It is common knowledge that the 3.4L engine used in the 93-95 Camaro/Firebirds is the easiest engine swap upgrade for the Fiero. It is a 60* V6 like the 2.8L and 3.1L and shares most mechanical dimensions. The swap is very cost effective and requires just a few mods for the engine to bolt right in. Having said that I would like to ask if in fact this engine is a true "bolt in" swap. If you don't consider the tuning aspect the answer is yes. When you do consider the tuning aspect the answer is no.
The chip in the Fiero ECM was optimized for a 2.8L with 8.5:1 C/R that runs 15 lb/hr. fuel injectors. The 3.4L is a larger displacement engine with 9:1 C/R which uses 17 lb hr. fuel injectors. The bore to stroke ratio of the 3.4L is 1.095 while the 2.8L is 1.17. as a result both the fueling and timing needs of the two engines are different . The performance characteristics of these two engines are not the same nor are the tuning specs. In particular the main timing tables in the chip program of the 3.4L are far different from those of the 2.8L.
Most people doing the swap just bolt the 3.4L in and hope for the best. While the 3.4L will run with the stock ECM 2.8L program, your power will be far from optimized. A time costly chip reprogram should also go with this swap. I'm working on a few of these programs right now and may have some info to share shortly. We are doing a data dump and comparison of the 2.8L, 3.1L and 3.4L programs to see how they differ.

------------------
87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

I would agree and say that it is most surely needed here. Thats the one thing that kept me from doing a 3.4 I hope it works out for you and everyone who does the swap after.

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There's a rumor floating around thirdgen.org on the PROM board that TunerCat may be releasing definition files for the Firebird V6. I'm guessing it uses the same ECM as the Fiero? Might be worthwhile checking that out.

quote Originally posted by AJ88: There's a rumor floating around thirdgen.org on the PROM board that TunerCat may be releasing definition files for the Firebird V6. I'm guessing it uses the same ECM as the Fiero? Might be worthwhile checking that out.

No. The firebird ECM for the 3.4 is NOT the same unit used in the Fiero. Furthermore, the ECM that the 3.4's use is an engine compartment mounted unit that requires different inputs than the Fiero unit; most importantly, the VSS (speedo).

The thing that puzzles me about this swap is why I am not seeing most people keeping the DIS coil pack that comes stock on the 3.4 but instead putting the 2.8 distributor in. I believe the stock fiero computer system will communicate with the DIS system via the same 4 wires it does with the distributor. However, there may be an issue as far as base timing is concerned which can be easily addressed by burning a chip.

------------------
1987 Pontiac Fiero Coupe #18,838
3800 Series II SFI
4T60-E Trans
3.33 Final Drive

1987 Pontiac GTA
5.7L SuperRam MPFI
4L60-E Trans
3.73 SRD

http://dtcc.cz28.com

Dennis,

I'd be interested in the chip reprogram. still building my 3.4 and getting ready for install, but have heard that they'd run a bit better with this mod. Please keep us updated!!!

quote Originally posted by AJ88: There's a rumor floating around thirdgen.org on the PROM board that TunerCat may be releasing definition files for the Firebird V6. I'm guessing it uses the same ECM as the Fiero? Might be worthwhile checking that out.

The ECM for the 93-95 Firebird/Camaro is an entirely different ECM than what was used on the Fiero and uses a different higher density memory chip. It would be a real pain to rewire the Fiero to use this ECM. However, if we did a dump of the eprom chip data from the Camaro/Firebird and read the values, the timing, fueling and enrichment tables could be programmed into the Fiero chip. This would provide factory settings for the program in the Fiero ECM. We could then use the original program parameters as a baseline for developing a high performance chip. This is my current project.

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87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

I'm also very interested in a 3.4 chip.

------------------

ClassicFiero.com

quote Originally posted by SubZero350: ...The thing that puzzles me about this swap is why I am not seeing most people keeping the DIS coil pack that comes stock on the 3.4 but instead putting the 2.8 distributor in. I believe the stock fiero computer system will communicate with the DIS system via the same 4 wires it does with the distributor...

About a year ago, someone else on the Forum had this same theory. (Seems like it was concerning a 3100 or 3400 "aluminum head" swap.) Said he was going to try to cobble something together, and would report back to us.
That's the last I remember hearing.

