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3.9L Supercharged vvt swap
Posted: Sat Apr 14, 2012 7:10 pm
by 1990BerettaGTZ2.3L
If I ever get my hands on a 96 do you think it would be hard to attempt because they are very similar to a 3100 anyway as far as the mounting goes anyway, just take a harness off a wrecked g6 or Malibu ss let me know your two cents I think it would be sweet opening the hood and seeing the 3900 cover under there and on top of that have it supercharged and run better than a 3400,or 3500 would only dream of running
Re: 3.9L Supercharged vvt swap
Posted: Sat Apr 14, 2012 7:21 pm
by 1990BerettaGTZ2.3L
Also I'm thinking of finding a 6 speed manual out a 3800sc grand prix

Re: 3.9L Supercharged vvt swap
Posted: Sat Apr 14, 2012 9:30 pm
by LOLVTEC
Well firstly the grand prixs never came with anything but an automatic. And there is no such thing as a supercharged 3900, unless you meant 3800 or you intend to supercharge a 3900. and if you went with a 3900 Vvt it's going to be a pita because you'd have to swap the whole cars wiring harnesses and ecms in order to get the vvt to work along with everything else.
I don't believe this has been done mostly because of how involved it is, I know that most people disable the vvt. There isnt much aftermarket for the 3900 either, thus far. Especially since it was only made a short while.
Re: 3.9L Supercharged vvt swap
Posted: Sat Apr 14, 2012 10:20 pm
by 1990BerettaGTZ2.3L
LOLVTEC wrote:Well firstly the grand prixs never came with anything but an automatic. And there is no such thing as a supercharged 3900, unless you meant 3800 or you intend to supercharge a 3900. and if you went with a 3900 Vvt it's going to be a pita because you'd have to swap the whole cars wiring harnesses and ecms in order to get the vvt to work along with everything else.
I don't believe this has been done mostly because of how involved it is, I know that most people disable the vvt. There isnt much aftermarket for the 3900 either, thus far. Especially since it was only made a short while.
my mistake I thought they did of course I didn't even look it up, had a chance to buy a Malibu ss and the dealer had it advertised as a 3.9L supercharged

Oh well but i was told that they put a 6 speed in one might have been the 5.3L only I'll check in to it
Re: 3.9L Supercharged vvt swap
Posted: Sat Apr 14, 2012 11:28 pm
by 2.2H8TA
To my knowledge the 3900 was mated to a 6 speed only in G6 GTP's. They were never supercharged. Malibu SS's are all automatics.
The 5.3L V8 that came in Impala and Monte Carlo SS's were all automatics also.
I was seriously thinking about this swap myself when I found a wrecked G6 GTP online. I thought, hmm... could I stuff that in my 96 Z26 instead of the eventual 3400 swap?
Re: 3.9L Supercharged vvt swap
Posted: Sun Apr 15, 2012 9:46 am
by heavywoody
Some people have done the 6spd swap (and that transmission was only available for 2 years maybe, so there won't be many around).
Mostly Fiero guys have done the 6spd swap and from what I've heard, it wasn't worth it. I want to say the transmission was weaker in design than the Getrag, but I don't know that for certain.
Re: 3.9L Supercharged vvt swap
Posted: Sun Apr 15, 2012 10:03 am
by LOLVTEC
^Jeff at EP confirmed the same thing when I was at his shop in Atlanta a few weeks ago... said it was a shitty transmission inferior to the getrags.
Re: 3.9L Supercharged vvt swap
Posted: Sun Apr 15, 2012 10:04 pm
by 1990BerettaGTZ2.3L
LOLVTEC wrote:^Jeff at EP confirmed the same thing when I was at his shop in Atlanta a few weeks ago... said it was a shitty transmission inferior to the getrags.
well I guess I'll do it a getrag when I do it then, right now I'm in process of trying to get a 77 trans am off a friend that junks cars it needs new sheet metal but for $650 I can't go wrong
Re: 3.9L Supercharged vvt swap
Posted: Sun Apr 15, 2012 10:31 pm
by beretta
this is a silly place to ask this.. but would it be possible to use the 3900 crank shaft in a 31/3400 engine and make it a stroker ?
or is it possible to use a 3400 crank in a 3100. or a 3500 crank in 3400..
I tryed looking for a stroker kit for our engines and found some for the older 2.8 fiero engines but nothing for the newer 3x00.
what would the ups and downs be from doing something like this
Re: 3.9L Supercharged vvt swap
Posted: Tue Apr 17, 2012 9:38 am
by LOLVTEC
Nothing, fairly certain they all have the same stroke. The 2.8 is has a shorter stroke. I don't think you can do the 3900 crank into anything, think it might have the same stroke as well...
I asked Milzy about a stroker crank back in the day... said it would cost about $3000 to have one made...
Re: 3.9L Supercharged vvt swap
Posted: Tue Apr 17, 2012 11:09 am
by 3X00-Modified
the 3400 is technically already a stroker motor... its a stroked 2.8 as Cam stated...
There are no custom parts for 3x00 engines other than what WOT-Tech sells.... People need to realize that they have little to no large aftermarket, Only a small following.
Re: 3.9L Supercharged vvt swap
Posted: Tue Apr 17, 2012 6:30 pm
by Kris GTwhat?
The closest you'd come to a stroker is using the 3.6 crank in a 3500. That makes it a 3.7, with a little machine work to fit. The big 3x00 guys have been talking about it but i dont think its been done yet
Re: 3.9L Supercharged vvt swap
Posted: Wed Apr 18, 2012 8:06 am
by LOLVTEC
Hmm that's cool... It will/could still work despite being a completely different engine? What's the max overbore on a 3400? Wonder what the displacement could be after a stroker crank and max overbore?
Re: 3.9L Supercharged vvt swap
Posted: Wed Apr 18, 2012 8:10 am
by 3X00-Modified
You really don't gain that much with displacement... Just put a damn snail on it and call it a day.
Re: 3.9L Supercharged vvt swap
Posted: Wed Apr 18, 2012 10:20 am
by woody90gtz
I looked in to going the 6spd route and I dont think it is weaker than the Getrags, but from what I gather it does not shift as well and there have been some driveability issues.