To do a swap to a 3.4, do I need the ECM from the donor, or can the 2.8 ecm be reprogrammed? Also, do I need the wiring harness, or can I use my old one? Does someone build them specifically for swaps?
For the 3.4 V6 swap (i.e. the Camaro engine), you can keep the Fiero ECM and wiring harness. The 3.4 V6 uses a few sensors that the Fiero doesn't... the knock sensor and crankshaft position sensor on the side of the block, and the cam position sensor on the front corner of the lower intake manifold. You can just leave them disconnected, or delete them. Then you swap on the intake, exhaust, timing cover, belt-driven accessories, sensors, etc from the Fiero, and you have an engine that looks almost exactly like the Fiero 2.8.
Excellent, thank you both for the input. I think I found one for $300 that my nephew is picking up. I know it's one of the easier swaps, I just didn't know about the ECM and harness. Still need to do more reading.
The only difference in the 2.8 and 93-95 Camaro/Firebird 3.4, as far as a swap is concerned is the location of the starter. Rodney's starter relocation jig is needed, and if using an automatic, a small angular section of the original starter boss has to be ground off for clearance. You will need an 88 flywheel or flexplate for the 3.4.
You may want to have your injectors rebuilt to provide 17 lb/hr flow. The original 3.4 injectors often give problems and staying with modified Fiero injectors should work without any problems. Otherwise, everything from the 2.8 is used on the 3.4. Its just like swapping tit for tit or tat for tat.
Thanks for the post reference. It is on my list of reading material.
fierofool,
Thanks for the input. I was aware of the starter relocation, and I was reading a document for the swap and read about the cutting needed for an automatic. Fortunately, I have the 5 speed getrag, so that won't be needed, but will still need a flywheel. Who would rebuild the injectors? Or can I just buy new?
You'll need a flywheel for the '88 Fiero V6, or a GM FWD car or minivan with a 3.1 / 3.4 / 3100 / 3400 V6. The '85-87 Fiero V6 flywheel will not work on the 3.4 V6, because the balance is different. The earlier Fiero V6 is externally balanced, whereas the '88 Fiero V6 and the 3.4 V6 are internally balanced.
In my link is information for Fuel Injector Connection, just outside Atlanta. They can re-flow your injectors. That's where I've gotten all mine, except the Mustang 19#. Those are still in the man's car, but still running rich after about 6 years. He just won't spend the money for new 17# injectors.
You'll need a flywheel for the '88 Fiero V6, or a GM FWD car or minivan with a 3.1 / 3.4 / 3100 / 3400 V6. The '85-87 Fiero V6 flywheel will not work on the 3.4 V6, because the balance is different. The earlier Fiero V6 is externally balanced, whereas the '88 Fiero V6 and the 3.4 V6 are internally balanced.
Doesn't even need to be a V6. I think mine came off a 2.2 or 2.4 cavalier. Same part numbers.
If you get everything set up right, you'll be very pleased. The 3.4 feels just about perfect for what the Fiero was meant to be. In other words, it can do what it looks like it can do. The 3800sc would be simply Badas$, but the 3.4 feels really good and well mannered. Unfortunately, with the extra power, you'll find yourself challenging more and spinning tires. Good news is, if you like to change tires out often, you'll be happy
I/m rather cautious when it come to these thread as I've seen them go downhill pretty quickly but i will give it a shot.
I bought my '88 Formula four years ago with 48K on the odometer. It was a well kept car but even so there were some things that needed fixing. The first year I replaced most of the electronic sensors, a new EGR hose and a new distributor.
Once those were taken care of I started the engine upgrades. It's all documented here -
Now, I wouldn't try to argue with the Fiero experts here as it would be like bringing a knife to a gun fight. I'm a pretty decent old style shade tree mechanic but nothing like some of the gents.
That said, I will offer a contrarian view. When I asked about where I might be, HP wise, after the work I did those in the know estimated 25-30 HP over stock. That feels about right by my butt dyno.