I like the idea, though. I'm not a purist, and I believe the 3.4 F-body induction system is probably much better suited to the engine than the one that fed the 2.8. Aside from that, it just looks cool.
Just my $.02.

Dennis, good luck with your project.
FWIW, I understand that someone else is already burning 3.4 chips for our application, but I believe that the EGR has been eliminated in his design. Many of us have to maintain the EGR system intact, in order to comply with the smog regs in our areas.

------------------
Raydar

From the Department of Redundancy Department.

Just for reference the ECM numbers of the 3.4L in Camaros and Firebirds are:
GM P/N 16172693 1993
GM P/N 16184737 / 16203281 1994
GM P/N 16188051 1995
Im trying to obtain a data dump of the programs in each of these ECM's to see the fuel and timing table readings that GM programmed. I will then plug these values into the chip for the Fiero ECM P/N 1227170 and start tweaking the tune from there. I believe that if a chip is developed for a Fiero ECM used to control a 3.4L; this may prove a very good mod. for optimizing power in the swap.
I just got an email from a fellow that said " well my 3.4L swap works "fine" with the stock ECM and chip". I agree that the stock ECM will run a 3.4L, but the power potential will be far from optimized.

------------------
87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

quote Originally posted by Raydar: FWIW, I understand that someone else is already burning 3.4 chips for our application, but I believe that the EGR has been eliminated in his design. Many of us have to maintain the EGR system intact, in order to comply with the smog regs in our areas.

Who running this setup? Do you have anymore info?

Dennis-- I would be intrested in a 3.4 chip. Mine is running too rich

quote Originally posted by ardenQ: Who running this setup? Do you have anymore info?...

I've tried. I can't remember the man's name.
Sorry.
You might try doing a search, although theres probably several hundred 3.4 posts by now. If I can remember his name, I'll post it.

------------------
Raydar

From the Department of Redundancy Department.

I couldn’t agree with you more. This was the limiting factor in my 3.4 swap. If I could go back I would have swapped in the Camaro ECM, sensors, and wiring also.

quote Originally posted by Dennis LaGrua: It is common knowledge that the 3.4L engine used in the 93-95 Camaro/Firebirds is the easiest engine swap upgrade for the Fiero. It is a 60* V6 like the 2.8L and 3.1L and shares most mechanical dimensions. The swap is very cost effective and requires just a few mods for the engine to bolt right in. Having said that I would like to ask if in fact this engine is a true "bolt in" swap. If you don't consider the tuning aspect the answer is yes. When you do consider the tuning aspect the answer is no. The chip in the Fiero ECM was optimized for a 2.8L with 8.5:1 C/R that runs 15 lb/hr. fuel injectors. The 3.4L is a larger displacement engine with 9:1 C/R which uses 17 lb hr. fuel injectors. The bore to stroke ratio of the 3.4L is 1.095 while the 2.8L is 1.17. [b]as a result both the fueling and timing needs of the two engines are different . The performance characteristics of these two engines are not the same nor are the tuning specs. In particular the main timing tables in the chip program of the 3.4L are far different from those of the 2.8L. Most people doing the swap just bolt the 3.4L in and hope for the best. While the 3.4L will run with the stock ECM 2.8L program, your power will be far from optimized. A time costly chip reprogram should also go with this swap. I'm working on a few of these programs right now and may have some info to share shortly. We are doing a data dump and comparison of the 2.8L, 3.1L and 3.4L programs to see how they differ. [/B]

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i guess this is where 1fst's piggy back system comes into play.. eh?

quote Originally posted by SubZero350: The thing that puzzles me about this swap is why I am not seeing most people keeping the DIS coil pack that comes stock on the 3.4 but instead putting the 2.8 distributor in. I believe the stock fiero computer system will communicate with the DIS system via the same 4 wires it does with the distributor. However, there may be an issue as far as base timing is concerned which can be easily addressed by burning a chip.

I wanted to use the DIS system so I could take advantage of the camaro intake. I think using that would solve alot of the air/fuel problems.

Dennis,
Put us on your early chip delivery list. Also, what you had said in earlier posts regarding which injectors to use, and the reason, sure made a lot of sense.

BTW, is Joe Wynman the ellusive fellow who may have already been burning chips for this application? He is in the NJ area, just wondered if you could put your heads together?

David & Hunt Breeze

Hi Dennis,

Since we have the 3.4L crate engine, this is an interesting subject for me. The idea of another 15 hp with a chip change (getting me to 150 at the wheels) is pretty appealing.

