Want to Turbo my 3400, need help/opinions

[Niteflight]

Hello all, I'm new here. I was wondering what is the best way to prepare my engine for boost? I plan on running 9psi boost intercooled on my 3400 engine in my Impala.

What should I get done/upgrade?
I hear connecting rods should be changed, and pistons, is this true? I would rather not spend more $$ on a 3500 top swap, Id rather work with what I have now.

Any and all help is appreciated.

[bszopi]

http://60degreev6.com/showthread.php?t=24943

[Niteflight]

Thanks, do any of those companies that make forged pistons have websites? I would like to get some.

I will try to find out what cam spec would be best for my engine without any porting of the heads.

I will also get ls6 valve springs, looks like everything else is fine.

Is that all I would need, seems like it shouldn't be to hard to get it boosted.

[AaronGTR]

At only 9psi you could run that on a stock engine and trans and be fine as long as you have proper fuel upgrades and computer tuning. Shot peened rods and forged pistons would be the two points to strengthen on internals though IMO. Ported heads and a reground cam would be the next best power adders. Focus on getting a good turbo setup made first though and on getting enough fuel for it!

[Niteflight]

Will do, I will also get some bigger injectors, the car will be tuned of course.

I just really want to know if there are any online retailers I can get rods and pistons from.

[IsaacHayes]

Look at MidnightRiderZ24's specs. Different trans and ECM, but still a 3400 motor with boost. (stock internals)

Springs are a must for the heads, don't forget to get the right seats and valve seals to make it all work. I don't know the combo of those for off the top of my head, but it's been discussed here before. Pistons it's possible to run stock but for peace of mind some forged would be more tough and more forgiving if your tune is not 100% dead on. Wiseco I've heard mentioned on here does pistons.

You'll likely need a larger fuel pump.
Injectors I heard the ones from a 4.2L trailblazer fit up no problem and work with your ECM, and are 28#. Not sure if 28# will support 9psi though..

[Niteflight]

1 more question... Do the 3.1l Turbo Grand prix turbo exhaust manifolds directly bolt up to the 3400 engine?

[Superdave]

1 more question... Do the 3.1l Turbo Grand prix turbo exhaust manifolds directly bolt up to the 3400 engine?

Yes but the ports overlap the 3400's D shape at the bottom corners. I ran gen 2 manifolds on a 3400 for a few months w/o problems.

[Niteflight]

Can the manifolds be slightly ported to open it all up, or will there still be some overlap?

thanks again.

[john_V63400]

Definitely make sure ur runing the right A/F ratio and the right plugs with the MAF, and a decent computer tune.

I didnt do the above and Blew 2 engines with only 8 pounds of boost, and I was runing forged pistons, but they broke, from what Im guessing is detonation, and pre ignition.

but definitely make sure you do those above 3 things

[Niteflight]

I will be using stock 2003 LA1 MAF is that fine ?

For plugs I will be getting NGK tr55ix Iridium plugs. I will also be getting bigger injectors. Tune will be done before I drive anywhere with the turbo setup.

I assume I should invest in a wideband, or some a/f ratio gauges.

[Superdave]

Can the manifolds be slightly ported to open it all up, or will there still be some overlap?

thanks again.

you can round out the transition at the bottoms and port them open a little more.. you don't want to go too much, that cast iron can crack pretty easy if you give it a weak spot.


I have my old ones somewhere, my shed is iced over right now but if it warms up this week i'll see if i can grab a closeup of the ports.

the overlap is minimal.. it's like 2% of the total port.

[AaronGTR]

Probably don't need a bigger fuel pump yet. The stock pump has supported a lot of HP. The 28lb injectors might be enough to support 9psi. Would be hard to tell until it's running and you can scan the injector pulse width, but they'll be close and a definite improvement from the stock 22lb injectors. You can always drop the boost 1-2psi if you find you're maxing them, and then upgrade to 36lb or 42lb injectors later.

Stock MAF is fine as long as you're using it. You can add a bigger one later if going for more HP, but not necessary. A/F ratio gauge won't do you any good unless you have a wideband sensor and controller. The cheap A/F gauges just read the stock sensor and aren't accurate for tuning. A wideband isn't absolutely necessary, but can help with tuning and you can get them for $400 and under now. Hope that helps a bit.

[Niteflight]

Does anyone know if 42ib upgraded injectors that fit the 3800/3800 supercharged engines will fit on a 3400, I can possibly get some that someone had purchased for their 3800.

[AaronGTR]

Yes, the 42lb lucas injectors will fit. I'm using them. You have to change the injector plugs on the wiring harness though (from delphi to bosch style). Same if you use the 36lb injectors from the 3800SC. Keep in mind the 42's have a different spray pattern too.