OK, so I picked up a 2004 Series III 3800/auto trans from a Grand Prix. I plan to keep the motor/trans combo together and use the car as a daily driver. The car is a 88 GT that is now a manual, so I have to swap the manual stuff for auto stuff, but that is not why I'm posting this thread.

I have been on the forum for over 10 years so I know to use the search function, I have, and as you can imagine, typing "3800 swap" into search gets you a lot of data.

I will be reading all I can about this swap, and I plan to attack this one like I did my 3.4 DOHC swap, only I plan to have this one done much, much faster. I'm not looking for the same level of detail as I had on the other swap, this is going to be a driver after all.

Having done a few swaps, i'm aware of the wiring harness/ECM having to be made. I know I'll need the ECM to be flashed so some of the data can be removed. I know i'll need to purchase or make mounts for the engine/trans to fit the 88 cradle. I know that the A/C lines may need to be modified to fit, and im going to have to figure out the exhaust.

Heres what i'm still trying to find out.

1) oil filter, I have read something about the oil filter bracket needing to be swapped out, because it may interfer with the cradle
2) series III vs. series II: do I need to convert to a series II ECM or can I keep the series III
3) Drive by wire TB: if I go with a SII TB, do I have to convert to to the SII ECM.
4) I can't find any good threads about moving the ALT down low and who makes the low mount ALT bracket.
5) What is up with that stupid heater hose design, is moving the ALT down low going to let me get rid of that stupid heater hose crap
6) and to follow up on #5, how do I connect up the heater hose's, I have read some posts about having to cap/plug something on the water pump or the intake, and then use a "T" fitting to tap into the return line.

OK, so I am just getting all my data. If anyone has a good thread for me to read, just pass me a link to the thread, I can read all night.

Again, with all the data on this forum about the 3800 swap, just using the search does not answer all my questions.

Thanks to you all in advance for the help, and i'm sure i'll be posting a bunch more questions soon.

(pictures to follow when I get them on my machine and into PIP)

Rob

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88 Coupe, CJB T-TOP, LS376 and a GT clip
88 GT, ex-parts car, soon to be a driver.
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[This message has been edited by qwikgta (edited 08-25-2012).]

If you decide to convert to a series II cable operated TB then everything must be changed to series II controls. You will need a 2003 GTP ECM (to shift the trans) and wilI need to change to series II sensors. If you just happen to have the 3800SC series III with the tap shift trans then you must stay with the ETC and add a custom tap shift mechanism. The trans would be marked CB if you have tap shift . Chances are that you do not have tap shift as it was a rare option so the 2003 ECM should do the trick.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner 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 "

So the $100 bucks I paid for the ECM/Haness on this SIII was a waste of money? And, I still have to pull a harness off of a SII motor, then replace/install any new sensor that does not fit (old SIII to new SII). Finally, I have to purchase a 2003 GP GTP ECM, since I have not seen any 2003 GP GTP's in the yard latly.

OK, well its getting interesting.

Thanks.

Rob

Come look at mine and you can check out what I did with hoses, intake, alt, etc.

PM or email if you want to check it out. Hands on might be the best bet.

Thanks Al, I will asking for some help, you can bet on it. I'd like to request some assistance with the low mount alt. I know you made your own and said it was easy. I'll get with you about this soon

Rob

I did a series II swap into my 88 a few years back, homemade mount at front of engine(ok right side), I think both trans mounts were from a citation with mods needed on the rear mount, added a water fill point using the neck from a jap radiator tied into one of the heater inlets, oil filter adaptor from a camaro 3800(less than 20 dollars), axles are both drivers side fiero auto axles using the cups from the 4t65e axles

I have a series 3 engine, but used series 2 controls. I don't care for DBW. Sinister did the low mount alternator, you might ask him what method he used. I made the motor mounts (not the transmission mounts, they are stock). I used a pair of Dodge truck 318 motor mounts, side by side, because I believe in overkill.

Thanks guys. Lots of good info.

Last night I stipped the motor of the harness and removed the alt, alt bracket, wp (heater assy) and any/all loose brackets on the motor. its nearly naked now.