In our case, the driveablility of the 3.4 with the 2.8 ECM is very good. Crisp and only slightly rich at idle. Our dyno results bear this out, I believe, in that they indicate it's putting out pretty much what GM says it should.

The thing I think is limiting the performance is the intake. You can see it plainly on the dyno that the top end just isn't there. This isn't something that the chip will correct. If someone comes up with a better intake, or is going to use the Firebird/Camaro intake, then a remap would really be something that could show some startling results.

I'm not saying your thoughts are wrong, I'm sure that there's going to be some performance gain. I'm running a Hypertech chip and had intended to take my stock chip to the dyno and swap them, to see the difference, but forgot. Have fun, good luck, and let us know what you find out.

John Stricker

quote Originally posted by Dennis LaGrua: Just for reference the ECM numbers of the 3.4L in Camaros and Firebirds are: GM P/N 16172693 1993 GM P/N 16184737 / 16203281 1994 GM P/N 16188051 1995 Im trying to obtain a data dump of the programs in each of these ECM's to see the fuel and timing table readings that GM programmed. I will then plug these values into the chip for the Fiero ECM P/N 1227170 and start tweaking the tune from there. I believe that if a chip is developed for a Fiero ECM used to control a 3.4L; this may prove a very good mod. for optimizing power in the swap. I just got an email from a fellow that said " well my 3.4L swap works "fine" with the stock ECM and chip". I agree that the stock ECM will run a 3.4L, but the power potential will be far from optimized.

If you have the Fiero intake and use the fuel mapping for the F-body intake, you may not fix the fueling problems. The fuel map seems to go more along with intake design than engine displacement. Look at these maps:

The top map is for a 305, the bottom is for a 350, but they are both Tuned Port Injection. They are different, but not by too terribly much. Now this is a map for a 350 engine, but with a short runner intake:
Now, that is really different! I had the best luck with matching the fuel map to the intake and adjust the overall fueling/timing. If you don't mind sharing, could you send me a copy of the bin file you are working on? I always like to add to my notebook any info that might be helpful for our Fiero friends.

How hard would it be to switch the Fiero's speed-density system over to a Mass-Airflow system? They seem to be much more forgiving of modifications.

On http://www.60degreev6.com one of the people put a 3.4 in an 82 Skylark that he added MPFI to. Using MAF, he said he got no driveability problems at all and it was pretty much plug and play.

Finally someone is thinking here. I also agree that some tweaking due to intake may be necessary. The 3.4 run on a 2.8 ECM may seem to run fine and feel fine but it is not optimized. My 3.4 runs rich at high RPM and not at idle. Every dyno run shown here falls around (at wheels) 140HP and 190TQ. If your PROM can improve that then put me in. I have cash in hand whenever you are ready. Travis system is another option but it seems to be in limbo lately.

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Alex4mulas :-)
N2O! 3.4!

What people don't seem to realize is that a "tweaker" like the aforementioned DynoTuner or an AFC can be used to facilitate the creation of a custom program. Install a dynotuner on a car and get it dialed in perfectly. Transfer the modifcations made on the dynotuner map to the VE tables stored in the calibration. Once that's done, zero out the dynotuner and install the new chip. It should be perfect right out of the box. This eliminates most of the time and expense of iteratively burning chips and gradually closing in on a good tune. This way the first chip you install is dead on.

Dennis,

Is it feasible to use the Firebird ECM by turfing the Fiero VSS and going with a hall-effect swithed style VSS like on the Baretta?

Or are there other limiting factors?

The Firebird 3.4 uses DIS ignition, and has a different ECM and intake. I would imagine you'd have to do a complete swap. Use the 3.4 with it's own ECM, intake, and DIS ignition, or use the Fiero ECM, intake, and distributor.

The 3.4's intake won't clear the Fiero distributor.

quote Originally posted by Formula88: The 3.4's intake won't clear the Fiero distributor.

Let me guess, the Firebird snorkle and distributor are on opposite ends of the block.

Perhaps a custom intake would work. Not too hard to make. Or easier still, what about doing an extrude job on a Fiero intake to up the volume and flow?

Has anyone tried this yet?

quote Originally posted by Formula88: The 3.4's intake won't clear the Fiero distributor.

Sure it will, just turn it around backward and add about 5 inches of tubing and a few other things that I have forgot. . .

