My bad. The block is an iron "skirted" style block, though.

 

I think you need to revisit some of your turbo buick information...this is not correct. As you can see by this page
http://www.gnttype.org/techarea/pict...lockguide.html
the N/A blocks and the turbo blocks are the same for 3.8 motors, even the metalurgy. The turbo 3.8 pistons were cast type pistons, not even forged...they are definitely better than the LT1 or LS1 pistons, but still not what a good aftermarket forged piston will be. Turbo Buick motors operate at around 8.5:1 compression, which is much better than an LS1 for boost, but they run almost 15psi stock which we aren't going to get close to without some bottom end work on these motors. Yes, forced induction does place stress on the motor, just as ANY HP increase will do, but it places less stress on the motor than more RPM does. I stand by that statement until someone can prove otherwise.

 

I say go forced induction, because over time you'll want more power, and I feel adding a charger is easier to do than pull the heads and throw in a new cam. Big cams tend to make driving pretty crappy, although that cam/head package at thunder racing looks pretty sweet. As far as the STS turbo that thing is pretty cheap, but having a turbo hang where someone can steal it really sucks, plus if your like me with longtube headers, you might not want to sell them and go back to stock. I am also wondering how low that thing hangs, cause I go over many speedbumps and steep driveways, I'd hate to scrape on that thing.

 

the stealing the turbo thing is definitely a concern, I would fab some way to lock it in place. As far as it hanging down, it looks like its actually above the rear end, pretty much in the same spot as the muffler, and I've never scraped that so I'm not too worried. I know Rick was also working on getting an intake tube put together for guys with headers (LT's being the first to come out) so that may not be an issue either anymore.

 

it doesnt hang much lower then the muffler, as for stealing, someone suggested tack welding the bolts, then when you go to remove them you can take a die grinder to remove them.

 

What he said-----------------Cartek, they are producing some awsome dyno/track times.

 

If two engines make the same amount of power and torque with the same redline, why does the bottom end care if it's boosted or not? Torque (and thus power at a given rpm) is created by MEP; whether the engine is boosted, or just breathes well, won't change that.

I'm not talking about the ability to not detonate; rather, the ability to endure the forces in a non-detonating engine.

Is there something i'm missing?

 

im guessing a FI motor is more likely to detonate. and im sure theres more to do with increased PSI as well.

 

You gotta ask your self, do you want to rebuild that motor at some point in time? Judging by what you want, do a heads and cam set up, put in like a Walbro 340 fuel pump and spray a lil shot of gas on top.

 

If two engines of the same size make the same torque and horsepower at the same rpm, then you're right: there isn't a difference.

However, a supercharged motor will tend to make more torque (BMEP) in the midrange, which contributes to increased ring and bore wear as well as detonation.

A HC motor will make less torque than a supercharged motor, but will maintain it to a higher rpm to make about the same peak hp. So, a HC motor will have less ring and bore wear and detonation will be far less likely. A supercharged motor, however, will make it's hp at a lower rpm, thus reducing inertial stresses on the crank, rods, and bearings, but increasing stresses due to high cylinder pressure such as rod compression, main bolt tension, main cap bending, etc. . .

So, in normal operation, bottom-end stresses may be a wash, but would take some finite element analysis to know for sure. The detonation issue, though, is a real one. Once detonation begins, all bets are off on the bottom end, pistons, and rings.

Two weeks ago, I ran my supercharged car for 4 full-throttle pulls and registered less than 2 degrees knock retard. In other words, the tune was safe. Last Saturday night, I broke a piston due to detonation and still can't figure out exactly why.

Not to mention, it is a total pain in the @ss to work on a supercharged motor.

Mike

 

I think I'd wait till I actually had the thing for a couple months before I started to recommend it to anyone.