Turbo 3400, F23 build, 1985 GT (Page 1/9)
1985 Fiero GT JAN 21, 06:12 PM
This will be the build thread for my 1985 Fiero GT, it won't be as accurate or all encompassing as others on this site, because I have accumulated nearly 2 years of work that has not been documented, but better to have a build thread than not.

Heavy inspiration for this build is drawn from "The White Bug" (by pmbrunelle) and the Porsche Eater turbo prototypes.
1985 Fiero GT JAN 21, 06:25 PM
This is my first car, 1985 Fiero GT, 4 speed, power windows, power mirrors, sunroof, I got it mid April 2023, for $5,500 cad, with 130,375 kms, I'm the third owner, it is originally a Quebec car (no front license plate mount that damages the bumper), but now it's registered to New Brunswick, it has paint that isn't great, good interior, no rust, has always been very mechanically sound, when I got it it was a little run down with a few common issues, cracked front exhaust manifold, dead headlight motors, ripped seat, oozing steering wheel, droopy headliner, cracked EGR tube, bad radio, etc. Good starter car because nothing wrong that some elbow grease won't fix.

[This message has been edited by 1985 Fiero GT (edited 01-21-2025).]

1985 Fiero GT JAN 21, 07:05 PM
Past upgrades/work done:

I've rebuilt the headlight motors with new brushes, gears, and bumpers,

Reupholstered the headliner, and remade the drivers side sun visor (new cloth sewn like original to form the pockets), and the passenger side (no pockets),

Replaced the seals on the sunroof bolts, drilled the drainage holes from the T.S.B.

All fluids flushed,

Rodney clutch Master, slave, and release arm,

Prolightz pl360 amber front marker lights, Fiero store led headlight kit, wired in some relays to give me "winky headlights", diode dynamics hp5 front side markers, hp3 rear side markers, 2357 rear tail lights, with web electrics 3 bulb sequential turn signals (all 3 red bulbs act as turn/stop lights), cheapo red led 194s in instrument cluster, all other interior/exterior lights LED except in radio/taillights, red led strips added to underside of decklid, powered by trunk light switch, and strips added to underside of decklid vents, powered by parking lights,

Newer 90s Pontiac cassette/radio, 10" under dash subwoofer, Rodney front speakers, pioneer 4" 2 way headrest speakers, aux port wired in, located beside 12v outlet,

Rodney distributor o-ring, fixed my oil leak,

All suspension bushings polyurethane, with Teflon tape wrapped around central core (no noticeable squeaks after 1.5 years of use), dogbone bushings polyurethane, new engine/trans mounts, Rodney solid cradle mounts,

Front shocks KYB, rear shocks Monroe,

Brake pads replaced with Bosch something or other, happy with them, good bite when cold, but after a couple stops, power increases to the point of easy lockup,

Installed 1984 Fiero shifter handle (shorter), replaced steering column (tilt mechanism would pop out of place and drop steering wheel into my lap when any force is exerted),

All pivot bushings (brake, clutch, shifter, transmission select, etc.),

Rodney leather shifter boot, Rodney shifter cables, Rodney lower temp fan switch, Rodney idler pulley and power pulley,

MSD ignition coil, red Taylor spark plug cables, new distributor cap/rotor,

Rodney EGR tube, welded cracked exhaust manifold, Fiero store exhaust studs,

Exhaust manifolds ported, intake manifolds ported/port matched,

New heater core,

Installed a 5 gallon aluminum fuel cell up front, spare tire delete (I have a can of fix a flat, a full plug/patch set, and an air compressor, carpeted front compartment, more storage space with the fuel cell than with the spare tire, and no weight increase (5 gallons of gasoline weighs as much as the spare tire),

Polished my original rims, new 215/60R14 BFGoodrich Radial T/A,

1.6 roller tipped rockers, new heads from 82 TA (at work), removed throttle body heater lines,

Irrationables garage steering wheel/shift knob, original charcoal color, red top marker, red stitching,

Mr Mike's seats, original light gray center/dark gray sides, leatherette, red GT strap, red piping,

Lloyds floor mats, Berber material, light gray/black salt/pepper color (very similar to factory carpet), red piping, red "Fiero GT" wording.

[This message has been edited by 1985 Fiero GT (edited 01-21-2025).]

1985 Fiero GT JAN 21, 07:24 PM
When I got it, one motor dead:


Old interior:

New interior:


I was the pace car for the last set of parade laps at the Fiero 40th:



Exterior:


LEDs:


Trunk lighting:


Frunk, storage compartments on each side of fuel cell:


Mock-up of turbo:


3400 engine coming home in my beater car:


F23 transmission, 2002 Sunfire, 120,000 kms:


Cradle out

[This message has been edited by 1985 Fiero GT (edited 01-21-2025).]

1985 Fiero GT JAN 21, 08:14 PM
I was reading Fiero Sounds site, and read about the 3400 engine he used, did some more research to find that it's stronger than the 3.4 Camaro engine, much better oiling/bottom end, and still compatible with the Fiero heads and intake. I wasn't wanting to do a turbo because of the weakness of the 2.8, and I thought it wouldn't be worth it to upgrade to the 3.4 Camaro engine because of the intake bottleneck, but the 3400 is strong enough to accept good boost, with the fuel heads has low enough compression to do that reliably, and with forced induction, intake bottlenecks don't matter as much, so it was the best of everything.

