89 beretta gtu 2.8-3.1 swap with upgrades

[Danhoff11]

yo everybody i have a 89 beretta gtu with a junk 2.8 in it. i recently bought an 88 with a 3.1 in it ( i came to the conclusion that the 88 cars motor is a mystery motor) anyway, i am going to be putting a cam, and bigger throttle body in it. if anybody would like to tell me some problems i might have before i start this would be great! thanks glad to be aboard 60v6!

[1988GTU]

The 2.8 to 3.1 MPFI swap is basically like swapping in another 2.8. There are subtle changes, but since you have the blown 2.8 for parts, everything should be swappable using common sense. Like coolant hose/tube routing, PCV tube location, mounts (if the 88 is not a beretta) . Also note that that 88 didn't come stock with a 3.1.


Most will say to 3x00 swap it, but if you're not that mechanically inclined, just do the 2.8 to 3.1 swap and then later if you want to take the plunge, you will have a base idea how things are setup in these cars.

Don't expect hp gains to be noticeable with anything you do for the 3.1/2.8 engines. If you want power you will need to go boosted or swap to a 3x00 engine.

[MY91GT(Z)]

couldnt said it any better and in most cases the 3x00 will get better mpg too

[kflo 93 gt]

Hopefully that 88 really has a 3.1 and not some previous owner who put a 3.1 plenum on the 2.8.

[1988GTU]

Yea check to make sure the PCV tube routed correctly. If there is a nipple covering a port on the LIM or bottom side of the plenum, then it's most likely a 2.8 with 3.1 UIM.

[danhoff1111]

this is danhoff11 i lost my password and the site kept running me in circles. anyway, the motor is a 3.1 im having the block with pistons and crank set out to be honed ect. i know im only getting a 15+ max hp gain with this swap, but i do hope to find a good chip to help with that (suggestions please!) and a mild cam (nothing major so i can run stock injectors and still have smooth idle) a 3x00 motor is to much fab'ing for me ecu swaps, i just wanted a reletively easy swap. before i buy a cam, whats my options, i looked at comp cams and somewhere else, and saw some that were stock compatable but yea. what motor can i steal a larger TB off to put on? yea that about all igot for now, if anybody needs any parts off an 88 beretta let me know, i also have a spare 5sp. if anybody is interested! thanks

[montess408]

you can look at crane cams or crower cams they have some choices too and as for injectors i was told ones to take some off a 3.3 buick motor as they are a little bigger not sure on a throttle body tho

[XLR8ING]

Don't go with bigger injectors unless you've programmed for it. Your computer will still open the injectors for the same amount of time as the smaller ones, and you'll just waste fuel, and wreck your spark plugs, O2 sensor and eventually your cat.
On a 2.8/3.1 you don't need bigger injectors until you get over 180-200 hp approx.

There's no stock throttle body that's bigger and will easily bolt on.

Good luck!

[danhoff1111]

well thats lame heres a pic of the beauty i call my retta. it has different rims on it now, dont have a pic but yea.

[danhoff1111]

well im sure somebody has done this exact rebuiild before, whats my roundabout hp going to come up to? i know my 3.1 on a cold, dry day will get 135-140??? with cam and superchip (still no desicions on that yet) what will i be around any guestamations?

[danhoff1111]

ok, ill stop forgetting stuff to ask right now, what year lower plenum can i use on mine? ive read about it but if you guys can just tell me the best way to go about doing it it would be greeeaat ok im done now

[XLR8ING]

On the Gen II 2.8 and 3.1 you can use any FWD 2.8/3.1MPFI intake manifolds from 1987 to 1993 or 1994 (depends on the car you get it from). You just have to use the matching upper and lower intakes. There's no real advantage to any of them though. Their basic designs are all the same.
A cam is a good start, and I'm guessing good for 10-15hp. You'll also notice a change in what rpm the power comes on. With these engines, you don't want a cam that will shift the power band too high in the rpm range because your exhaust and intake manifolds will start being too restrictive for that kind of flow over 5000 rpm.

[Superdave]

the crane H260-2 cam is a great upgrade to a 3.1.

as for Superchips.. stay far away from them, fastchips, Hypertech etc.. after adding a cam your best option is to have it tuned by someone or buy a performance chip from someone who actually knows what they're doing. www.wot-tech.com

[danhoff1111]

superchips wasent really my choice. i more or less used it as a "desciption" as a ecu upgrade. but i sent the block out, like i said with crank, and pistions in it still, the shop is going to get a cam for me? not sure if theyve done it yet but we made sure to tell them i wanted one. i looked at wot-tech's selection of chips but they really dont give a hp boost, i know it prolly varies on app but id like to know a base ammnt. im still curious to see what this motor will get (hp) after completion im SURE someone has done this rebuild lol but hey ill keep you all posted, and give more pics when the block returns.

[kflo 93 gt]

Make sure you see the actual box and everything the cam came in. Otherwise I've got $10 saying they'll put a Melling cam in it and charge you for the one you want. Melling offers an extra torque cam or something, and it works with the stock ecm. I used to upsell people at parts stores that had to buy 3.1 fwd cams. It happened twice, both times the guys were happy that I sold them on a more powerful cam. But it still isn't as good as the Crane that Dave listed.

How are you going to know otherwise? Make sure you get to see the box.