Noticed that I can't remove the second dogbone mount until I remove the exhaust crossover tube. I am assuming that the second dogbone mount is the one I use on the front of my engine to create a bone mount ??? agian, I guess its known information so its not talked about much.

I've read some threads about belt routing, and different methods to mount the Alt, and in each case, the motor is a 3800 SC not a NA. As I was looking at the stripped motor I wondered what was keeping me from removing the intake and putting on a Supercharger???? I know the lower end of this motor is not beefed up to take the SC, but it was a thought. I know that the 2005+ NA motors were the same as the SC motors on the inside, but this one is a 2004.

I checked the trans and its not a tap shift model, and i still need to figure out what to do about axles. I did get the tripots ends that go into the trans, and I have read a few posts about making up custom axles, but im not even close to that yet.

I know this motor has the return-less fuel system, and I plan to use a system similar to the setup used on my LS3 motor. It uses a C5 vette fuel filter/pressure regulator that provides a fuel line in with a return line back to the tank, and the other end has the fuel feed line. (so its two lines in, one out) I assume this will work, but have to check the fuel pressure out to see if it will work with the NA motor.

I still have to do some reading on the harness/ECM setup, and look at a few wire diagrams to figure out how im going to wire up the harness, as I was removing the wires, it seemed to me that in the end, its still just about 15-20 sensors feeding into a main box that feeds into the ECM. I still have the fuze box attached to this harness, and I figure that I will be removing it or if I use it make it smaller and put it out of the way. I removed the fuze box on my 3.4 DOHC motor harness, and it was just a matter of finding the function on the Fiero fuze box and routing the wires to it.

One last question, from the above post from Dennis, I see I will need a 2003 GP GTP ECM, but will any 2003 ECM work with a reflash/recode from Ryan? I can find a 2003 ECM, but just don't think i'll find one from that exact car. Will any 2003 3800 NA work?

Thanks agian guys, I will continue to update this thread with new questions as I get them. And again, pictures soon.

Rob

Yes Ryan should be able to flash a 2003 NA PCM to a 2003 SC PCM provided he has the data to flash it. You are best to ask him this directly. His email is sp1@gmtuners.com

quote Originally posted by qwikgta: Thanks guys. Lots of good info. Last night I stipped the motor of the harness and removed the alt, alt bracket, wp (heater assy) and any/all loose brackets on the motor. its nearly naked now. Noticed that I can't remove the second dogbone mount until I remove the exhaust crossover tube. I am assuming that the second dogbone mount is the one I use on the front of my engine to create a bone mount ??? agian, I guess its known information so its not talked about much. I've read some threads about belt routing, and different methods to mount the Alt, and in each case, the motor is a 3800 SC not a NA. As I was looking at the stripped motor I wondered what was keeping me from removing the intake and putting on a Supercharger???? I know the lower end of this motor is not beefed up to take the SC, but it was a thought. I know that the 2005+ NA motors were the same as the SC motors on the inside, but this one is a 2004. I checked the trans and its not a tap shift model, and i still need to figure out what to do about axles. I did get the tripots ends that go into the trans, and I have read a few posts about making up custom axles, but im not even close to that yet. I know this motor has the return-less fuel system, and I plan to use a system similar to the setup used on my LS3 motor. It uses a C5 vette fuel filter/pressure regulator that provides a fuel line in with a return line back to the tank, and the other end has the fuel feed line. (so its two lines in, one out) I assume this will work, but have to check the fuel pressure out to see if it will work with the NA motor. I still have to do some reading on the harness/ECM setup, and look at a few wire diagrams to figure out how im going to wire up the harness, as I was removing the wires, it seemed to me that in the end, its still just about 15-20 sensors feeding into a main box that feeds into the ECM. I still have the fuze box attached to this harness, and I figure that I will be removing it or if I use it make it smaller and put it out of the way. I removed the fuze box on my 3.4 DOHC motor harness, and it was just a matter of finding the function on the Fiero fuze box and routing the wires to it. One last question, from the above post from Dennis, I see I will need a 2003 GP GTP ECM, but will any 2003 ECM work with a reflash/recode from Ryan? I can find a 2003 ECM, but just don't think i'll find one from that exact car. Will any 2003 3800 NA work? Thanks agian guys, I will continue to update this thread with new questions as I get them. And again, pictures soon. Rob

The aluminum mount that is by the coolant temp sensor usually becomes the dogbone mount for Fiero swaps.