So, with the addition of the rockers I am perfectly happy with this car. No it's not a Corvette killer but it is a lively little weekender.
When I did my 3.4 (using 3100 block bored to 3.4 w/Camaro pistons) I bought new Camaro injectors. Feels like it needs no reprogramming with 88 ECM. I read people had trouble with Multec injectors pre-88.
Don't use the Fiero injectors, they flow significantly less than the stock 3.4 do. I've never had any issues with the 3.4 injectors.
The 3.4 will have less power than the expected 160 i you stick the Fiero intake on it, as it is restrictive. Either machine the Fiero intake if you want stock appearance, or use the higher flow 3.4 intake.
A good running 2.8 will dyno at 115rwhp behind a manual from the rated 140hp. A good running 3.4 will dyno at 135rwhp behind a manual with no mods from the rated 160hp. Both engines incur a 25hp loss for accessories and drivetrain weight/drag since those are the same. I haven't seen any dynos with the Camaro intake but you'd need to also switch the ECM and ignition to DIS in order to use it. (A good time to go 7730 conversion since Camaro's ECM is non-programmable.)
I'll have a dyno later this week of my car with a 3100 bored to 3.4L block+stock roller cam using stock Camaro 9:1 pistons, DAWG intake mod and ported heads along with Sprint manifolds and Fiero Store cross-over with stock exhaust. No tuning. Stock 88ECM, Camaro injectors.
[This message has been edited by lou_dias (edited 01-16-2017).]
Don't use the Fiero injectors, they flow significantly less than the stock 3.4 do. I've never had any issues with the 3.4 injectors.
The 3.4 will have less power than the expected 160 i you stick the Fiero intake on it, as it is restrictive. Either machine the Fiero intake if you want stock appearance, or use the higher flow 3.4 intake.
http://www.v6f-body.com/sho...t=1242#throttle_body Surprisingly, the Camaro throttle body is only 50mm compared to the Fiero's 52mm. The only real problem with the Fiero intake is the neck. To solve that you can switch to the Firebird 2.8 intake like I am doing so on my oval track car or doing the DAWG mod like I did to my daily along with boring the Fiero TB to 57mm or buying the Fiero Store's 56mm TB. I hope to mount the 89-92 F-body twin 42mm TB to the ported 2.8 intake on the Fiero that I use at the oval track. The twin 42mm adds up to a single 59mm TB.
[This message has been edited by lou_dias (edited 01-16-2017).]
I have a bunch of 3.4 how-to swap videos on YouTube you can check out. I also have a video on doing the 7730 ECM swap if you decided to upgrade that as well. Instead of posting links to each how to video you can check out this PFF link.
Can anyone give me a part number of what is need to do the 1.6 rocker arm upgrade for the 3.4? To include rockers and pushrods if necessary. OP, sorry to thread highjack but my question is along the same lines as yours and didn't want to start a new thread. Thanks in advance, Tate
Can anyone give me a part number of what is need to do the 1.6 rocker arm upgrade for the 3.4? To include rockers and pushrods if necessary. OP, sorry to thread highjack but my question is along the same lines as yours and didn't want to start a new thread. Thanks in advance, Tate
Can anyone give me a part number of what is need to do the 1.6 rocker arm upgrade for the 3.4? To include rockers and pushrods if necessary. OP, sorry to thread highjack but my question is along the same lines as yours and didn't want to start a new thread. Thanks in advance, Tate
No sweat, Tate. Hope you get the info you need.
Thanks everyone for the input. I began the process of removing my engine this past weekend. Still waiting on my 3.4 to arrive. May be awhile. I'm to the cradle bolts at the moment using Toddster's procedure. Broke my 18mm socket, so figured that was a good stopping point. Need to get an impact socket and try that route. Broke my cradle bolts loose on the rear of the cradle, but didn't go any further, so I'm not sure if they are spinning or not. Hoping I don't have to cut into the frame, but will do it if I need to.