Now, that thing would have been nice if I had the VE table from the Camaro to copy into my PROM.

quote Originally posted by Will: What people don't seem to realize is that a "tweaker" like the aforementioned DynoTuner or an AFC can be used to facilitate the creation of a custom program. Install a dynotuner on a car and get it dialed in perfectly. Transfer the modifcations made on the dynotuner map to the VE tables stored in the calibration. Once that's done, zero out the dynotuner and install the new chip. It should be perfect right out of the box. This eliminates most of the time and expense of iteratively burning chips and gradually closing in on a good tune. This way the first chip you install is dead on.

I'm not sure of the fuel map in the Dynotuner can be transferred to the main fuel table of the prom with success. This is because I believe that the Dynotuner box interferes with and corrects the fuel readings external to the ECM. Kind of like having both the ECM and the D-T box combine for joint control.
If you want to do a custom VE and power enrichment table "on the fly" there are several emulators that plug into the Fiero ECM prom chip socket. These are laptop programmable and can create a binary file. When you get the program right just transfer the program to a chip.
I'm not sure that the Dynotuner can be used the same way as an emulator can but Ed Senf should answer this question.
BTW does this box really exist or is it still "vaporware". Has anyone used one besides the inventor?

------------------
87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

quote Originally posted by Dennis LaGrua: I'm not sure of the fuel map in the Dynotuner can be transferred to the main fuel table of the prom with success. This is because I believe that the Dynotuner box interferes with and corrects the fuel readings external to the ECM. Kind of like having both the ECM and the D-T box combine for joint control. If you want to do a custom VE and power enrichment table "on the fly" there are several emulators that plug into the Fiero ECM prom chip socket. These are laptop programmable and can create a binary file. When you get the program right just transfer the program to a chip. I'm not sure that the Dynotuner can be used the same way as an emulator can but Ed Senf should answer this question. BTW does this box really exist or is it still "vaporware". Has anyone used one besides the inventor?

Basically, what the box does is dial in a percentage change. The program stores a table of precentage change in fueling vs. RPM vs. (presumably) load. Just take the values from this table one by one and apply them to the appropriate table in the calibration file, then burn one chip and get it right. Once that's done, transfer the dynotuner to the next car you want to tune.

I would be willing to bet that the base VE table curves of the 3.4 and are very similar, a difference quite like the comparison between the 305 and 350. Probably just need to adjust things up or down a bit, which I could do with just a few mouse clicks using the prom editing software I developed. Actually, a simple change to the injector constant would probably surfice.

BTW, you do not need to use the camaro intake just to retain the DIS ignition. Just leave the distributor block off plate on the 3.4 installed, use the Fiero intake like you normally would, and find a place to mount the coil pack. Splicing in the PCM is probably the biggest hurdle, but its more time consuming than it is difficult.

I get to have fancy graphs too

[This message has been edited by 00lE (edited 07-24-2002).]

I'd think that with the Fiero intake runners,the larger motor would tend to run like a Buick,with just a surge of low end grunt that fades away rapidly.Some added runner volume would be a real plus in getting the most out of that swap.
SplitSecond makes fuel controllers for just about anything,but you have to call them and ask;they don't list anything really on their website.With the different exhaust on a Fiero versus a Camaro,the settings are going to be off.

The fiero intake system and the Camaro intake system are almost identical to each other. They both use the same size throttle bodies and bottom and middle intake manifolds. The top manifolds are different in shape but the runner sizes are basically the same.

I can only imagine that they would have very close CFM flow rates. It looks like GM redesigned the top intake system to make access to the injectors and other parts a little easier.

------------------

I think you may be comparing it to the old Camaro 2.8 engine and not the 93-95 3.4. As far as I remember they look very different. I may be wrong...

The fuel and timing curves for a 3.4 and the Fiero 2.8 are different. The timing curve is set to the camshaft. The camshaft in the 3.4 is the "economy" cam. The camshaft in the Fiero 2.8 is the performance cam. The other problem is the Fiero TB is 300cfm and bored 5mm is 320cfm. If you put the performance cam into a 3.4, you will need to get a TB that is about 350cfm. Otherwise at wide open throttle you are starving the engine of air causing it to run rich. Changing the engine controls to a Mass Air setup eliminates many problems. The 2.8L is set up for speed density control. Unless you are using forced induction like a turbo, the engine will never be fully efficent.