Literally that day I found a 3400 a few hours away, 170,000 kms, I picked it up for $500, after more research (pmbrunelle's 4 speed blowing up), and an issue with my 4 speed, I decided to go with the getrag F23 5 speed, spent about $500 on 2, a low mileage ecotec one, and a higher mileage gm metric one, I split the case and used the low mileage insides and the high mileage case, which left me with a high mileage ecotec one for spare parts or whatever.

I rebuilt the 3400, with new main and rod bearings, new timing set, all new gaskets and seals, new water pump, timing cover, oil pump, flywheel, spec 3+ clutch.

I got a maxpeedingrods t04e t3/t4 turbo, I've heard they can last a good long time, if not, oh well, it was cheap, silicone intakes water to air intercooler kit, recirculating blow off valve, and all the intake tubing necessary.

I'll be using the factory Y pipe, with the joint area feeding right into the turbo, outlet pointing forward to the cabin, a 90*, then going down to the rest of the factory exhaust system (which is still in great shape, rust free), I will use exhaust wrap on the y-pipe and downpipe, a turbo blanket on it, and additional heat shielding on the shifter cables, firewall (by turbo), etc. as needed.

Intercooler core will be where the cruise control would be, it's a pass through type, with the turbos outlet pointing down, and the hot pipe down by the transmission, then going up through the intercooler, then straight forwards and then two 45*s to bring it to the throttle body. The heat exchanger will be up front, filling nearly the whole opening from the air redirector underneath to the bumper structure in front.

The ECM will be a mega squirt 3 pro mini, sequential fuel injection, and just enough i/o without breaking the bank to badly.
eph_kay JAN 22, 02:10 PM
Very exciting build, I loved the turbo 3400 I had in my Fiero for awhile, I went ahead and did the aluminum heads and matching intake since I went megasquirt, but the stock iron stuff does have a great look in the engine bay

If you have any questions or need any help with the megasquirt let me know, I used MicroSquirt and then moved it over to my vr6 turbo build that replaced the 3400, but I will be converting this car over to the ms3 mini soon as well

Chris
1985 Fiero GT JAN 22, 02:13 PM

quote
Originally posted by eph_kay:

Very exciting build, I loved the turbo 3400 I had in my Fiero for awhile, I went ahead and did the aluminum heads and matching intake since I went megasquirt, but the stock iron stuff does have a great look in the engine bay

If you have any questions or need any help with the megasquirt let me know, I used MicroSquirt and then moved it over to my vr6 turbo build that replaced the 3400, but I will be converting this car over to the ms3 mini soon as well

Chris



Ok, sounds good, the software is very easy for me to understand, but I'm sure there will be hiccups haha
pmbrunelle JAN 23, 11:46 PM

quote
Originally posted by 1985 Fiero GT:
I got a maxpeedingrods t04e t3/t4 turbo, I've heard they can last a good long time, if not, oh well, it was cheap, silicone intakes water to air intercooler kit, recirculating blow off valve, and all the intake tubing necessary.

I'll be using the factory Y pipe, with the joint area feeding right into the turbo, outlet pointing forward to the cabin, a 90*, then going down to the rest of the factory exhaust system (which is still in great shape, rust free), I will use exhaust wrap on the y-pipe and downpipe, a turbo blanket on it, and additional heat shielding on the shifter cables, firewall (by turbo), etc. as needed.

Intercooler core will be where the cruise control would be, it's a pass through type, with the turbos outlet pointing down, and the hot pipe down by the transmission, then going up through the intercooler, then straight forwards and then two 45*s to bring it to the throttle body. The heat exchanger will be up front, filling nearly the whole opening from the air redirector underneath to the bumper structure in front.



I'm curious to see what sort of shift linkage solution you come up with that will fit with all that stuff.

I'm currently working on the shift linkage for my F23 and I'm finding it to be a challenge.
1985 Fiero GT JAN 23, 11:52 PM

quote
Originally posted by pmbrunelle:


I'm curious to see what sort of shift linkage solution you come up with that will fit with all that stuff.

I'm currently working on the shift linkage for my F23 and I'm finding it to be a challenge.



I already have that basically figured out, just have to put it together, using the parts of the Muncie, rotated 180* (arm on right side of shaft instead of left side, select pivot behind shaft instead of in front) all I have to do is get the shift arm onto the shaft (either reduce the diameter of it, or open up the hole a little) and mount the pivot for the select arm (still thinking of the best way to do that). I welded up the shifter cables retaining mount things, in the correct position, and if my measurements are correct, they will run under (instead of over) the y pipe to deal with the additional distance to travel (of course I'll insulate well)

Mock-up

[This message has been edited by 1985 Fiero GT (edited 01-23-2025).]

jelly2m8 JAN 25, 04:11 AM

quote
[B]Originally posted by 1985 Fiero GT:[/B

Cradle out





I have no idea why Cliff won't implement a LIKE function on these forums....anyway, this pic reminds me of how my Fiero evolved. Tired of the leaking valve covers.... I got those off, may as well put valve seals while I'm in it... Oh! that valve stem face has a nick in it... off with the head... Long story short.. Engine, transmission and Electronics swap / upgrade.


Fiero better than ever