I'm sure once I get my 3.4, I'll be back on here to ask questions. Thanks again.
Lots of 3.4L swaps have been done with good results. If the expected result is a bit more power than the 2.8L then you will be pleased. Like BillS said the Fiero intake will limit power especially in the 4800-5500 RPM band but overall the result will still be an improvement. As suggested use the Fiero harness, ECM and the 3.4L injectors etc.. IIRC the 3.4TDC flywheel will also fit. Some small adjustments to the ECM program are usually required.
------------------ " 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, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, 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 "
Dyno in. This rebuild involved boring a 3100 to 3.62" (3.4L) and using stock Camaro pistons. Stock 3100 (1996) cam with one set of lobes showing some wear. Motor originally had a blown head gasket with AL heads. This is my daily so I didn't go crazy with it. Mild port job on heads, Sprint manifolds and 57mm TB + DAWG mod with Fiero Store cross-over and stock exhaust and muffler. Did 145rwhp @4400. Stock 88ECM, no tuning. Stock middle intake and mild port job on lower. Stock Camaro injectors. Runs just as rich as all stock Fieros. A/F ratio was at 11:1 after 4800rpm... Seems like fixing the A/F ratio would put it over 150rwhp...maybe more since it was rich across the board...just less so at lower rpm.
Interesting that with my older 3.4 Camaro rebuilds that I needed a performance cam and modified exhaust to get over 142rwhp... That should tell you something about the newer blocks with roller cams...
I really see the biggest downside to higher rpm is the coil and the cam, not the intake. DIS really made a big difference in higher rpm, well with my code anyway. The stock Coil suffers above 4500 rpm. Yes gains can be had with the intake, but math shows it does flow enough for a 3.4 at the VE a 3.4 has, people on here try to do the math at 100% VE which is just wrong. Another myth is the 2hp gain with the 1.6 rockers as it came from bad info from desktop dyno, Camaro guys have gained 15hp with the roller tipped 1.6 rockers. Math alone shows 11hp.
Edit to add: the 88 flywheel can be bought at O'Riellys auto parts for $60
[This message has been edited by sardonyx247 (edited 01-22-2017).]
Normally I would agree with you as I've had ignition issues show up as extreme dips in my dyno and those can be seen back in my 2009 dyno. I ran the car to 5700 rpm and didn't see that. The Fiero is just poorly tuned from the factory... Also, the torque didn't fall off quickly after 4000rpm, if the tune was *proper*, power would have been higher than 4400 rpm. I'll try to post a picture tomorrow. A typical 3.4 swap should produce 200 ft*lbs and I was only at 193. Again, a decent tune should put me in that neighborhood. I'm going to order some 256k chips to do my own tuning but, I think having a better exhaust would have probably resulted in a leaner mixture so I will consider that as well. A stock 1 7/8" exhaust is just a sin for a 3.4L engine...
The Fiero Store now offeres a cross-over pipe for the 85-87 V6's with a 2.25" downpipe but not the rest of the system. For 88, the down pipe section is still 2"... :/ Basically a proper exhaust could show a 10-20 hp gain with no other changes. Bring back the Trueleo headers!
[This message has been edited by lou_dias (edited 01-23-2017).]
Still making 130 rwhp @ 5250 rpm... As you can see, it starts to get rich at 3200 rpm. I have an adjustable FPR from the Fiero Store and this was with the pressure dialed down to 34. Previously it was going below 10:1 after 4800...but who knows, perhaps the Fiero Store bolt-on gauge is inaccurate and I was too high from the beginning, however the fuel ratio pattern is the same as every other stock Fiero. I'd like to edit the .bin file and shorten the BPW and increase the fuel pressure. At part throttle prior to the run, the a/f ratio was reading between 14 and higher where it belongs. As you can see, with a little tuning, the peak torque could be extended to the cam's advertised 4000rpm. Again, this is running the stock exhaust from the downpipe to the tips. Fiero Store cross-over and Spring F1 manifolds. Camaro 9:1 pistons with stock 3100 roller cam with some signs of lobe wear.
