Hey guys, new to the site, but not new to fieros. I recently aquired a 4.6 northstar complete with auto trans and wiring and computer. Planning on putting it in my 84 fiero. I saw a couple of pictures of guys doing this. Is it possible to use the caddys auto tranny in the fiero? I saw a guy had a kit from design1conversions but i dont think the company is in business anymore because i cannot find them on the internet. any help with this would be appreciated! Thanks in advance!
That's a 4T80-E transmission..... not often used in Fieros because it's heavier than the 4T60.. but you should be able to use the SEARCH function and learn some things.
Be sure to include the archives in your search.
[This message has been edited by Gall757 (edited 03-31-2016).]
Yup that trans will fit in a Fiero but it's a bit of a squeeze. You will have make your own mounts and it forces you to move the motor to the passenger side a bit so you will likely have to alter the pasenger side strut tower a bit to clearance the N* cam position sensor and forsure if you have an 88.
Good for you. Love the northstar. I don't know anything about the auto swap, so I'll let other guys answer any questions on that regard. Keep in mind you will get a lot of guys telling you not to go ahead with the project as there are cheaper and some will argue better options.. But in the end it's your decision.
It'll be a tough swap for the electrical...but nothing insurmountable. Make sure you make a build thread. Lots of people will be interested to watch the progression!
Yes, you can use the automatic trans that comes with the N* engine. It fits and works fine in a fiero. There's enough room between the strut tower on the right with the early 84-87's and about 1/4 inch in the 88's. There is about 1 inch between the front firewall and the stock caddy alternator and plenty of room with the back firewall.
If this is what you would like to do with your 99 motor, then you will need to do the following:
1) Modify your cradle (front and back) and make engine mounts. I use 4 total: two front and back. 2) Use a couple of the caddy data modules so you have proper trans first gear starts. There are also other controller options like a LS1 PCM and trans controller. 3) Cut half of the rear trunk out if you plan to use the existing Caddy header and crossover pipe 4) Wire it using the caddy harness and computer and feed it the voltage or cab sensors you need from your fiero stock harness. 5) Plumb it to your existing fiero plumbing V6 radiator will work but a V8 aluminum one is better 6) Cut each cadillac automatic axel 3/4 of an inch 7) Minor mods: auto selector switch position and cable mount 8) Suggested: drill out your head bolt holes and install Norm's inserts. Never have a problem with head sealing if you do this. 9) Modify the right deck lid hinge
You will smile with a N* in your fiero!
If you can't fab or weld, you can get someone to do it for you. If it isn't an option in your area, then you probably ought to consider a 3800 SC engine since all the aftermarket stuff like engine mounts are available and virtually no fabbing is required since you just buy the parts and assemble.
Hope that helps you in your decision making.
-dave
[This message has been edited by IXSLR8 (edited 04-01-2016).]
...or buy this cradle. (Not mine.) Link You'll need the 88 suspension hardware, some Arraut strut adapters, and coil-overs, but if that's too much trouble, then so is this swap.
[This message has been edited by Raydar (edited 04-01-2016).]
awesome!!! thank you guys so much. i will definately keep posting my progress as i get started. i am so excited about getting started. i can weld and fab a lot of stuff so i don't think it will be too big of a problem. fun part will be figuring out where to put the mounts so it slides right in. With those mods, will that disable the abs and ride control and all that special stuff?
What axel set-up are you using with the auto 4T80E RCR?
-dave
It's been 8 yrs(??) Geez, where does the time go. I managed to find this " I need two 12" Berretta axles, and two tri-pots from a 4.9L Caddillac. This is the combination AJ used on his. " from a previous thread. I also used the outers from a Celebrity wagon (medium duty like the Pontiac 6000). I'll continue looking for more info.
I've been cutting each caddy 4T80E axel. 3/8 an inch off each end and recutting the ring grooves. I use the stock Caddilac tripod on the transmission side and the stock Fiero manual tranny tripod/spindle on the hub side.
[This message has been edited by IXSLR8 (edited 04-06-2016).]
this place is awesome guys! just wondering how you determined the placement of the 4.6 with the tranny on the fiero cradle? Did you center it how the 2.8 engine was sitting in there?
I centered the trans outputs as best as possible while keeping that monster inside the left rail of the cradle. IXS mentioned having to cut the trunk if you plan to use the N* exhaust manifolds and crossover but that wasn't the case in my 85 GT. There are some pics in this thread https://www.fiero.nl/forum/Forum1/HTML
On another note.... In an 84 you may have to relocate the C500 connector. Its on the firewall in an 84. I think you'd have to move it over to where they are on all the other years because I don't think there's enough slack in the existing 84 wiring to get it far enough out of the way of the N*.
[This message has been edited by Dave E Bouy (edited 04-07-2016).]
On another note.... In an 84 you may have to relocate the C500 connector. Its on the firewall in an 84. I think you'd have to move it over to where they are on all the other years because I don't think there's enough slack in the existing 84 wiring to get it far enough out of the way of the N*.
Funny, I just posted this in another thread...
Not a lot of room, but it fits.
And, as Dave said, I centered mine as best I could.
