Go boost if you want more than 220 HP ever.

Turbo is the way to go if you want power, but it comes with an expense.

 

Those are your ONLY 2 choices in the 1st statement is true.
Secondly, you will need a 4T65E-HD tranny, and hopefully the axles to go with it.

More HP = more breakage = beefier parts

 

well my tranny is gonna need to be rebuilt i belive the accident damaged it in some way, b/c some times it will put itself into neutral at a stop & when i goto take off it waits a second than bangs into gear, & ive found a few L67s with trannys for around 2500, with 50-60k miles on them which is what i got on my car

 

These trannies aren't the toughest things Chevy ever built anyway. Just have it rebuilt with a stronger valve body and shift kit and it should be fine.

After building a couple of engines (a 390 for my car and a 302 for another guy's '74 Ford F-100), and reading from people who know what they're talking about, I'm convinced there is only one way to build power in these cars. I've seen alot of stuff go down at the drag strip, I've talked to alot of racers who've done alot of things.

An exception to what I'm about to say may be doing a top end swap on these things since Chevrolet built a different set of heads and probably had the same crank shaft and rods in teh 3800's across the line.

But if you go supercharging the car you have now, of course, if you just put a supercharger on, you'll be blowing your flames out. You've got to have heads that can handle the extra air being forced into the engine. So you do a top end swap, but now all the power and roaming around town with that much power beats on your crank shaft, so you end up using all that power and beating your crank to death. So you get a stronger crank, and take off again. But now your rods can't handle it, so you sling a rod through the side of the block and now you've got a small fire on your hands while you sit on the side of the road.

From what I've seen, there are two ways to go in this engine building thing. You can go all out, or make small modifications. I think you should first decide how much more money you want to put in the car, and then decide from tehre how much power you can build. But make sure you build your engine so that each and every part can take the amount of horsepower you are going to be putting down!!

 

Top swap, or nitrous. A top swap + all the simple, cheap bolt ons can get you an easy 300 crank hp for $1000-2000.

This depends how much power you want. I'd suggest looking here:

http://www.clubgp.com/newforum/tm.as...mode=1&smode=1

If you look at that list, the most hardcore (and company sponsored I may add) NA car only did 247 WHP- most basic bolt on 3.4" L67s run about 230-240 WHP for comparison purposes- and that NA setup is maxed out.

Then look at the supercharged setups, they max out about 400-420 WHP on the M90.

The turbo setups max out at 600++ WHP.

IMO, I would stay NA and do basic bolt ons if you're looking for VERY minor HP improvements (ie 10-15 WHP). Then, I would go top swap or L67 swap for 40-100 WHP improvements (a stock swap would net you the lower end- the upper end would be with other mods). Too much more than that, and I really think you'd be better off considering going turbo. Its a good deal more expensive up front, but if you're looking for big power gains, its the way to go.

Really depends how much you want to spend and how much power you want to make.

Because even a stock L67 is stupid quick in a Fiero, and its a pretty common and relatively easy swap.

I disagree with this also for a top swap. A full 4t65HD swap is far from necessary for a top swap. Realistically, he can upgrade his current 4t65 to HD for fairly little money and labor by changing the diff/diff cover/ and drivers axle.

If your current tranny is bad, a compelte L67/4t65hd swap isn't a bad idea at all. However, $2500 is pretty steep- even for 60k miles. You've got to figure, you can get a complete running 97, 98 grand prix GTP with 100k miles or so for about $3000- so paying almost that much for just a powertrain is high. I wouldn't look to spend much over $1500 for a powertrain. Heck, what is salvage value for a totalled GTP? Thats how I got my swap- I bought a totalled 98 gtp for $1500 with about 70k on the car- and I got practically everything with it- and that was years ago- prices have come down a good bit since then.

There is no stronger valve body available for the 4t65's- not to mention, the valve body isnt' a major failure point anyways- its the hard parts (input shaft, etc) and the drive chain.

The heads are practically the same on all 3800s, regardless of what brand the car was sold under. The only minor difference is injector location between the L36 and L67.

As I said above, this is incorrect- the heads between the NA 3800 and supercharged 3800 are virtually identical. So he does not have to change heads. For a top swap, you must change the heads anyways to accomodate the injector location for the L67- but if you stick the same SC on with the ZZP SS kit, you use your stock heads. Regardless, they flow the same.

As I said in the other thread- none of this applies to the 3800. There is only 1 aftermarket crank currently being made, and to do that setup would probably run at least $3-5k. There is no reason to be worried about the crank or rods, I have neither seen either fail from too much power on a 3800. This isn't a SBC, so you can't really generalize all engines like this.