3400 performance build, which direction?

[Bridgetown]

Well, I have got my 3400 fiero running pretty darn good now. It is pretty much stock, but it dynoed a solid 178 whp, which is great... for now. My plan has always been to get the setup running good, work out all the bugs over time, and in the mean time build a full out performance engine and when it is complete swap out the stock 3400 for a meaner version. I am looking for advice/opinions on how to build the performance engine. I am in the research stage now, and have aquired some new parts for the build (LX5 tb, poly engine mounts). My problem is that I keep going back and forth between going forced induction, or high compression/high rev NA. What I am looking for in the end is a reliable +/-300 crank horsepower engine. This is going in a sports car, I do short trips, occational road/autocross racing, but mostly Sunday blasts on good roads in the summer. So, keeping this in mind, I don't want a lumpy, drag racing engine that only runs good under wot. Or an engine with 2 weeks of turbo lag. I am planning on spending some descent coin on quality parts to acheive my goal. So let me hear what you guys can come up with.

[mickaz]

then my friend, I suggest a 3500 hybrid a bigger throttle body, and if its not enough a cam And A TUNE!

[Bridgetown]

So, wouldn't, for the work, it be easier to just swap in the complete 3500 rather then a hybrid 3400/3500? Plus you would get the added displacement.

[mickaz]

yes but i said that because you already had all the bugs fixed and i was not sure you were interrested in buying naother engine. the job needed for a car that got a 3400 is very simple, like doing a head gasket but a 3500 would mean having to remove your allready good engine to put the other .

another point, 300 hp NA will give you a somewhat less interesting engine for everyday. a turbo is going to be your best bet.

[Bridgetown]

another point, 300 hp NA will give you a somewhat less interesting engine for everyday. a turbo is going to be your best bet.

Could you elaborate on this a bit?

[mickaz]

well there is a guy that as 300+ NA (superdave he will chime in sooner or later...) and I don't think he uses is car for everyday driving. the thing is he got a wild cam, and that,s the only way to achieve 300. with a turbo it could run like a normal car when you want and up the boost when you want more power.

[Superdave]

"redbird" has a 3500 swapped 5 speed Sunbird that's making right around 300 @ the crank. He daily drives it, even through winter. It's a stock bottom end, .506 lift cam and a ported top end with a good exhaust and intake setup.

Mine is not a daily driver however i'm going to try to use it as one once it's running again.

[Bridgetown]

Well, my car is not a daily driver by any means either. But I do want good useable power, throughout the rpm range. Not just all out wot power. Is there forged internal parts available for the 3400? If I go turbo I want to make the engine as reliable as possible. I would still stay below say, 10 psi, but forged internals would be nice insurance to have. Doesn't the 3500 have forged parts? How come nobody turbos those engines?

[mickaz]

look in the section of the forum called 'Boost' they will help you with that. and it's been done. the guy who tunes asylum car as a 3500 turbo in a cavalier, but the 3400 a lot of people have boost on them.

[pocket-rocket]

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

[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..

[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

[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.

[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]

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.