I'm wanting to turbo my 2.8 v6 in my 85gt. It has a brand new rebuild done to it so I don't want to swap it out for a 3800sc as I would like to get my use out of an essentially new engine. Turbo seems like the best way to get the most performance that I can get out of the engine and while I understand that it won't be crazy difference it will at least be a little better than stock. Maybe other things to help wake up the engine a bit, dosen't have to be a turbo. So what are the best ways to go about this, kits, build threads and lists would be awesome, estimated cost would be rad to. I appreciate the help guys and once again the goal is to keep the 2.8l.

The archives here are full of threads regarding 2.8's that have been turboed or supercharged. I think it's safe to say that most people who've done it wouldn't do it again. Not much bang for the buck compared to other engine options.

The other concern would be the year of 2.8 you have. The '88 2.8 had modifications done to improve it's oil distribution/lubrication.

I have a "2.8" turbo project. My engine doesn't displace 2.8 litres, but it's essentially a stock-ish engine.
https://www.fiero.nl/forum/Forum2/HTML/142133.html

For a detailed cost breakdown, see my running tally in Canadian dollars:
https://www.fieromontreal.c...86.msg36196#msg36196
It's the cost for a semi-rebuilt turbo engine + transmission. Use google translate if required.

It may be wise to hold off on starting a big project like this now. As we head deeper into recession, the money may be better used for something else...

That said, if you happen run out of cashflow, you can simply stop buying parts for your project car. It's a better situation to be in than having a car loan with monthly payments...

[This message has been edited by pmbrunelle (edited 03-22-2020).]

quote Originally posted by Monkeybean007: I'm wanting to turbo my 2.8 v6 in my 85gt. It has a brand new rebuild done to it so I don't want to swap it out for a 3800sc as I would like to get my use out of an essentially new engine. Turbo seems like the best way to get the most performance that I can get out of the engine and while I understand that it won't be crazy difference it will at least be a little better than stock. Maybe other things to help wake up the engine a bit, dosen't have to be a turbo. So what are the best ways to go about this, kits, build threads and lists would be awesome, estimated cost would be rad to. I appreciate the help guys and once again the goal is to keep the 2.8l.

Be very conservative, 7psi tops. I don't believe any of the iron head 2.8L motors received hypereutectic pistons since they were being phased in with the aluminum head motors around 1988. The 2.8s I broke down all had old style cast pistons which were nowhere near as strong as the hypereutectics. I ended up breaking a ring land on one of the cast pistons after about 3 yrs of irregular driving use and don't recall it being associated with spark knock, or any detonation. It appeared to have just given out resulting in a considerable increase in blow-by gasses from the valve cover vent as a sign there was a problem.

If you look up a picture of the pistons, particularly one matching the part# used in your motor, you should have an idea of what you're working with. The pistons used in the iron head 2.8L have two big gaps of missing material support below the second ring land, that's where the piston broke. The hypereutectic pistons do not have that gap/window of missing ring land support.

The only hypereutectic piston failure I had was from repeat severe detonation in a 3.4L, resulting from fuel and spark control deficiencies that resulted from a ground strap accidentally being left disconnected after engine install. The engine knock was very loud and unmistakable and the damage was the result of repeatedly subjecting the motor to the condition in frustration before discovering the cause. The ring lands were intact, but the top edge of some of the pistons were chipped. The 2.8L with the broken ring land was never subjected to anything like that.

There's a world of difference between a naturally aspirated 2.8L and a boosted 2.8L and it will bear itself out in the way you drive the car as a result, making the chances pretty good that you will encounter a piston failure, especially with a manual transmission.

Not worth it just enjoy driving a mid engine car and leave it at that. 3800sc can be bought for 200-500 dollars tops with low miles still. Hell I seen some with 150,000 miles swapped into fieros with small mods and still run like a bat out of hell. Either run a f23 or f40 if going standard or a 4t65ehd for auto and you’ll have yourself a nice fun fiero. The fiero with a 2.8 4 speed or 5 speed bone stock is fun as it is imo for a fun around town cruiser. Definitely is a awesome head turner in my area of south coast mass. I haven’t seen any other except for 1 a 87-88 base coupe notch no gt’s yet like I got 😁

My first engine upgrade was to add a turbo to my 2.8L. I had it running for about a year at 5 psi of boost without problems but it was on a relatively low mileage engine. The next upgrade was an 3.4L engine replacement with Ross Forged pistons a turbo cam and a fresh rebuild with 10 psi of boost. Except for a lumpy idle that engine ran great but it was designed for boost. If your rebuild has hypereutectic or forged pistons I would say its going to work but if it has cast pistons then just keep the boost to 5 psi. That will still provide far better performance than stock. If you are concerned about knock, switch to the 85 ECM, add the knock sensor, ESC module wire it in and turn the switch on in the program for knock sensing.

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" 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 "

My route was similar to the one Dennis took, although after turboing a stock 2.8 for awhile (you get around 190 bhp) I built a 3.2 engine - the long stroke 3.1/3.4 crank with 0.040" over bore, custom cam, forged pistons and a lot of hear work (result much closer to 300 bhp @ 10 psi).

Too bad you already rebuilt the engine - the longer stroke is well worthwhile but you need to change pistons and crank to get it.