Increased displacement vs. forced induction

[Edmond]

Can you guys give me the benefits and downfalls of each?

Which is safer?

Cheaper?

More efficient?

Easier to do?

Given the choice, which would you do?

 

[klb76]

The idea of turbos and whatnot sounds very attractive and "cool" but I have heard it too many times that "there is no replacement for displacement" so my vote goes for bore + stroke. Although I really don't know the benefits and downfalls of each.

klb

 

[Mako]

If your technically inclined and have the time and money to invest into learning how to care and feed for a forced induction motor, I promise you won't be dissapointed.

Otherwise, stick with the simplicity of a naturally aspirated motor. In both cases More Cubes are better.

My Vette has a NA 383 (390RWHP) and my Z28 has a SC 383 (510RWHP).

Both are a total blast to drive.

CYa!
Mako

 

[Evolution1980]

In my completely novice opinion...

Safer? That's relative. Safer in what regards?

Cheaper? Nitrous (you didn't list it). Supercharger gets 2nd place.

More Efficient? Bore & Stroke

Easier to do? Supercharge

I think it's all about effieciency. But it could probably be argued in many ways. I myself would tend to modify the engine first (stroke it to 383, change the heads & cam), then once the normally aspirated ("NA") is maxed out as far as safe tolerances, then I'd go to a supercharger.

If you are just looking for some quick go-fast juice, throw a nitrous system on it. The downsides to NOS is that it can get expensive if you have a thing for keeping the juice on, as well as improperly done can do irreversable damage to your engine and do it fast at that! But if you get a moderate progressive system (say 100hp or less), that may be enough for you if it's only an occasional yearning... "Progressive" means that it doesn't just open up the tanks full blast. It increases the NO2 shot along with the needs of the engine, which I believe is better and safer for you, your car, and your wallet.

 

[Edmond]

I ruled nitrous out because it just seems to dangerous for me. I don't like the idea of having more explosive materials on board.

From the reading that I've done, a supercharger can be put on yourself at home in about 8-10 hours with the basic tools right?

When I said safer, I meant in regards to the safety of the whole auto. Which one will cut my auto life shorter barring an accident.

 

[BigRed]

IMHO

No one is happy with what they got LOL :L

Turbo's are not my cup of tea

Superchargers are wonderful however your going to hurt the motor because we did not upgrade our bottom end for the increased power/torque.

Bore and stroke => Step 1 then supercharge LOL :L

 

[Edmond]

If your technically inclined and have the time and money to invest into learning how to care and feed for a forced induction motor, I promise you won't be dissapointed.

Otherwise, stick with the simplicity of a naturally aspirated motor. In both cases More Cubes are better.

My Vette has a NA 383 (390RWHP) and my Z28 has a SC 383 (510RWHP).

Both are a total blast to drive.

CYa!
Mako

That Z28 is street legal right? How does that drive in the street? All that power must be very difficult to put down on the pavement cleanly.

 

[Mako]

That Z28 is street legal right? How does that drive in the street? All that power must be very difficult to put down on the pavement cleanly.

Yep it is. Drives like any other Camaro pretty much, until your right foot gets all itchy, than it's yeeeehaaaaw time I am running the stock shocks with stock rear springs, what are called 1LE front springs and 1LE sway bars and subframe connectors. This is a pretty mild street friendly combo.

The 1LE Camaro was the tire and suspension package for racer boys direct from Chevy, kinda like a Z06 without the hot bullet under the hood.

The tires are way over matched (17x275 SZ-50's), it's almost like driving a Zamboni above 4000RPM - the rear end justs floats around It's a wonderful "problem" to have I promise you.

The Vette blows the tires away as well, but being a 100HP down, it's just not as enthusiastic about it compared to the Z28.

CYa!
Mako

 

[dry sump]

bullet proof

You've got to start at the bottom. Steel crank, rods, etc. Then you can add the juice on top. Remember "there's no replacement for displacement".

 

[Vettelt193]

The old theory is there is no replacement for displacement.... but, with the new engines today, with every part fabricated to closer tolerances than ever before, supercharging is usually perfectly safe.
In the good ole days, it wasn't nearly as safe (as far as longevity is concerned) to supercharge or turbocharge an engine... most people still think back to those days really...

The only place the old displacement theory is completely correct is between two equally set-up engines... a supercharged 383 will have more power than a supercharged 350, etc.

