Turbocharging the 2.8 (Page 1/4)
Junkbox12 MAY 09, 11:06 PM
Hey guys, I'm picking up my old project with my 85 gt that has a 2.8 bored to a 3.1. I have a t3/t4 turbocharger and most of the necessary components however I am looking for some advice. I plan on pushing around 10 psi of boost with the stock fuel regulator but I have an aftermarket regulator that I was considering using on the return line to help with the boost pushing back on the fuel lines. Besides this I also have the Ford 25lbs injectors as well as the 17lbs injectors from the fiero store.

I am trying to figure out the best and most simple configuration for the fuel to work with the boost.

Does anyone have any thoughts on the regulators or which injectors would be best?
Thanks in advance.

[This message has been edited by Junkbox12 (edited 05-09-2017).]

shemdogg MAY 09, 11:25 PM
Sounds cool throw up some pics! Id go with an adjustable regulator and try the 17lb injectors first till u get it dialed in. No ford parts on a cheby meng!

shem
Synthesis MAY 10, 10:18 AM
Before anyone comes in here and says "Why? V8 r better!" or "Why not 3800SC?", just do what you want to do, and photo document the journey for us.
Junkbox12 MAY 10, 11:23 AM
Thanks for the replies, I did more research and found that others were experiencing too much fuel with the 19lbs injectors so the 17lbs seem to be the right fit for the moment along with the adjustable fuel pressure regulator on the return line so I think I'll take your advice there shem.

Truth be told I already have a pretty clean 86 gt with the 3800sc conversion but this project I'm on now is the fiero I had since high school and I happened to come across a full turbo kit for rather cheap so I figured it would be fun to do. Lol

I will post some pictures but keep in mind that this is a limited budget build and will be as simple as possible (so it probably won't look fantastic lol)

BTW the Ford injectors i have are 19lbs instead of 25 like I thought, so I have access to the 15, 17, and 19 injectors.

[This message has been edited by Junkbox12 (edited 05-10-2017).]

pmbrunelle MAY 10, 07:55 PM
The stock regulator already has a manifold pressure reference line; it's already set up from the factory to balance each psi of boost pressure with one psi of additional fuel pressure.

So I would just keep the stock regulator; one less adjustment to mess around with (and potentially screw up).

I would use the biggest injectors among your set. The tune should be reducing the pulse widths to avoid over-fueling at low loads.

If 15 lb/hr was good enough for a 140 hp engine, 17 lb/hr isn't much of a step up... With a turbo, you'll be flowing more air, but if you can't deliver more fuel to match the increased airflow, then you won't gain power.

I'm currently in the midst of a turbo Fiero engine project!
hnthomps MAY 10, 08:09 PM
I had a turbo 2.8 engine in a car when I purchased it. The engine had around 60 k miles on it and was rapidly failing with around a 7 psi boost. I took a quick look when the engine was pulled for a 3800 SC swap and the bearings were shot. Oiling on the 2.8 is not so good. That being said, I do also have a turbo 3.4 (push rod type) that is doing rather well. I have had a turbo failure but that is all. BTW, I used 19# Ford injectors in this engine and it ran way rich prior to custom reprograming of the ECU. Do not be surprised if your project runs rather rich at first.

Nelson
Dennis LaGrua MAY 12, 10:54 AM
If you turbo the 2.8L the reprogramming of the timing tables for boost and vacuum in the ECM prom and the use of a 2 BAR MAP sensor is mandatory. A knock sensor is also recommended but you will need the 85 Fiero V6 ECM, an ESC module and a knock sensor. There is a switch in the 85 V6 program for turning on the knock sensor. You might be able to get close on the fueling with injector and fuel pressure adjustments but spark timing is very critical. With boost, excessive advance that you will get in the stock V6 timing table program will blow the engine up in a short while.
If you do the job right, the increase in performance will be significant.

------------------
" 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 "

jjd2296 SEP 21, 02:06 PM
I know this post is a few years old but i do have a question. I will be boosting (SC to be exact) my 3.4 PR build. I have done a tone of work to this engine (well not really all me) to get it to around 185-190hp (estimate) which puts me at the limit for the 17lb injectors before SC.

Im going with 8lbs of boost so that should mean that I need 28lb injectors so that I have some room to play with.
jjd2296 SEP 21, 02:07 PM

quote
Originally posted by hnthomps:

I had a turbo 2.8 engine in a car when I purchased it. The engine had around 60 k miles on it and was rapidly failing with around a 7 psi boost. I took a quick look when the engine was pulled for a 3800 SC swap and the bearings were shot. Oiling on the 2.8 is not so good. That being said, I do also have a turbo 3.4 (push rod type) that is doing rather well. I have had a turbo failure but that is all. BTW, I used 19# Ford injectors in this engine and it ran way rich prior to custom reprograming of the ECU. Do not be surprised if your project runs rather rich at first.

Nelson



how much boost you running on that 3.4? i take it all you did was swap the block no other performance work?
Dennis LaGrua SEP 21, 07:48 PM

quote
Originally posted by jjd2296:


how much boost you running on that 3.4? i take it all you did was swap the block no other performance work?



If you run Ross Forged pistons they can handle high boost like 10-12 psi but you will still be limited by the rods. I've run constant 12 psi boost in my 3.4L P/R engine, with a turbo program 2 bar map, knock sensor and an adjustable FP regulator and all has run fine. I also use the Bosch 69225 fuel pump that can supply even a V8's needs.

------------------
" 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, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, 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 "