Can someone explain how these two different forms of boost work and what the advantages and dissadvantages are? Thanks.

 

My understanding:

Turbo - exhaust driven, free power

Supercharger - belt driven off the engine, robs power to make power

 

superchargers provide constant positive boost pressure, if that makes sense. Turbo's only produce boost whent they are engaged. So in a manner of speaking a supercharger puts constant strain on your motor & was metioned in the post before mine they also rob power to make power ..... READ: No running the A/C & youll get full power , if u run the a/c youre cutting your power increase by at least one fourth. I had a 91 volvo turbo 740 converted to a super charger for about on year, one year until the supercharger put a strian on the 2nd & 4th cylinders so much the piston connecters broke and shot the pistons into the under side of my ported & remachined head($2000 worth of mods) and broke out the sides of the cylinder block. In the end when the motor was off you could put your hand through the block pretty picture, right? Any its was just par for the course as the original mileage when it was converted was approx 75,000 miles.

 

if your thinking about superchargers remember its a whole different ball game with the power produced & your flywheel & clutch if you have a standard tranny. youll losethat clutch right away if you like to do power drops. PS dont forget to get stronger valves & springs cause a supercharger like i said runs constantly there is no "here comes the power" feeling like with a turbo

 

Super chargers are belt driven so you do not get any lag. Some super charges do make boost at all times. Some do not. There are positive blowers, roots type blowers, eatons, etc. Most superchargers that are found on modern cars are Eatons. They only produce boost when they are engaged. There is some parisitic loss due to being belt driven, but, you can make a very driveable fast car with one. The Jackson Racing units for the Miatas are awesome. Many club racers use them in SCCA. I am a fan of the turbo charger, but I like super chargers too. The are also easier to but on a V engine.

 

Contrary to popular belief, turbochargers are not free power. They eat some horsepower just like a supercharger would, but as to how much is subject to speculation. The turbine wheel must be placed in the exhaust gas flow; this causes a restriction in the exhaust system and reduces power a little. With both technologies, the benefits far outweigh the costs. A 50-100% horsepower gain tends to mask a loss of 1-5%.

Also a little known fact: both types actually increase the volumetric efficiency (thereby overall efficiency) of your engine. This means more power with less gas. Of course a 100HP turbo kit will mask this fact due to the raw increase in fuel demand overall.

I personally think turbos rock. Maybe it's from all the years of owning Kawasaki motorcycles with their notoriously wicked powerbands. (When I bought my ZX6, the standing joke with my buddies was 9-grand = hyperspace. It would pull nicely up to 9000RPM, then it was like someone hit a 100-shot of nitrous; it would damn-near rip you off the bike on your way to triple digits.) I love the element of surprise when you get that "kick in the pants." It just seems to make things faster.

 

i have to agree with you on the power band. although i don't have the experience on the bike as you do, i know what its like to have a turbo power band. some people don't like the lag, but for me it doesn't bother me in the least. feeling that sudden hit of accel is awesome. when i drive an n/a car around i am constantly waiting for the power to hit. i have driven my friends G60 Corrado, full worked super charger, smaller pulleys, all that. but its just not the same pull as a turbo. it was the best handling car i have driven though. anyway.
i don't think it will be possible for me to buy a N/A car after my tsi.

-PJ

 

How come this thread comes up over and over? You should check out howthingswork.com. It explains a lot (with diagrams), but if you absorb all the info in the previous posts, you should be alright too. Turbocharger = exhaust driven supercharger.

 

http://auto.howstuffworks.com/question122.htm

 

I finally found it!!!

Digging through my back issues (Aug 2001) of SportCompactCar, I found the issue that has part of the series "Suck, Squish, Bang, Blow - Superchargers vs. Turbochargers part IX". This was part of a 10(?) issue series on various engine stuff starting in Aug 99. If you really wanna get geeky about it, this is one of the best articles ever written on the subject. It steps through all the major differences/advantages of each system. It seems turbos (generally) use a slightly more efficient impeller design and are available in all kinds of sizes and types which makes it much easier for tuning. They work better in high-horsepower/boost applications found in racing. Also, they are more intercooler friendly than supers. For smaller applications, superchargers can reach 110% volumetric efficiency, which is better than small turbos and can provide more power at low boost levels.

Great article. I highly suggest it to everyone to buy or bug a friend for these back issues...it's great geek-stuff.

 

yeah, i remember getting that issue. it really helped me learn the pros and cons of both, as well as how they work.

-PJ

 

www.howstuffworks.com