I want to stress that my previous CAMARO engine rebuilds required an aftermarket cam and freer flowing exhaust to go over 140rwhp... I've done 3 of them hitting 142, 145 and 149.8 rwhp... With a better exhaust alone, the entire band would shift and torque would go over 200 ft*lbs... Also, my middle intake here is 100 % stock. Lower is only lightly ported.
[This message has been edited by lou_dias (edited 01-26-2017).]
You got me thinking about this. Some info: in PE mode (Power Enrichment) IE Wide Open Throttle you want about 12.5:1 not the 14 as you mentioned, 14.6/7 is best for CAT operation, but PE wants richer best power output. 10 is too rich. The ECM runs PE the richer of what is learned or stock tables, as not to go lean. To explain my thoughts, following the dyno, where the power drop the A/F (Air Fuel) follows the power drop, shows running low on air flow, can't say if it is the intake track or cam. Any chance you have(or can find) 2 dynos same engine, but with a cam change, and no other changes, that would help figure this out. But it does show the ECM should be re-tuned at the power drop and up, to keep the A/F level, and the pressure increased to resume the 12.5(ish) during the lower rpms, that should bring the power up a bit.
No that's not right. I've done lots of dyno-tuning. Engines make the most power at 14.7:1. For some silly reason, tuners believe 13 is "safer" incase "something goes wrong". I mean an injector or fuel pump works or it doesn't. Tuning for 13:1 or below only wastes gas. When something goes wrong, that extra thousandth of a second at 13:1 ain't gonna save poop. At part throttle your car is running quite comfortably around 14.7:1. Guess what type of driving you do more of: WOT or part throttle? 14.7:1 seems pretty safe to me...
GM had crappy factory tunes until about 2004.
[This message has been edited by lou_dias (edited 01-27-2017).]
At part throttle your car is not in PE mode, If you were good at tuning (or knew how) you would not be using an adjustable fuel pressure regulator, you would be tuning the ECM. An adjustable fuel pressure regulator is for people who don't know how to tune. This has been proven for decades. Very well proven.
Edit to add: A cam that has wear is garbage as it will wipe the lobes quickly, and even if it doesn't you don't have all the lift as you should, the hardness is only on the surface, experienced engine builders knows to replace any cam that has wear. Also a 2.8 bored out is NOT a 3.4. Totally different blocks.
2nd edit to add: GM had good tunes as you can't gain much tuning a GM engine, but they did have sloppy tolerances. Japs had bad tunes but tight tolerances, thus hon-duhs gain alot from tuning. GM you get more from blueprinting an engine but not much from a tune.
[This message has been edited by sardonyx247 (edited 01-27-2017).]
I have an adjustable FPR because I didn't want to do tuning because by my math, going from a 2.8 to a 3.4 requires 18.1 # injectors and the Camaro injectors are 17#. Hence, I raised the FPR to compensate... I did this dyno out of curiosity and transparency. A lot of people talk a good game but have posted no dynos.
This is my daily, not a car I will spend much more money on. I have another car for that which makes a lot more power.
Lou, I have to disagree with your math formula. Or most correctly, injector rebuilders and manufacturers disagree. All the injector size calculators I've ever found use number of cylinders and horsepower at the crank to determine injector flow rates, at a maximum of 85% duty cycle and the Fiero's stock pressure of 43.5 psi.
Using the specs for a stock Camaro/Firebird 93-95 3.4 engine, rated at 160 crank horsepower, the proper injector size is 16+ lb/hr. A 17 lb/hr injector actually flows something like 16.6 lb/hr. Just as the stock Fiero injector truly flows just over 14 lb/hr but is rounded up to 15. https://fuelinjectorclinic.com/flow-calculator
Lou, I have to disagree with your math formula. Or most correctly, injector rebuilders and manufacturers disagree. All the injector size calculators I've ever found use number of cylinders and horsepower at the crank to determine injector flow rates, at a maximum of 85% duty cycle and the Fiero's stock pressure of 43.5 psi.