If the Corvette fuel pressure regulator doesn't work, a 99-04 Jeep Grand Cherokee filter/regulator provides 49.2 (+/- 5) PSI, which is what the supercharged 3800 requires.

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My project: 3800 Series III Supercharged + F40 6-speed into an 87 GT. Wish me luck!

So I went back to the yard today to get a few more things. Picked up a 2002 SII cable TB with mini pigtail harness. I see that ZZPerf makes a $99 adaptor to mate up the SII TB to a SIII intake. I guess i'll be getting one of those.

I also see that Dennis used a N* TB and a LS1 MAF. On this NA motor, is there any benefit to going with the larger TB/MAF combo or sticking with the SII TB?

I also picked up a oil filter bracket off a Gen 4 Camaro w/ 3800 and i see now that it wont work. It interfers with the axle stub, so I guess that one will go back. I took a chance on it with out doing enough reading on which one I need.

Good to know that any 2003 SII ECM will work, (i hope) because I think I'll have a better chance finding any old 2003 model in the yard than a specific car.

Ill contact him to find out before I pull anything this time.

Thanks again for all who have posted.

Rob

Send me a link to the adapter. I know this local guy with a mill and lathe and I doubt he would charge $99 to make a flat plate with a few bolts.

https://www.fiero.nl/forum/Forum2/HTML/116948.html

Much appreciated. Sure I could whip out something for that if I had the two pieces in front of me.

quote Originally posted by AlanD: Much appreciated. Sure I could whip out something for that if I had the two pieces in front of me.

What you think Al? I'm not in a hurry, I can provide you with a template that has both sides of the SIII intake/SII TB. I just don't have access to the equipment like you do. :-)

Rob

quote Originally posted by qwikgta: So I went back to the yard today to get a few more things. Picked up a 2002 SII cable TB with mini pigtail harness. I see that ZZPerf makes a $99 adaptor to mate up the SII TB to a SIII intake. I guess i'll be getting one of those. I also see that Dennis used a N* TB and a LS1 MAF. On this NA motor, is there any benefit to going with the larger TB/MAF combo or sticking with the SII TB? I also picked up a oil filter bracket off a Gen 4 Camaro w/ 3800 and i see now that it wont work. It interfers with the axle stub, so I guess that one will go back. I took a chance on it with out doing enough reading on which one I need. Good to know that any 2003 SII ECM will work, (i hope) because I think I'll have a better chance finding any old 2003 model in the yard than a specific car. Ill contact him to find out before I pull anything this time. Thanks again for all who have posted. Rob

N* TB and LS1 MAF sensor is for more air flow, better throttle response and allows room for future mods. Be prepard for some reprogramming/tuning if you go this route. The starting point is the importation of the LS1 MAF sensor table values into the program.
The 2003 NA and SC PCM's are identical except for the program.
The reason that you use the 03 PCM is that its the only series II computer that will shift the 04-up 4T65eHD transmissions.
The standard Grand Prix 3800 oil filter adapter works fine.
I used an 03 harness and the 03 fuse box. Unorthodox approach but higher current is now available to the injectors and far less wiring changes as fan, fuel pump, & A/C relays are already wired in. Hook up power. ground and a few other connections and the engine runs. The later 3800 harnesses might work but more wiring changes would be required.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner 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 "

quote Originally posted by qwikgta: What you think Al? I'm not in a hurry, I can provide you with a template that has both sides of the SIII intake/SII TB. I just don't have access to the equipment like you do. :-) Rob

Shouldn't be an issue. Looks simple. I have everything from 3/16" to 1" plate here so should be easy. I'm headed to Djibouti to check out a craft tomorrow but can catch up when I'm back in a few weeks.
Al

Dennis,
Thanks for the info. Fully understand about the N*/LS MAF. I was asking to see if using it with the NA motor was overkill. I also noticed that the SII TB is smaller than the SIII, so my thought was that the N* would not restrict air flow. Finally understand now why the 2003 year is needed. I did not know that the 2003 SII would work the SIII trans. You stated the the SII ECM will shift the 4t65eHD, but since this is a N/A motor, I have the 4t65e trans right? the HD was only in the SC motors?