 

[55 Hotie]

Re: nitrous being an explosive.....
What Nitrous does is chemically increase the amount of oxygen in the combustion process....It is not an "Explosive"per se. When Nitrous is used, the amount of fuel has to be dramatically increased to support increased combustion, and keep the nitrous from acting like a bellows and melting those expensive aluminum pieces....
A lot of people don't understand the difference between Nitrous and Nitro....Nitromethane. Nitromethane is the fuel that is used in Top Fuel, Funny Car and pro mod motors...If it is ever used in a street motor, it is an anomolie.
A mild shot of nitrous on an unmodified engine would provide a noticable increase in power without damaging the engine, but you know the old saying, if some is good, then more........
I have two nitrous setups in my garage, and one of these days i'm going to build the ultimate small block sleeper, but until that happens, I'm building an old reliable bulletproof 355 Roller motor with a B&M supercharger...Should make only about 495 Horses and 470 ft/lbs torque...That should be good enough to handle most rice and almost all 5.0's
Thadd

 

[Evolution1980]

Tangent Alert

I'm building an old reliable bulletproof 355 Roller motor with a B&M supercharger...Should make only about 495 Horses and 470 ft/lbs torque...That should be good enough to handle most rice and almost all 5.0's
Thadd

I should hope so! :L {End of tangent}

 

[Ken]

I'll just insert this again since Thadd brought it up.

Check this post I put up back in April of this year: Curious about Nitromethane?

_ken

 

[55 Hotie]

Edmond;
To add fuel (so to speak) to the fire, the best of all worlds is a large displacement mild engine with a supercharger putting out mild boost!!!
Cost and your level of ability to build an engine come into play. To do it properly, one should buy "good" parts. A 383 is an easy and relatively inexpensive motor to build. I personally have built seven or eight of them, and if I were to build another one I would use some time tested pieces. I have found that a cast crank will be adequate in all but the most radical street engines...Pink 5.7 or Powdered metal rods will work fine especially if the fastners are upgraded. If there was any kind of a chance that I would supercharge or use nitrous, I would Forged pistons...A set of Hypereutectics go for around $280, the last Forged that I bought were Ross, and the were close to $600...But there are other forged pistons that are cheaper.
Many speed equipment manufacturers sell "rotating assemblies" that are crank, rods, pistons, pins, rings, bearings, and in some cases gaskets and cam shaft and timing set. I've seen them with forged pistons and a stroker crank for well under a grand.
Camshaft selection is an arcane science. Once you determine your combination, call your favorite cam grinder and tell them what you want to do.
It is also possible to built really big small blocks. A 400 block bored .030 over and stuffed with a 4" stroker crank comes out a 434 cubic inches.
I built one of these for a kid with a third gen Camaro, and he ran low 12's his first time down the drag strip...On radials through the mufflers. That's impressive and fast !!! That motor is now in a 67 Camaro and it runs low 11's on drag radials....
I didn't mean to write a novel...sorry

 

[55 Hotie]

Hi Ken...I thought about you today as I was driving past Ruby's...How's things ????
Thadd

 

[Edmond]

Thadd,

So what you're saying is that a very reliable and powerful combination would be a mildly built 383 + a supercharger with mild boost?

As for what I want to do with a car like that, it won't be for the drag strip. It would be used for everyday driving, with very little expressway driving. The power would be used for passing and occassional "fun."

 

[dry sump]

Built a few small blocks for SCCA. Had the parts for a 422 SB but never got it together. I like the idea of a strong 383 and add the goodies as the money rolls in!!
Right now a mild 427 is good for me.

 

[Edmond]

I see quite a few people have voted, but I also want to hear your reasoning behind your vote. I need knowledge!

 

[bradfordsvettes]

i believe you would have less plumbing with a super charger and a more flat torque curve because it is is always pumping and less under hood heat . the turbo needs to spin up before hp increases start lots of plumbing lots of extra heat. no substitute for cubes but both a super charger and turbo can be added later . and add ons are always novel . if the boost is kept within reasonable limits longevity is not a real problem . remember turbo regals,typhoons and syclones to name a few and a lot of gm cars are super charged these days regal ,grand prix, bonnieville and buick ultras only my 2 cents steve

 

[55 Hotie]

I guess that I wasn't as clear as I could have been...If I were in your position, I would build the 383, but build it using quality pieces so that I could supercharge it at a later time. I prefer the supercharger route to the turbo because of the plumbing issues, and there are bolt on supercharger kits available for a ton less money.
A torquey 383 will float your boat, and adding a supercharger will make you exstatic to the point that none of your friends can stand to be around you, but your car will be BAD!!!!!!