SC vs Turbo (simple question)

I've heard that superchargers add torque and horsepower while turbos just add horsepower.

Is that how it works?

(please no flames even if my question sounds stupid, I dont know much about cars, just basic maintenance and some basic facts)

[nocutt]

Horsepower is actually a mathematical derivative of torque...torque rules in all instant. This is an oversimplification...both SC and turbo add hp plus torque all things remaining equal, however looking at an equivalent dyno for the same engine with this two different power adders the turbo will produce more torque overall and more of it in the higher RPMs in addition to a peaky HP curve, while an SC will provide more torque at lower RPMs, the torque curve is also very flat on most SCs (Centrifugal units hold an exception). I think most important is how power is delivered across the band...this is where the term "area under the curve" applies...

makes perfect sense.

[SilverEcstasy]

Also, don't want to forget the simple thing.

SC = Constant via pulley. Power all the time
Turbo = Spools up to produce boost/power

[Schweppe23]

I think thats what the intercooler is for.

Pat Lavanty

GA has a ton of power down low, so the whole "spooling up" isnt really a big issue - you can easily roast your tires w/o any sort of boost!

As for the turbo + CAI comment, Mike man, think logically for a minute about that! Those radio waves from the cell phones @ your job are nukin' your brain!!


- Ryan

[SilverEcstasy]

Originally posted by GrafxWerks
GA has a ton of power down low, so the whole "spooling up" isnt really a big issue - you can easily roast your tires w/o any sort of boost!

As for the turbo + CAI comment, Mike man, think logically for a minute about that! Those radio waves from the cell phones @ your job are nukin' your brain!!


- Ryan

What can I say..Nextel's are famous for causing interfernce with radio speakers and other electronics. Must be those phones messin with the plate in my head

[AaronGTR]

Originally posted by GrafxWerks
GA has a ton of power down low, so the whole "spooling up" isnt really a big issue - you can easily roast your tires w/o any sort of boost!

As for the turbo + CAI comment, Mike man, think logically for a minute about that! Those radio waves from the cell phones @ your job are nukin' your brain!!


- Ryan

The problem is, to get the most out of the SC and the turbo especially, you have to modify the intake and exhaust for higher top end flow. Backpressure kills turbo response. But when you do that you lose some of that low end torque. A roots blower will gain back some low end torque and has instant throttle response. A centrifugal blower has a higher power peak but very little down low. A small turbo will spool very quickly but produce a limited amount of power. A bigger turbo will have a much higher capacity to produce power, but will have very poor throttle response and lose a lot of power down low due to the change in flow characteristics.

[Doug]

Some of you guys way overplay turbo lag. Were not putting T-78s on our cars.

[koolZ71]

Originally posted by MikeNT256
Also, don't want to forget the simple thing.

SC = Constant via pulley. Power all the time
Turbo = Spools up to produce boost/power

not nessisarily, not trying to flame just pointing something out, u can get a veined turbo, to were it has boost from idle, dont ask me how they work cause i dont know but i know the gerritt turbo we are putting on the 04 duramax diesel engine has no spool up time

[Craig99SE2]

Yeah, lag is a moot point unless you run a Turbonetics 60-1 or something. (like Doug said)...

The old Garret AVN had the "adjustable vanes", but was a "dog" if you will. They always seemed to get carbon buildup and get jammed. However, Aerocharger makes one that works like a champ! It is not oiled via the engine, but by it's own sump of aircraft grade oil. It uses spring tension to give a steeper angle of attack on the incoming air to provide more boost at lower RPM's, then at higher RPM, it flattens out. It basically provides a variable A/R compressor housing. GREAT product! The BMW guys running M3 and M5's LOVE these things!

The downside ... they start at about $3500 a pop! DOH!

hey you know how people say a turbo is stage 1, 2, 3, 4..?

what is that supposed to mean? It doesnt look like it is rated by power because "its turbo" stage 2 barely adds like 60 hp(?)

From 180 to 240 thats nothing. Besides it barely ends up doing like about 200 to the wheels anyway tops. N20 can even add more.

Can't 3400 take any boost at all? Or is it just companies selling ****ty products for now to cut cost due to the lack of competition and demand for it?

[Craig99SE2]

Originally posted by CaliGrandAM
hey you know how people say a turbo is stage 1, 2, 3, 4..?

It usually refers to the components included in the kitand the level of boost, etc. For example:

Stage 1 could be 5psi with just a turbo for $2500
Stage 2 could include an intercooler and up the boost to 8psi for $3500
Stage 3 could be 12psi with an ignition system, exhaust, etc. for $5000

... you get the point ...

Can't 3400 take any boost at all?

The stock LA1 will handle around 8-10psi of boost as is. If you go any higher, you need to lower the compression ratio and start adding stronger components. The amount of boost the engine can hold depends on how strong the bottom-end is built. Problem is that no one sells "drop-in" upgraded bottom-end components for us which forces us to get custom parts made. This translates to having to sell organs to be able to afford these mods.

For more turbo info, check out my website in my sig ...

[SpyhunteR]

also air/fuel tuning also has a lot to play on how long those internals will last under the boost... let's not forget that..

[Craig99SE2]

Originally posted by SpyhunteR
also air/fuel tuning also has a lot to play on how long those internals will last under the boost... let's not forget that..

I thought that was a given? But if not, my psi estimates consider being properly tuned. For that matter, you could blow an engine at 0psi if you run it too lean and cause detonation ...

[SpyhunteR]

eh.. all I know is that the headgaskets dont' like boost over a certain limit... hehehe..

[Pacman]

Originally posted by GrafxWerks
As for the turbo + CAI comment, Mike man, think logically for a minute about that!
- Ryan

wait, i dont think im getting something here. my friend with a MR2 turbo has a cold air. what's wrong with that?

Can the engine handle the power well though? Like intake, header, exhaust, n20 100shot, ecu, etc...?

Or is it just boost that engine has a problem with past like 8psi.

Just calculating it looks like lets say 100hp from regular mods compared to 10psi from the turbo would be the same power adder. But then turbo is a dangerous one?

[iceman]

Originally posted by Pacman
wait, i dont think im getting something here. my friend with a MR2 turbo has a cold air. what's wrong with that?

Mike said something extremely stupid which has since been edited....

[nocutt]

[i]Just calculating it looks like lets say 100hp from regular mods compared to 10psi from the turbo would be the same power adder. But then turbo is a dangerous one? [/b]

Let say engine A and engine B are the same with similar drivetrain as well...you do mods to engine A (with stock componenets) and you are able to encompass a 100 hp from all the mods and then you take engine B add a turbo with complimentary mods (bolt-ons nevertheless) xhaust, intake & an IC to also encompass 100 hp. Now as long as you can have the right AFR + igntn map on both engines believe it or not the turbo engine will be waaay faster...plus I will add with the right maintainance, engine B will do better in longevity. Remember it only takes 50% more power on a turbo engine to gain roughly 100 hp...On engine A you will have to do more and more than likely rev the engine more, which WILL cause longevity issues...but this isn't the point! We are all enthusiast seeking more or less the same thing...Naturally aspirated or uNatural aspirated the area under the curve is one of the biggest variable that comes into play when trying to understand power with FI especially from a turbo, it just creates a lot of room...