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.
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).]
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,
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).]
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.
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
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
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.
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).]
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.
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.
Well, one more evening of work on my Fiero, I got the old engine off the cradle, new engine on the cradle, the old rubber engine mount was separated, I don't know whether the 1985 is different, or maybe there are several different oil pan options for the 3400, but I had to notch the engine to rubber mount bracket to clear the oil pan, the front "shock" fit fine using 2 out of 3 of the original bolts (top hole does not exist, any thoughts/potential issues with leaving it like that?)I know the 88s have to notch the oil pan a little in some way, but if I had notched the oil pan on my bracket, I'd have had a big hole, which brings me to my second, rather disappointing part, the big hole in the oil pan. I drilled a hole for the turbo oil return, but I forgot that the starter existed, so I put it right there, so now I either have a big hole in my oil pan, or I get a new one, so that will be on the way soon.
I’m not so sure about the shift cable being laid flat over the transaxle. With that angle, the shift cable force will not only cause rotation (which is desired) of the F23’s shift shaft, but will also push/pull the shift shaft in an axial direction (i.e. the select direction), so the shifter might hang up in the gates.
I’m tilting my shift cable a bit (but much less than yours), and I plan on installing stiffer centering springs so the shifter will remain in the 3-4 plane despite the shift cable force causing a select force as a side effect.
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2/3 bolts for the engine mount damper sounds sketchy.
I’m not so sure about the shift cable being laid flat over the transaxle. With that angle, the shift cable force will not only cause rotation (which is desired) of the F23’s shift shaft, but will also push/pull the shift shaft in an axial direction (i.e. the select direction), so the shifter might hang up in the gates.
I’m tilting my shift cable a bit (but much less than yours), and I plan on installing stiffer centering springs so the shifter will remain in the 3-4 plane despite the shift cable force causing a select force as a side effect.
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2/3 bolts for the engine mount damper sounds sketchy.
Good point, I haven't finalized anything, I'll see how much extra cable I have once it's in the car, get as much tilt as possible, my cable mounts aren't fastened on yet, so they were sagging under the weight of the cabin end of the cables, which makes them look less angled than I intend, I will look more into that though.
One thing to remember is that the 88 Fiero (and obviously the 3400 engine) didn't even have the dampener, I don't know whether it was deemed entirely unnecessary due to the internal balancing of the newer engines or whatever, it does seem unnecessary with the dogbone, and it doesn't carry any if the weight of the engine.
For low NVH, you want a soft rubber dogbone. However, a soft rubber dogbone alone may allow the powertrain to move around too much.
The damper is an auxiliary dogbone that becomes stiff for rapid powertrain rocking movements, such as on launch, or hard shifts. The rest of the time, it does nothing.
For 1988 they probably just stiffened up the rubber dogbone enough to no longer require the damper.
For low NVH, you want a soft rubber dogbone. However, a soft rubber dogbone alone may allow the powertrain to move around too much.
The damper is an auxiliary dogbone that becomes stiff for rapid powertrain rocking movements, such as on launch, or hard shifts. The rest of the time, it does nothing.
For 1988 they probably just stiffened up the rubber dogbone enough to no longer require the damper.
Then I'm set, I have a poly dogbone, and couldn't care less about NVH haha
Man, I'm having flashbacks to when I started building my car 15 years ago....
are you planning to update to DIS while you're changing from OBD1 to MS? I'd recommend it. Also, be aware your 2.8 timing cover might not fit the 3400 oil pan, IIRC you have to get a 88 timing cover.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
Man, I'm having flashbacks to when I started building my car 15 years ago....
are you planning to update to DIS while you're changing from OBD1 to MS? I'd recommend it. Also, be aware your 2.8 timing cover might not fit the 3400 oil pan, IIRC you have to get a 88 timing cover.
Nope, I'm keeping the distributor, by choice, but using the cam and crank sensors in the block for positioning for the sequential fuel injection (all calculation is computer, distributor will basically just be there for the looks), I already purchased a new 88 timing cover, 88 flywheel, gaskets, etc.