Using the specs for a stock Camaro/Firebird 93-95 3.4 engine, rated at 160 crank horsepower, the proper injector size is 16+ lb/hr. A 17 lb/hr injector actually flows something like 16.6 lb/hr. Just as the stock Fiero injector truly flows just over 14 lb/hr but is rounded up to 15. https://fuelinjectorclinic.com/flow-calculator
You are probably correct which explains my rich condition at WOT. I just used simple math: 15/2.8*3.4 = 18.2 (by vague memory I wrote 18.1 earlier) I compensated by lowering the FPR since I wasn't prepared to do any actual tuning and you can see that the A/F ratio pattern is equivalent to my *other* 3400 hybrid conversion where I made a lot more power on the stock ECM but with Mustang injectors... I'm not sure of the changes DarthFiero had made on the chip I was running but he probably had lowered by BPW to compensate for the injectors. https://www.fiero.nl/forum/F...ML/075502-3.html#p98
[This message has been edited by lou_dias (edited 01-27-2017).]
I had a friend run mustang injectors on his 3.4, he decided to hook it to a smog machine to see what it ran, his car was blowing in the 600-700 range instead of the max 220ppm allowed. He had never smogged a car before as where he lived he never had to, Stock ECM, mustang injectors run real rich.
An ECM can learn to richen up smaller injectors(up to the point they are static), but it won't lean out bigger ones (This is ONLY in PE mode) as I said before PE is ALWAYS the richer of learned or stock tables. Just FYI
I've been there with a crate 3.4 and Mustang 19# Bosch injectors and a used 3.4 with 17# Rochesters, stock ECM and FP regulator on both. 19's were slightly rich but the Rochesters were unbearable, but it was also due to a poor quality used engine. I'm running 17# M50 BMW 17# modified pintle injectors in my stock 3.4 with Fiero ECM and FP regulator. Raydar says blm maxes out but I have about 20K on it and really have had no problems.
I've been there with a crate 3.4 and Mustang 19# Bosch injectors and a used 3.4 with 17# Rochesters, stock ECM and FP regulator on both. 19's were slightly rich but the Rochesters were unbearable, but it was also due to a poor quality used engine. I'm running 17# M50 BMW 17# modified pintle injectors in my stock 3.4 with Fiero ECM and FP regulator. Raydar says blm maxes out but I have about 20K on it and really have had no problems.
With the Mustang injectors,I had to adjust the BPW to Voltage table but that was using the 7730. On my 4.9, I had to have the BPW dropped by 25% when using the 19# Bosch Design 3 injectors from a Ford Thunderbird...
IMO, the only thing you should use an adjustable FPR for is to get your injectors at the optimal flow rate. Once you get that dialed in, any fuel tuning should be done via the ECM. There's a good reason for this. Adjusting fuel pressure affects fueling across the board. So if you try to "tune" part of the fuel map by adjusting fuel pressure, you can inadvertently cause problems in other parts of the fuel map.
IMO, the only thing you should use an adjustable FPR for is to get your injectors at the optimal flow rate. Once you get that dialed in, any fuel tuning should be done via the ECM. There's a good reason for this. Adjusting fuel pressure affects fueling across the board. So if you try to "tune" part of the fuel map by adjusting fuel pressure, you can inadvertently cause problems in other parts of the fuel map.
Yes, that's exactly what I was doing. I assumed I'd be lean but was actually rich and had to dial it back below stock pressure (according to the Fiero Store add-on gauge anyway) and I've since picked up 2mpg. If I were to tune, I would flatten the A/F ... then play with timing, then readjust the A/F since advancing the timing can make you lean. But this is a daily so those things aren't a priority. I recently learned that I can use my 512k chips on a stock ECM by changing the address mapping value so I will probably just fix the A/F for now...
