Beretta.net

hello everyone i have a lot of questions pertaining to the 3400 swap, but i'll kinda give the background a little bit.

A bit ago i acquired a 1992 GT Beretta with the 3.1 MPFI and the Muncie 5 speed and all i had to do was get it road worthy to have it, all i needed to do was the front brakes and the trouble of tracking down a new shifter cable for the forward/backward motion on the tranny.  i put a cold air intake/k&n filter on it and when the clutch went belly up i put a stage three clutch in it and it was fun for a while but then i suddenly for no reason we can tell externally i lost compression in the driver side cylinder on the backside.

during the time i was driving the car i was looking into doing the swap and still at this time have a line on a 3400 (aparently) out of a 2003 Grand Am GT and i want to go through with the swap so i can get my car back on the road.  I have gone through the 3400swap.com guide a few times and for the most part it is straight forward but i have come up with a few questions that i wanna make sure i  have straight before i go head first into this swap.

Exhaust:  do the 3.1 MPFI exhaust manifolds bolt up? do the 3400 manifolds differ that much in the installation  and if they do how much would it potentially effect the over al performance?

3100 Belt: if the 3400 is going in the car why is it you would use the 3100 belt? i know you use the main drive belt of the crank of the 3100 but it seems to be mostly identical, and in that case do you need to change that pulley?

Fuel rails: this is one of the more important questions i have, i planned on getting the WOT-tech pre burned chip for the 3400 swap for my car so that the computer will run the engine better, and i figured that since i was going to do that y not use the lager fuel injectors but what bothered me was the splicing.  is it really that hard? do the wires match up that easily? should i do it at the rail wiring harness connector or do it on the injector ends? what type of connection will be the strongest and best shielded for the splicing (butt connectors, soldering, heat shrink wraps with the soldering band in them)?

Coolant gauge sensor:  this was on page 14 of the guide and honestly its my other big concern seeing as it is the other big issue in the swap and i really have no interpretation for it and how to handle it, suggestions are really appreciated on this one.

Egr: do I need to find an adapter? Delete it? Suggestions?

and thats really my highlight points i would like help with, any answers and help will be much appreciated, thank you in advance for any help. 

The only one I can help you with is the exhaust. Yes, the 3.1 "log style" manifold do bolt up but are horribly restrictive, and would make you lose a decent amount of potential power. I don't know how much, but it may be noticeable. Wot-Tech.com makes headers for our cars if you're interested. I think that there is a "header" style manifold from 3100 equipped cars that may be far less restrictive but you would need a custom downpipe to make that work. I'm not sure what cars they come in so someone will have to fill in on that.

Actually, one more, EGR. WOT-tech accessories

Look here, there is a delete kit and an EGR adapter. you can go either way, delete it or have yours work, but if you DO delete it, you'll have to have your chip adjusted to not get a CEL light.

Thanks wanko, ya i am kinda on a budget for the time being and headers are a little high up there on the want but can't afford, lol.

i guess what i really wonder is, is it a smart thing to delete the egr even if i chip it? or does the original egr on the 3100 bolt up to the 03 3400?

You will need some accessories, etc. from a 3100-powered Beretta in order to do the swap as well as relocate your coil packs, etc. too. I'll bet that is the reason for the 3100 belt.

Splicing the injectors isn't that hard. Get plain metal butt connectors and solder them and then heat shrink.

Even though the 3.1 log manifolds bolt to the 3400, i WOULD NOT use them. The 3400 head uses a "D" shaped port and the log ports are round. Even though the round part of the "D" matches the upper part of the round port, the squared part of the "D" port will make the exhaust "hit" the exhaust manifold and, i would think, make flow even worse. Hell, i bet you wouldn't even get them to seal.

3400 swap guide should have listed cars that have an appropriate downpipe that will work with the Beretta.

There was a 3500 that dynoed with a 3400 tune, running on 2.8 log manifolds and still put down OVER 200whp. With that being said, 3.1 manifolds wouldn't be the end of the world, especially if you massaged the ports to match the cylinder heads better. Using the 3400 manifolds you need to get a different downpipe or have one made. -> If you go that route you'll need to find a downpipe flange, and I think that 2.5" pipe 2 bolt flange with appropriate bolt spacing would work well. Those are available on the cheap.

3100 Beretta/Corsica stuff you're going to need - throttle cable, power brake booster vacuum line, power steering pump, and the engine to body fuel lines really help a lot too.

On the injector stuff - cutting and splicing is truly the only way to go if you want to use the multec-2 injectors. When I did mine I busted out the soldering iron and just sat down and did it. I hate wiring, but its really not bad. If you're going to use multec2 injectors, you must use the 55psi fuel pressure regulator - which to me means just go buy the newest 3400 you can find. Anything from 2003-2005 would be ideal, with lowest mileage and newness taking precedence. If you do that, you just leave the injectors, fuel rails and fpr on the engine. Here is where the 3100 fuel lines come in handy, they thread right into the 3400 rails and the line routing is much preferred to what will come on your 3400.

The belt stuff is all engine dependent. My routing is set up like a 3.1 would have had. I used a 67.5" belt which would be a K060675 Gates number. Also don't forget the new upper radiator hose you'll need - I used a Gates 21991 which is the Montana lower hose. Any parts counter guy with at least 1 arm and 8th grade intelligence should be able to cross reference those numbers.