I’m not sure about the 3400 cam sensor being compatible with MegaSquirt.
I remember ericjon262 welding onto a camshaft to make a half-moon sensor… maybe he can say a bit more about this.
Depending on how long ago or what version of megasquirt he used, maybe it wasn't supported, I'm using a version of the 3 pro, and per the manual it supports all the gm 7x types, 1 tooth, 4x, and 6x cam gears, if that doesn't work, I will figure something out with the distributor like you did.
[This message has been edited by 1985 Fiero GT (edited 02-01-2025).]
MS cam sensor support is a mess for me specifically. I can't speak to whether or not it will work for you.
As far as I am aware, there are three cam sensor arrangements on a stock 60V6.
From right to left,
Single tooth at approximately #4 TDC, this is earlier 3100/3400 engines, and as far as I am aware, ALL aftermarket camshafts.
1/2 polled, the sensor trigger is a 175 degree trigger, starting on cylinder 4 TDC. this was used on LX9 engines, and maybe some later 3400's.
VVT, the VVT camshafts have a specific, odd shaped trigger, and a completely different camshaft nose.
it's worth mentioning, the LX9, and earlier camshafts can be swapped, the VVT cam is specific, and the only non VVT cam I am aware of that's a direct swap, is the LNJ 3400 cam, which is a completely unique beast from a control standpoint.
I'm not sure how specifically to make your cam, work with 7x, and the MS3, but I am willing to help figure it out. if you have the engine apart, it might not be a bad idea to install a 60-2 (58x) trigger wheel, but that's not quite a walk in, walk out adventure. I like the 60-2 wheel, because it's by far the most common wheel out there, and should have the most support.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
I’m not sure about the 3400 cam sensor being compatible with MegaSquirt.
I remember ericjon262 welding onto a camshaft to make a half-moon sensor… maybe he can say a bit more about this.
among other things, I still have that cam, it's a bit of an oddball cam, pretty aggressive too.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
MS cam sensor support is a mess for me specifically. I can't speak to whether or not it will work for you.
As far as I am aware, there are three cam sensor arrangements on a stock 60V6.
From right to left,
Single tooth at approximately #4 TDC, this is earlier 3100/3400 engines, and as far as I am aware, ALL aftermarket camshafts.
1/2 polled, the sensor trigger is a 175 degree trigger, starting on cylinder 4 TDC. this was used on LX9 engines, and maybe some later 3400's.
VVT, the VVT camshafts have a specific, odd shaped trigger, and a completely different camshaft nose.
it's worth mentioning, the LX9, and earlier camshafts can be swapped, the VVT cam is specific, and the only non VVT cam I am aware of that's a direct swap, is the LNJ 3400 cam, which is a completely unique beast from a control standpoint.
I'm not sure how specifically to make your cam, work with 7x, and the MS3, but I am willing to help figure it out. if you have the engine apart, it might not be a bad idea to install a 60-2 (58x) trigger wheel, but that's not quite a walk in, walk out adventure. I like the 60-2 wheel, because it's by far the most common wheel out there, and should have the most support.
Yeah, I'll have to see, I have not removed or touched the camshaft, so I'm not going to do anything until I know that it will not work as it is right now, if I can't easily get the cam sensor working, I'll maybe figure out a distributor trigger instead.
I made this for my LX9, but I'm under tighter space restrictions in that area than you are. The lower is a stock oil pump drive, the upper is a Jeep 4.0 cam sensor.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
I made this for my LX9, but I'm under tighter space restrictions in that area than you are. The lower is a stock oil pump drive, the upper is a Jeep 4.0 cam sensor.
thanks, I cut the two parts in a lathe for a light press fit, and then smashed them together. making the shaft was significantly harder.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
Alright, my cam wheel is a simple half high half low, I don't know the specific wording, but yeah, megasquirt should be able to use that hopefully, did the majority of the engine harness wiring today, man that is not something I want to do to many times more, it ain't pretty, but it'll work (to be determined haha).