3400 top swap with bigger injectors????

[BerettaZ26]

hello everybody,
I've got a 94 Beretta Z26 with the 3100 V6, my question is I've heard a lot about the 3400 top swap with bigger injectors and was wondering how much HP would I gain and is it really worth it, I've already done the normal CAI upgrade to it with a 160 degree thermostat and I was also wanting to put a 59mm throttle body on it from a 3400 but like I said how much HP would I get from the top swap, injectors and the TB?
Just somebody let me know
Thanx.

[88corsica5spd28]

Use the stock thermostat. There's a sticky on that subject.

As far as numbers for the top swap, i have no idea. But you'll notice the difference.

[BerettaZ26]

The reason I put the 160 in it was a while back I had a 93 Corsica with a 3.1 MPFI and when I put a hypertech chip in it, it called for a 160 and I figured that it would need it when I put a programmer or chip in this 94 3100 SFI, so what harm would it do to keep the 160 in it?

[3400-95-Modified]

Currently the 160 actually prevents the engine from getting to appropriate operating temperature... The lowest thermostat you should use is a 180 from a Cavalier, that's all that I'm running.

Regarding the top end swap, you can pick up anywhere between 15-20hp going from small port 3100 to large port 3400. I dyno'd my car once and stock 3100 I was 127whp and then with a 3400 I got 145whp, and the .3 displacement between the 3100 and 3400 block did not account for that power difference... You see the most gains because the small port setup is choking the engine quite a bit so you could see similar gains by just doing the top end.

[SappySE107]

160 is not an upgrade. If you are racing, then it can be useful but on the street, no way. Increased cylinder wall wear, decreased oil chain intervals, no hp gain. Tunercat is the only way to tune a 94 computer and its just fan turn on time to match your thermostat. Bunch of marketing bullshit pretty much.

Large port swap should be worth roughly 15 hp at the crank. We found our port work added 8 whp on a 3400, which already has the large port manifolds. 65mm TB added 2 hp so a 59 isn't going to do much of anything. The increased throttle response feels a lot better though with a larger throttle body.

If you go with larger injectors, a tune will be necessary.

[BerettaZ26]

So I need to put my stock thermostat back in?, where would I go and about how much would they charge for a tune to run bigger injectors????

[3400-95-Modified]

Well I preface my statement with larger injectors wont help you much unless your maxing them out, which I know you are not, and you may not even max out the 3100 ones with the 3400 top end. Secondly... With it being a 94 Beretta your only option is http://beretta.net/forum/viewtopic.php?f=9&t=10294 I highly doubt any shops have this and can tune the car for you but I could be wrong, you'd have to call around and ask. This car has a very limited performance market and many shops that do tuning don't have the utilities to support this make/model so you are typically on your own.

[BerettaZ26]

correct me if I'm wrong but didn't the Grand Am's come with the 3400? My question is If I can get my hands on a Grand Am with a H.O. V6 or Ram Air V6 would these intakes be better than one from a base 3400?

[SappySE107]

Same manifolds.

http://www.wot-tech.com/index.php?page=small-port-vs-large-port-3100-manifolds

http://www.wot-tech.com/index.php?page=choosing-3100-3400-manifolds

http://www.wot-tech.com/index.php?page=94-99-3100-large-port-swap

[Superdave]

Bigger injectors aren't needed in your case. Your stock ones will support the power you'll be making.


As already stated you have limited to no tuning ability, knowing that you can go a couple ways.

One would be to piggyback a tuneable ECU with your current one, which is a bunch of wiring and headaches but it's been done quite a few times. OBD1 1227730 ECM's work for this as well as aftermarket like the Megasquirt. I've seen it in person and tuned a '7730 in a '97 Sunfire with a 3500 V6 that had a 4cyl. It works pretty good.

The other option is rather old school and inaccurate but it works too. You can buy an adjustable fuel pressure regulator and first set it to the stock fuel pressure (43 PSI) then slightly increase it to get the tune dialed in.

Not sure if you can datalog your '94 ECM or not, if so that will be very important.



I would swap on the 3400 heads and lower intake, then use a 3500 upper intake with a TB adapter and a 56mm TB. You will definitely feel a kick in the pants from that. Should be worth an easy 20 HP, maybe more.


Yes, ditch the 160 thermostat. put in a stock one if that's what the fan temps are set to turn on at.

[3400-95-Modified]

As already stated you have limited to no tuning ability, knowing that you can go a couple ways.

One would be to piggyback a tuneable ECU with your current one, which is a bunch of wiring and headaches but it's been done quite a few times. OBD1 1227730 ECM's work for this as well as aftermarket like the Megasquirt. I've seen it in person and tuned a '7730 in a '97 Sunfire with a 3500 V6 that had a 4cyl. It works pretty good.

The other option is rather old school and inaccurate but it works too. You can buy an adjustable fuel pressure regulator and first set it to the stock fuel pressure (43 PSI) then slightly increase it to get the tune dialed in.

Not sure if you can datalog your '94 ECM or not, if so that will be very important.

With the new Tunercat setup he has the same ability as say a 94 Camaro so yeah he can datalog the 94 ECU as well as re-flash it like OBDII style but it's OBDI emissions standards.

It's more the fact that he's probably not going to find a shop that will have the required software, license and bins to tune since it is a very uncommon request, so he's on his own unless he can find a local enthusiast who has the equipment once again, far and few in between.

[caffeine]

But if you feel like learning it yourself, Tunercats is relatively inexpensive and all you need besides that is a cable. For a cheaper alternative you can use Tunerpro to edit the bin files and winflash to flash the pcm