Over the past few years of learning about cars and how they work I have always noticed something when it comes to forced induction. The the exception of the mini S cars with smaller displacement are almost always turbocharged; where as larger displacement engines (V8) are typically supercharged. Why is this? As supercharges are coupled with a pully there is no lag as there is with a turbo making it great for road racing and street driving. I don't know why anyone hasn't made any effort (that I know) to supercharge a SC/Supra as it would race well. There are plenty of turbo'd SC's/Supra's that road race very well, but wouldn't a supercharger be better?

 

hell, I dont know lol, all I can figure is that superchargers are more predictable, and you have the torque for a large displacement engine, therefore, parasitic loss would be less of a %. turbochargers also produce more torque and more torque on an already torquey engine isnt always a better thing when it comes to OEMs. Just what seems logical to me

 

Turbochargers can fit on any engine type, given the use of the appropriate exhaust manifold and a decompressed engine block. However, the turbo must be sized properly according to the application. Small turbos mean faster boost responses, but limited amounts of boost. Larger sized turbos take up more time to build up boost, but they give a lot of boost. Turbochargers are propelled by the exhaust gas velocity of the vehicle and are directly proportional to the temperature of the engine. Turbos feed on fresh oil constantly, so oils with high ratings must be used in the vehicle.
Superchargers use the same concept as turbochargers in the effect that it also compresses air. Superchargers can also be made to fit on any type of engine, and only comes in two types of kits. Both are fanbelt pulley driven units. When it comes to horsepower and torque, superchargers can gain as much as 40 percent in horsepower and 50 percent in torque with the use of just a base kit.

The advantages of turbocharging is the ability to increase horse power using boost controllers and changing turbo units. Turbos give you more power using a pulling effect type of forced induction. However, on the down side, turbos tend to produce more heat as the boost increases, therefore intake temperatures increase causing dense air that cannot be compressed. This usually happens after 5 psi. To solve this problem, an intercooler may be added to help prevent detonation. The other problem with turbo charging is that it requires more maintenance because the amount of heat associated with the boost, this means the turbo must cool down after aggressive driving for about 2 to 3 minutes at idle. Installing a turbo timer is the best bet. Turbos must also be allowed to heat up before aggressive driving.
Unlike the turbochargers that require cool down time, or warm up time, the supercharger is ready to go when you are. At 2000rpm, boost is already available with a supercharger. When it comes to fuel efficiency, superchargers actually kind of help to improve your MPG. The reason for better mileage is the fact that you do not have to drive the engine at full throttle due to available boost. However, anytime that you drive aggressively, fuel efficiency will suffer.
Due to the fact that the supercharger is pulley driven, there is some strain put on the engine. Also, where as with the use of an intercooler with the turbo setup and you have the use of practically unlimited boost, you are limited to what the supercharger has to offer.
Installation of a supercharger usually takes about 6 to 8 hours… if you are mechanically inclined and there is no cutting or welding required. Superchargers also tend to last longer than turbo chargers because they do not require much maintenance and have a self contained oil supply.

Turbochargers and Superchargers are two of the best ways to accomplish your goals by producing more power and faster times. Both have great sounds, the superchargers with their aggressive whistling sound, and the turbos with their jet engine type sound.
In a nutshell, Turbochargers are efficient and flexible, allowing a wide range of swaps and upgrades to achieve the desired power output. They are not noisy and do not rob any power from the engine, however they do require a little more attention than superchargers. This setup is ideal for front wheel drive and lightweight cars, due to the lack of traction when you launch from a dead stop; the lag in boost is actually an advantage. You don't want your boost to kick in before you get traction.

Superchargers give you instant boost on demand and require very low maintenance. With boost available at 2000rpm, you don't have to watch the other guy start jump pass you for long. This setup is ideal if you have a rear wheel drive car with lots of horse power to spare, then the petty power it steals from the engine is well compensated for.

http://www.trinituner.com/shop/tvss.asp

 

The Scion tC comes with an optional TRD Supercharger kit and that car is smaller displacement. We have members who have turbocharged the Lexus V8 engine. Just some examples that you can build either application for any engine, its just easier and more cost effective as far as percentage power gain relative to cost is concerned to go one route or the other most of the time.