Does Joe Wynman's 3.4 chip do anyhthing or help the air/fuel issue? My car really dies after 2nd gear and runs rich as well. When I emailed Joe he said I would need 24lbs Ford injectors? Would those be needed? I haven't heard of many people running his chip or even tested to see any dyno improvements. I think a custom chip burnt for each 3.4 application would be great. I think it would make a world of difference. 15 hp is probably good for a couple tenths in the quarter mile. Plus having the engine tuned perfect it would make nitrous and turbo setups that much better. How did you go about a chip for your 3.4 Turbo Dennis? Looks like it runs good. Let me know about all this as I am very interested in any ideas about other chips because the only known one I have heard of is Joe's and would like some input about it.

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1987 GT 5 spd: 2.8L
(15.57 @ 87mph)
1988 Formula 5 spd: 3.4
(15.56 @ 84mph)

the stock chip set and the hypertech, ads, jwt and jet are hardly optimised...(for the 2.8 at least) just an ok running program.. having dynoed the ads strip, hypertech and Jet units not a single one was worth the box they were shipped in.

just curious.. why spend the $ on a set parameter bunrt chip when you can have a tunable unit with room for serious expansion for only a little more?

just my nickles worth.

edit ---
Raydar.. i'll bring my laptop to do a quick demo of the software and it's abilites saturday to the Ga. Fieros Meeting.

[This message has been edited by 1FST2M6 (edited 08-08-2002).]

quote Originally posted by 1FST2M6: the stock chip set and the hypertech, ads, jwt and jet are hardly optimised...(for the 2.8 at least) just an ok running program.. having dynoed the ads strip, hypertech and Jet units not a single one was worth the box they were shipped in. just curious.. why spend the $ on a set parameter bunrt chip when you can have a tunable unit with room for serious expansion for only a little more? just my nickles worth. [This message has been edited by 1FST2M6 (edited 08-08-2002).]

Ed has made some very valid points. His Dynotuner will certainly offer more flexibility than a chip but you need to install the box properly and own a laptop computer to do your own tuning. For the backyard tuner this may or may not prove to be the answer.
I would think that the idea of the Dynotuner came from an old idea called an Eprom emulator- a device which plugs into the prom socket and is laptop programable. An emulator provides the ability to develop a program and duplicate chip function via a laptop. You can then dump this program into a bin file and burn the program into a chip. The Dynotuner seems to interfere with the ECM's inputs and tricks it into doing different things. I'm still not sure how the timing and fueling can be optimized in this way but I'm not here to doubt anyones word or ability.
I also believe that the Hypertech and ADS chip programs are of very minimal value. My opinion comes from use and resulting ET's. Ed apparently has more scientific information via the dyno runs.
If a chip is optimized and programmed correctly for a certain engine it is a simple and easy way to go especially for the novice.
I'm not taking sides or trying to convince anyone on which approach is better, However, if you have a Dynotuner or a laptop programmable ECM, you'll really need to know what you are doing or you stand the risk of burning a piston or blowing a $$$$$ engine. As the Dynotuner becomes more popular, I would think that users can share info that will make it much easier to program.
Getting back to the 3.4L; it is a difficult engine to tune as the 2.8L plenum and throttle body are not sized for this engine. The airflow characteristics above 4500-5000 RPM are quite poor. That is why I went with Turbocharging. Really wakes this engine up!!

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87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

Ok. I have decided that sometimes knowledge is not always good!! Ignorance sometimes is bliss.
What I am wondering...
I am looking at transplanting a motor into an 88 coupe. It is for a kit car project. I was considering a stock 2.8 (85 motor, rebuilt by myself), but then was considering a 3.4 with the 2.8 intake and such. after reading this thread, I don't know...
Can anyone advise me? I am looking for an engine combo with pep, driveability, and one that doesn't kill me at the pump. I'm not going to the dragstrip, but don't want to be embarassed at the stoplight by every kid with a honda.
Any advice?

SMorris,
I don't know what kind of kitcar you were planning on, but having driven a Countach (and presently building a Diablo) I can assure you that you will be "challenged" by every 'Vette, 'Stang, and whatever else you meet on the road....so to avoid embarresment, I'd plan on at least a SC3800 or a V8, just for appearances, you understand.

I know you didn't budget this, I went thru the same thing, but why put all that work into what looks like a supercar but accelerates like an overworked Fiero.

David Breeze

-Bump-