I don't recall seeing any 4 cylinder swaps - has anyone done them?
The obvious candidate is the Ecotec - they were available in a couple of FWD configurations that should be adaptable to the Fiero. Dead easy to get c. 375 bhp from them or more if you are prepared to buy some pistons and they take up less space than a V8.
Ecotec Swaps have been done in Fieros. I would say they were never real popular but we did have a few guys here a while back who did them. One member even made a swap kit but I can't recall his name. You can purchase ready made swap harnesses for the early engines but hard to find for the later engines.
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So the Ecotec is one engine that a lot of people are into but.... if you are up for the work involved, I would recommend a K series. this is all dependent on whether or not you are up for spending extra money on axles for the Honda transmissions. The K series are fantastic engines and its almost fits too perfectly in the Fiero, but its definitely a challenging swap. Not many have done it but there are Facebook groups out there for K swapped Fieros with guys that are more then happy to help with any questions you have for it.
Ive been working on my K swap for almost a full year now, and im close to getting the car driving. I know a guy on Facebook that tracks his K Fiero and it blazes through the track. Other then these two engines, the Honda K series and the Ecotec, im not aware of any other swaps.
well, im bias soo..
[This message has been edited by BruhMans06 (edited 05-29-2025).]
The K series is a great engine, though often expensive to build (as I expect you found out) but for c. 200 bhp they are pretty bulletproof.
The reason I'd prefer a turbo Ecotec is lower cost, already designed for fairly high output levels (stock options for the 2.0 of 260 bhp and you can get c. 375 bhp without going inside the engine (that's what I have in my Solstice).
The turbo LNF came in transverse front mount in the HHR SS and Cobalt SS - I wonder if the whole power unit/transaxle could be fitted to a Fiero?
I went after market turbo on my 88 Fiero GT - built a stroker 3.1 and ran it at 10 psi with no issues for twenty years -- limited the boost to 10 psi as it is such a swine of a job to fit an intercooler on a Fiero but it was fast and reliable.
The Ecotec is a strong and (fairly) modern engine - so far it has been putting out the 375 bhp at 25 psi max boost in my Solstice for 16 years......
Ecotec swap are around, but I think the Transmission changes required, and the ECU tuning limitations stop a lot of people.
The trans changes could well be difficult - hs anyone tried to see if the whole lump can be fitted to a Fiero?
I'm not aware of any limitations on the tuning end - you just get an ECM from the car the LNF came from and have it tuned - there are people running well beyond 400 bhp on that engine and ECM - some of the Cobalt SS guys are crazy - here is one with 500 bhp on the street:
I remember you! It's been a minute. Hope you are doing well.
I'm surprised more people haven't jumped into this thread. There are several people here who have swapped Ecotecs into Fieros. I've even thought about it, but it requires a few cradle mods, and I don't weld, so... But even a stock 2.4 is worth ~170 HP, right out of the box. And since that's the engine used in the Polaris Slingshot, there are quite a few aftermarket performance bits available.
Roger Thelin has been building swap brackets, cradle sections, etc., for a long time. His web page is currently unreachable, but I would expect that he's still out there, doing stuff. His phone number is in the link, below. https://www.fiero.nl/forum/Forum4/HTML/074936.html
[This message has been edited by Raydar (edited 05-29-2025).]
I know that there have been quite a few V8 swaps done and presumably the transaxle takes the torque. My LNF puts out 347 Tq at the wheel s- not sure how that translates into traditional power at the flywheel. Can the Fiero transaxle accommodate that? It is similar to the LS engines.
The Buick Regal came with e 2.0L Turbo and the F40 trans, I would assume, it could fully be swapped, haven't seen it though.
The supercharged Cobalt SS drivetrain has been down at least once, the axles for that application are bolt in on the Fiero with a F35/F40 transmission.
The practical life of the Fiero transmission is over. Parts are hard to find.
The thing I loved about my turbo Fiero was that you could get on it quite hard from a stop and unlike regular front engined cars that would spin their wheels, the Fiero would simply go - without any drama, and with good tires without even a squeal of rubber. That rear weight bias over the driving wheels worked beautifully.
I lived out of town on a winding fairly open winding highway and a guy with an Acura NSX ( Original 1990s version - another car with a potent mid engine) was often going home from work at the same time as I did. I could floor the Fiero and pull away from him steadily. He finally gave up trying. Only talked to him once and he asked what my car had in it - told him it was a stock engine with a bit of a custom exhaust system (not entirely inaccurate!)
LD9 Twin Cam and Quad-4 are popular swaps of course.
