I have 2 3800's available and I want to get the best swap possible. (Page 1/1)
mtbraatz MAY 09, 06:35 PM
First off, I have never done an engine swap on a Fiero before, though I have helpes with a few on Civics, and am very mechanically inclined. A Fiero was my very first car, and it was stolen and destroyed 8 months after I got it. Almost 20 years later, I bought a 1986 Fiero GT last week and want to complete the swap I was preparing to do 20 years ago.

So the first engine is a 3800 SC II with 114,000 kms on it in a 1997 Buick Riviera. This is a complete car with engine, harness, ECU, PCM, drive axels, everything. He wanted $900CDN for everything.

The second engine is a 3800 SC III with 11,000 kms on it in a 2005 Grand Prix that was T-boned passenger side. This car is also mostly complete in the engine bay, minus the alternator removed. He wanted $500CDN for everything.

I want the best possible motor/blower setup that is relevantly easy to swap into the Fiero(being that this will be my first complete solo swap). I want to reuse the Getrag 5 speed that I already have.

It is my understanding that the best possible swap for me, given these 2 available motors is the the block, heads and blower from the Series 3 Grand Prix that had barely even been broke in yet, then grab EVERYTHING else from the Series 2 Buick Riviera except the engine. This would include all wiring, power steering pump, A/C pump, A/C condenser, alternator, fuel lines, throttle body and entire air intake setup, vacuum lines, ECU, PCM, mounts. Basically everything that touches the block, heads or blower. This should make for the easiest swap to complete with the 5Speed Manual, leaving room for me to purchase the HP Tuner ECU reprogrammer and unlock the additional power of the Series 3 with some MAF reprogramming.

Are there any parts I missed? Once I strip these cars, they will be squished for recycle so I only get one shot at sourcing everything I need without having to pay for it again down the road.

I would rather wind up with to many parts and be able to use whatever worked best/easiest for the swap. Both are at local-ish wreckers, but not the same one (of course).

Thanks in advance, and thanks for being here guys!

PS My goal will be to swap the motor and run it stock for this summer. This fall the car will get a complete restoration of the interior/body (which is more my forte) and the engine will get the wiring harness rerouted for a cleaner look, etc.

[This message has been edited by mtbraatz (edited 05-09-2019).]

Gall757 MAY 09, 10:08 PM
Welcome to the forum!

I think most folks would use the Series 2 engine and not worry about the mileage. (71,000 mi) assuming it is also a crash car or it runs.

[This message has been edited by Gall757 (edited 05-09-2019).]

olejoedad MAY 10, 07:19 AM
Lower mile S3, Northstar throttle body, LQ4 MAF
darbysan MAY 10, 11:17 AM
The riviera harness is unique in that it has a large disconnect connector allowing for easy removal of the engine. It does make for a more complicated wiring. Axles won't matter if you are re-using the Getrag. The newer engine will require modifications to the TB, MAF, etc as mentioned above. If the harness is similar to the GTP of earlier years, the wiring is much simpler than the Riviera. You could possibly reuse the entire harness including fusebox and Cruise Control and only need a couple of connections to the Fiero, with all of the harness including the ECM in the engine compartment. Lower mileage, better harness, lower cost (not including cost of TB, MAF, Etc) I think I would go with the newer engine.

One other thing to consider, if you can buy the entire car, is that you may be able to recover some of your costs by parting out some of the parts. I got over $1K US for parts on the Riviera, and Several hundred on the GP I used.

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'87 GT , '00 3800 Series II SC, 4t65e, Vue Power Steering. (SOLD)

[This message has been edited by darbysan (edited 05-10-2019).]

mtbraatz MAY 11, 12:30 AM
In the event that I use the newer series 3 for all of it's upgrades and benefits, am I still grabbing all of the accessories and other gadgets from the 97 Riviera? Am I using the series 2 PCM/ECU? I do not want drive by wire or any of that crap either which as I understand it, I am deleting by using the LT1 throttle body and LQ4 MAF sensor?

As far as I understand it, I want everything but the block, heads, intake and SC from the series 2. Including oil filter adapter and everything else. I would likely just grab both harnesses since I would be hitting both yards anyways. Then I can just use whichever seems easier to trim down and install to the Fiero.

[This message has been edited by mtbraatz (edited 05-11-2019).]

olejoedad MAY 11, 12:50 AM
S3 engine/supercharger/exhaust
S2 harness/MAP/Alternator
Northstar Throttle Body
LQ4 MAF
Dennis LaGrua MAY 11, 09:33 AM
I would prefer using the low mileage engine for the swap
My series III swap combo:
2006 3800SC engine w 4T65eHD transmission (uses a different mount on the trunk side)
Cavilier./Beretta axles
3.4" Pulley
2000 N* throttle body
early LS1 MAF sensor
2003 GTP PCM
series II harness with new EV6 injector connectors (series II engines used EV1 connetors)
S2 fuel pressure regulator (mine located near the fuel filter
changes to the PCM program required importing the LS1 MAF table and tweaking it for exact fueling
re-scaling the throttle position PE table.
If you use the 3.4" ( smaller pulley) for higher boost, the higher efficiency of the Gen V supercharger will require adding an intercooler. I used the ZZ short stack.

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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 "

mtbraatz MAY 11, 08:05 PM
So I want the Riviera's S2 ECU and the GTP's S3 PCM?

Where/how do I reprogram the PCM for proper fuel management?

Where/how would you mount an intercooler that it would get sufficient air flow to cool the incoming air? I want to scoop both rear quarters and draw air from both sides, plumb it into a collector, then into the IC. I am thinking this will require me to lose the entire rear trunk area to make room for that system, although that puts the IC right beside the exhaust system.

Thanks so much for your feedback guys! Hoping to get the swap parts picked up next week or the week thereafter!
Dennis LaGrua MAY 11, 08:36 PM

quote
Originally posted by mtbraatz:

So I want the Riviera's S2 ECU and the GTP's S3 PCM?

Where/how do I reprogram the PCM for proper fuel management?

Where/how would you mount an intercooler that it would get sufficient air flow to cool the incoming air? I want to scoop both rear quarters and draw air from both sides, plumb it into a collector, then into the IC. I am thinking this will require me to lose the entire rear trunk area to make room for that system, although that puts the IC right beside the exhaust system.

Thanks so much for your feedback guys! Hoping to get the swap parts picked up next week or the week thereafter!


The idea here is to run your series III engine as a series II with the cable operated throttle body.
If you go stick with the series III engine then you can use a TP PCM 96-02
If you go auto you will need the 03 GTP PCM as its the only non drive by wire PCM that will shift your 03-07 transmission
ZZP performance sells an under the supercharger intercooler kit.

------------------
" 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 "

[This message has been edited by Dennis LaGrua (edited 05-11-2019).]