This is my 1986 Fiero SE with a V8 engine installed by
V-8 Archie on 2000 Aug 19.
New Chevy ZZ4 crate engine, 350 ci (5735cc) V8
GM TPI (90-92 Corvette fuel injection)
ZZ4 rated power at the crankshaft:
Horsepower: 355 @ 5250 rpm
Torque: 405 @ 3500 rpm
Dyno-tested power at the drive wheels:
Horsepower: 260 @ 4700 rpm
Torque: 340 @ 3300 rpm
Frequently Asked Questions
Q: How does it handle with the extra weight of the V8 engine?
A: About the same. The stock curb weight for my Fiero SE is about 2600 lbs. I understand the V8 adds about 85 lbs over the stock V6.
But there are other reasons to upgrade the suspension. The extra acceleration can cause a lot more rear squat on take-off, and stiffer springs and struts will fix that. And if you're going to have a sports car engine, you may as well have sports car handling to go with it.
Anyway, I upgraded my suspension long before I had this V8 installed. Another thing to consider is a brake upgrade.
Q: What transmission did you use?
A: The original 5-speed Getrag/Muncie transmission. Archie says any of the Fiero 4- and 5-speed transmissions should hold up fine with the power of a V8, although he recommends beefing up the 3-speed automatic.
Q: How does the clutch handle the torque?
A: It's probably the weakest point in the system, I think. Archie installed a Centerforce high performance clutch. It is grippier than a stock clutch yet easy to push. However, you can only fit so big of a clutch inside the stock Fiero transmission housing. It can slip under heavy low-RPM load. I didn't do a good job breaking it in, which may have something to do with it. Also, it currently has an occasional shuddering problem.
Q: Won't your axles break?
A: No. I've never heard of anyone having axle problems. Archie says axles will never break with his kit. His method of mounting keeps the transmission in the original position. Since axle length doesn't change, the original axles are used.
Q: Won't it overheat?
A: No. Archie recommends replacing the stock 2-core radiator with a 4-core, and he installed one in my car. The electric radiator fan is set to run constantly, although that is optional. My temperature gauge never reads above normal, about 190 degrees, whether it's idling or driving.
Q: Where does the battery go?
A: It's moved to the front compartment since it won't fit with the V8. Archie uses a custom holder to mount it underneath the spare tire.
Q: How fast is it?
A: I've hit 130 mph before the handling got very dangerous and I had to back off. With improved aerodynamics, it will go much faster. Redline would come at about 155 mph with the Getrag/Muncie 5-speed. Only about 130 mph I think with the Fiero 4-speed transmission. 0-60 time is somewhere between 5 and 6 seconds. Someday I might have a 1/4-mile time :)
Q: What's the gas mileage?
A: 13-20 mpg. I usually get about 120 city miles from my little 8-gallon tank. The ZZ4 requires 92 octane.
Q: What kind of exhaust do you have?
A: Dual exhaust with Sanderson center-dump headers. Two catalytic convertors and resonator tips, but no mufflers because there's not enough room for everything unless you take away a lot of trunk space. It's extremely loud under acceleration, although idle noise isn't too terrible.
Q: How much did the conversion cost?
A: Mine cost $11,000. That's $3700 for the ZZ4 engine and $1400 for the TPI, which Archie supplied; $3200 for Archie's Master Build V8 Conversion Kit; $2500 labor for him to install everything. There are so many options, your cost will vary. You'd save a lot of money supplying your own engine and doing the job yourself. Archie's shop does excellent work. They had my Fiero for 10 weeks for the V8 conversion; your results will vary.
Problems (=fixed, =current minor, =current major)
These are the problems I've had with my Fiero that are related to the V8 conversion. I do recommend V-8 Archie's work, but if you're looking for reliability like a low-mileage Honda, this is not it.
While driving it home from V-8 Archie, one of the exhaust pipes came loose from a header, because the nuts had vibrated off the bolts. Fixed by a Midas shop for $13. They installed double nuts, and I haven't had the problem since.
When the car was in the shop getting the wheels rebalanced, a coolant coupling under the passenger door caught on the ramp and came loose, spilling all the coolant. They fixed the coupling and refilled the coolant for free.
The engine would sometimes die during a hard right-hand corner. Usually it started right up again. Diagnosed as a bad ignition coil and replaced for $--?.
Clutch master cylinder started bleeding through and had to be replaced, for free under warranty since it had been replaced less than a year before along with the slave cylinder.
Rear back-up lights didn't work after the conversion. I had the back-up switch in the transaxle replaced for $50.
V-8 Archie had the alternator rebuilt ($125), but since the conversion the voltage was always below the normal level. In 3 months, the alternator died, and it was replaced for $400 parts and labor. Now it's working at the proper voltage. But it should have been just a $100 replacement to begin with.
V-8 Archie removed one of the two torque rods from the rear decklid as part of the conversion, so the decklid no longer stayed up when open. I bought a single gas strut from Rodney Dickman for $56. It works well.
The TPS (throttle position sensor) suddenly quit working properly, causing a code 22, rougher running, and less horsepower. A replacement TPS cost $--?, and I modified it and installed it the same way V-8 Archie had done.
6 months after the V8 conversion, the wire to the engine ECM came disconnected, causing the engine to suddenly quit on the highway. Diagnosed and repaired for $60.
Spare tire was very difficult to remove from its compartment, with the battery now positioned underneath it. I fixed this by trimming off some excess plastic from the spare tire well.
Cigarette lighter power port hasn't worked since the conversion. I haven't looked into why yet.
Exhaust is loud (although it sounds good). I was pulled over once for it. I'm looking into what kind of muffler I might be able to stuff in there.
Clutch shudders sometimes. Not sure if it's going to have to be fixed - scary.
Throttle is stiff and sticky. It requires a lot of pressure on the gas pedal, and it doesn't always return to idle speed when you let off the gas. I installed an extra spring to help return the throttle to idle. The throttle body is going to require some lubrication and/or cleaning.
Fuel pump is sometimes very noisy, making a high-pitched whine. It's a new pump, installed with the engine.
This page updated 2001 Feb 17.