I know where there's a Quad-4 already on a cradle, with a 5-Speed Getrag, waiting to go into a car. If you're interested, I'll PM you the information. It's not mine, I don't know how much they want for it.
I'm not looking for any projects - I have too many cars on hand now! Up to a half dozen and some need reawakening after a long sleep. I owned an 87 and 88 Fiero GT at the same time which was a great way to be able to assess the two - conclusion was that the 88 was far better than the earlier cars. I sold the 88 when I bought my Solstice, only the second American car I wanted to own and I am still happy with it. I also drive a BMW Z4MC in the summer and have a rebodied MG with a 3.4 GM driveline I installed - great fun with only 2000 lbs. I also have a street MG, my old race car (also MG) and a Jensen Interceptor.
I just started this thread as I drop by once in awhile and wondered whether anyone was updating their Fieros with more modern power - I personally prefer the high tech turbo smaller engines to the V8s for swapping.
Depending on power objectives, 4-cylinder engines are likely to require a turbo to meet the power requirement.
However, with a turbo comes lag.
I don't have much driving time in turbo cars; the most turbo experience is with my Fiero.
Here is an example of a WOT 2->3 shift in my Fiero. Going from 100 kPa to 180 kPa MAP takes ~0.5 seconds after the shift.
Accelerating in straight lines with high traction the lag is fine, but in corners I do not have much confidence in the car. It is hard to modulate the throttle pedal and have the engine react now, linearly. Maybe more seat time would help things (my car spends too much time down for service).
Anyway, the lag reduces confidence, yet increases scariness and excitement at the same time. Whether this is a plus or a minus, I am not sure!
I definitely see how a naturally aspirated powerplant would be a nice thing to have in a sports car. A mechanically-driven supercharger would be the same.
quote
Originally posted by BillS: The Ecotec is a strong and (fairly) modern engine - so far it has been putting out the 375 bhp at 25 psi max boost in my Solstice for 16 years......
How long does it take to spool up the turbo to get that 25 psi boost pressure?
The higher the boost pressure, the greater the lag time, as the turbo has to accelerate to a higher RPM.
The turbo I use on my Solstice is a stock K04 with a larger impeller to move more air. Going larger often results in more lag but this is nicely sized and makes power quickly and smoothly all the way up. This sort of mod doesn't necessarily add much power but what it does is prevent fall off in power as rpm increase - the stock turbo runs out of puff before you hit maximum rpm. The improved one is very smooth and the power doesn't taper off as it does with a stock one as you pass about 5,000 rpm. It allows you to do a sub 4 second 0-60
My Dad has had as many Mazda Miata's as I have had Fieros (and Chevy Vegas). His Miata's had 2.0 litrre 4 cylinder engines. They were faster than my 2.8 Fieros. I guess it could be gearing.
I've thought about it quite a bit. For an Ecotec. They're cheap and plentiful. You can use an F23 transmission. Stock axles. Mounts available from Roger Thelin. Although, I'd make my own. Shift linkage is available from several sources. www.fierospace.com is where I'd go if I didn't make my own.
Clutch can be a stock Cobalt SS or similar FWD application. Get one to meet your power needs. Flywheel is either an 8 bolt for the boosted application, or 6 bolt for NA. F23's are plentiful still. I have a pile of them in my garage.
There's the Supercharged version or turbo. I think there's been more SC'd ecotecs in fieros. Not including the NA. The turbo would be more fab to fit vs SC. I'm okay with this.
My thought was to get an LE5. Get it drivable. I wanted to go with VVT and direct injection if possible. Then turbo. Unless I found a turbo at the upull it yard.
Non GS Buick regals with the turbo seem to be more common as far as TC'd cars go. The LDK ecotec. 220hp/258tq. I'm pretty sure it's less power from the tune but Same turbo and other hardware. Direct injected and VVT.
I only want 1 fiero. That's my choptop. It's going to end up with an LS4. Although it currently has a 3800SC. And I have another 88gt with a non running 3800SC that I just picked up as a project(back on the road now) I'll likely sell it once the choptop is all put back together.
I don't see myself getting another fiero. So I'll never get to do an ecotec. There's only so much time in a day. And I'd rather go fishing.
My Dad has had as many Mazda Miata's as I have had Fieros (and Chevy Vegas). His Miata's had 2.0 litrre 4 cylinder engines. They were faster than my 2.8 Fieros. I guess it could be gearing.
And an Ecotec is a common swap in them. I think it has more to do with availability of the Ecotec vs a Mazda engine. Or turbo 2.3 that was in the mazda speed versions. the 2.0 has similar output to the ecotec.
