3400 performance build, which direction?

[Superdave]

excuse be for being dumb but do you have the dohc 3.4 or just the ohv 3.4? cuz my 3.1 ohv w/ a cam only made 146 whp i cant image 3.1-3.4 is that much of a difference if they are both ohv

Stock 3400 5 speed swapped jbodies put down 180-200 WHP all day long depending on the dyno.

[pocket-rocket]

you should always intercool IMHO. keep that air cool..especially (like you said) cuz u have a mid engine.

I agree with Rootie. It's NEVER a bad thing to intercool a boost setup. I'm not experienced with boosting 3400's, so I'll leave the 7psi question to someone more qualified. But, FWIW, with one atmosphere (14.7psi) if you are pushing 178, you should theoretically see almost an 89 hp increase from running almost another half atmosphere of pressure (in a perfect world).

[Rootie524]

you should always intercool IMHO. keep that air cool..especially (like you said) cuz u have a mid engine.

[Bridgetown]

I've seen a 3.4 DOHC turbo (with stock internals) running ~10psi IIRC. I think he even daily drives it. I know he's on Pennocks. I know his first name was Matt, but I don't remember his last name. Think about the tight quarters in that bay along with the heat build up. He's had it going for a few years now. A turbo might be easier and less problematic than you realize. Not to mention it would be totally street friendly vs a huge cammed out monster performance rebuild on a NA car. The consensus is the more you push something NA, the less streetable it gets from what I've read in my years of messing with cars. Don't take this the wrong way, but I don't think you realize how strong stock internals really are in these engines. There's been a number of people going 10+ psi on stock engines, not to mention look how long they last completely stock. I bet a well cared for and maintained 3400 would last over 300k miles, which in itself is a testament to it's strength. GM didn't want these engines to be complete crap because of how many vehicles they went in. That would be a huge repair bill for them if they failed early in life, so they built them well.

Is intercooling necessary if I am staying under 10 psi? What kind of power can I expect by adding say, 7 psi to a completely stock 3400?

[Bridgetown]

There is probabley a couple more hp left in the motor too with some tunning. When I did that dyno run my engine was running off a stock tune for an '95 iron head 3.4. I have since upgraded to the 7730 with the 3400 tune from WOT tech. I haven't dynoed since changing the computer.

[Rootie524]

yeah but 3.1-3.4..its not much. but if that accounts for most of that HP difference i can't wait to drop my built 3.4 block in.

[pocket-rocket]

There are other factors too. Displacement, and it's possible his could be a factory freak too.

[Rootie524]

then i guess the power difference is because of the 5spd like pocket-rocket said. when people said a 5spd would be night and day..i didnt know it would be THAT night and day. damn

[Bridgetown]

Yes, been talked about MANY times, no one has gone through with it.

For a real nice setup,

* 3400 block
* 2.8 crank
* Custom pistons to work with the 3400 bore and 2.8 crank (high compression here would be good too. Lower velocity with short stroke means more resistance to pre-ignition)
* Healthy cam (to bleed off some compression and make power too)
* 3500 top end for maximum breathing
* Headers

That would be a high revving powerful small displacement motor.

What about something like this? Has anyone done this setup yet, or anything similar, I think this could suit my needs quite well.
Discussion here http://60degreev6.com/forum/showthre...highlight=3000
Where might one get these mystery pistons?

[Bridgetown]

excuse be for being dumb but do you have the dohc 3.4 or just the ohv 3.4? cuz my 3.1 ohv w/ a cam only made 146 whp i cant image 3.1-3.4 is that much of a difference if they are both ohv

I have 2002 3400 froma grandam gt. I have a FWD 5 speed getrag trans. no ac, no power steering, 2.5" exhaust witha spintek muffler, dry cone filter and a "ram air" intake.

[pocket-rocket]

I've seen a 3.4 DOHC turbo (with stock internals) running ~10psi IIRC. I think he even daily drives it. I know he's on Pennocks. I know his first name was Matt, but I don't remember his last name. Think about the tight quarters in that bay along with the heat build up. He's had it going for a few years now. A turbo might be easier and less problematic than you realize. Not to mention it would be totally street friendly vs a huge cammed out monster performance rebuild on a NA car. The consensus is the more you push something NA, the less streetable it gets from what I've read in my years of messing with cars. Don't take this the wrong way, but I don't think you realize how strong stock internals really are in these engines. There's been a number of people going 10+ psi on stock engines, not to mention look how long they last completely stock. I bet a well cared for and maintained 3400 would last over 300k miles, which in itself is a testament to it's strength. GM didn't want these engines to be complete crap because of how many vehicles they went in. That would be a huge repair bill for them if they failed early in life, so they built them well.

[Bridgetown]

There are a couple things holding me back from going boost on the 3400. First, I don't want to add boost on the stock internals and just cross my fingers, which means tearing down an engine. Which would be as much work as going with a hybrid NA setup. Secondly, being that my car is mid-engined, it already runs a hotter engine bay then a front-engined car. So, I would need to spend some time/money engineering solutions so I don't have any issues with heat. Lastly, the turbo plumbing is tricky and will likely cost more then a fwd car would. I think a turbo setup will end up being the most expensive and least reliable of my three options (Hybrid, 3500 swap, turbo 3400). I think that I will stay NA, at least on this car. Now I just need to weigh the pros and cons of a hybrid or going with a complete 3500. Thanks to everyone for the advice so far.

[pocket-rocket]

He's probably also running a manual transmission. Manuals don't have as much drive-train loss when it comes to WHP. Reason being is direct driven gears and direct driven clutch vs the fluid coupling between the engine and transmission. Then you have the pump being driven off of that to supply fluid pressure to everything. Modern day automatics are more efficient than the ones from back in the day due to technology though.

[Rootie524]

excuse be for being dumb but do you have the dohc 3.4 or just the ohv 3.4? cuz my 3.1 ohv w/ a cam only made 146 whp i cant image 3.1-3.4 is that much of a difference if they are both ohv

[Superdave]

I think a few people are trying to find the limit of the NA 3500 before going with boost as well.

With any luck we'll know this year..