car to the 86, and then use the V-6 / 5-speed cradle to put into the 87 chassis.
Everything is pretty much unbolt and rebolt - linkages are no problem, etc, but there are a few items that must be considered.

There are some wiring differences regarding the manual to auto swap in the area of the brake/clutch pedal for TC unlock and Cruise Control.

The radiators may be different. The OEM manual trans radiator won't have the tranny cooler provisions in the driver side radiator side tank. Easily solved by using an aftermarket radiator or swapping between the two cars.
The clutch/brake pedal assemblies will need to be swapped.

There are a few other items, but it's easier since you have two cars sitting to use as references.

If you decide to go this route, contact me if you run into any issues.

As to a Getrag 5-speed behind the 3800sc - no, just no.
The TEP (Triple Edge Performance) transmission is the 4T65E-HD and is bullet proof behind the 3800.
The 3800 will quickly destroy the Getrag, and controlling the auto trans behind the 2.8 Fiero V-6 will not be easy.

(Post edited to clarify model years of cars)

[This message has been edited by olejoedad (edited 03-27-2022).]

Dennis LaGrua MAR 26, 04:45 PM

quote
Originally posted by olejoedad:

The TEP (Triple Edge Performance) transmission is the 4T65E-HD and is bullet proof behind the 3800.
The 3800 will quickly destroy the Getrag, and controlling the auto trans behind the 2.8 Fiero V-6 will not be easy.




We did two 3800SC swaps about 12 years ago. Both guys insisted in reusing their Getrag and a short time later blew them up. One was so bad that the case ended up in pieces. Obviously the cars were not driven gently. One reason might be that the transmissions are old but even when new they were designed for a maximum of 200 ft lbs of torque. You greatly exceed design limits, drive hard and that's what happens.
As for using an auto behind the 2.8L/3.1L/3.4L the 4T60 seems like the best choice to me. You may be able to use the 4T65e but that would require an expensive add on transmission controller. If you use the 3800SC and the 4T65eHD that goes behind it along with the original PCM you should be OK to over 325HP. The LS4 cars and the Fiero swaps use that box.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

olejoedad MAR 26, 05:08 PM
Yeah, over torque the Getrag and the intermediate shaft has a tendency to push into the bellhousing.

That makes for a really bad day.
reinhart MAR 27, 08:29 AM
I'm not sure what all went into your body kit, but personally I think it would be easier to switch the kit body over rather than the cradle/engine/wiring/PCM/etc. Unless there was some sort of frame stretch, that is.

The bodies could be switched in a weekend. The cradle/etc could also be done in a week or so, but the probability of needing to do troubleshooting for months after that is significant with an engine swap.

Also I'd prefer the 88 frame over the 86 any day of the week.
olejoedad MAR 27, 10:20 AM
Some clarification....

The O/P messaged me last night.

The 3800 car is an 87, not an 88.

The cradle swap would be far easier than switching bodies.

I will edit my earlier postings to remove references to the 88 Formula and ensuing confusion that resulted.
Superm1952 MAR 27, 02:38 PM
The frame has been stretched under the kit. OH LORD NO. My feet are colder then warm. U all would say I probably would not experience the true power of the 3800 mated to the 5 speed. Would I really be chasing the tune for months?? Just wanted to Thank You all for your feedback..... In the end its up to me to pull the trigger..... Now if I could only get off the fence.
olejoedad MAR 27, 05:43 PM
"Chasing the tune for months"?

No. Unless you have an inexperienced tuner mess with it.
I only trust a select few to tune the swaps we do.

There would be some retuning needed (even with the auto trans) when swapping to the Lambo rebody due to weight and rear tire diameter differences.
Raydar MAR 27, 10:33 PM

quote
Originally posted by theogre:

No-one asked "What Auto is it?" ???

Because if has an unit ends w/ E then more work to eliminate the trans from the engine.




'scuse me?!


quote
Originally posted by Raydar:
...
Is the automatic the stock Fiero automatic? Or is it the one that came with the 3800? If that's the case, is it a 4T60E or 4T65E? The 65 is a much revised piece, and is very well suited to the 3800.


olejoedad MAR 28, 08:11 AM
Superm1952, if the chassis is stretched on the Lambo car the cradle may have been modified as well.

This might complicate your plans a bit, depending on how the 3800 drivetrain is mounted to the cradle.
If the mounts are bolted on, it may be rather easy, but if the mounts are welded to the cradle, more difficult.

Additionally, depending on how the wiring was modified for the stretched wheelbase, the 3800 wiring may need some revision as well.

All of it doable, just more time consuming.

[This message has been edited by olejoedad (edited 03-28-2022).]