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3800sc transmission questions... by CanadianFieroOwner
Started on: 07-16-2015 01:21 AM
Replies: 8 (258 views)
Last post by: Dennis LaGrua on 07-17-2015 11:48 AM
CanadianFieroOwner
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Report this Post07-16-2015 01:21 AM Click Here to See the Profile for CanadianFieroOwnerClick Here to Email CanadianFieroOwnerSend a Private Message to CanadianFieroOwnerEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well, this winter I am planning on putting a 3800sc in my car, I already have a motor lined up. So here's the question, I have a speed transmission in the car right now, would it be able to withstand the power of the 3800? I don't wanna be throwing clutches often as the car will be driven somewhat hard, would my tranny be able to handle it? Should I put a F23 in it? I've heard they are the best for the swap. Or depending on what transmission I get with the donor car, should I put that in. I have a standard at the moment, but, it doesn't really matter whether I have standard or automatic. Which would also be the cheaper option and better in the long run? Thanks for the help,

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-Ryan, 16, Just bought my First Fiero to Fix up and have a fun car to drive. Any help about the car will be appreciated.
1985 Fiero 4spd 6Cyl.

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olejoedad
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Report this Post07-16-2015 09:11 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
If you have no preference between manual and auto, the 4T65E that GM mated to the engine is a great choice for you. It will take the power, and is your least expensive option.
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darbysan
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Report this Post07-16-2015 10:41 AM Click Here to See the Profile for darbysanClick Here to Email darbysanSend a Private Message to darbysanEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm in the process of doing this same swap, and decided to switch from the 5-speed Getrag to the Auto that came in the donor car. 1) Cheaper . Flywheel and clutch will cost minimum $600+. 2) More Reliable- The Stock trans is not able to handle a lot of rough driving with higher power, so likely you will be back soon changing out your trans or clutch- more money. 3) Gear ratios are better. The auto trans will still get you off the line quick, but at highway speeds your RPM's will be down, giving better mileage.

Manual to Auto swap checklist
http://www.thefierofactory.com/qaautoswap.php

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'87 GT in process, including GA / Seville brakes, Poly Suspension, '95 3800 Series 1 SC ( 225 hp ) T460e.

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Dennis LaGrua
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Report this Post07-16-2015 05:14 PM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
Some 3800SC swap owners have used the Muncie and Getrag with varying degrees of success but regardless you end up with an unmatched powertrain. GM engineers would have never specified a 170 ft lb rated transmission behind a more powerful 3800.
The safest bet is to use the matching 4T65eHD transmission rated for the 3800SC power. If you must have a stick the F40 6 speed will bolt up and can handle the power but some fabricating will be needed to modify the Fiero shifter and clutch systems.

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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/Heddman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, 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 "

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CanadianFieroOwner
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Report this Post07-17-2015 12:26 AM Click Here to See the Profile for CanadianFieroOwnerClick Here to Email CanadianFieroOwnerSend a Private Message to CanadianFieroOwnerEdit/Delete MessageReply w/QuoteDirect Link to This Post
So, is the 4T65eHD transmission, the one that comes stock with the Donor cars or do I have to get then from other cars? And if so, which ones.

Thanks for all the help so far
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Riddick85
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Report this Post07-17-2015 12:44 AM Click Here to See the Profile for Riddick85Send a Private Message to Riddick85Edit/Delete MessageReply w/QuoteDirect Link to This Post
Yes the trans that come with the donor car is a 4t65ehd. The hd version i believe is only on supercharged cars though.

Personally, I would just stick with a manual if your car is setup for it and you have the money to spend on it (yes it really is $600+ or so). I have a stock getrag in mine currently and I know I will blow it up eventually (I have only had the 3800 in since april so I think I still have some time). My plan is to buy a f23 and get it all setup to go in for when it dies and since I will be dropping the motor at that point it is a good time for a cam too. Just my thinking.

Also, you wont kill your clutch often so long as you buy a good one. The go to one for a 3800SC fiero swap is the spec 3+. That's what I have and I couldn't be happier. Drives like a normal vehicle with no chatter and doesn't grab like the puck style clutch would. It actually feels on par with my 2010 jetta, which is a stick, that is my daily driver.
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CanadianFieroOwner
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Report this Post07-17-2015 12:47 AM Click Here to See the Profile for CanadianFieroOwnerClick Here to Email CanadianFieroOwnerSend a Private Message to CanadianFieroOwnerEdit/Delete MessageReply w/QuoteDirect Link to This Post
Alright, thanks, I'll give that some thinking, I'll have to see mostly on how the tranny with the Donor car looks and how much it'll cost to get it running well, and weigh my options. Thanks
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thismanyfieros
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Report this Post07-17-2015 11:26 AM Click Here to See the Profile for thismanyfierosClick Here to Email thismanyfierosSend a Private Message to thismanyfierosEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have been running the 365 spd Muncie in my 3800 sc car for over 10 years now.. I beat on it and it's been fine... I do have a spare just in case... but light to light its a fun ride..
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Dennis LaGrua
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Report this Post07-17-2015 11:48 AM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by thismanyfieros:

I have been running the 365 spd Muncie in my 3800 sc car for over 10 years now.. I beat on it and it's been fine.


With careful use and minimal, if any 1/4 mile runs, others have had luck with the 5 speed. One of the main problems with the Getrag is that some Fiero engine swappers believe that they were built to last forever. They bolt a newer more powerful engine onto a trans designed for 170 ft lbs of torque, that has 200,000 miles on it and expect it to last.
My solution for the stick swap is to make certain that the Getrag that you are using is in excellent condition , (low mileage or rebuilt) and the addition of a second dogbone mount on the transmission side. IMO, a heavy 3800SC launch will add excessive rotational stress on the Getrag case at the mount area. The case doesn't flex and it cracks. By minimizing transmission movement it should extend transmission life. Of the three blown Getrags that I have seen, the cases were cracked and/or shattered.
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