So it sounds like I want to go the 2003 SII route and I'll be on the look out for the 2003 combo. (Edit - a 2003 GP just made it to my local PnP) I pulled the fuze box with the 04 when I pulled it, and I assumed that when making the harness up, that the fuze box would get elliminated. ( it did when I built my 3.4 DOHC harness).

Do you think its possible to use the 04 harness, remove the pins from the ECM connector and then find the correct pin on the SII ECM connector and install the wire. I plan to remove each wire and create the harness like GURU did so that each wire is routed correctly and is either cut short or lengthened to reach the ECM. I don't plan to move the battery up front on this car, and I plan to put the ECM in the stock Fiero location. You think this is wise, or just toss the 04 harness and start with the 2003?

I was on Ryans page and found the SII 1996-2002 wire diagrams. I did not see a 2003 one. Is the 2003 wired up like the other SII motors or is it different? I am not working on the harness yet, but I was printing off stuff I will need. Not sure if its just an oversight on the years or if its that much different.

I know that when I made my 3.4 DOHC harness, I was using a 1996 motor and a 1991 harness, (OBD I to OBD II). Some of the sensor's and plugs from the 91 harness did not fit into the 96 sensors, is this what you meen when you say that i'll have to "change to series II sensors".

Thanks again to all who have posted or PM'd me with information.

Rob

[This message has been edited by qwikgta (edited 08-29-2012).]

OK, so been reading all the threads I can, and this is what I have

Being an 88, I want to modify a Fiero Thermostate housing and use the heater hose attached to it for routing to my heater core
I need to block off the two heater ports, one on the intake and one on the water pump. I have read that I can use two freeze plugs w/ some JB Weld
I have moved the rear dog bone mount to the front and now have to create some type of mount for the Alt. I want to use the SIII Atl.
I have removed the EGR and plan to plug it at the intake and manifolds.
I am using the stock exhaust mani's for now, but may look at headers later, I see the they offer GP headers for about $400 bucks I will have to cut up some of the trunk but thats ok.
I am going to use the SII TB mounted to the intake with an adapter plate.
I have turned the fuel rail around so that it exits to the rear vice the front.
I will be using a new fuel pump (not sure which one yet) and using a C5 filter/pressure regulater for the returnless fuel system.
I will switch the valve covers around and have them painted (are they plastic or aluminum)
I will have the Intake cleaned and painted or powdercoated.
If I go with the stock exhaust manifolds, I will get them ceramic coated. including the crossover tube.
I may attempt to make my own motor and trans mounts.
I see that WCF has a lot of conversion parts already made up for sale, but I am going to attempt to make most of mine.
I am going to use the A/C hose off the 2004 GP and put the 88 Fiero end on it so it connects to the Fiero.
I still need to figure out the ECM/Harness.
I still need to figure out the Cruise Control, but I think I need to get one off a SII 3800, and wire it up.

I found a 2003 GP in the yard, but it had a 3100 V6 so I didn't take the ECM/Harness. Will the 2003 GP w/ 3100 motor work the 2004 GP 3800 motor. I know I need to get a 2003 GP one to shift the trans, but will the 3100 work?

Is it possible to use the 2004 harness off the GP, just stip off wire loom, and then take each individual wire out and re-pin the wires into a 1997-2002 ECM bracket. Then instll the bracket into a 2003 ECM. ( I cut off the end of a 2002 Harness, and I was going to remove the wires, and then put each wire from the 2004 harness into the correct spot.

OK, enough for now, more later.

Rob

two threads merged into one:

any new updates here: https://www.fiero.nl/forum/Forum1/HTML/089035.html

Rob