 

i know you do find a few examples of turbo'd v8's and supercharged 4's, (mercedes kompressors) but in general you find turbo 4's and 6's and supercharged 8's. Infact I have never seen a supercharged 6 (please give me examples). I would like to see a supercharged SC300 just to see how it acts, and more importantly how well it would drive on the track.

 

Here's a good example on why it just depends on what you want.

Mercedes SL55 is a 5.4L which is supercharged.
Mercedes SL600 is a 5.5L which is turbocharged.

I think with the advent of variable sized turbos, it's only a matter of time until most performance versions of cars come with them. Either that or (iirc) the SLK400 had three turbos; one big one and two small ones. That'll reduce lag (to an extent) and still give you boost in the higher rpm ranges.

 

Hopefully you're not talking in general (otherwise my example would be an VY Aussie Holden Commodore S like my nieghbour's). I'm pretty sure I've seen a supercharger kit for the 2JZGE floating around on the net somewhere.

 

Mercedes C32 is a supercharged 6.

 

There are plenty of supercharged fours and sixes. Go to jacksonracing.com and see all the superchargers they have for many different cars.

As far as why people go with either turbos or superchargers, it's usually mostly just a combination of economics and complication.

Turbocharging a V6 is much more complicated than a straight six. Supercharging that same V6 is easier, simpler, less complicated and quite possibly much cheaper.

It depends on the car, the budget and the goals. They are different methods of getting the same job done.

 

Gm and Ford have made a few SC'd v-6s. The Thunderbird SC coupe and the Pontiac Bonneville SSEI are two off the top of my head. Although both of those were made in the mid and late 1990s. I believe GM still uses the SC'd 3.8 V6 somewhere in their lineup. The Saturn Ion Redline uses a 2.0L SC'd 4 cylinder.

 

I think that may be the Pontiac GTP.

 

The thunderbird was a supercharged 6 banger that was underpowered.....I had one for a while...

Well my guess is - Smaller engines rev higher which is beneficial to an exhaust driven turbo, where as the V8 motors can run a supercharger much easier then a smaller motor.. Superchargers are powered off the belt driven system and engine crank...Remember a good amount of engine power is needed to run the superchargers..4 bangers I would think just aren't up for the task like a V8 motor would be...Also, I wouild think the Exhaust driven turbo's typically perform better on higher reving smaller engines which would create more exhaust flow to run the turbo's...V8 may be a little slower in that regard.....

That is my take on it...and I could be wrong...

 

that's exactly the answer i was looking for. Sadly the only S/C 6 i knew was GM's 3.8...forgot about the C32.

why would it be harder to turbo a V6 instead of an I6? What if the engine was transverse mounted

 

A turbo on any engine will always perform better than a supercharger at the same psi and simillar in size. You are using exahust pusle that, that cost the motor nothing in terms of power, to spool the turbo. At the same time im not saying a turbo is better than a supercharger or vice versa. There are its pros and cons to each system. I personally like turbos but im a little bias .

There are kits for IS300 but the kit would only work for 98 cars since pre 98 had distributor that would be in the way.

 

Pro's and Cons -

The turbo's for the most part are exhaust driven which means there is some lag time at idle. In other words the engine needs to rev up to a certain rpm to actually get the turbo's boosting and working to produce engine power.....Delay or lag time sucks with turbo's, especially with smaller motors that already lack lowend torque at takeoff/idle..Slow starts is what you will get, unless you roast and pop the clutch from launch.. You may also get too much wheel burnout when poping the clutch at launch with the turbo's engaged....You get the picture...

Superchargers - These bad boys run off the engine crank so when the engine turns so does the supercharger...No Delay and instant boost is what you get... However, power is sucked from the engine and not from the exhaust to run the supercharger..(root chargers).Engine power is lost from the crank with the charger...So the supercharger better be big one if you want to get big results...Paxtons, Vortec, etc....The Eatons are relatively small in comparison...

Just for the record Nos beats them both out running at the same power......Nitrous is instant torque and responsiveness at the wheels....


So with all that being said I would take a car that is supercharged over the car that is turbo'd if they both were dishing out the same amount of horse power and the costs of both were the same to setup.. It would be a no brainer..... The supercharged car would simply be faster and more responsive out of the blocks and also in most cases the acceleration is more controlled at launch.....

If I am looking for future fuel economy and cost savings to set up the turbo's vs. superchargers I would most likely look to turbo every time on the same car...